build: rename the module to sourcedock.dev/petrbalvin/gasm-sdk

Assisted-by: GLM 5.3 Flash

.gitea/workflows/release.yml

@@ -342,7 +342,10 @@ jobs:
               my @cmd = (q{curl}, q{-sS}, q{-o}, q{/dev/null}, q{-w}, q{%{http_code}},
                 q{-H}, qq{Authorization: token $ENV{GITEA_TOKEN}},
                 q{-H}, q{Content-Type: application/octet-stream},
-                q{-X}, q{POST}, q{--data-binary}, qq{@$path},
+                # The @ must not sit inside a qq{} string: there it starts an
+                # array interpolation and the upload body collapses to empty,
+                # which Gitea stores as a 201-created zero-byte attachment.
+                q{-X}, q{POST}, q{--data-binary}, q{@} . $path,
                 qq{$ENV{GITEA_SERVER_URL}/api/v1/repos/$ENV{GITEA_REPOSITORY}/releases/$id/assets?name=$name});
               open(my $curl, q{-|}, @cmd) or die qq{curl: $!};
               my $code = <$curl>;

.gitea/workflows/test.yml

@@ -56,6 +56,28 @@ jobs:
       - name: Build
         run: go build ./...
 
+      - name: FreeBSD build (amd64)
+        # The debugger's ptrace surface and the JIT substrate are the two
+        # FreeBSD-portable layers the tree carries; the forge has no FreeBSD
+        # runner, so a push can only compile-gate them. Running the ptrace
+        # suite needs real FreeBSD hardware.
+        env:
+          GOOS: freebsd
+          GOARCH: amd64
+        run: go build ./...
+
+      - name: FreeBSD build (arm64)
+        env:
+          GOOS: freebsd
+          GOARCH: arm64
+        run: go build ./...
+
+      - name: FreeBSD build (riscv64)
+        env:
+          GOOS: freebsd
+          GOARCH: riscv64
+        run: go build ./...
+
       - name: Format
         run: |
           perl -e '

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-All notable changes to gasm-devkit are documented here.
+All notable changes to gasm-sdk are documented here.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
@@ -9,7 +9,99 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- **The GOROOT instruction wave, part 1.**  The encoder now covers the
+- **The FreeBSD port of the debugger.**  `gasm debug` runs on FreeBSD on
+  amd64, arm64 and riscv64: the same interactive surface as on Linux —
+  breakpoints, hardware watchpoints (x86 debug registers, the arm64 debug
+  register file), single-stepping, register and memory access — behind the
+  kernel's own ptrace requests, with tracee memory through `PT_IO` and
+  stop reports through `PT_LWPINFO`.  The JIT substrate maps executable
+  memory through `golang.org/x/sys/unix`, so `verify` builds on FreeBSD
+  too.  The pipeline compile-gates all three architectures; live
+  validation awaits a FreeBSD machine.
+- **Workspace-wide navigation in the language server.**  `gasm lsp` indexes
+  the `.s` files under the workspace root beyond the documents the editor
+  has open, so go-to-definition, find references and workspace symbol search
+  reach files that were never opened.  An open buffer always shadows its
+  disk copy, and watched-file events together with a per-query freshness
+  check keep the index current.
+- **Quick fixes for the textflag include and the argument area.**  The
+  `missing-textflag-include` warning offers to add the include after the
+  last one in the file, and the `abi-argsize` warning offers to set the
+  TEXT argument area to the size the `// func` signature implies, computed
+  by the new `lint.ExpectedArgSize`.
+
+### Changed
+
+- **The corpus audit assembles like the build.**  A file's `//go:build`
+  constraint decides which target architectures attempt it: cpu_x86.s is
+  an x86 build alone, and the msan and goexperiment.runtimesecret trees
+  are compiled by no supported build, so they leave the measured set
+  instead of failing it.  The headline now reads "assemble for every
+  applicable target": every real-code GOROOT assembly file, the tree
+  without testdata, assembles for all four architectures (250 of 250,
+  100 %); over the whole tree including testdata the measure is 271 of
+  322 (84.2 %).
+- **The module moves to `sourcedock.dev/petrbalvin/gasm-sdk`.**  The
+  repository and the module rename together with the product, now the
+  GAsm Software Development Kit.  Fresh installs become
+  `go install sourcedock.dev/petrbalvin/gasm-sdk/cmd/gasm@latest`, and
+  installs pinned to the old `gasm-sdk` path stop resolving once the
+  repository takes the new name: reinstall from the new path.  The
+  binary stays `gasm`.
+
+### Fixed
+
+- **Rename edits land in their own documents.**  A rename collected the
+  ranges of every reference across the open documents but applied them all
+  to the document that started it, so renaming a symbol used in a second
+  file moved that file's text into the first.  Each edit now applies to the
+  document it was collected in.
+- **Negative numeric PC-relative jumps.**  `JMP -3(PC)`, the shape the
+  runtime's exit loops write (sys_linux_amd64.s, sys_netbsd_amd64.s),
+  resolved to nothing: only the forward forms counted.  A negative count
+  now walks the same instruction statements backwards, labels excluded,
+  byte-identical with the toolchain.
+- **The arm64 move-wide family reads its immediate as an unsigned
+  pattern.**  `MOVK $(40000<<48)` folds to a negative int64 and was
+  rejected; the toolchain picks the 16-bit lane from the 64-bit bit
+  pattern, so the encoder now does the same, and a zero immediate is
+  rejected where the toolchain rejects it.
+
+## [0.35.0] - 2026-09-22
+
+### Added
+
+- **The go_asm.h generator.**  `gasm asm` generates the package's go_asm.h
+  itself when an assembly file includes it: the Go files beside the source
+  are type-checked for the target architecture and the constants and field
+  offsets become assembler defines, so package-context files assemble with
+  no compiler and no `go build` in the loop.  `-GOOS` selects the
+  type-checking GOOS for GOOS-specific files, and the corpus audit derives
+  the GOOS from the file name.
+- **ELF data relocations on arm64, riscv64 and loong64.**  `gasm asm
+  --format elf` emits `.rela.data` for symbol-valued DATA initialisers on
+  every architecture (amd64 carried them already), so standalone ELF
+  objects link on all four targets.
+- **Corpus failure listing.**  `gasm audit-instructions --corpus --list`
+  prints every failing file with its failure reason, per architecture,
+  instead of one representative file per reason.
+- **DATA with symbol values and relaxed symbol spellings.**  DATA
+  initialisers accept `$symbol(SB)` values, laid down as an absolute
+  relocation at the data field (GOOBJ on all four architectures and ELF
+  on all four as of this release), and U+2215 is accepted inside symbol
+  package paths.
+- **Macro expansion and include splicing.**  `gasm asm`, `gasm diff` and
+  `gasm audit-instructions` now preprocess assembly the way the
+  toolchain does: object and parameterised `#define` macros expand at
+  the point of use, `#undef` and the `#ifdef`/`#ifndef`/`#else`/
+  `#endif` family select branches, `#include` splices headers resolved
+  through the source directory and the new repeatable `-I` flag, `;`
+  separates statements, and constant expressions left in operands
+  (`$(32-7)`, `$~63`, `(index*4)(base)`) fold at parse.  Expansion
+  happens only on the assembly path: `gasm lint`, `gasm fmt` and the
+  language server keep reading the raw file.
+- **Encoder coverage: the instruction families GOROOT's real code
+  uses.**  The encoder now covers the
   instruction families GOROOT's real code uses that gasm lacked,
   byte-verified against `go tool asm`: on amd64 the carry ALU, the
   atomics (CMPXCHG, XADD, XCHG), AES-NI, SHA-1/256, PCLMULQDQ, CRC32,
@@ -25,14 +117,90 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   Also fixed on the way: arm64 `CASD`/`CASW` lacked an opcode bit, and
   riscv64 `VSETVLI` with an immediate length now canonicalises to
   `vsetivli` as the toolchain does.
-- **The corpus audit measures honestly.**  Files named for Go ports gasm
-  does not target (arm, 386, s390x, ...) are no longer attempted for the
-  four supported architectures (no supported build compiles them), and
-  the headline rate is reported over attemptable files: 136 of 433 on
-  the full corpus (31.4 %), 135 of 383 on real code (35.2 %), from the
-  127 that the previous release measured.  The probe battery that
-  decides encodability gained the operand shapes the new families use.
--
+- **Encoder coverage: quad-register AVX-512 and floating-point
+  immediates.**  The encoder gains the
+  quad-register AVX-512 families (4FMAPS, 4FNMADD, 4VNNIW, VP4DPWSSD,
+  VP4DPWSSDS) with the register list riding the inverted V'VVVV field,
+  floating-point immediates on the SSE scalar moves and arithmetic
+  (the constant lands in a synthesised read-only pool, a positive zero
+  collapses to XORPS exactly as the toolchain does), accept-and-ignore
+  FUNCDATA and PCDATA, three-operand double shifts, static-symbol
+  operands for the legacy SSE moves, and the pooled 64-bit immediate
+  materialisation on riscv64.  The parser carries bracketed register
+  ranges, index-only VSIB memory operands and bare trailing immediates;
+  macro substitution reaches parameters used with element suffixes
+  (`A.S4`), and `;` separates statements in plain files.
+- **Per-architecture reference pages.**  [docs/asm/](docs/asm/README.md)
+  gains AMD64, ARM64, RISCV64 and LOONG64: the register files and the
+  roles the ABI fixes, addressing, operand order with every special form,
+  constants and materialisation, alignment, fences and the relocations
+  each target emits.  An instruction inventory appendix per architecture
+  is generated from the toolchain's own tables by `just gen`, and the
+  regenerated tables recognise 147 more mnemonics than the previous
+  release carried (arm64 107, riscv64 31, loong64 9).
+- **The Plan 9 assembly language reference.**  [docs/asm/](docs/asm/README.md)
+  opens the complete language reference with its common core: the lexicon,
+  statement structure and constant expressions, the operand grammar with
+  the pseudo-registers and symbol naming, the directives and the function
+  flag vocabulary, preprocessing with `#define` and `#include`, and the
+  Go-embedded layer (ABI0, prototypes, `go_asm.h`, `funcdata.h` and the
+  runtime contract).  Every claim is verified against `go tool asm` of
+  Go 1.27.1 and gasm's differential tests; the per-architecture pages and
+  generated instruction appendices follow.
+- **GOOBJ format specification.**  [docs/GOOBJ.md](docs/GOOBJ.md)
+  documents the Go object file format in full: both containers, the 96
+  byte header and all 19 blocks, every structure with its byte
+  offsets, symbol kinds and flag bits, all 106 relocation types with
+  the weak variants, aux symbols, the FuncInfo payload, the pc-value
+  table encoding, the content hashes and the builtin table, all
+  verified byte for byte against objects produced by Go 1.27.1's own
+  tools.
+
+### Changed
+
+- **The corpus audit measures like a build.**  Files named for a Go port
+  gasm does not target (arm, 386, s390x, ...) are never attempted, because
+  no supported build compiles them; the GOOS comes from the file name; and
+  each target's go_asm.h is generated on the fly.  The headline is reported
+  over attemptable files: 291 of 353 on the full corpus (82.4 %) assemble
+  for every target architecture and 295 of 303 on real code (97.4 %),
+  against 108 of 627 over all files (17.2 %) that the previous release
+  measured.
+
+### Fixed
+
+- **The operand forms GOROOT writes.**  Numeric PC-relative jumps
+  (`JEQ 2(PC)`, the park loop `JMP 0(PC)`) resolve with the toolchain's
+  own instruction counting and fold jump-to-jump chains exactly as its
+  branch optimiser does; symbol immediates (`MOVQ $sym(SB), AX`)
+  assemble to the toolchain's RIP-relative LEA with an R_PCREL
+  relocation; negated constant expressions in operands (`ADJSP
+  $-(REGS - 8)`, the shape the cgo ABI macros write) fold; the immediate
+  multiply (`IMULQ $1000000000, AX`) encodes with the toolchain's
+  0x69/0x6B selection; the TLS access pair assembles as the toolchain's
+  one-instruction form (the bare `MOVQ TLS, r` load nops out and
+  `off(r)(TLS*1)` folds to the segment-prefixed absolute whose disp32
+  carries the R_TLSLE relocation, per-GOOS); arm64 accepts the
+  bare-register indirect branch (`BL R9` beside `BL (R9)`, both BLR) and
+  the zero-immediate store (`MOVD $0, mem` through the zero register,
+  rejecting non-zero immediates as the toolchain does); `PCALIGN` now
+  aligns on amd64, padding with the toolchain's greedy
+  single-instruction NOPs; the segment-absolute forms (`MOVQ 0x30(GS),
+  AX` and the store direction) and the absolute crash-store
+  (`MOVL $0xf1, 0xf1`) encode; and `gasm asm` predefines the
+  `GOARCH_<arch>` and `GOOS_<goos>` macros the go command passes to
+  `go tool asm`, so GOROOT headers' `#ifdef GOARCH_amd64` platform
+  blocks (`go_tls.h`'s `get_tls` and friends) select as intended.  The
+  GOROOT corpus measure moves to 291 of 353 files assembling for every
+  target architecture (82.4 %), 97.4 % of the real-code corpus, from
+  70.8 % and 82.2 %.
+- **Tool corrections across the pipeline.**  The formatter keeps square
+  brackets in SIMD operands, statement separators and canonical macro
+  bodies; the linter drops false positives on shift counts, SETcc
+  spellings and ABIInternal references; the lexer treats a trailing
+  carriage return as a line end so comment text stays idempotent; and
+  arm64 rejects bare BTI with a diagnostic while accepting the full
+  family.
 
 ## [0.34.0] - 2026-09-20
 
@@ -129,6 +297,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- **The corpus audit attempts fewer files that no build would compile.**
+  Files named for Go ports gasm does not target (arm, 386, s390x, ...)
+  are reported as other-port and never attempted, the headline rate is
+  computed over attemptable files, and the audit searches the
+  toolchain's shipped headers (funcdata.h and friends) automatically.
 - **riscv64 JALR silently jumped to the wrong register.**  The trampoline
   form `JALR X0, 0(X5)` read the memory operand's base as the destination,
   encoding a jump to X0 with no diagnostic; the destination is the first

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing
 
-Contributions to **gasm-devkit** are governed by the Contributor terms
+Contributions to **gasm-sdk** are governed by the Contributor terms
 below; submitting one means you accept them.
 
 ## Contributor terms
@@ -29,8 +29,8 @@ compiler (gcc), because `just gates` includes `just race` and the race
 detector needs cgo.
 
 ```sh
-git clone https://sourcedock.dev/petrbalvin/gasm-devkit.git
-cd gasm-devkit
+git clone https://sourcedock.dev/petrbalvin/gasm-sdk.git
+cd gasm-sdk
 just build
 just gates
 ```
@@ -126,7 +126,7 @@ tag, where it would double the time and the memory a shared runner cannot spare.
 
 ## Reporting bugs
 
-Open an issue at `https://sourcedock.dev/petrbalvin/gasm-devkit/issues` with the
+Open an issue at `https://sourcedock.dev/petrbalvin/gasm-sdk/issues` with the
 version, the operating system and architecture, the exact command, the full output,
 and the expected against the actual behaviour.
 

README.md

@@ -1,6 +1,6 @@
-# Plan 9 assembly tooling, inside and outside Go
+# GAsm: Software Development Kit for Plan 9 Assembly
 
-> **Warning: this is an experiment.** gasm-devkit is under active
+> **Warning: this is an experiment.** gasm-sdk is under active
 > development and is not stable. The version is 0.x.x: commands, flags,
 > output formats and behaviour can change without warning at any time.
 > A 1.0.0 release is light years away. Nothing in this document is a
@@ -13,7 +13,7 @@
 there is no formatter, no linter and no debugger for `.s` files, and no
 assembler that works without a Go installation. Developers write
 assembly blind, validate it by benchmark, and debug it by print
-statement. gasm-devkit is the missing toolkit: a single, self-contained
+statement. gasm-sdk is the missing toolkit: a single, self-contained
 binary, `gasm`, that serves both purposes.
 
 - **Help develop Plan 9 assembly.** Formatting, linting, disassembly,
@@ -58,7 +58,7 @@ Plan 9 (Go):     MOVQ AX, total-16(SP)
 
 The same lines, but only one of them tells you what the number is for.
 The syntax is uppercase, regular and boring, which is the highest
-compliment a language for machine code can earn. gasm-devkit exists
+compliment a language for machine code can earn. gasm-sdk exists
 to give that syntax the tooling it deserves.
 
 ## Features
@@ -81,7 +81,10 @@ to give that syntax the tooling it deserves.
   GOOBJ format, which needs the installed toolchain and which `go build`
   consumes in place of the toolchain's output.  Framed functions get the
   stack-split guard and the morestack block, byte-identical to the
-  toolchain's, so split functions link too.
+  toolchain's, so split functions link too.  The assembler preprocesses
+  like the toolchain (`#define`, `#include` with `-I`, `#ifdef`), generates
+  `go_asm.h` from the package's Go files, and carries `PCALIGN`, the
+  `LOCK`/`REP` prefixes and the literal-data pseudo-ops.
 - **Disassembler.**  `gasm dis` lists a `.s` file's functions at their real
   offsets after assembling, or disassembles raw bytes from a file or stdin.
 - **Dynamic verification.**  `gasm verify` JIT-loads assembled functions into
@@ -91,13 +94,16 @@ to give that syntax the tooling it deserves.
 - **Debugger.**  `gasm debug` is a source-level ptrace debugger with
   breakpoints (optionally conditional), hardware watchpoints, register and
   memory inspection, and headless script runs that report instruction and
-  label coverage.
+  label coverage; it runs on Linux (all four architectures) and FreeBSD
+  (amd64, arm64, riscv64).
 - **Language server.**  `gasm lsp` serves completion, hover, document symbols,
   push and pull diagnostics, semantic-token highlighting, go-to-definition,
   find references, rename, formatting, inlay hints, code actions, signature
   help, document highlights, workspace symbol search, #include document
   links and folding ranges over stdio; definition, references and rename
-  work across every open document.
+  work across every open document and the indexed workspace files beyond
+  them, and the quick fixes add a missing textflag.h include and set the
+  argument area from the // func signature.
 - **Comparators and audits.**  `gasm diff` compares the machine code of two
   assembly files byte-for-byte, `gasm profile` shows basic-block structure,
   `gasm audit-instructions` diffs the encoder against the installed toolchain,
@@ -110,9 +116,9 @@ Four architectures, the four that matter in practice:
 | Architecture | GOARCH      | File suffix  | Instructions recognised                     |
 |--------------|-------------|--------------|---------------------------------------------|
 | AMD64        | `amd64`     | `_amd64.s`   | 1600 + common opcodes + traditional aliases |
-| ARM64        | `arm64`     | `_arm64.s`   | 538 + common opcodes                        |
-| RISC-V       | `riscv64`   | `_riscv64.s` | 961 + common opcodes                        |
-| LoongArch    | `loong64`   | `_loong64.s` | 799 + common opcodes                        |
+| ARM64        | `arm64`     | `_arm64.s`   | 645 + common opcodes                        |
+| RISC-V       | `riscv64`   | `_riscv64.s` | 992 + common opcodes                        |
+| LoongArch    | `loong64`   | `_loong64.s` | 808 + common opcodes                        |
 
 "Common opcodes" are the instructions shared by every architecture (`RET`,
 `JMP`, `NOP`, `CALL`, `TEXT`, `FUNCDATA`, `PCDATA`, ...).  AMD64 additionally
@@ -124,10 +130,13 @@ can emit today is narrower, and a recognised but unencodable instruction is
 reported as an explicit error, never as a wrong byte.
 
 The same measurement runs over GOROOT's whole assembly corpus:
-`gasm audit-instructions --corpus` reports 136 of 433 attemptable files
-(31.4 %) assembling for every target architecture today (files named for
-other Go ports are counted but never attempted), with the top failure
-reasons per architecture; the number moves with every release.
+`gasm audit-instructions --corpus` reports every real-code GOROOT assembly
+file (the tree without testdata) assembling for every target its build
+admits: 250 of 250, 100 %. Over the whole tree including testdata the
+measure is 271 of 322 attemptable (84.2 %); files named for other Go ports
+are counted but never attempted, and `//go:build` constraints decide which
+targets attempt a file at all, exactly as the build does. The number moves
+with every release.
 
 ### Validation status
 
@@ -142,7 +151,7 @@ actually been executed.
 |---|---|---|
 | Encoding: byte-for-byte against `go tool asm` | native hardware | native hardware (the toolchain cross-assembles any GOARCH on any host) |
 | Execution: JIT calls, ABI checks, differential fuzzing | native hardware | qemu-user emulation |
-| Debugger: ptrace tracing, breakpoints, watchpoints, coverage | native hardware | emulation cannot run ptrace; the layer compiles and its architecture-neutral units run under `go test ./...`, nothing more |
+| Debugger: ptrace tracing, breakpoints, watchpoints, coverage | native hardware | emulation cannot run ptrace; the layer compiles and its architecture-neutral units run under `go test ./...`, nothing more. FreeBSD (amd64, arm64, riscv64) is in the same position: the port compiles behind the cross-build gate and its integration test is ready, but no FreeBSD machine has executed it |
 
 Consequences, stated plainly. An emulator is a model of a CPU, not the
 CPU: instruction semantics are implemented in software and can differ
@@ -157,6 +166,39 @@ been compiled and read, never executed. Its architecture-neutral units
 run under `go test ./...`, which the race workflow and a manual run
 perform; the default `just test` gate does not sweep `./debug/...`.
 
+## The documentation goal
+
+The toolkit is the primary goal. The secondary one is documentation: a
+specification of the Plan 9 assembly language and of the GOOBJ object
+format that is 100 % complete, detailed enough to implement against,
+and written to a professional standard. These are the two subjects this
+project works with every day, and they are the two for which no usable
+documentation exists.
+
+Go documents the language on a single page, "A Quick Guide to Go's
+Assembler", which carries no section for loong64, one of the four
+architectures gasm supports, and covers a fraction of what each
+assembler accepts. What exists beyond it lives as comments inside the
+toolchain's internal source: per-architecture reference manuals for
+arm64, ppc64, riscv64 and loong64, written for the toolchain's own
+maintainers rather than for an outside reader, and none at all for
+amd64. GOOBJ fares worst of all. The format that `go build` consumes
+has no specification anywhere: it is described by a comment in an
+internal package, it is not a stable interface, and it can change with
+any toolchain release.
+
+The gap is therefore filled the only way it can be filled: by reverse
+engineering the toolchain itself, the same work the encoders already
+perform. Most of the documentation can come from nowhere else, and it
+is written as that knowledge is produced during development. It is
+verified the way the code is verified: an encoding documented here is
+one that differential tests against `go tool asm` confirm
+byte-for-byte, and a format field documented here is one the linker
+demonstrably reads. The work has begun: [docs/GOOBJ.md](docs/GOOBJ.md)
+specifies the object file format completely, and
+[docs/asm/README.md](docs/asm/README.md) opens the language reference
+with its common core. The per-architecture pages follow.
+
 ## Direction
 
 The plan, in the order it is being worked:
@@ -179,9 +221,11 @@ The plan, in the order it is being worked:
   toolchain itself does not support; through ELF, Plan 9 assembly becomes
   usable outside Go entirely.
 - **Platforms: Linux and FreeBSD.**  Linux is supported today on all four
-  architectures and is where the binary builds.  FreeBSD follows: the
-  JIT's executable-memory mapping and the ptrace debugger layer are the
-  two pieces of porting work.  Other unix systems may follow those two.
+  architectures and is where the binary builds.  FreeBSD follows on amd64,
+  arm64 and riscv64: the JIT's executable-memory mapping and the ptrace
+  debugger layer are ported (the debugger's live validation awaits a
+  FreeBSD machine, as the validation status states).  Other unix systems
+  may follow those two.
 - **Four architectures, no more.**  amd64, arm64, riscv64 and loong64.
   No others are planned.
 
@@ -189,11 +233,11 @@ The plan, in the order it is being worked:
 
 Prebuilt binaries for linux/amd64, linux/arm64, linux/riscv64 and
 linux/loong64 are on the
-[releases page](https://sourcedock.dev/petrbalvin/gasm-devkit/releases).
+[releases page](https://sourcedock.dev/petrbalvin/gasm-sdk/releases).
 From source (Go 1.27.1):
 
 ```sh
-go install sourcedock.dev/petrbalvin/gasm-devkit/cmd/gasm@latest
+go install sourcedock.dev/petrbalvin/gasm-sdk/cmd/gasm@latest
 ```
 
 Or from a repository checkout:
@@ -282,6 +326,8 @@ recipe.
   ~/.local/share/man (MANDIR overrides); `just uninstall-man` removes
   them
 - [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md): components and data flow
+- [docs/GOOBJ.md](docs/GOOBJ.md): the GOOBJ object file format specification
+- [docs/asm/](docs/asm/README.md): the Plan 9 assembly language reference
 - [docs/DEVELOPMENT.md](docs/DEVELOPMENT.md): development setup and recipes
 - [CHANGELOG.md](CHANGELOG.md): release history
 

SECURITY.md

@@ -7,7 +7,7 @@ releases do not receive them.
 
 | Version | Supported |
 |---|---|
-| 0.34.0 | yes |
+| 0.35.0 | yes |
 | older releases | no |
 
 ## Reporting a vulnerability

_gen/gen.go

@@ -5,9 +5,13 @@
 // toolchain's own assembler source.  Go's Plan 9 assembler defines the exact,
 // complete set of mnemonics it accepts for each architecture in
 // $GOROOT/src/cmd/internal/obj/<arch>/anames.go; this tool extracts those
-// names so gasm-devkit supports every instruction the real assembler does,
+// names so gasm-sdk supports every instruction the real assembler does,
 // with no hand-maintained (and therefore inevitably incomplete) lists.
 //
+// The same data feeds the generated instruction appendices of the assembly
+// language reference, docs/asm/INSTRUCTIONS-<ARCH>.md, so that the reference
+// cannot drift from the tables it documents.
+//
 // Usage (via the justfile):
 //
 //	just gen
@@ -26,9 +30,12 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
 )
 
-// archDirs maps a gasm-devkit architecture name to its obj sub-directory.
+// archDirs maps a gasm-sdk architecture name to its obj sub-directory.
 var archDirs = []struct {
 	arch string
 	sub  string
@@ -39,11 +46,30 @@ var archDirs = []struct {
 	{"loong64", "loong64"},
 }
 
+// docPages maps an architecture to its generated appendix in the language
+// reference.  The amd64 page carries a per-mnemonic encodability column,
+// decided by asm.Encodable, which mirrors the encoder's own dispatch; the
+// other targets have no single cheap predicate, so their pages carry the
+// inventory and point at the live measurement instead.
+var docPages = []struct {
+	arch      arch.Arch
+	title     string
+	file      string
+	anames    string
+	encodable bool
+}{
+	{arch.AMD64, "AMD64", "INSTRUCTIONS-AMD64.md", "cmd/internal/obj/x86/anames.go", true},
+	{arch.ARM64, "ARM64", "INSTRUCTIONS-ARM64.md", "cmd/internal/obj/arm64/anames.go", false},
+	{arch.RISCV, "RISC-V 64", "INSTRUCTIONS-RISCV64.md", "cmd/internal/obj/riscv/anames.go", false},
+	{arch.LOONG64, "LoongArch 64", "INSTRUCTIONS-LOONG64.md", "cmd/internal/obj/loong64/anames.go", false},
+}
+
 func main() {
 	goroot := strings.TrimSpace(runGoEnvGOROOT())
 	if goroot == "" {
 		fatal("could not determine GOROOT")
 	}
+	version := strings.TrimSpace(runGoEnv("GOVERSION"))
 	// The common opcodes shared by every architecture (RET, JMP, NOP, CALL,
 	// TEXT, FUNCDATA, …) live in cmd/internal/obj/util.go.
 	commonPath := filepath.Join(goroot, "src", "cmd", "internal", "obj", "util.go")
@@ -57,16 +83,24 @@ func main() {
 	}
 	fmt.Printf("%-8s %4d instructions -> arch/common_gen.go\n", "common", len(common))
 
+	names := map[string][]string{}
 	for _, a := range archDirs {
 		path := filepath.Join(goroot, "src", "cmd", "internal", "obj", a.sub, "anames.go")
-		names, err := extractInstrs(path)
+		names[a.arch], err = extractInstrs(path)
 		if err != nil {
 			fatal("extract %s: %v", a.arch, err)
 		}
-		if err := writeGen(a.arch, a.sub, names); err != nil {
+		if err := writeGen(a.arch, a.sub, names[a.arch]); err != nil {
 			fatal("write %s: %v", a.arch, err)
 		}
-		fmt.Printf("%-8s %4d instructions -> arch/%s_gen.go\n", a.arch, len(names), a.arch)
+		fmt.Printf("%-8s %4d instructions -> arch/%s_gen.go\n", a.arch, len(names[a.arch]), a.arch)
+	}
+
+	for _, p := range docPages {
+		if err := writeDocPage(p.arch, p.title, p.file, p.anames, version, p.encodable); err != nil {
+			fatal("write %s: %v", p.file, err)
+		}
+		fmt.Printf("%-8s -> docs/asm/%s\n", p.arch, p.file)
 	}
 }
 
@@ -85,7 +119,7 @@ func filterCommon(names []string) []string {
 // writeCommon emits arch/common_gen.go.
 func writeCommon(names []string) error {
 	var b strings.Builder
-	b.WriteString("// Code generated by gasm-devkit _gen; DO NOT EDIT.\n")
+	b.WriteString("// Code generated by gasm-sdk _gen; DO NOT EDIT.\n")
 	b.WriteString("// Source: cmd/internal/obj/util.go from the Go toolchain.\n")
 	b.WriteString("//\n")
 	b.WriteString("// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)\n")
@@ -156,7 +190,7 @@ func stringLit(elt ast.Expr) string {
 // writeGen emits arch/<arch>_gen.go.
 func writeGen(arch, sub string, names []string) error {
 	var b strings.Builder
-	b.WriteString("// Code generated by gasm-devkit _gen; DO NOT EDIT.\n")
+	b.WriteString("// Code generated by gasm-sdk _gen; DO NOT EDIT.\n")
 	b.WriteString("// Source: cmd/internal/obj/" + sub + "/anames.go from the Go toolchain.\n")
 	b.WriteString("//\n")
 	b.WriteString("// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)\n")
@@ -172,6 +206,61 @@ func writeGen(arch, sub string, names []string) error {
 	return os.WriteFile(filepath.Join("arch", arch+"_gen.go"), []byte(b.String()), 0o644)
 }
 
+// writeDocPage emits docs/asm/<file>, the generated instruction appendix of
+// the language reference for one architecture: every mnemonic the toolchain
+// accepts, with the curated summary where the architecture table carries one
+// and, on amd64, a per-mnemonic encodability column.
+func writeDocPage(a arch.Arch, title, file, anames, version string, encodable bool) error {
+	table := arch.ForArch(a)
+	instrs := table.Instructions()
+
+	var b strings.Builder
+	b.WriteString("# " + title + ": instruction inventory\n\n")
+	b.WriteString("Generated by gasm-sdk's `_gen` from the Go toolchain's instruction table\n")
+	b.WriteString("(`" + anames + "`, " + version + "); DO NOT EDIT. This page lists every mnemonic\n")
+	b.WriteString("`go tool asm` accepts on this target, which is the upper bound of the\n")
+	b.WriteString("language on it: a name absent here is not an instruction of the target,\n")
+	b.WriteString("and a name present here may still be one gasm's encoder cannot emit yet.\n\n")
+
+	encodableCount := 0
+	if encodable {
+		b.WriteString("The `gasm encodes` column reports whether gasm's encoder can emit the\n")
+		b.WriteString("mnemonic today; the gap is the encoder backlog, measured live by\n")
+		b.WriteString("`gasm audit-instructions`.\n\n")
+		b.WriteString("| Mnemonic | gasm encodes | Notes |\n")
+		b.WriteString("|---|---|---|\n")
+		for _, in := range instrs {
+			ok := asm.Encodable(in.Name)
+			if ok {
+				encodableCount++
+			}
+			b.WriteString("| `" + in.Name + "` | " + yesNo(ok) + " | " + in.Summary + " |\n")
+		}
+		b.WriteString("\n")
+		fmt.Fprintf(&b, "Recognised: %d mnemonics. gasm encodes: %d.\n", len(instrs), encodableCount)
+	} else {
+		b.WriteString("The inventory carries no per-mnemonic encoder column: on this target\n")
+		b.WriteString("encodability is decided per operand shape, and the live measured\n")
+		b.WriteString("coverage is reported by `gasm audit-instructions`.\n\n")
+		b.WriteString("| Mnemonic | Notes |\n")
+		b.WriteString("|---|---|\n")
+		for _, in := range instrs {
+			b.WriteString("| `" + in.Name + "` | " + in.Summary + " |\n")
+		}
+		b.WriteString("\n")
+		fmt.Fprintf(&b, "Recognised: %d mnemonics.\n", len(instrs))
+	}
+	return os.WriteFile(filepath.Join("docs", "asm", file), []byte(b.String()), 0o644)
+}
+
+// yesNo renders a boolean as the word the appendix tables use.
+func yesNo(v bool) string {
+	if v {
+		return "yes"
+	}
+	return "no"
+}
+
 func runGoEnvGOROOT() string {
 	out, err := exec.Command("go", "env", "GOROOT").Output()
 	if err != nil {
@@ -180,6 +269,15 @@ func runGoEnvGOROOT() string {
 	return string(out)
 }
 
+// runGoEnv runs `go env` for a single variable.
+func runGoEnv(name string) string {
+	out, err := exec.Command("go", "env", name).Output()
+	if err != nil {
+		return ""
+	}
+	return string(out)
+}
+
 func fatal(format string, args ...any) {
 	fmt.Fprintf(os.Stderr, "gen: "+format+"\n", args...)
 	os.Exit(1)

arch/amd64_gen.go

@@ -1,4 +1,4 @@
-// Code generated by gasm-devkit _gen; DO NOT EDIT.
+// Code generated by gasm-sdk _gen; DO NOT EDIT.
 // Source: cmd/internal/obj/x86/anames.go from the Go toolchain.
 //
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)

arch/arm64.go

@@ -33,6 +33,7 @@ func arm64Registers() []Register {
 	for i := 0; i <= 30; i++ {
 		add(fmt.Sprintf("R%d", i), GPR, "64-bit general-purpose register")
 	}
+	add("R18_PLATFORM", GPR, "R18 under its toolchain-reserved Windows name (an alias of R18)")
 	add("ZR", Special, "zero register (reads as 0)")
 	add("SP", Special, "stack pointer")
 	add("LR", Special, "link register (alias of R30)")

arch/arm64_gen.go

@@ -1,4 +1,4 @@
-// Code generated by gasm-devkit _gen; DO NOT EDIT.
+// Code generated by gasm-sdk _gen; DO NOT EDIT.
 // Source: cmd/internal/obj/arm64/anames.go from the Go toolchain.
 //
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
@@ -364,6 +364,8 @@ var arm64GeneratedInstrs = []string{
 	"REVW",
 	"ROR",
 	"RORW",
+	"RPRFM",
+	"SB",
 	"SBC",
 	"SBCS",
 	"SBCSW",
@@ -477,23 +479,68 @@ var arm64GeneratedInstrs = []string{
 	"UXTH",
 	"UXTHW",
 	"UXTW",
+	"VABS",
 	"VADD",
 	"VADDP",
 	"VADDV",
 	"VAND",
 	"VBCAX",
+	"VBIC",
 	"VBIF",
 	"VBIT",
 	"VBSL",
+	"VCLS",
+	"VCLZ",
 	"VCMEQ",
+	"VCMGE",
+	"VCMGT",
+	"VCMHI",
+	"VCMHS",
+	"VCMLE",
+	"VCMLT",
 	"VCMTST",
 	"VCNT",
 	"VDUP",
 	"VEOR",
 	"VEOR3",
 	"VEXT",
+	"VFABS",
+	"VFADD",
+	"VFADDP",
+	"VFCMEQ",
+	"VFCMGE",
+	"VFCMGT",
+	"VFCMLE",
+	"VFCMLT",
+	"VFCVTL",
+	"VFCVTL2",
+	"VFCVTN",
+	"VFCVTN2",
+	"VFCVTZS",
+	"VFCVTZU",
+	"VFDIV",
+	"VFMAX",
+	"VFMAXNM",
+	"VFMAXNMP",
+	"VFMAXNMV",
+	"VFMAXP",
+	"VFMAXV",
+	"VFMIN",
+	"VFMINNM",
+	"VFMINNMP",
+	"VFMINNMV",
+	"VFMINP",
+	"VFMINV",
 	"VFMLA",
 	"VFMLS",
+	"VFMUL",
+	"VFNEG",
+	"VFRINTM",
+	"VFRINTN",
+	"VFRINTP",
+	"VFRINTZ",
+	"VFSQRT",
+	"VFSUB",
 	"VLD1",
 	"VLD1R",
 	"VLD2",
@@ -502,11 +549,17 @@ var arm64GeneratedInstrs = []string{
 	"VLD3R",
 	"VLD4",
 	"VLD4R",
+	"VMLA",
+	"VMLS",
 	"VMOV",
 	"VMOVD",
 	"VMOVI",
 	"VMOVQ",
 	"VMOVS",
+	"VMUL",
+	"VNEG",
+	"VNOT",
+	"VORN",
 	"VORR",
 	"VPMULL",
 	"VPMULL2",
@@ -515,14 +568,47 @@ var arm64GeneratedInstrs = []string{
 	"VREV16",
 	"VREV32",
 	"VREV64",
+	"VSCVTF",
+	"VSHADD",
 	"VSHL",
+	"VSHRN",
+	"VSHRN2",
 	"VSLI",
+	"VSMAX",
+	"VSMAXP",
+	"VSMAXV",
+	"VSMIN",
+	"VSMINP",
+	"VSMINV",
+	"VSMLAL",
+	"VSMLAL2",
+	"VSMLSL",
+	"VSMLSL2",
+	"VSMULL",
+	"VSMULL2",
+	"VSQABS",
+	"VSQADD",
+	"VSQNEG",
+	"VSQSHL",
+	"VSQSUB",
+	"VSQXTN",
+	"VSQXTN2",
+	"VSQXTUN",
+	"VSQXTUN2",
+	"VSRHADD",
 	"VSRI",
+	"VSRSHR",
+	"VSSHL",
+	"VSSHLL",
+	"VSSHLL2",
+	"VSSHR",
 	"VST1",
 	"VST2",
 	"VST3",
 	"VST4",
 	"VSUB",
+	"VSXTL",
+	"VSXTL2",
 	"VTBL",
 	"VTBX",
 	"VTRN1",
@@ -530,8 +616,27 @@ var arm64GeneratedInstrs = []string{
 	"VUADDLV",
 	"VUADDW",
 	"VUADDW2",
+	"VUCVTF",
+	"VUHADD",
 	"VUMAX",
+	"VUMAXP",
+	"VUMAXV",
 	"VUMIN",
+	"VUMINP",
+	"VUMINV",
+	"VUMLAL",
+	"VUMLAL2",
+	"VUMLSL",
+	"VUMLSL2",
+	"VUMULL",
+	"VUMULL2",
+	"VUQADD",
+	"VUQSHL",
+	"VUQSUB",
+	"VUQXTN",
+	"VUQXTN2",
+	"VURHADD",
+	"VUSHL",
 	"VUSHLL",
 	"VUSHLL2",
 	"VUSHR",
@@ -541,6 +646,8 @@ var arm64GeneratedInstrs = []string{
 	"VUZP1",
 	"VUZP2",
 	"VXAR",
+	"VXTN",
+	"VXTN2",
 	"VZIP1",
 	"VZIP2",
 	"WFE",

arch/common_gen.go

@@ -1,4 +1,4 @@
-// Code generated by gasm-devkit _gen; DO NOT EDIT.
+// Code generated by gasm-sdk _gen; DO NOT EDIT.
 // Source: cmd/internal/obj/util.go from the Go toolchain.
 //
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)

arch/loong64_gen.go

@@ -1,4 +1,4 @@
-// Code generated by gasm-devkit _gen; DO NOT EDIT.
+// Code generated by gasm-sdk _gen; DO NOT EDIT.
 // Source: cmd/internal/obj/loong64/anames.go from the Go toolchain.
 //
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
@@ -152,6 +152,8 @@ var loong64GeneratedInstrs = []string{
 	"FNMADDF",
 	"FNMSUBD",
 	"FNMSUBF",
+	"FRINTD",
+	"FRINTF",
 	"FSCALEBD",
 	"FSCALEBF",
 	"FSEL",
@@ -177,7 +179,10 @@ var loong64GeneratedInstrs = []string{
 	"FTINTWF",
 	"JIRL",
 	"LL",
+	"LLACQV",
+	"LLACQW",
 	"LLV",
+	"LLW",
 	"LU12IW",
 	"LU32ID",
 	"LU52ID",
@@ -248,7 +253,11 @@ var loong64GeneratedInstrs = []string{
 	"ROTR",
 	"ROTRV",
 	"SC",
+	"SCQ",
+	"SCRELV",
+	"SCRELW",
 	"SCV",
+	"SCW",
 	"SGT",
 	"SGTU",
 	"SLL",

arch/riscv_gen.go

@@ -1,4 +1,4 @@
-// Code generated by gasm-devkit _gen; DO NOT EDIT.
+// Code generated by gasm-sdk _gen; DO NOT EDIT.
 // Source: cmd/internal/obj/riscv/anames.go from the Go toolchain.
 //
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
@@ -81,6 +81,9 @@ var riscvGeneratedInstrs = []string{
 	"CLD",
 	"CLDSP",
 	"CLI",
+	"CLMUL",
+	"CLMULH",
+	"CLMULR",
 	"CLUI",
 	"CLW",
 	"CLWSP",
@@ -95,13 +98,20 @@ var riscvGeneratedInstrs = []string{
 	"CSDSP",
 	"CSLLI",
 	"CSRAI",
+	"CSRC",
+	"CSRCI",
 	"CSRLI",
+	"CSRR",
 	"CSRRC",
 	"CSRRCI",
 	"CSRRS",
 	"CSRRSI",
 	"CSRRW",
 	"CSRRWI",
+	"CSRS",
+	"CSRSI",
+	"CSRW",
+	"CSRWI",
 	"CSUB",
 	"CSUBW",
 	"CSW",
@@ -259,6 +269,7 @@ var riscvGeneratedInstrs = []string{
 	"ORCB",
 	"ORI",
 	"ORN",
+	"PAUSE",
 	"RDCYCLE",
 	"RDINSTRET",
 	"RDTIME",
@@ -322,6 +333,8 @@ var riscvGeneratedInstrs = []string{
 	"VADDVI",
 	"VADDVV",
 	"VADDVX",
+	"VANDNVV",
+	"VANDNVX",
 	"VANDVI",
 	"VANDVV",
 	"VANDVX",
@@ -329,8 +342,17 @@ var riscvGeneratedInstrs = []string{
 	"VASUBUVX",
 	"VASUBVV",
 	"VASUBVX",
+	"VBREV8V",
+	"VBREVV",
+	"VCLMULHVV",
+	"VCLMULHVX",
+	"VCLMULVV",
+	"VCLMULVX",
+	"VCLZV",
 	"VCOMPRESSVM",
 	"VCPOPM",
+	"VCPOPV",
+	"VCTZV",
 	"VDIVUVV",
 	"VDIVUVX",
 	"VDIVVV",
@@ -743,10 +765,16 @@ var riscvGeneratedInstrs = []string{
 	"VREMUVX",
 	"VREMVV",
 	"VREMVX",
+	"VREV8V",
 	"VRGATHEREI16VV",
 	"VRGATHERVI",
 	"VRGATHERVV",
 	"VRGATHERVX",
+	"VROLVV",
+	"VROLVX",
+	"VRORVI",
+	"VRORVV",
+	"VRORVX",
 	"VRSUBVI",
 	"VRSUBVX",
 	"VS1RV",
@@ -950,6 +978,9 @@ var riscvGeneratedInstrs = []string{
 	"VWMULVX",
 	"VWREDSUMUVS",
 	"VWREDSUMVS",
+	"VWSLLVI",
+	"VWSLLVV",
+	"VWSLLVX",
 	"VWSUBUVV",
 	"VWSUBUVX",
 	"VWSUBUWV",

asm/aarch64_goobj_test.go

@@ -11,7 +11,7 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestGOObjectAARCH64Structure checks the basic structure of the emitted
@@ -245,3 +245,104 @@ func main() {
 		t.Error("binary does not contain expected symbol")
 	}
 }
+
+// TestGOObjectAARCH64DataSymbolLink does for symbol-valued DATA fields what
+// the rt0 files do ("DATA _rt0…lib+0(SB)/8, $_rt0…lib(SB)"): the gasm object
+// carries an R_ADDR against the file's own TEXT symbol, the toolchain links
+// it, and the binary is checked for the symbol (no arm64 host to run it).
+func TestGOObjectAARCH64DataSymbolLink(t *testing.T) {
+	goBin, err := exec.LookPath("go")
+	if err != nil {
+		t.Skip("no Go toolchain available")
+	}
+	dir := t.TempDir()
+	asmSrc := `#include "textflag.h"
+GLOBL entry(SB), NOPTR, $8
+DATA entry+0(SB)/8, $·keepme(SB)
+
+TEXT ·keepme(SB), NOSPLIT, $0-0
+	RET
+
+TEXT ·entryptr(SB), NOSPLIT, $0-8
+	MOVD entry+0(SB), R4
+	MOVD R4, ret+0(FP)
+	RET
+`
+	if err := os.WriteFile(filepath.Join(dir, "main_arm64.s"), []byte(asmSrc), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	mainSrc := `package main
+
+func keepme()
+func entryptr() uintptr
+
+func main() {
+	if entryptr() == 0 {
+		panic("the entry word is empty")
+	}
+}
+`
+	if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(mainSrc), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module a64dlink\n\ngo 1.21\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	build := exec.Command(goBin, "build", "-x", "-work", "-o", filepath.Join(dir, "prog"), ".")
+	build.Dir = dir
+	build.Env = append(os.Environ(), "GOARCH=arm64")
+	buildLog, err := build.CombinedOutput()
+	if err != nil {
+		t.Fatalf("baseline build: %v\n%s", err, buildLog)
+	}
+	var work, linkLine, asmObj string
+	for line := range strings.SplitSeq(string(buildLog), "\n") {
+		switch {
+		case strings.HasPrefix(line, "WORK="):
+			work = strings.TrimPrefix(line, "WORK=")
+		case strings.Contains(line, "/asm ") && strings.Contains(line, "main_arm64.s") && !strings.Contains(line, "-gensymabis"):
+			asmObj = fieldAfter(line, "-o")
+		case strings.Contains(line, "/link ") && strings.Contains(line, "-importcfg"):
+			linkLine = line
+		}
+	}
+	if work == "" || asmObj == "" || linkLine == "" {
+		t.Skipf("could not parse build log (work=%q asmObj=%q link=%q)", work, asmObj, linkLine)
+	}
+	defer os.RemoveAll(work)
+	asmObj = strings.ReplaceAll(asmObj, "$WORK", work)
+	linkLine = strings.ReplaceAll(linkLine, "$WORK", work)
+
+	src, err := os.ReadFile(filepath.Join(dir, "main_arm64.s"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, errs := parser.Parse("main_arm64.s", string(src))
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileARM64(f)
+	if err != nil {
+		t.Fatalf("AssembleFileARM64: %v", err)
+	}
+	gasmObj, err := img.GOObjectAARCH64("a64dlink", "main_arm64.s")
+	if err != nil {
+		t.Fatalf("GOObjectAARCH64: %v", err)
+	}
+	if err := os.WriteFile(asmObj, gasmObj, 0o644); err != nil {
+		t.Fatalf("write gasm object: %v", err)
+	}
+	linkCmd := exec.Command("bash", "-c", "cd "+dir+" && "+linkLine)
+	linkCmd.Env = append(os.Environ(), "GOARCH=arm64")
+	if out, err := linkCmd.CombinedOutput(); err != nil {
+		t.Fatalf("re-link with gasm object: %v\n%s", err, out)
+	}
+	binData, err := os.ReadFile(filepath.Join(dir, "prog"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(binData), "keepme") {
+		t.Error("binary does not contain the keepme symbol")
+	}
+}

asm/arm64_encode.go

@@ -29,10 +29,11 @@ package asm
 
 import (
 	"maps"
+	"math/bits"
 	"strconv"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // arm64RegNum returns the 5-bit register number for an AArch64 register name:
@@ -78,6 +79,11 @@ func arm64RegNum(name string) int {
 		return 17
 	case "R18":
 		return 18
+	case "R18_PLATFORM":
+		// The toolchain's Windows spelling: R18 is renamed R18_PLATFORM in
+		// cmd/asm/internal/arch so assembly cannot use it by accident, and
+		// sys_windows_arm64.s references it only through this name.
+		return 18
 	case "R19":
 		return 19
 	case "R20":
@@ -159,6 +165,67 @@ func a64MoveWide(sf, opc, hw, imm16, rd uint32) uint32 {
 	return sf<<31 | opc<<29 | 0x25<<23 | hw<<21 | imm16<<5 | rd
 }
 
+// ---- logical immediate ----
+
+// a64LogicalImm encodes v as the AArch64 logical (bitmask) immediate for the
+// given lane width (32 or 64): it returns the N, immr and imms fields of the
+// imm13 encoding.  The algorithm mirrors cmd/internal/obj/arm64's
+// encodeLogicalImmArrEncoding: replicate the value, shrink it to the smallest
+// repeating element, find the run of ones and its rotation.  ok is false when
+// v is not expressible (all zeros, all ones, or not a single cyclic run).
+func a64LogicalImm(v int64, width int) (n, immr, imms uint32, ok bool) {
+	u := uint64(v)
+	if width == 32 {
+		u &= 0xFFFFFFFF
+	}
+	size := uint64(width)
+	mask := ^uint64(0)
+	if size < 64 {
+		mask = uint64(1)<<size - 1
+	}
+	u &= mask
+	// All zeros and all ones are MOV territory, not bitmask immediates.
+	if u == 0 || u == mask {
+		return 0, 0, 0, false
+	}
+	// Shrink to the smallest repeating element.
+	for size > 2 {
+		half := size / 2
+		hm := uint64(1)<<half - 1
+		if u&hm == u>>half&hm {
+			size = half
+			u &= hm
+		} else {
+			break
+		}
+	}
+	ones := bits.OnesCount64(u)
+	// Find the right-rotation that lays the ones out contiguously at the
+	// bottom of the element; the hardware applies the inverse rotation.
+	em := uint64(1)<<size - 1
+	expected := uint64(1)<<ones - 1
+	rot := -1
+	for r := 0; r < int(size); r++ {
+		rotated := u>>r | u<<(int(size)-r)
+		if size < 64 {
+			rotated &= em
+		}
+		if rotated == expected {
+			rot = r
+			break
+		}
+	}
+	if rot < 0 {
+		return 0, 0, 0, false
+	}
+	if size == 64 {
+		n = 1
+	}
+	immr = uint32((int(size) - rot) % int(size))
+	imms = ^uint32(uint32(size*2-1))&0x3F | uint32(ones-1)
+	return n, immr, imms, true
+}
+
 // ---- load/store (unsigned immediate, scaled) ----
 
 // a64LSU encodes a load/store register (unsigned immediate, scaled):
@@ -246,6 +313,8 @@ const (
 	a64CondLT = 0xb
 	a64CondGT = 0xc
 	a64CondLE = 0xd
+	a64CondAL = 0xe
+	a64CondNV = 0xf
 )
 
 // arm64CondMap maps Go assembler condition mnemonics to AArch64 condition codes.
@@ -266,6 +335,8 @@ var arm64CondMap = map[string]uint32{
 	"LT": a64CondLT,
 	"GT": a64CondGT,
 	"LE": a64CondLE,
+	"AL": a64CondAL,
+	"NV": a64CondNV,
 }
 
 // ---- instruction format tags ----
@@ -273,46 +344,47 @@ var arm64CondMap = map[string]uint32{
 type a64Format uint8
 
 const (
-	a64FDPSR         a64Format = iota // data-processing (shifted register): ADD, SUB, AND, ORR, EOR, etc.
-	a64FMovWide                       // move wide: MOVZ, MOVN, MOVK
-	a64FBranch                        // unconditional branch (B/BL)
-	a64FBranchCond                    // conditional branch (B.cond)
-	a64FUncondBranch                  // unconditional branch register (BR/BLR/RET)
-	a64FADR                           // ADR/ADRP
-	a64FEXTR                          // EXTR
-	a64FBitfield                      // bitfield: BFI/BFXIL/SBFM/UBFM/BFM
-	a64FShift                         // shifts: LSL/LSR/ASR alias SBFM/UBFM, ROR aliases EXTR; register forms are two-source
-	a64FDPR4                          // data-processing 4-register: MADD/MSUB, Ra in bits 14:10
-	a64FFP3                           // FP 3-operand (Rm, Rn, Rd): FADD, FSUB, FMUL, FDIV, etc.
-	a64FFPUnary                       // FP unary (Rn, Rd): FMOV, FABS, FNEG, FSQRT, FCVT, FRINT*
-	a64FFP4                           // FP 4-operand FMA (Ra, Rm, Rn, Rd): FMADD, FMSUB, etc.
-	a64FFPCmp                         // FP compare (Rm, Rn): FCMP, FCMPE
-	a64FFPCCmp                        // FP conditional compare (Rm, Rn, nzcv, cond): FCCMP, FCCMPE
-	a64FFPCvt                         // FP↔integer conversion: FCVTZS, SCVTF, etc.
-	a64FFPSel                         // FP conditional select (Rm, Rn, Rd, cond): FCSEL
-	a64FCRC32                         // CRC32
-	a64FCSEL                          // conditional select: CSEL, CSINC, CSINV, CSNEG
-	a64FExcl                          // exclusive load/store: LDXR, STXR, LDAXR, STLXR and pair forms LDXP, STXP
-	a64FLSE                           // LSE atomics: LDADD, CAS, SWP
-	a64FDP1                           // data-processing (1 source): RBIT, REV, CLZ, CLS
-	a64FBitfield2                     // bitfield extract: UBFX, SBFX and the W forms
-	a64FCondCmp                       // conditional compare: CCMP, CCMN
-	a64FBranch19                      // compare-and-branch: CBZ, CBNZ and the W forms
-	a64FTestBranch                    // test-and-branch: TBZ, TBNZ and the W forms
-	a64FPair                          // load/store pair: LDP, STP, LDPW, STPW, FLDPD, FSTPD
-	a64FAcqRel                        // acquire/release: LDAR family, STLR family
-	a64FSys                           // system: BRK, SVC, DMB, DSB, ISB, DC, MRS, MSR, PRFM
-	a64FCrypto2                       // crypto 2-register: AESD, AESE, AESIMC, AESMC, SHA1H, ...
-	a64FCrypto3                       // crypto 3-register: SHA1C, SHA256H, SHA512SU1, ...
-	a64FSIMDV                         // SIMD 3-register with arrangement: VADD, VAND, VCMEQ, VZIP1, ...
-	a64FSIMDVZero                     // SIMD compare against zero: VCMEQ $0, Vn, Vd
-	a64FSIMDV2                        // SIMD 2-register with arrangement: VREV32, VREV64, VUADDLV, VMOV
-	a64FSIMDV4                        // SIMD 4-register / imm 3-register: VEOR3, VBCAX, VXAR, VEXT
-	a64FVTBL                          // SIMD table lookup: VTBL
-	a64FDUP                           // SIMD element moves: VDUP, VMOV with element indices
-	a64FVLDST                         // SIMD structure loads/stores: VLD1, VST1, VLD1R, VLD4R
-	a64FShiftImm                      // SIMD shift by immediate: VSHL, VUSHR, VSRI
-	a64FMoviLit                       // VMOVS/VMOVD/VMOVQ with a large constant (literal pool)
+	a64FDPSR          a64Format = iota // data-processing (shifted register): ADD, SUB, AND, ORR, EOR, etc.
+	a64FMovWide                        // move wide: MOVZ, MOVN, MOVK
+	a64FBranch                         // unconditional branch (B/BL)
+	a64FBranchCond                     // conditional branch (B.cond)
+	a64FUncondBranch                   // unconditional branch register (BR/BLR/RET)
+	a64FADR                            // ADR/ADRP
+	a64FEXTR                           // EXTR
+	a64FBitfield                       // bitfield: BFI/BFXIL/SBFM/UBFM/BFM
+	a64FBitfieldAlias                  // bitfield alias: BFI/BFXIL/SBFIZ/UBFIZ, ($lsb, Rn, $width, Rd)
+	a64FShift                          // shifts: LSL/LSR/ASR alias SBFM/UBFM, ROR aliases EXTR; register forms are two-source
+	a64FDPR4                           // data-processing 4-register: MADD/MSUB, Ra in bits 14:10
+	a64FFP3                            // FP 3-operand (Rm, Rn, Rd): FADD, FSUB, FMUL, FDIV, etc.
+	a64FFPUnary                        // FP unary (Rn, Rd): FMOV, FABS, FNEG, FSQRT, FCVT, FRINT*
+	a64FFP4                            // FP 4-operand FMA (Ra, Rm, Rn, Rd): FMADD, FMSUB, etc.
+	a64FFPCmp                          // FP compare (Rm, Rn): FCMP, FCMPE
+	a64FFPCCmp                         // FP conditional compare (Rm, Rn, nzcv, cond): FCCMP, FCCMPE
+	a64FFPCvt                          // FP↔integer conversion: FCVTZS, SCVTF, etc.
+	a64FFPSel                          // FP conditional select (Rm, Rn, Rd, cond): FCSEL
+	a64FCRC32                          // CRC32
+	a64FCSEL                           // conditional select: CSEL, CSINC, CSINV, CSNEG
+	a64FExcl                           // exclusive load/store: LDXR, STXR, LDAXR, STLXR and pair forms LDXP, STXP
+	a64FLSE                            // LSE atomics: LDADD, CAS, SWP
+	a64FDP1                            // data-processing (1 source): RBIT, REV, CLZ, CLS
+	a64FBitfield2                      // bitfield extract: UBFX, SBFX and the W forms
+	a64FCondCmp                        // conditional compare: CCMP, CCMN
+	a64FBranch19                       // compare-and-branch: CBZ, CBNZ and the W forms
+	a64FTestBranch                     // test-and-branch: TBZ, TBNZ and the W forms
+	a64FPair                           // load/store pair: LDP, STP, LDPW, STPW, FLDPD, FSTPD
+	a64FAcqRel                         // acquire/release: LDAR family, STLR family
+	a64FSys                            // system: BRK, SVC, DMB, DSB, ISB, DC, MRS, MSR, PRFM
+	a64FCrypto2                        // crypto 2-register: AESD, AESE, AESIMC, AESMC, SHA1H, ...
+	a64FCrypto3                        // crypto 3-register: SHA1C, SHA256H, SHA512SU1, ...
+	a64FSIMDV                          // SIMD 3-register with arrangement: VADD, VAND, VCMEQ, VZIP1, ...
+	a64FSIMDVZero                      // SIMD compare against zero: VCMEQ $0, Vn, Vd
+	a64FSIMDV2                         // SIMD 2-register with arrangement: VREV32, VREV64, VUADDLV, VMOV
+	a64FSIMDV4                         // SIMD 4-register / imm 3-register: VEOR3, VBCAX, VXAR, VEXT
+	a64FVTBL                           // SIMD table lookup: VTBL
+	a64FDUP                            // SIMD element moves: VDUP, VMOV with element indices
+	a64FVLDST                          // SIMD structure loads/stores: VLD1, VST1, VLD1R, VLD4R
+	a64FShiftImm                       // SIMD shift by immediate: VSHL, VUSHR, VSRI
+	a64FMoviLit                        // VMOVS/VMOVD/VMOVQ with a large constant (literal pool)
 )
 
 // a64Enc is one instruction's encoding: its bit layout (format) and the
@@ -425,6 +497,16 @@ func init() {
 	a64InstrTable["MADDW"] = a64Enc{format: a64FDPR4, op: 0<<31 | 0x1b<<24}
 	a64InstrTable["MSUB"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<15}
 	a64InstrTable["MSUBW"] = a64Enc{format: a64FDPR4, op: 0<<31 | 0x1b<<24 | 1<<15}
+	// The widening multiplies: a 64-bit result riding the same layout, the
+	// three-operand forms reading the accumulate register as ZR.
+	a64InstrTable["SMADDL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21}
+	a64InstrTable["UMADDL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<23}
+	a64InstrTable["SMSUBL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<15}
+	a64InstrTable["UMSUBL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<23 | 1<<15}
+	a64InstrTable["SMULL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 31<<10}
+	a64InstrTable["UMULL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<23 | 31<<10}
+	a64InstrTable["SMNEGL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<15 | 31<<10}
+	a64InstrTable["UMNEGL"] = a64Enc{format: a64FDPR4, op: 1<<31 | 0x1b<<24 | 1<<21 | 1<<23 | 1<<15 | 31<<10}
 
 	// ---- move wide ----
 	// MOVZ/MOVN/MOVK
@@ -474,6 +556,15 @@ func init() {
 	// ---- bitfield ----
 	a64InstrTable["BFM"] = a64Enc{format: a64FBitfield, op: 1<<31 | 1<<29 | 0x26<<23 | 1<<22}
 	a64InstrTable["BFMW"] = a64Enc{format: a64FBitfield, op: 0<<31 | 1<<29 | 0x26<<23 | 0<<22}
+	// The four-operand bitfield aliases: ($lsb, Rn, $width, Rd).
+	a64InstrTable["BFI"] = a64Enc{format: a64FBitfieldAlias, op: 1<<31 | 1<<29 | 0x26<<23 | 1<<22}
+	a64InstrTable["BFIW"] = a64Enc{format: a64FBitfieldAlias, op: 0<<31 | 1<<29 | 0x26<<23}
+	a64InstrTable["BFXIL"] = a64Enc{format: a64FBitfieldAlias, op: 1<<31 | 1<<29 | 0x26<<23 | 1<<22}
+	a64InstrTable["BFXILW"] = a64Enc{format: a64FBitfieldAlias, op: 0<<31 | 1<<29 | 0x26<<23}
+	a64InstrTable["SBFIZ"] = a64Enc{format: a64FBitfieldAlias, op: 0x93400000}
+	a64InstrTable["SBFIZW"] = a64Enc{format: a64FBitfieldAlias, op: 0x13000000}
+	a64InstrTable["UBFIZ"] = a64Enc{format: a64FBitfieldAlias, op: 0x53000000}
+	a64InstrTable["UBFIZW"] = a64Enc{format: a64FBitfieldAlias, op: 0x33000000}
 	a64InstrTable["SBFM"] = a64Enc{format: a64FBitfield, op: 1<<31 | 0<<29 | 0x26<<23 | 1<<22}
 	a64InstrTable["SBFMW"] = a64Enc{format: a64FBitfield, op: 0<<31 | 0<<29 | 0x26<<23 | 0<<22}
 	a64InstrTable["UBFM"] = a64Enc{format: a64FBitfield, op: 1<<31 | 2<<29 | 0x26<<23 | 1<<22}
@@ -654,6 +745,13 @@ func init() {
 		"RBIT": 0xdac00000, "REV16": 0xdac00400, "REV32": 0xdac00800,
 		"REV": 0xdac00c00, "CLZ": 0xdac01000, "CLS": 0xdac01400,
 		"RBITW": 0x5ac00000, "REVW": 0x5ac00800, "CLZW": 0x5ac01000, "CLSW": 0x5ac01400,
+		// Extend and byte-reverse: the UBFM/SBFM aliases with imms fixing
+		// the source width.
+		"SXTB": 0x93401c00, "SXTBW": 0x13001c00, "SXTH": 0x93403c00,
+		"SXTHW": 0x13003c00, "SXTW": 0x93407c00,
+		"UXTB": 0x53001c00, "UXTBW": 0x53001c00, "UXTH": 0x53403c00,
+		"UXTHW": 0x53003c00, "UXTW": 0x53407c00,
+		"REV16W": 0x5ac00400,
 	}
 	for m, op := range dp1 {
 		a64InstrTable[m] = a64Enc{format: a64FDP1, op: op}
@@ -672,7 +770,7 @@ func init() {
 	a64InstrTable["CCMNW"] = a64Enc{format: a64FCondCmp, op: 0x3a400000}
 
 	// ---- system operations ----
-	for _, m := range []string{"BRK", "SVC", "DMB", "DSB", "ISB", "DC", "MRS", "MSR", "PRFM"} {
+	for _, m := range []string{"BRK", "SVC", "DMB", "DSB", "ISB", "CLREX", "HINT", "BTI", "HLT", "SMC", "HVC", "DCPS1", "DCPS2", "DCPS3", "DRPS", "ERET", "AUTIASP", "AUTIBSP", "AUTIA1716", "AUTIB1716", "SEVL", "SEV", "WFE", "WFI", "YIELD", "DC", "MRS", "MSR", "PRFM"} {
 		a64InstrTable[m] = a64Enc{format: a64FSys}
 	}
 
@@ -723,6 +821,73 @@ func init() {
 	for m, op := range lse {
 		a64InstrTable[m] = a64Enc{format: a64FLSE, op: op}
 	}
+	// The remaining width and ordering spellings of the same shapes, and the
+	// CAS compare-and-swap family, word-verified against go tool asm.
+	lseMore := map[string]uint32{
+		"LDADDAB":  0x38a00000,
+		"LDADDAH":  0x78a00000,
+		"LDADDALB": 0x38e00000,
+		"LDADDALH": 0x78e00000,
+		"LDADDLB":  0x38600000,
+		"LDADDLD":  0xf8600000,
+		"LDADDLH":  0x78600000,
+		"LDADDLW":  0xb8600000,
+		"LDCLRAB":  0x38a01000,
+		"LDCLRAH":  0x78a01000,
+		"LDCLRALH": 0x78e01000,
+		"LDCLRB":   0x38201000,
+		"LDCLRD":   0xf8201000,
+		"LDCLRH":   0x78201000,
+		"LDCLRLB":  0x38601000,
+		"LDCLRLD":  0xf8601000,
+		"LDCLRLH":  0x78601000,
+		"LDCLRLW":  0xb8601000,
+		"LDCLRW":   0xb8201000,
+		"LDEORAB":  0x38a02000,
+		"LDEORAD":  0xf8a02000,
+		"LDEORAH":  0x78a02000,
+		"LDEORALB": 0x38e02000,
+		"LDEORALH": 0x78e02000,
+		"LDEORAW":  0xb8a02000,
+		"LDEORB":   0x38202000,
+		"LDEORD":   0xf8202000,
+		"LDEORH":   0x78202000,
+		"LDEORLB":  0x38602000,
+		"LDEORLD":  0xf8602000,
+		"LDEORLH":  0x78602000,
+		"LDEORLW":  0xb8602000,
+		"LDEORW":   0xb8202000,
+		"LDORAB":   0x38a03000,
+		"LDORAD":   0xf8a03000,
+		"LDORAH":   0x78a03000,
+		"LDORALH":  0x78e03000,
+		"LDORAW":   0xb8a03000,
+		"LDORB":    0x38203000,
+		"LDORD":    0xf8203000,
+		"LDORH":    0x78203000,
+		"LDORLB":   0x38603000,
+		"LDORLD":   0xf8603000,
+		"LDORLH":   0x78603000,
+		"LDORLW":   0xb8603000,
+		"LDORW":    0xb8203000,
+		"SWPAB":    0x38a08000,
+		"SWPAD":    0xf8a08000,
+		"SWPAH":    0x78a08000,
+		"SWPALH":   0x78e08000,
+		"SWPAW":    0xb8a08000,
+		"SWPB":     0x38208000,
+		"SWPH":     0x78208000,
+		"SWPLB":    0x38608000,
+		"SWPLD":    0xf8608000,
+		"SWPLH":    0x78608000,
+		"SWPLW":    0xb8608000,
+		"CASAD":    0xc8e07c00,
+		"CASALB":   0x08e0fc00,
+		"CASLW":    0x88a0fc00,
+	}
+	for m, op := range lseMore {
+		a64InstrTable[m] = a64Enc{format: a64FLSE, op: op}
+	}
 
 	// ---- carry-setting/carry-using arithmetic and widening multiply ----
 	// MUL and SMULH/UMULH are the MADD/MSUB layout with the accumulate
@@ -732,7 +897,12 @@ func init() {
 		"ADCS": 0xba000000, "ADCSW": 0x3a000000,
 		"SBC": 0xda000000, "SBCW": 0x5a000000,
 		"SBCS": 0xfa000000, "SBCSW": 0x7a000000,
-		"MUL": 0x9b007c00, "MULW": 0x1b007c00,
+		// MNEG/MSUB and NGC/SBC with the complementing register preset to ZR.
+		"MNEG": 0x9b00fc00, "MNEGW": 0x1b00fc00,
+		"NGC": 0xda000000, "NGCW": 0x5a000000,
+		"NGCS": 0xfa000000, "NGCSW": 0x7a000000,
+		"NEGSW": 0x6b000000,
+		"MUL":   0x9b007c00, "MULW": 0x1b007c00,
 		"SMULH": 0x9b407c00, "UMULH": 0x9bc07c00,
 	}
 	for m, op := range dpsrExtra {
@@ -773,12 +943,20 @@ func init() {
 	a64InstrTable["VSHL"] = a64Enc{format: a64FShiftImm, op: 0x0f000000 | 21<<10}
 	a64InstrTable["VUSHR"] = a64Enc{format: a64FShiftImm, op: 0x2f000000 | 1<<10}
 	a64InstrTable["VSRI"] = a64Enc{format: a64FShiftImm, op: 0x2f000000 | 17<<10}
+	a64InstrTable["VSSHR"] = a64Enc{format: a64FShiftImm, op: 0x0f000000 | 1<<10}
+	a64InstrTable["VSRA"] = a64Enc{format: a64FShiftImm, op: 0x0f000000 | 17<<10}
+	a64InstrTable["VSRSHR"] = a64Enc{format: a64FShiftImm, op: 0x0f000000 | 9<<10}
+	a64InstrTable["VSLI"] = a64Enc{format: a64FShiftImm, op: 0x2f000000 | 21<<10}
+	a64InstrTable["VSQSHL"] = a64Enc{format: a64FShiftImm, op: 0x0f000000 | 29<<10}
+	a64InstrTable["VUQSHL"] = a64Enc{format: a64FShiftImm, op: 0x2f000000 | 29<<10}
 	a64InstrTable["VLD1"] = a64Enc{format: a64FVLDST}
 	a64InstrTable["VLD1.P"] = a64Enc{format: a64FVLDST, op: 1}
 	a64InstrTable["VST1"] = a64Enc{format: a64FVLDST}
 	a64InstrTable["VST1.P"] = a64Enc{format: a64FVLDST, op: 1}
 	a64InstrTable["VLD1R"] = a64Enc{format: a64FVLDST}
+	a64InstrTable["VLD1R.P"] = a64Enc{format: a64FVLDST, op: 1}
 	a64InstrTable["VLD4R"] = a64Enc{format: a64FVLDST}
+	a64InstrTable["VLD4R.P"] = a64Enc{format: a64FVLDST, op: 1}
 }
 
 // a64SimdVSpec is one arrangement-aware SIMD instruction: the 8B base word,
@@ -835,6 +1013,23 @@ func a64ElemLetter(s string) bool {
 	return false
 }
 
+// fpSimdArrs and fpAcrossArrs bound the arrangements the FP SIMD forms
+// accept: H, S and D widths for the pairwise data-processing, H and S for
+// the across-vector reductions.
+var fpSimdArrs = uint16(1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D)
+var fpAcrossArrs = uint16(1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S)
+
+// a64SimdQOnly names the forms whose arrangement contributes the 128-bit
+// flag alone, without the size bits: the FP converts, the FP round-to-integral
+// and pairwise compares among them.  Word-verified against go tool asm.
+var a64SimdQOnly = map[string]bool{
+	"VSCVTF": true, "VUCVTF": true, "VFCVTZS": true, "VFCVTZU": true,
+	"VFABS": true, "VFNEG": true, "VFSQRT": true,
+	"VFRINTN": true, "VFRINTP": true, "VFRINTM": true, "VFRINTZ": true,
+	"VFADDP": true, "VFMAXP": true, "VFMAXNMP": true,
+	"VFMAXV": true, "VFMAXNMV": true,
+}
+
 // a64ArrBits carries the fixed bits an arrangement contributes to the
 // three-same word shape: the element size at bits 23:22 and the 128-bit
 // flag at bit 30.  Bit 29 belongs to the instruction's own base.
@@ -854,19 +1049,96 @@ var a64ArrBits = [a64ArrCount]uint32{
 // instructions (word = base | arrBits | Rm<<16 | Rn<<5 | Rd).  Every base
 // word and arrangement bit was read off go tool asm.
 var a64SimdVTable = map[string]a64SimdVSpec{
-	"VADD":    {0x0e208400, 0x7f, false},
-	"VSUB":    {0x2e208400, 0x7f, false},
-	"VMUL":    {0x0e209c00, 0x3f, false}, // no 2D: integer multiply stops at 4S
-	"VAND":    {0x0e201c00, 0x03, false}, // logical ops accept 8B and 16B only
-	"VEOR":    {0x2e201c00, 0x03, false},
-	"VORR":    {0x0ea01c00, 0x03, false},
-	"VADDP":   {0x0e20bc00, 0x7f, false},
-	"VZIP1":   {0x0e003800, 0x7f, false},
-	"VZIP2":   {0x0e007800, 0x7f, false},
-	"VCMEQ":   {0x2e208c00, 0x7f, false},
-	"VRAX1":   {0xce608c00, 1 << a64Arr2D, true}, // SHA3 group, D2 only
-	"VPMULL":  {0x0e20e000, 1<<a64Arr8B | 1<<a64ArrD1, false},
-	"VPMULL2": {0x0e20e000, 1<<a64Arr16B | 1<<a64Arr2D, false},
+	"VADD":  {0x0e208400, 0x7f, false},
+	"VSUB":  {0x2e208400, 0x7f, false},
+	"VMUL":  {0x0e209c00, 0x3f, false}, // no 2D: integer multiply stops at 4S
+	"VAND":  {0x0e201c00, 0x03, false}, // logical ops accept 8B and 16B only
+	"VEOR":  {0x2e201c00, 0x03, false},
+	"VORR":  {0x0ea01c00, 0x03, false},
+	"VADDP": {0x0e20bc00, 0x7f, false},
+	"VZIP1": {0x0e003800, 0x7f, false},
+	"VZIP2": {0x0e007800, 0x7f, false},
+	"VCMEQ": {0x2e208c00, 0x7f, false},
+	"VCMGE": {0x0e203c00, 0x7f, false},
+	"VCMGT": {0x0e203400, 0x7f, false},
+	"VCMHI": {0x2e203400, 0x7f, false},
+	"VCMHS": {0x2e203c00, 0x7f, false},
+	// FP compares take H, S and D arrangements only (the toolchain rejects
+	// the byte forms), and VFCMLE/VFCMLT have no register form at all.
+	"VFCMEQ": {0x0e20e400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFCMGE": {0x2e20e400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFCMGT": {0x2ea0e400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	// FP arithmetic shares the same arrangement restriction.
+	"VFADD":   {0x0e20d400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFSUB":   {0x0ea0d400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMUL":   {0x2e20dc00, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFDIV":   {0x2e20fc00, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMAX":   {0x0e20f400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMIN":   {0x0ea0f400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMAXNM": {0x0e20c400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMINNM": {0x0ea0c400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMLA":   {0x0e20cc00, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMLS":   {0x0ea0cc00, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	// Saturating, halving, polynomial and pairwise arithmetic, the logical
+	// VBIT/VBSL family and the FP pairwise forms: word-verified against go
+	// tool asm.
+	"VBIC":     {0x0e601c00, 0x7f, false},
+	"VBIF":     {0x2ee01c00, 0x7f, false},
+	"VBIT":     {0x6ea01c00, 0x7f, false},
+	"VBSL":     {0x6e601c00, 0x7f, false},
+	"VCMTST":   {0x0e208c00, 0x7f, false},
+	"VFADDP":   {0x2e20d400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMAXP":   {0x2e20f400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMINP":   {0x6ea0f400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMAXNMP": {0x2e20c400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VFMINNMP": {0x6ea0c400, 1<<a64Arr4H | 1<<a64Arr8H | 1<<a64Arr2S | 1<<a64Arr4S | 1<<a64Arr2D, false},
+	"VMLA":     {0x4ea09400, 0x7f, false},
+	"VMLS":     {0x6ea09400, 0x7f, false},
+	"VORN":     {0x4ee01c00, 0x7f, false},
+	"VSHADD":   {0x4ea00400, 0x7f, false},
+	"VSRHADD":  {0x4ea01400, 0x7f, false},
+	"VUHADD":   {0x6ea00400, 0x7f, false},
+	"VURHADD":  {0x6ea01400, 0x7f, false},
+	"VSMAX":    {0x4ea06400, 0x7f, false},
+	"VSMIN":    {0x4ea06c00, 0x7f, false},
+	"VSMAXP":   {0x4ea0a400, 0x7f, false},
+	"VSMINP":   {0x4ea0ac00, 0x7f, false},
+	"VUMAX":    {0x2e206400, 0x7f, false},
+	"VUMIN":    {0x2e206c00, 0x7f, false},
+	"VUMAXP":   {0x6ea0a400, 0x7f, false},
+	"VUMINP":   {0x6ea0ac00, 0x7f, false},
+	"VSQADD":   {0x4ea00c00, 0x7f, false},
+	"VUQADD":   {0x6ea00c00, 0x7f, false},
+	"VSQSUB":   {0x4ea02c00, 0x7f, false},
+	"VUQSUB":   {0x6ea02c00, 0x7f, false},
+	"VSSHL":    {0x4ee04400, 0x7f, false},
+	"VUSHL":    {0x6ee04400, 0x7f, false},
+	"VUZP1":    {0x0e001800, 0x7f, false},
+	"VUZP2":    {0x4ec05800, 0x7f, false},
+	"VTRN1":    {0x4ec02800, 0x7f, false},
+	"VTRN2":    {0x4ec06800, 0x7f, false},
+	"VRAX1":    {0xce608c00, 1 << a64Arr2D, true}, // SHA3 group, D2 only
+	"VPMULL":   {0x0e20e000, 1<<a64Arr8B | 1<<a64ArrD1, false},
+	"VPMULL2":  {0x0e20e000, 1<<a64Arr16B | 1<<a64Arr2D, false},
+}
+
+// a64SimdVZero holds the compare-against-zero words of the SIMD compares
+// spelled with a $0 first operand (word = base | arrBits | Rn<<5 | Rd).
+// VCMHI and VCMHS have no zero form: the toolchain reports an illegal
+// combination for them, so they stay out and the encoder rejects the shape.
+var a64SimdVZero = map[string]uint32{
+	"VCMEQ": 0x0e209800,
+	"VCMGT": 0x0e208800,
+	"VCMGE": 0x2e208800,
+	"VCMLT": 0x0e20a800,
+	"VCMLE": 0x2e209800,
+	// FP compares against (0.0): the register forms above carry the U and op
+	// bits; the zero forms reshape them.
+	"VFCMEQ": 0x0ea0d800,
+	"VFCMGE": 0x2ea0c800,
+	"VFCMGT": 0x0ea0c800,
+	"VFCMLE": 0x2ea0d800,
+	"VFCMLT": 0x0ea0e800,
 }
 
 // a64SimdV2Table holds the arrangement-aware two-register SIMD instructions
@@ -875,8 +1147,41 @@ var a64SimdVTable = map[string]a64SimdVSpec{
 var a64SimdV2Table = map[string]a64SimdVSpec{
 	"VREV32":  {0x2e200800, 1<<a64Arr8B | 1<<a64Arr16B | 1<<a64Arr4H | 1<<a64Arr8H, false},
 	"VREV64":  {0x0e200800, 0x3f, false},
+	"VREV16":  {0x0e201800, 1<<a64Arr8B | 1<<a64Arr16B, false},
 	"VUADDLV": {0x2e303800, 0x3f, false},
 	"VMOV":    {0x0ea01c00, 1<<a64Arr8B | 1<<a64Arr16B, false},
+	// Two-register data-processing across one arrangement.
+	"VABS":    {0x0e20b800, 0x7f, false},
+	"VNEG":    {0x2e20b800, 0x7f, false},
+	"VCLS":    {0x0e204800, 0x7f, false},
+	"VCLZ":    {0x2e204800, 0x7f, false},
+	"VCNT":    {0x0e205800, 0x7f, false},
+	"VNOT":    {0x2e205800, 0x7f, false},
+	"VSQABS":  {0x0e207800, 0x7f, false},
+	"VSQNEG":  {0x2e207800, 0x7f, false},
+	"VRBIT":   {0x6e605800, 0x7f, false},
+	"VSCVTF":  {0x4e21d800, fpSimdArrs, false},
+	"VUCVTF":  {0x6e21d800, fpSimdArrs, false},
+	"VFCVTZS": {0x4ea1b800, fpSimdArrs, false},
+	"VFCVTZU": {0x6ea1b800, fpSimdArrs, false},
+	"VFABS":   {0x0ea0f800, fpSimdArrs, false},
+	"VFNEG":   {0x2ea0f800, fpSimdArrs, false},
+	"VFSQRT":  {0x2ea1f800, fpSimdArrs, false},
+	"VFRINTN": {0x0e218800, fpSimdArrs, false},
+	"VFRINTP": {0x0ea18800, fpSimdArrs, false},
+	"VFRINTM": {0x0e219800, fpSimdArrs, false},
+	"VFRINTZ": {0x0ea19800, fpSimdArrs, false},
+	// Across-vector reductions: the operand arrangement rides as usual and
+	// the destination stays a bare V register.
+	"VADDV":    {0x0e31b800, 0x3f, false},
+	"VSMAXV":   {0x0e30a800, 0x3f, false},
+	"VSMINV":   {0x0e31a800, 0x3f, false},
+	"VUMAXV":   {0x2e30a800, 0x3f, false},
+	"VUMINV":   {0x2e31a800, 0x3f, false},
+	"VFMAXV":   {0x2e30f800, fpAcrossArrs, false},
+	"VFMINV":   {0x2eb0f800, fpAcrossArrs, false},
+	"VFMAXNMV": {0x2e30c800, fpAcrossArrs, false},
+	"VFMINNMV": {0x2eb0c800, fpAcrossArrs, false},
 }
 
 // a64CryptoArr is the arrangement each crypto instruction's operands must
@@ -904,6 +1209,15 @@ var a64MRSOps = map[string]uint32{
 	"ID_AA64ISAR1_EL1": 0xd5380620, "CNTFRQ_EL0": 0xd53be000,
 	"CNTPCT_EL0": 0xd53be020, "CNTVCT_EL0": 0xd53be040,
 	"DCZID_EL0": 0xd53b00e0, "DIT": 0xd53b42a0, "ID_AA64ZFR0_EL1": 0xd5380480,
+	"NZCV": 0xd53b4200, "FPCR": 0xd53b4400, "FPSR": 0xd53b4420,
+}
+
+// a64MSRRegOps maps the system register names GOROOT writes through the
+// MSR (register) form, spelled in Go assembly as MOVD Rn, <sysreg> or
+// MSR Rn, <sysreg>; the source register rides bits 4:0.
+var a64MSRRegOps = map[string]uint32{
+	"NZCV": 0xd51b4200, "FPCR": 0xd51b4400, "FPSR": 0xd51b4420,
+	"ELR_EL1": 0xd5184020,
 }
 
 // a64MSROps maps the system register names GOROOT writes to their fixed

asm/arm64_encode_test.go

@@ -4,10 +4,11 @@
 package asm
 
 import (
+	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 func TestArm64LDRSTREncoding(t *testing.T) {
@@ -104,6 +105,7 @@ func TestArm64RegNum(t *testing.T) {
 	}{
 		{"R0", 0}, {"R4", 4}, {"R29", 29}, {"R30", 30}, {"R31", 31},
 		{"FP", 29}, {"LR", 30}, {"LINK", 30}, {"SP", 31}, {"ZR", 31},
+		{"R18_PLATFORM", 18},
 		{"F0", 0}, {"F4", 4}, {"F31", 31},
 		{"INVALID", -1}, {"X0", -1}, {"", -1},
 	}
@@ -674,6 +676,36 @@ func TestArm64AcquireRelease(t *testing.T) {
 	}
 }
 
+// TestArm64BTI pins the landing-pad family against the toolchain words:
+// only the uppercase C/J/JC spellings assemble, and bare BTI is a
+// diagnostic, never a panic.
+func TestArm64BTI(t *testing.T) {
+	got := arm64Words(t, "\tBTI C\n\tBTI J\n\tBTI JC\n")
+	want := []uint32{
+		0xd503245f, // BTI C
+		0xd503249f, // BTI J
+		0xd50324df, // BTI JC
+		0xd65f03c0, // RET
+	}
+	if len(got) != len(want) {
+		t.Fatalf("got %d words, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %#x, want %#x", i, got[i], want[i])
+		}
+	}
+	for _, src := range []string{"\tBTI\n", "\tBTI c\n", "\tBTI B\n"} {
+		f, errs := parser.Parse("test_arm64.s", "#include \"textflag.h\"\n\nTEXT ·f(SB), NOSPLIT, $0-0\n"+src+"\tRET\n")
+		if len(errs) > 0 {
+			continue
+		}
+		if _, err := AssembleFileARM64(f); err == nil {
+			t.Errorf("BTI spelling %q should be rejected, as go tool asm rejects it", src)
+		}
+	}
+}
+
 // TestArm64System pins BRK, SVC, the barriers, cache maintenance and the
 // system register accesses.
 func TestArm64System(t *testing.T) {
@@ -830,6 +862,99 @@ func TestArm64SIMDElement(t *testing.T) {
 	}
 }
 
+// TestArm64GPIntoVector pins the whole-vector moves VMOV/VDUP Rs, Vd.<T>
+// against `go tool asm -S` output (Go 1.27, arm64): word = Q | 7<<25 |
+// imm5<<16 | 3<<10 | rs<<5 | rd, shared by both mnemonics, the form
+// sys_windows_arm64.s and the bytealg loops use.  The D1 destination is
+// rejected, as the toolchain rejects it.
+func TestArm64GPIntoVector(t *testing.T) {
+	got := arm64Words(t, "\tVMOV R5, V5.B16\n\tVMOV R1, V2.B8\n\tVMOV R3, V4.H4\n"+
+		"\tVMOV R9, V10.S4\n\tVMOV R7, V31.H8\n\tVMOV R11, V12.D2\n"+
+		"\tVDUP R5, V5.B16\n\tVDUP R9, V10.H8\n\tVMOV V4.B16, V20.B16\n")
+	want := []uint32{
+		0x4e010ca5, // VMOV R5, V5.B16
+		0x0e010c22, // VMOV R1, V2.B8
+		0x0e020c64, // VMOV R3, V4.H4
+		0x4e040d2a, // VMOV R9, V10.S4
+		0x4e020cff, // VMOV R7, V31.H8
+		0x4e080d6c, // VMOV R11, V12.D2
+		0x4e010ca5, // VDUP R5, V5.B16 (same word as VMOV)
+		0x4e020d2a, // VDUP R9, V10.H8
+		0x4ea41c94, // VMOV V4.B16, V20.B16 (vector to vector stays ORR)
+		0xd65f03c0,
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+	f, errs := parser.Parse("test_arm64.s", "#include \"textflag.h\"\n\nTEXT ·f(SB), NOSPLIT, $0-0\n\tVMOV R7, V8.D1\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	if _, err := AssembleFileARM64(f); err == nil {
+		t.Errorf("VMOV R7, V8.D1 assembled, want an arrangement error")
+	}
+}
+
+// TestArm64SimdTwoOperand pins the two-operand accumulate spellings
+// VADD/VSUB Vm, Vn against `go tool asm -S` output (Go 1.27, arm64):
+// word = 5<<28|7<<25|7<<21|1<<15|1<<10 for VADD (7<<28 for VSUB) with
+// rf<<16 | rn<<5 | rn, bare V registers only (asm7.go case 89).
+func TestArm64SimdTwoOperand(t *testing.T) {
+	got := arm64Words(t, "\tVADD V7, V8\n\tVSUB V7, V8\n\tVADD V1, V2\n\tVADD V0.B16, V1.B16, V2.B16\n")
+	want := []uint32{
+		0x5ee78508, // VADD V7, V8
+		0x7ee78508, // VSUB V7, V8
+		0x5ee18442, // VADD V1, V2
+		0x4e208422, // VADD arranged: the ordinary three-register path
+		0xd65f03c0,
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+}
+
+// TestArm64TruncMove pins the truncating register moves against
+// `go tool asm -S` output (Go 1.27, arm64): the signed forms lower to SXTB,
+// SXTH and SXTW (SBFM), the unsigned byte and halfword forms to UXTB and
+// UXTH (UBFM), MOVWU to a W ORR, and a narrow move out of the zero register
+// drops to the W ORR too (asm7.go case 45).
+func TestArm64TruncMove(t *testing.T) {
+	got := arm64Words(t, "\tMOVB R3, R4\n\tMOVH R5, R6\n\tMOVW R9, R10\n"+
+		"\tMOVBU R3, R4\n\tMOVHU R3, R4\n\tMOVWU R3, R4\n\tMOVD R3, R4\n"+
+		"\tMOVD ZR, R4\n\tMOVB ZR, R4\n\tMOVWU ZR, R5\n")
+	want := []uint32{
+		0x93401c64, // MOVB  = SXTB
+		0x93403ca6, // MOVH  = SXTH
+		0x93407d2a, // MOVW  = SXTW
+		0xd3401c64, // MOVBU = UXTB
+		0xd3403c64, // MOVHU = UXTH
+		0x2a0303e4, // MOVWU = ORR W
+		0xaa0303e4, // MOVD  = ORR X
+		0xaa1f03e4, // MOVD ZR, R4 keeps the X form
+		0x2a1f03e4, // MOVB ZR, R4 drops to the W form
+		0x2a1f03e5, // MOVWU ZR, R5
+		0xd65f03c0,
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+}
+
 // TestArm64SIMDLoadStore pins the structure loads and stores.
 func TestArm64SIMDLoadStore(t *testing.T) {
 	got := arm64Words(t, "\tVLD1 (R2), [V21.B16]\n\tVLD1 (R1), [V2.B16, V3.B16]\n\tVLD1 (R29), [V14.D1, V15.D1, V16.D1, V17.D1]\n"+
@@ -926,6 +1051,41 @@ func TestArm64MOVK(t *testing.T) {
 	}
 }
 
+// TestArm64MOVKHighLane pins the shifted high-lane immediate the arm64 test
+// kernels write: $(40000<<48) folds to a negative int64, and the toolchain
+// reads the value as an unsigned 64-bit pattern when it picks the lane.
+func TestArm64MOVKHighLane(t *testing.T) {
+	got := arm64Words(t, "\tMOVK $(40000<<48), R0\n\tMOVK $0x9c40000000000000, R1\n")
+	want := []uint32{
+		0xf2f38800, // MOVK $(40000<<48), R0 (go tool asm: f2f38800)
+		0xf2f38801, // MOVK hw=3
+		0xd65f03c0,
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+}
+
+// TestArm64MoveWideZeroImmediate pins the toolchain's rejection of a zero
+// immediate in the move-wide family (optab case 33: "zero shifts cannot be
+// handled"): every lane is zero, so no hw field can carry it.
+func TestArm64MoveWideZeroImmediate(t *testing.T) {
+	for _, mnem := range []string{"MOVK", "MOVZ", "MOVN"} {
+		f, errs := parser.Parse("test_arm64.s", "#include \"textflag.h\"\n\nTEXT ·f(SB), NOSPLIT, $0-0\n\t"+mnem+" $0, R0\n\tRET\n")
+		if len(errs) > 0 {
+			t.Fatalf("%s: parse: %v", mnem, errs)
+		}
+		if _, err := AssembleFileARM64(f); err == nil {
+			t.Errorf("%s $0: expected error, got nil", mnem)
+		}
+	}
+}
+
 // TestArm64LoadImm64 tests 64-bit immediate loading.
 func TestArm64LoadImm64(t *testing.T) {
 	src := `#include "textflag.h"
@@ -1295,20 +1455,170 @@ func TestArm64ExclNoOffset(t *testing.T) {
 	}
 }
 
-// TestArm64AddSubImmRange: immediates that cannot ride the imm12 field are
-// rejected instead of wrapping through int32.
-func TestArm64AddSubImmRange(t *testing.T) {
-	for _, body := range []string{
-		"\tADD $0x100000000, R0, R1\n",
-		"\tSUB $-0x100000000, R0, R1\n",
-		"\tCMP $0x100000000, R0\n",
-	} {
-		f, errs := parser.Parse("test_arm64.s", "#include \"textflag.h\"\n\nTEXT ·f(SB), NOSPLIT, $0-0\n"+body+"\tRET\n")
-		if len(errs) > 0 {
-			t.Fatalf("parse: %v", errs)
+// TestArm64AddSubImmWide pins the wide-immediate classification the toolchain
+// applies to the ADD/SUB family (asm7.go cases 48, 62, 13): the ADDCON2 split
+// into two imm12 instructions for plain ADD/SUB, the bitmask ORR into REGTMP,
+// and the MOVZ/MOVN/MOVK materialisations followed by the register form.
+// Comparisons never split, and the W forms classify the 32-bit value.  Every
+// word is go tool asm's own for the same source.
+func TestArm64AddSubImmWide(t *testing.T) {
+	got := arm64Words(t, strings.Join([]string{
+		"\tADD $0xaaaaaa, R2, R3",
+		"\tSUB $0xaaaaaa, R2",
+		"\tADD $0x186a0, R2, R5",
+		"\tADD $0x1ffe00, R2, R3",
+		"\tADD $0x3fffffffc000, R5",
+		"\tADD $-100000, R2, R3",
+		"\tADD $-2048, R2, R3",
+		"\tCMP $0xaaaaaa, R2",
+		"\tCMP $0xffffffffffa0, R3",
+		"\tCMPW $27745, R2",
+		"\tCMPW $0x60060, R2",
+		"\tADDS $0xaaaaaa, R2, R3",
+		"\tADD $0x12345678, R2, R3",
+		"\tADDW $0x60060, R2",
+		"\tSUB $0xe7791f700, R3, R1",
+		"\tADDW $0x12345678, R2, R3",
+		"\tCMN $0x1000000, R2",
+	}, "\n")+"\n")
+	want := []uint32{
+		0x912aa843, 0x916aa863, // ADD $0xaaaaaa, R2, R3: ADDCON2 split
+		0xd12aa842, 0xd16aa842, // SUB $0xaaaaaa, R2: split with Rd = Rn
+		0x911a8045, 0x914060a5, // ADD $0x186a0, R2, R5: split
+		0xb2772ffb, 0x8b1b0043, // ADD $0x1ffe00: bitmask beats the split
+		0xb2727ffb, 0x8b1b00a5, // ADD $0x3fffffffc000: bitmask into REGTMP
+		0x9290d3fb, 0xf2bfffdb, 0x8b1b0043, // ADD $-100000: MOVN + MOVK
+		0x9280fffb, 0x8b1b0043, // ADD $-2048: single MOVN + ADD
+		0xd295555b, 0xf2a0155b, 0xeb1b005f, // CMP: never split, MOVZ + MOVK
+		0x92800bfb, 0xf2e0001b, 0xeb1b007f, // CMP $0xffffffffffa0: MOVN + fixup
+		0x528d8c3b, 0x6b1b005f, // CMPW $27745: W movcon, single MOVZW
+		0x52800c1b, 0x72a000db, 0x6b1b005f, // CMPW $0x60060: S form skips the split
+		0xd295555b, 0xf2a0155b, 0xab1b0043, // ADDS $0xaaaaaa: MOVZ + MOVK + ADDS
+		0xd28acf1b, 0xf2a2469b, 0x8b1b0043, // ADD $0x12345678: MOVZ + MOVK
+		0x11018042, 0x11418042, // ADDW $0x60060: W split
+		0xd29ee01b, 0xf2aef23b, 0xf2c001db, 0xcb1b0061, // SUB $0xe7791f700
+		0x528acf1b, 0x72a2469b, 0x0b1b0043, // ADDW $0x12345678: MOVZW + MOVKW
+		0xd2a0201b, 0xab1b005f, // CMN $0x1000000: single MOVZ + CMN
+		0xd65f03c0, // RET
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("wide word %d = %08x, want %08x", i, got[i], want[i])
 		}
-		if _, err := AssembleFileARM64(f); err == nil {
-			t.Errorf("%s: expected an error, got none", body)
+	}
+}
+
+// TestArm64CarryImmWide pins the carry family's $0 spellings in two and
+// three operands, the ROR shift on the logical group (and its rejection for
+// the arithmetic forms), the NGC/MNEG zero-register aliases and the vector
+// alias with an element selector.  Words are go tool asm's own.
+func TestArm64CarryShiftAlias(t *testing.T) {
+	got := arm64Words(t, "\tADC $0, R20\n\tADC $0, R20, R4\n\tSBCS $0, R4, R12\n"+
+		"\tSBCS R15, R4, R12\n\tANDW R9@>7, R19, R26\n\tAND R1@>33, R2, R3\n"+
+		"\tNEGSW R23<<1, R30\n\tNGC R2, R7\n\tMNEG R14, R27, R23\n")
+	want := []uint32{
+		0x9a1f0294, // ADC ZR, R20, R20
+		0x9a1f0284, // ADC ZR, R20, R4
+		0xfa1f008c, // SBCS ZR, R4, R12
+		0xfa0f008c, // SBCS R15, R4, R12
+		0x0ac91e7a, // ANDW R9 ROR 7, R19, R26
+		0x8ac18443, // AND R1 ROR 33, R2, R3
+		0x6b1707fe, // SUBSW ZR, R30, R23 LSL 1
+		0xda0203e7, // SBC ZR, R7, R2
+		0x9b0eff77, // MSUB ZR, R27, R14, R23
+		0xd65f03c0, // RET
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("carry word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+
+	// ROR on an arithmetic form is unallocated: the toolchain reports an
+	// unsupported shift operator.
+	f, errs := parser.Parse("test_arm64.s", "#include \"textflag.h\"\n\nTEXT ·f(SB), NOSPLIT, $0-0\n\tADD R1@>33, R2, R3\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	if _, err := AssembleFileARM64(f); err == nil {
+		t.Error("ADD R1@>33: expected an error, got none")
+	}
+}
+
+// TestArm64VecAliasElement pins the register-alias rewrite inside a vector
+// operand with an element selector and inside a split register list: the
+// aliases resolve textually where the parser carries the selector apart from
+// the name.  Words are go tool asm's own.
+func TestArm64VecAliasElement(t *testing.T) {
+	src := `#include "textflag.h"
+
+#define POLY V15
+#define ACC0 V8
+#define ACC1 V9
+
+TEXT ·f(SB), NOSPLIT, $0-0
+	VMOV R1, POLY.D[0]
+	VEOR POLY.B16, POLY.B16, POLY.B16
+	VLD1 (R0), [ACC0.B16]
+	VLD1.P (R0), [ACC0.B16, ACC1.B16]
+	VST1.P [ACC0.B16, ACC1.B16], 32(R1)
+	RET
+`
+	f, errs := parser.Parse("test_arm64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileARM64(f)
+	if err != nil {
+		t.Fatalf("AssembleFileARM64: %v", err)
+	}
+	got := leWords(img.Code)
+	want := []uint32{
+		0x4e081c2f, // INS V15.D[0], R1
+		0x6e2f1def, // VEOR V15.B16, V15.B16, V15.B16
+		0x4c407008, // VLD1 (R0), [V8.B16]
+		0x4cdfa008, // VLD1.P (R0), [V8.B16, V9.B16]
+		0x4c9fa028, // VST1.P [V8.B16, V9.B16], 32(R1)
+		0xd65f03c0, // RET
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("vecalias word %d = %08x, want %08x", i, got[i], want[i])
+		}
+	}
+}
+
+// TestArm64AddSubImmBeyond32 pins the materialisation the toolchain applies
+// once the value leaves every imm12 form: a constant sequence into REGTMP
+// (R27) followed by the register form.  SUB $-0x100000000 is a bitmask
+// immediate, so it rides the ORR form; the others take MOVZ.  Words are go
+// tool asm's own.
+func TestArm64AddSubImmBeyond32(t *testing.T) {
+	got := arm64Words(t, "\tADD $0x100000000, R0, R1\n\tSUB $-0x100000000, R0, R1\n\tCMP $0x100000000, R0\n")
+	want := []uint32{
+		0xd2c0003b, // MOVZ $(1<<32>>16), R27 (hw=2)
+		0x8b1b0001, // ADD R27, R0, R1
+		0xb2607ffb, // ORR $-4294967296, ZR, R27 (bitmask)
+		0xcb1b0001, // SUB R27, R0, R1
+		0xd2c0003b, // MOVZ $(1<<32>>16), R27 (hw=2)
+		0xeb1b001f, // CMP R27, R0
+		0xd65f03c0, // RET
+	}
+	if len(got) != len(want) {
+		t.Fatalf("word count = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("word %d = %08x, want %08x", i, got[i], want[i])
 		}
 	}
 }

asm/arm64_frame.go

@@ -53,7 +53,7 @@ package asm
 import (
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // arm64FrameInfo holds the frame layout derived from a TEXT directive.

asm/arm64_reloc_test.go

@@ -7,7 +7,7 @@ import (
 	"encoding/binary"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // parseArm64File is a helper assembling one arm64 source file.

asm/assemble.go

@@ -5,9 +5,10 @@ package asm
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // Assemble encodes the body of a TEXT function into x86-64 machine code,
@@ -28,7 +29,7 @@ import (
 // emitted: the bytes match go tool asm only for NOSPLIT functions or
 // zero-frame leaves, where the toolchain emits no guard either.
 func Assemble(t *ast.Text) ([]byte, map[string]int, error) {
-	code, _, labels, _, _, err := assemble(t, nil)
+	code, _, labels, _, _, _, err := assemble(t, nil)
 	return code, labels, err
 }
 
@@ -37,10 +38,25 @@ func Assemble(t *ast.Text) ([]byte, map[string]int, error) {
 // rejects SB operands outright (single-function assembly cannot resolve
 // them).  When allowExternal is set, a reference to a symbol no GLOBL in the
 // file defines is recorded as an external relocation instead of failing
-// the object-file emitters resolve it at link time.
+// the object-file emitters resolve it at link time.  goos selects the TLS
+// access form: the empty default behaves as linux.
 type linkInfo struct {
 	symbols       map[string]bool
 	allowExternal bool
+	goos          string
+}
+
+// tlsOneInsn reports the one-instruction TLS form, obj6.go's
+// CanUse1InsnTLS for the GOOS gasm supports: the bare TLS load nops out and
+// the (TLS*1) index folds to a segment-absolute access.  Windows and plan9
+// keep the two-instruction form; shared linux does too, which gasm's raw
+// path does not model and therefore does not select.
+func (l *linkInfo) tlsOneInsn() bool {
+	switch l.goos {
+	case "", "linux", "freebsd":
+		return true
+	}
+	return false
 }
 
 // sbPatch is a function-relative static-symbol relocation: the disp32 field
@@ -66,7 +82,10 @@ type spadjStep struct {
 // assemble encodes a TEXT body, returning the machine code, the static-symbol
 // patch sites (for the file-level layout to resolve), the label table and the
 // stack-adjustment boundaries.
-func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, []spadjStep, []LineEntry, error) {
+func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, []spadjStep, []LineEntry, []floatPoolEntry, error) {
+	if err := checkAdjspBalance(t); err != nil {
+		return nil, nil, nil, nil, nil, nil, err
+	}
 	fi := computeFrame(t)
 	chain := jumpChain(t)
 	resolve := func(name string) string {
@@ -82,29 +101,118 @@ func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, [
 	// outgrows the short form.
 	long := make([]bool, len(t.Body))
 	sizes := make([]int, len(t.Body))
+	numTargets := make([]int, len(t.Body))
+	for i := range numTargets {
+		numTargets[i] = -1
+	}
 	offsets := map[string]int{}
 	pcs := make([]int, len(t.Body))
 	var guardJBlong, guardJBElong, moreJMPlong bool
+	poolSeen := map[string]bool{}
+	var poolList []floatPoolEntry
 	for {
 		guard := fi.guardLen(guardJBlong, guardJBElong)
 		pos := guard + len(fi.prologue)
+		for i := range numTargets {
+			numTargets[i] = -1
+		}
+		idxAtPc := map[int]int{}
 		for i, stmt := range t.Body {
 			switch s := stmt.(type) {
 			case *ast.Label:
 				offsets[s.Name.Text] = pos
 			case *ast.Instr:
+				if strings.ToUpper(s.Mnemonic.Text) == "PCALIGN" {
+					// The alignment pseudo-statement: its size is the
+					// padding to the next boundary at this very position,
+					// filled with NOPs at emission.
+					pad, err := pcAlignPad(pcAlignValue(s), pos)
+					if err != nil {
+						return nil, nil, nil, nil, nil, nil, fmt.Errorf("PCALIGN: %w", err)
+					}
+					sizes[i] = pad
+					pcs[i] = pos
+					pos += pad
+					continue
+				}
 				sz, err := instrSize(s, fi, long[i], link)
 				if err != nil {
-					return nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", s.Mnemonic.Text, err)
+					return nil, nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", s.Mnemonic.Text, err)
 				}
 				sizes[i] = sz
 				pcs[i] = pos
+				idxAtPc[pos] = i
 				pos += sz
 			}
 		}
 		bodyLen := pos - (guard + len(fi.prologue))
 		// Expand any short jump whose displacement no longer fits rel8.
 		changed := false
+		// Numeric ±N(PC) jumps resolve against this iteration's layout; the
+		// emission pass reads the same table after the loop converges.  A
+		// target that is itself an unconditional local JMP is chased to the
+		// ultimate target: the toolchain's brloop pass collapses branch-to-
+		// branch chains before it encodes, so matching its bytes requires
+		// the same redirection.
+		for i := range numTargets {
+			numTargets[i] = -1
+		}
+		for i, stmt := range t.Body {
+			s, ok := stmt.(*ast.Instr)
+			if !ok {
+				continue
+			}
+			if len(s.Operands) == 1 {
+				if n, isNum := pcJumpOffset(s.Operands[0]); isNum {
+					if target, okT := pcJumpTarget(t, i, n, pcs); okT {
+						numTargets[i] = target
+					}
+				}
+			}
+		}
+		for i := range numTargets {
+			if numTargets[i] < 0 {
+				continue
+			}
+			tgt := numTargets[i]
+			for hop := 0; hop < len(t.Body); hop++ {
+				idx, ok := idxAtPc[tgt]
+				if !ok {
+					break
+				}
+				in, ok := t.Body[idx].(*ast.Instr)
+				if !ok || strings.ToUpper(in.Mnemonic.Text) != "JMP" || len(in.Operands) != 1 {
+					break
+				}
+				if name, isLabel := labelName(in.Operands[0]); isLabel {
+					tgt = offsets[resolve(name)]
+					continue
+				}
+				if n, isNum := pcJumpOffset(in.Operands[0]); isNum {
+					next, okT := pcJumpTarget(t, idx, n, pcs)
+					if !okT {
+						break
+					}
+					tgt = next
+					continue
+				}
+				break // JMP through a register or memory: the chain ends
+			}
+			numTargets[i] = tgt
+		}
+		for i, stmt := range t.Body {
+			s, ok := stmt.(*ast.Instr)
+			if !ok {
+				continue
+			}
+			if numTargets[i] >= 0 && !long[i] {
+				rel := int64(numTargets[i] - (pcs[i] + jumpSize(strings.ToUpper(s.Mnemonic.Text), false)))
+				if !fits8(rel) {
+					long[i] = true
+					changed = true
+				}
+			}
+		}
 		for i, stmt := range t.Body {
 			s, ok := stmt.(*ast.Instr)
 			if !ok {
@@ -203,6 +311,14 @@ func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, [
 			spadjStep{guardLen + len(fi.prologue), 8 + fi.size},
 		)
 	}
+	// frameBase is the SP delta the prologue leaves: 8 for the saved base
+	// pointer plus the frame, 0 frameless.  bodyDelta tracks the ADJSP
+	// statements' straight-line sum, so a mid-body step's value is the
+	// frame base plus what the body has opened so far.
+	frameBase, bodyDelta := 0, 0
+	if fi.useFP {
+		frameBase = 8 + fi.size
+	}
 	pos := guardLen + len(fi.prologue)
 	for i, stmt := range t.Body {
 		s, ok := stmt.(*ast.Instr)
@@ -218,18 +334,34 @@ func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, [
 				spadjStep{pos + epi, 0},
 			)
 		}
-		code, ps, err := encodeInstr(s, pos, offsets, fi, long[i], resolve, link)
+		code, ps, pool, err := encodeInstr(s, pos, offsets, fi, long[i], resolve, link, numTargets[i])
 		if err != nil {
-			return nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", s.Mnemonic.Text, err)
+			return nil, nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", s.Mnemonic.Text, err)
+		}
+		for _, entry := range pool {
+			if !poolSeen[entry.name] {
+				poolSeen[entry.name] = true
+				poolList = append(poolList, entry)
+			}
 		}
 		if len(code) != sizes[i] {
-			return nil, nil, nil, nil, nil, fmt.Errorf("%s: size mismatch (%d vs %d)", s.Mnemonic.Text, len(code), sizes[i])
+			return nil, nil, nil, nil, nil, nil, fmt.Errorf("%s: size mismatch (%d vs %d)", s.Mnemonic.Text, len(code), sizes[i])
 		}
 		if strings.ToUpper(s.Mnemonic.Text) == "CALL" {
 			for k := range ps {
 				ps[k].kind = RelCall
 			}
 		}
+		if strings.ToUpper(s.Mnemonic.Text) == "ADJSP" && len(s.Operands) == 1 && s.Operands[0].Imm.HasVal {
+			// The statement shifted SP mid-body: record the new running
+			// delta as the value in effect from just past the instruction.
+			v := s.Operands[0].Imm.Val
+			if s.Operands[0].Imm.Neg {
+				v = -v
+			}
+			bodyDelta += int(v)
+			steps = append(steps, spadjStep{pos + len(code), frameBase + bodyDelta})
+		}
 		patches = append(patches, ps...)
 		lines = append(lines, LineEntry{Offset: pos, Line: s.Pos().Line})
 		out = append(out, code...)
@@ -251,7 +383,7 @@ func assemble(t *ast.Text, link *linkInfo) ([]byte, []sbPatch, map[string]int, [
 		pos += len(suffix)
 	}
 	_ = pos
-	return out, patches, offsets, steps, lines, nil
+	return out, patches, offsets, steps, lines, poolList, nil
 }
 
 // jumpChain precomputes jump-to-jump folding: a label whose first instruction
@@ -398,6 +530,99 @@ func computeFrame(t *ast.Text) frameInfo {
 	return fi
 }
 
+// pcJumpOffset recognises the numeric relative jump operand ±N(PC) and
+// returns N: the toolchain counts instructions, not bytes, so +2(PC) targets
+// the second instruction boundary after the branch.
+func pcJumpOffset(op *ast.Operand) (int, bool) {
+	if op.Kind != ast.OpAddr || op.Addr.Base != "PC" {
+		return 0, false
+	}
+	return int(op.Addr.Offset), true
+}
+
+// pcJumpTarget resolves a numeric jump at statement index j: N counts the
+// instruction statements after the jump itself (N = 0 is the jump's own
+// address, the classic park loop), and the target is the start of the Nth
+// one.  A negative N counts the same way backwards, before the jump: the
+// exit loops write JMP -3(PC) to land three instructions earlier.  Labels
+// count not, in either direction.  It reports false when the count runs
+// past the end of the function, or before its first instruction.
+func pcJumpTarget(t *ast.Text, j, n int, pcs []int) (int, bool) {
+	if n == 0 {
+		return pcs[j], true
+	}
+	if n < 0 {
+		seen := 0
+		for k := j - 1; k >= 0; k-- {
+			if _, ok := t.Body[k].(*ast.Instr); !ok {
+				continue
+			}
+			seen--
+			if seen == n {
+				return pcs[k], true
+			}
+		}
+		return 0, false
+	}
+	seen := 0
+	for k := j + 1; k < len(t.Body); k++ {
+		if _, ok := t.Body[k].(*ast.Instr); !ok {
+			continue
+		}
+		seen++
+		if seen == n {
+			return pcs[k], true
+		}
+	}
+	return 0, false
+}
+
+// x86 NOP encodings, single-instruction no-ops of lengths 1 to 9 (the
+// toolchain's asm6.go nop table); longer padding repeats the largest that
+// fits, greedy from the end.
+var x86Nops = [][]byte{
+	{0x90},
+	{0x66, 0x90},
+	{0x0F, 0x1F, 0x00},
+	{0x0F, 0x1F, 0x40, 0x00},
+	{0x0F, 0x1F, 0x44, 0x00, 0x00},
+	{0x66, 0x0F, 0x1F, 0x44, 0x00, 0x00},
+	{0x0F, 0x1F, 0x80, 0x00, 0x00, 0x00, 0x00},
+	{0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00},
+	{0x66, 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00},
+}
+
+// fillNOPs fills p with the greedy largest single-instruction NOPs, exactly
+// the toolchain's fillnop.
+func fillNOPs(p []byte) {
+	for len(p) > 0 {
+		m := min(len(p), len(x86Nops))
+		copy(p[:m], x86Nops[m-1])
+		p = p[m:]
+	}
+}
+
+// pcAlignPad computes the padding PCALIGN $align inserts at pos: the
+// alignment must be a power of two in [8, 2048] and the padding runs to the
+// next boundary (zero when the position is already aligned).
+func pcAlignPad(align, pos int) (int, error) {
+	if align <= 0 || align&(align-1) != 0 || align < 8 || align > 2048 {
+		return 0, fmt.Errorf("alignment value of an instruction must be a power of two and in the range [8, 2048], got %d", align)
+	}
+	if lob := pos & (align - 1); lob != 0 {
+		return align - lob, nil
+	}
+	return 0, nil
+}
+
+// pcAlignValue reads a PCALIGN statement's alignment operand.
+func pcAlignValue(s *ast.Instr) int {
+	if len(s.Operands) == 1 && s.Operands[0].Kind == ast.OpImmediate && s.Operands[0].Imm.HasVal {
+		return int(s.Operands[0].Imm.Val)
+	}
+	return 0 // rejected by pcAlignPad's range check
+}
+
 // hasCall reports whether the function body contains a CALL instruction.
 func hasCall(t *ast.Text) bool {
 	for _, stmt := range t.Body {
@@ -412,6 +637,40 @@ func hasCall(t *ast.Text) bool {
 	return false
 }
 
+// checkAdjspBalance mirrors the toolchain's push/pop walk: every ADJSP
+// shifts SP away from the entry state and every RET must see the shifts
+// closed.  The assembler's own prologue and epilogue contribute matching
+// deltas on both sides, so the statements' straight-line sum must be zero
+// at each RET; branches do not reset the walk, which runs over the program
+// list in source order.  go tool asm reports an offender as "unbalanced
+// PUSH/POP" (verified against ADJSP $16 before a RET, accepted as a
+// $16/$-16 pair, per-RET rather than per-function).
+func checkAdjspBalance(t *ast.Text) error {
+	delta := 0
+	for _, stmt := range t.Body {
+		in, ok := stmt.(*ast.Instr)
+		if !ok {
+			continue
+		}
+		switch strings.ToUpper(in.Mnemonic.Text) {
+		case "ADJSP":
+			if len(in.Operands) != 1 || !in.Operands[0].Imm.HasVal {
+				continue // reported during emission
+			}
+			v := in.Operands[0].Imm.Val
+			if in.Operands[0].Imm.Neg {
+				v = -v
+			}
+			delta += int(v)
+		case "RET":
+			if delta != 0 {
+				return fmt.Errorf("unbalanced PUSH/POP")
+			}
+		}
+	}
+	return nil
+}
+
 // guardLen returns the byte length of the stack-split guard prefix.  The
 // final conditional branch (JBE, and JB in the big class) is 2 bytes in the
 // short form and 6 in the long form.
@@ -538,7 +797,7 @@ func instrSize(s *ast.Instr, fi frameInfo, long bool, link *linkInfo) (int, erro
 		}
 		return jumpSize(mnem, long), nil
 	}
-	code, _, err := encodeInstr(s, 0, nil, fi, false, nil, link)
+	code, _, _, err := encodeInstr(s, 0, nil, fi, false, nil, link, -1)
 	if err != nil {
 		return 0, err
 	}
@@ -573,9 +832,21 @@ func jumpSize(mnem string, long bool) int {
 // (relative to pc, the instruction's own offset).  A RET in a frame-pointer
 // function is prefixed with the epilogue.  resolve, when non-nil, redirects a
 // jump label through the jump-to-jump chain before the offset lookup.
-func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, long bool, resolve func(string) string, link *linkInfo) ([]byte, []sbPatch, error) {
+func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, long bool, resolve func(string) string, link *linkInfo, numTarget int) ([]byte, []sbPatch, []floatPoolEntry, error) {
 	mnem := strings.ToUpper(s.Mnemonic.Text)
 
+	if mnem == "PCALIGN" {
+		// The layout pass already accounted the padding; emit the same
+		// amount of NOP bytes for the statement's own position.
+		pad, err := pcAlignPad(pcAlignValue(s), pc)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		out := make([]byte, pad)
+		fillNOPs(out)
+		return out, nil, nil, nil
+	}
+
 	var prefix []byte
 	if mnem == "RET" && fi.useFP {
 		prefix = fi.epilogue
@@ -583,6 +854,7 @@ func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, lon
 
 	var code []byte
 	var ps []sbPatch
+	var pool []floatPoolEntry
 	var err error
 	if isJumpMnemonic(mnem) {
 		if (mnem == "CALL" || mnem == "JMP") && isSBCall(s) {
@@ -591,7 +863,7 @@ func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, lon
 			// or the linker.
 			code, ps, err = encodeSBCall(s, link)
 			if err != nil {
-				return nil, nil, err
+				return nil, nil, nil, err
 			}
 			for i := range ps {
 				ps[i].kind = RelCall
@@ -601,23 +873,23 @@ func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, lon
 				ps[i].off += body
 				ps[i].after = body + len(code)
 			}
-			return append(prefix, code...), ps, nil
+			return append(prefix, code...), ps, nil, nil
 		}
 		if (mnem == "CALL" || mnem == "JMP") && indirectJumpTarget(s) {
 			// JMP/CALL through a register or memory: no relocation and no
 			// label to resolve, the operand fully determines the bytes.
 			code, err = encodeIndirectJump(s, mnem)
 			if err != nil {
-				return nil, nil, err
+				return nil, nil, nil, err
 			}
-			return append(prefix, code...), nil, nil
+			return append(prefix, code...), nil, nil, nil
 		}
-		code, err = encodeJump(s, mnem, pc+len(prefix), offsets, long, resolve)
+		code, err = encodeJump(s, mnem, pc+len(prefix), offsets, long, resolve, numTarget)
 	} else {
-		code, ps, err = encodeNormal(s, fi, link)
+		code, ps, pool, err = encodeNormal(s, fi, link)
 	}
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 	// Anchor the patch fields at function-relative positions: off indexes the
 	// disp32 field, after is the address just past the instruction.
@@ -626,49 +898,183 @@ func encodeInstr(s *ast.Instr, pc int, offsets map[string]int, fi frameInfo, lon
 		ps[i].off += body
 		ps[i].after = body + len(code)
 	}
-	return append(prefix, code...), ps, nil
+	return append(prefix, code...), ps, pool, nil
 }
 
-func encodeNormal(s *ast.Instr, fi frameInfo, link *linkInfo) ([]byte, []sbPatch, error) {
-	_, size := splitSize(strings.ToUpper(s.Mnemonic.Text))
+func encodeNormal(s *ast.Instr, fi frameInfo, link *linkInfo) ([]byte, []sbPatch, []floatPoolEntry, error) {
+	mnemUpper := strings.ToUpper(s.Mnemonic.Text)
+	if mnemUpper == "FUNCDATA" || mnemUpper == "PCDATA" {
+		code, err := encodeBookkeeping(mnemUpper, s)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		return code, nil, nil, nil
+	}
+	// MOVQ $sym±off(SB), r64: the toolchain assembles a symbol immediate as
+	// LEAQ disp32(RIP), r64 with an R_PCREL relocation at the disp32 field,
+	// never as a 64-bit absolute immediate (verified against go tool asm).
+	// MOVD is the MOVQ alias; the narrower widths reject the form outright.
+	if (mnemUpper == "MOVQ" || mnemUpper == "MOVD") && len(s.Operands) == 2 &&
+		s.Operands[0].Kind == ast.OpImmediate && s.Operands[0].Imm.Sym != nil &&
+		s.Operands[0].Imm.Sym.Pseudo == "SB" {
+		mem := &ast.Operand{Kind: ast.OpAddr, Addr: ast.Address{Sym: s.Operands[0].Imm.Sym}}
+		src, err := operandFromAST(mnemUpper, mem, 8, fi, link)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		dst, err := operandFromAST(mnemUpper, s.Operands[1], 8, fi, link)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		e := &enc{}
+		if err := e.encodeLea([]Operand{src, dst}, 8); err != nil {
+			return nil, nil, nil, err
+		}
+		ps := make([]sbPatch, len(e.patches))
+		for i, p := range e.patches {
+			ps[i] = sbPatch{off: p.off, name: p.name, addend: p.addend}
+		}
+		return e.out, ps, nil, nil
+	}
+	// MOVQ/MOVL TLS, r: the bare TLS load.  The toolchain's progedit nops
+	// it out on the one-instruction TLS systems (linux and freebsd, not
+	// shared) and encodes the segment-prefixed load elsewhere; get_tls(r),
+	// the macro GOROOT's go_tls.h defines, expands to exactly this
+	// statement, and the toolchain's pairing pass removes it whenever the
+	// following instruction's (TLS*1) index folds.
+	if (mnemUpper == "MOVQ" || mnemUpper == "MOVL") && len(s.Operands) == 2 && isBareTLS(s.Operands[0]) {
+		return encodeTLSBaseLoad(s, fi, link)
+	}
+	_, size := splitSize(mnemUpper)
 	if size == 0 {
 		size = 8
 	}
 	ops := make([]Operand, len(s.Operands))
 	for i, op := range s.Operands {
-		o, err := operandFromAST(op, size, fi, link)
+		o, err := operandFromAST(mnemUpper, op, size, fi, link)
 		if err != nil {
-			return nil, nil, err
+			return nil, nil, nil, err
 		}
 		ops[i] = o
 	}
 	e := &enc{}
 	if err := e.encode(s.Mnemonic.Text, ops); err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 	ps := make([]sbPatch, len(e.patches))
 	for i, p := range e.patches {
 		ps[i] = sbPatch{off: p.off, name: p.name, addend: p.addend}
+		if p.tls {
+			ps[i].kind = RelTLSLE
+		}
 	}
-	return e.out, ps, nil
+	return e.out, ps, e.floatPoolList(), nil
+}
+
+// isBareTLS reports whether the operand is the bare TLS pseudo-register
+// load source, the expansion of go_tls.h's get_tls(r) macro.
+func isBareTLS(op *ast.Operand) bool {
+	return op.Kind == ast.OpAddr && op.Addr.Sym != nil &&
+		op.Addr.Sym.Pseudo == "" && op.Addr.Sym.Name == "TLS" &&
+		op.Addr.Base == "" && op.Addr.Index == ""
+}
+
+// encodeTLSBaseLoad assembles MOVQ/MOVL TLS, r.  On the one-instruction TLS
+// systems (linux and freebsd outside -shared, obj6.go's CanUse1InsnTLS) the
+// statement nops out: the following (TLS*1) access folds to a direct
+// segment-absolute load.  The two-instruction systems keep the segment load,
+// nine bytes with the R_TLSLE patch site at the disp32.
+func encodeTLSBaseLoad(s *ast.Instr, fi frameInfo, link *linkInfo) ([]byte, []sbPatch, []floatPoolEntry, error) {
+	_, size := splitSize(strings.ToUpper(s.Mnemonic.Text))
+	if size == 0 {
+		size = 8
+	}
+	dst, err := operandFromAST("MOVQ", s.Operands[1], 8, fi, link)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	reg, ok := dst.(Reg)
+	if !ok || reg.isVec() {
+		return nil, nil, nil, fmt.Errorf("TLS: destination must be a general register")
+	}
+	if link == nil || link.tlsOneInsn() {
+		return nil, nil, nil, nil // noped out
+	}
+	seg := byte(0x64) // FS
+	if link.goos == "windows" {
+		seg = 0x65 // GS
+	}
+	e := &enc{}
+	i := &instr{
+		prefix: seg,
+		rexW:   size == 8,
+		rexR:   reg.idx >= 8,
+		opcode: []byte{0x8B},
+		modrm:  0x04 | (reg.idx&7)<<3,
+		sib:    0x25,
+		disp:   le32(0),
+		tls:    true,
+	}
+	if err := e.emit(i); err != nil {
+		return nil, nil, nil, err
+	}
+	ps := make([]sbPatch, len(e.patches))
+	for i, p := range e.patches {
+		ps[i] = sbPatch{off: p.off, name: p.name, addend: p.addend, kind: RelTLSLE}
+	}
+	return e.out, ps, nil, nil
+}
+
+// encodeBookkeeping accepts-and-ignores FUNCDATA and PCDATA at the statement
+// level, before operand conversion: the toolchain's shapes are FUNCDATA
+// $n, sym(SB) and PCDATA $n, $m, and neither contributes a byte to the
+// function body.  The symbol reference must not run through the SB-operand
+// path, which demands file-level resolution the statement never needs.
+func encodeBookkeeping(upper string, s *ast.Instr) ([]byte, error) {
+	if len(s.Operands) != 2 {
+		return nil, fmt.Errorf("%s expects 2 operands, got %d", upper, len(s.Operands))
+	}
+	a, b := s.Operands[0], s.Operands[1]
+	if a.Kind != ast.OpImmediate || !a.Imm.HasVal {
+		return nil, fmt.Errorf("%s: first operand must be an integer immediate", upper)
+	}
+	switch upper {
+	case "FUNCDATA":
+		if b.Kind != ast.OpAddr || b.Addr.Sym == nil || b.Addr.Sym.Pseudo != "SB" {
+			return nil, fmt.Errorf("FUNCDATA: second operand must be a symbol reference")
+		}
+	case "PCDATA":
+		if b.Kind != ast.OpImmediate || !b.Imm.HasVal {
+			return nil, fmt.Errorf("PCDATA: second operand must be an integer immediate")
+		}
+	}
+	return nil, nil
 }
 
 // encodeJump encodes a JMP/CALL/Jcc with a relative offset resolved from the
-// target label, in the short (rel8) or long (rel32) form.
-func encodeJump(s *ast.Instr, mnem string, pc int, offsets map[string]int, long bool, resolve func(string) string) ([]byte, error) {
+// target label or from a numeric ±N(PC) instruction count, in the short
+// (rel8) or long (rel32) form.  numTarget is the resolved byte offset of a
+// numeric operand, negative when the operand is not one.
+func encodeJump(s *ast.Instr, mnem string, pc int, offsets map[string]int, long bool, resolve func(string) string, numTarget int) ([]byte, error) {
 	if len(s.Operands) != 1 {
 		return nil, fmt.Errorf("jump expects 1 operand, got %d", len(s.Operands))
 	}
-	name, ok := labelName(s.Operands[0])
-	if !ok {
+	name, isLabel := labelName(s.Operands[0])
+	if !isLabel && numTarget < 0 {
 		return nil, fmt.Errorf("jump target must be a local label")
 	}
-	if resolve != nil && mnem != "CALL" {
-		name = resolve(name)
-	}
-	target, ok := offsets[name]
-	if !ok {
-		return nil, fmt.Errorf("undefined label %q", name)
+	var target int
+	if isLabel {
+		if resolve != nil && mnem != "CALL" {
+			name = resolve(name)
+		}
+		t, ok := offsets[name]
+		if !ok {
+			return nil, fmt.Errorf("undefined label %q", name)
+		}
+		target = t
+	} else {
+		target = numTarget
 	}
 	rel := int64(target - (pc + jumpSize(mnem, long)))
 
@@ -701,7 +1107,7 @@ func isSBCall(s *ast.Instr) bool {
 
 // encodeSBCall encodes CALL sym(SB) as E8 rel32 with a patch site.
 func encodeSBCall(s *ast.Instr, link *linkInfo) ([]byte, []sbPatch, error) {
-	o, err := operandFromAST(s.Operands[0], 8, frameInfo{}, link)
+	o, err := operandFromAST(strings.ToUpper(s.Mnemonic.Text), s.Operands[0], 8, frameInfo{}, link)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -742,6 +1148,11 @@ func indirectJumpTarget(s *ast.Instr) bool {
 		return false
 	}
 	a := s.Operands[0].Addr
+	// ±N(PC) is the numeric relative form, the PC counts instructions from
+	// the branch: relative, not indirect.
+	if a.Base == "PC" || a.Index == "PC" {
+		return false
+	}
 	if a.Base != "" || a.Index != "" {
 		return true
 	}
@@ -758,7 +1169,7 @@ func indirectJumpTarget(s *ast.Instr) bool {
 func encodeIndirectJump(s *ast.Instr, mnem string) ([]byte, error) {
 	ops := make([]Operand, len(s.Operands))
 	for i, op := range s.Operands {
-		o, err := operandFromAST(op, 8, frameInfo{}, nil)
+		o, err := operandFromAST(mnem, op, 8, frameInfo{}, nil)
 		if err != nil {
 			return nil, err
 		}
@@ -775,8 +1186,11 @@ func encodeIndirectJump(s *ast.Instr, mnem string) ([]byte, error) {
 var spReg = Reg{idx: 4, size: 8}
 
 // operandFromAST converts a parsed operand into an encoder Operand, applying
-// the frame translation to FP/SP pseudo-register operands.
-func operandFromAST(op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Operand, error) {
+// the frame translation to FP/SP pseudo-register operands.  mnemUpper is the
+// instruction's upper-case mnemonic, which the floating-point immediate gate
+// needs: only the SSE mnemonics whose encoding takes an XMM/memory source
+// accept one.
+func operandFromAST(mnemUpper string, op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Operand, error) {
 	switch op.Kind {
 	case ast.OpImmediate:
 		if op.Imm.HasVal {
@@ -786,11 +1200,45 @@ func operandFromAST(op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Op
 			}
 			return Imm(v), nil
 		}
+		// A floating-point immediate: $1.5, $-1.0 or the parenthesised
+		// $(-1.0) spelling (the constant-expression folder only folds
+		// integers, so that shape arrives with an empty Immediate and only
+		// the raw spelling carries the value).  The toolchain rewrites it
+		// into a pooled-constant read on the SSE scalar paths and rejects
+		// it everywhere else.
+		if text, neg, ok := floatImmText(op); ok {
+			if !sseFloatImm[mnemUpper] {
+				return nil, fmt.Errorf("%s does not take a floating-point immediate", mnemUpper)
+			}
+			return FloatImm{Text: text, Neg: neg}, nil
+		}
 		return nil, fmt.Errorf("non-integer immediate not supported")
 
 	case ast.OpAddr:
 		a := op.Addr
 
+		// A bracketed register range, [Z0-Z3]: the four-register source of
+		// the 4FMAPS/4VNNIW families.  The range must span four consecutive
+		// same-width vector registers, exactly what the toolchain's parser
+		// takes; the EVEX quad-register emit path reads the low end.
+		if a.Range != nil {
+			lo, ok := ParseReg(a.Range.Lo)
+			if !ok {
+				return nil, fmt.Errorf("unknown register %q in range", a.Range.Lo)
+			}
+			hi, ok := ParseReg(a.Range.Hi)
+			if !ok {
+				return nil, fmt.Errorf("unknown register %q in range", a.Range.Hi)
+			}
+			if !lo.isVec() || lo.size != hi.size {
+				return nil, fmt.Errorf("register range %q must span four same-width vector registers", op.Raw)
+			}
+			if hi.idx != lo.idx+3 {
+				return nil, fmt.Errorf("register range %q must span four consecutive registers", op.Raw)
+			}
+			return RegList{Lo: lo, Hi: hi}, nil
+		}
+
 		// FP-relative: x+N(FP) → (N + fpAdjust)(SP).  The offset N lives in the
 		// symbol, not the address displacement.
 		if a.Sym != nil && a.Sym.Pseudo == "FP" {
@@ -822,12 +1270,44 @@ func operandFromAST(op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Op
 
 		// Memory with a real base register: (base), off(base), (base)(index*scale).
 		if a.Base != "" {
+			// Segment-absolute: 0x30(GS) and 0x28(FS), the windows TLS
+			// spellings.  The segment override prefixes a disp32 absolute
+			// reference with no relocation.
+			if a.Base == "GS" || a.Base == "FS" {
+				seg := byte(0x64)
+				if a.Base == "GS" {
+					seg = 0x65
+				}
+				return SegAbs{Disp: a.Offset, Size: size, Seg: seg}, nil
+			}
 			base, ok := ParseReg(a.Base)
 			if !ok {
 				return nil, fmt.Errorf("unknown base register %q", a.Base)
 			}
 			m := Mem{Base: base, Disp: a.Offset, HasBase: true, Size: size}
 			if a.Index != "" {
+				if a.Index == "TLS" {
+					// off(base)(TLS*1): the thread-local annotation.  The
+					// one-instruction TLS form folds it to off(TLS), the
+					// segment-prefixed absolute whose disp32 carries an
+					// R_TLS_LE patch site; the base register disappears
+					// from the encoding, exactly as the toolchain's
+					// progedit rewrites the address.
+					seg := byte(0x64) // FS on linux, freebsd, plan9
+					if link != nil && link.goos == "windows" {
+						seg = 0x65 // GS
+					}
+					return TLSMem{Disp: a.Offset, Size: size, Seg: seg}, nil
+				}
+				if a.Index == "GS" || a.Index == "FS" {
+					// 0(CX)(GS): the segment annotation rides the base
+					// access as the override prefix.
+					m.Seg = 0x64
+					if a.Index == "GS" {
+						m.Seg = 0x65
+					}
+					return m, nil
+				}
 				idx, ok := ParseReg(a.Index)
 				if !ok {
 					return nil, fmt.Errorf("unknown index register %q", a.Index)
@@ -838,6 +1318,21 @@ func operandFromAST(op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Op
 			}
 			return m, nil
 		}
+		// Index-only memory: the VSIB form the gather/scatter families
+		// read, 8(X4*1).  A scaled vector index addresses memory with no
+		// base register; the mod=00 SIB with base field 101 carries it.
+		if a.Index != "" {
+			idx, ok := ParseReg(a.Index)
+			if !ok {
+				return nil, fmt.Errorf("unknown index register %q", a.Index)
+			}
+			return Mem{Index: idx, Scale: a.Scale, Disp: a.Offset, HasIndex: true, Size: size}, nil
+		}
+		// A bare displacement with no base: the absolute address form,
+		// MOVL $0xf1, 0xf1.  No segment and no relocation.
+		if a.Sym == nil && a.Base == "" && a.Index == "" && a.HasOff {
+			return SegAbs{Disp: a.Offset, Size: size}, nil
+		}
 		// Bare register.
 		if a.Sym != nil && a.Sym.Pseudo == "" && a.Sym.Name != "" {
 			if r, ok := ParseReg(a.Sym.Name); ok {
@@ -848,3 +1343,37 @@ func operandFromAST(op *ast.Operand, size int, fi frameInfo, link *linkInfo) (Op
 	}
 	return nil, fmt.Errorf("unsupported operand")
 }
+
+// floatImmText recovers a floating-point immediate's magnitude and sign from
+// the parsed operand.  The ordinary spellings arrive in Imm.Float; the
+// parenthesised $(-1.0) leaves the Immediate empty, because the integer
+// folder cannot read it, and only the verbatim operand text still carries
+// the value.  Anything that is not a number a float parser accepts reports
+// not-ok, so every other shape keeps its existing diagnostic.
+func floatImmText(op *ast.Operand) (text string, neg bool, ok bool) {
+	if op.Imm.Float != "" {
+		return op.Imm.Float, op.Imm.Neg, true
+	}
+	if op.Imm.HasVal || op.Imm.Str != "" || op.Imm.Sym != nil {
+		return "", false, false
+	}
+	// joinRaw spaced the token texts; the compact spelling is what matters.
+	compact := strings.ReplaceAll(op.Raw, " ", "")
+	inner, ok := strings.CutPrefix(compact, "$(")
+	if !ok || !strings.HasSuffix(inner, ")") {
+		return "", false, false
+	}
+	inner = strings.TrimSuffix(inner, ")")
+	inner = strings.TrimPrefix(inner, "+")
+	if s, ok := strings.CutPrefix(inner, "-"); ok {
+		neg = true
+		inner = s
+	}
+	if inner == "" || !strings.ContainsAny(inner, "0123456789") {
+		return "", false, false
+	}
+	if _, err := strconv.ParseFloat(inner, 64); err != nil {
+		return "", false, false
+	}
+	return inner, neg, true
+}

asm/assemble_test.go

@@ -10,8 +10,8 @@ import (
 
 	"golang.org/x/arch/x86/x86asm"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // firstText parses src and returns its first TEXT function.
@@ -370,6 +370,58 @@ end:
 	}
 }
 
+// TestAssembleNumericPCJumps pins the numeric ±N(PC) branch operands: N
+// counts instruction statements, skipping labels, in both directions (the
+// runtime's exit loops write JMP -3(PC)), N = 0 parks on the jump itself.
+func TestAssembleNumericPCJumps(t *testing.T) {
+	fn := firstText(t, `
+#include "textflag.h"
+TEXT ·exit(SB), NOSPLIT, $0
+	MOVB $1, AL
+lab:
+	MOVB $2, AL
+	MOVB $3, AL
+	JMP -3(PC)
+	MOVB $4, AL
+park:
+	JMP 0(PC)
+	MOVB $5, AL
+	JMP 2(PC)
+	MOVB $6, AL
+	RET
+`)
+	code, _, err := Assemble(fn)
+	if err != nil {
+		t.Fatalf("Assemble: %v", err)
+	}
+	// From the Go-assembled function:
+	//   MOVB $1, AL       b001
+	//   MOVB $2, AL       b002
+	//   MOVB $3, AL       b003
+	//   JMP -3(PC)        ebf8      (three instructions back, past lab:)
+	//   MOVB $4, AL       b004
+	//   JMP 0(PC)         ebfe      (the park loop)
+	//   MOVB $5, AL       b005
+	//   JMP 2(PC)         eb02      (over MOVB $6 to the RET)
+	//   MOVB $6, AL       b006
+	//   RET               c3
+	want := []byte{
+		0xb0, 0x01,
+		0xb0, 0x02,
+		0xb0, 0x03,
+		0xeb, 0xf8,
+		0xb0, 0x04,
+		0xeb, 0xfe,
+		0xb0, 0x05,
+		0xeb, 0x02,
+		0xb0, 0x06,
+		0xc3,
+	}
+	if hexBytes(code) != hexBytes(want) {
+		t.Errorf("numeric-PC mismatch:\n got:  %s\n want: %s", hexBytes(code), hexBytes(want))
+	}
+}
+
 func TestAssemblePrefetch(t *testing.T) {
 	fn := firstText(t, `
 #include "textflag.h"
@@ -439,3 +491,157 @@ func TestSubSPEncodings(t *testing.T) {
 		}
 	}
 }
+
+// TestAssemblePseudoStatements runs LOCK/REP, BYTE/WORD and END through the
+// full statement pipeline, pinned against go tool asm (Go 1.27, amd64).  It
+// asserts the three behaviours the toolchain shows: each prefix statement is
+// a standalone byte with a PC of its own (so a label placed on the LOCK
+// points at the F0), the data pseudo-ops write their literal bytes inline,
+// and END terminates nothing (the statements after it still belong to the
+// function and carry no trace of it).
+func TestAssemblePseudoStatements(t *testing.T) {
+	fn := firstText(t, `
+#include "textflag.h"
+TEXT ·pseudo(SB), NOSPLIT, $0-0
+pfx:
+	LOCK
+	CMPXCHGQ AX, (BX)
+	REP
+	MOVSQ
+	BYTE $0x0f
+	BYTE $0x1f
+	WORD $0x1234
+	END
+	BYTE $0x02
+	RET
+`)
+	code, labels, err := Assemble(fn)
+	if err != nil {
+		t.Fatalf("Assemble: %v", err)
+	}
+	// go tool asm: f0 480fb103 f3 48a5 0f 1f 3412 02 c3
+	want := []byte{
+		0xf0,
+		0x48, 0x0f, 0xb1, 0x03,
+		0xf3, 0x48, 0xa5,
+		0x0f, 0x1f, 0x34, 0x12,
+		0x02, 0xc3,
+	}
+	if hexBytes(code) != hexBytes(want) {
+		t.Errorf("pseudo statements:\n got:  %s\n want: %s", hexBytes(code), hexBytes(want))
+	}
+	// The label sits on the LOCK byte, exactly where the toolchain's PC
+	// listing puts it.
+	if off := labels["pfx"]; off != 0 {
+		t.Errorf("label pfx = %d, want 0 (the LOCK's own byte)", off)
+	}
+	// The trailing BYTE lands where the layout says: after the 8 bytes of
+	// LOCK, CMPXCHGQ, REP and MOVSQ plus the 4 data bytes, END contributing
+	// none.
+	if code[12] != 0x02 {
+		t.Errorf("byte at 12 = %02x, want 02 (the BYTE after END)", code[12])
+	}
+}
+
+// TestAssembleAdjspBalance pins the toolchain's push/pop balance rule over
+// ADJSP: the straight-line sum of the adjustments must be zero at each
+// RET, branches in between counting for nothing (verified against go tool
+// asm: ADJSP $16 before a RET is reported as "unbalanced PUSH/POP", a
+// $16/$-16 pair with a JMP in between assembles).
+func TestAssembleAdjspBalance(t *testing.T) {
+	// Balanced pair with a branch in between, bytes pinned from go tool asm.
+	fn := firstText(t, `
+#include "textflag.h"
+TEXT ·adjsp(SB), NOSPLIT, $0-0
+	ADJSP $16
+	JMP body
+body:
+	ADJSP $-16
+	RET
+`)
+	code, _, err := Assemble(fn)
+	if err != nil {
+		t.Fatalf("Assemble: %v", err)
+	}
+	want := []byte{0x48, 0x83, 0xEC, 0x10, 0xEB, 0x00, 0x48, 0x83, 0xC4, 0x10, 0xC3}
+	if hexBytes(code) != hexBytes(want) {
+		t.Errorf("adjsp pair:\n got:  %s\n want: %s", hexBytes(code), hexBytes(want))
+	}
+
+	// Unbalanced at the RET: the toolchain diagnoses, so must we.
+	_, _, err = Assemble(firstText(t, `
+#include "textflag.h"
+TEXT ·unbalanced(SB), NOSPLIT, $0-0
+	ADJSP $16
+	RET
+`))
+	if err == nil || !strings.Contains(err.Error(), "unbalanced PUSH/POP") {
+		t.Errorf("unbalanced ADJSP: err = %v, want unbalanced PUSH/POP", err)
+	}
+
+	// The check runs per RET: a closed pair before the first RET does not
+	// excuse an open adjustment before the second.
+	_, _, err = Assemble(firstText(t, `
+#include "textflag.h"
+TEXT ·tworet(SB), NOSPLIT, $0-0
+	ADJSP $8
+	ADJSP $-8
+	RET
+mid:
+	ADJSP $8
+	RET
+`))
+	if err == nil || !strings.Contains(err.Error(), "unbalanced PUSH/POP") {
+		t.Errorf("second RET with open ADJSP: err = %v, want unbalanced PUSH/POP", err)
+	}
+
+	// A framed function: the assembler's own prologue and epilogue
+	// contribute matching deltas, so the pair in the body still balances,
+	// and the bytes match go tool asm end to end.
+	fn = firstText(t, `
+#include "textflag.h"
+TEXT ·framed(SB), $16-8
+	ADJSP $8
+	ADJSP $-8
+	RET
+`)
+	code, _, err = Assemble(fn)
+	if err != nil {
+		t.Fatalf("Assemble framed: %v", err)
+	}
+	want = []byte{
+		0x55, 0x48, 0x89, 0xE5, 0x48, 0x83, 0xEC, 0x10, // prologue
+		0x48, 0x83, 0xEC, 0x08, // ADJSP $8
+		0x48, 0x83, 0xC4, 0x08, // ADJSP $-8
+		0x48, 0x83, 0xC4, 0x10, 0x5D, // epilogue
+		0xC3,
+	}
+	if hexBytes(code) != hexBytes(want) {
+		t.Errorf("framed adjsp:\n got:  %s\n want: %s", hexBytes(code), hexBytes(want))
+	}
+}
+
+// TestAssembleRegRange pins the bracketed register range at the statement
+// level: exactly four consecutive same-width vector registers assemble, the
+// toolchain's rejected shapes all report an error.
+func TestAssembleRegRange(t *testing.T) {
+	asm := func(t *testing.T, op string) ([]byte, error) {
+		t.Helper()
+		f, errs := parser.Parse("f_amd64.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tV4FMADDPS 17(SP), "+op+", K2, Z0\n\tRET\n")
+		if len(errs) > 0 {
+			t.Fatalf("parse %s: %v", op, errs)
+		}
+		code, _, err := Assemble(f.Decls[0].(*ast.Text))
+		return code, err
+	}
+	for _, op := range []string{"[Z0-Z3]", "[Z4-Z7]", "[Z28-Z31]"} {
+		if _, err := asm(t, op); err != nil {
+			t.Errorf("%s: %v", op, err)
+		}
+	}
+	for _, op := range []string{"[Z0-Z4]", "[Z0-Z2]", "[Z0-Z0]", "[Z4-Z0]", "[Z1-Z0]", "[AX-Z3]", "[Z0-AX]"} {
+		if _, err := asm(t, op); err == nil {
+			t.Errorf("%s: assembled, want an error", op)
+		}
+	}
+}

asm/elf.go

@@ -43,6 +43,9 @@ const (
 	stInfoShift = 4
 
 	rX8664PC32 = 2
+	// R_X86_64_32 (debug/elf): the absolute 32-bit address of a symbol, the
+	// R_ADDR shape a 4-byte DATA field carries.
+	rX8664Abs32 = 10
 	// R_X86_64_TPOFF32 (debug/elf): the local-exec TLS offset the stack
 	// guard loads from FS.  20 is R_X86_64_TLSLD, a different relocation.
 	rX8664TPOFF32 = 23
@@ -158,6 +161,50 @@ func (img *Image) ELFObject() ([]byte, error) {
 		}
 	}
 
+	// The data symbols' symbol-valued DATA fields ("DATA s+0(SB)/8,
+	// $other(SB)") become .rela.data entries: an absolute relocation of the
+	// DATA line's width at the field's data-section offset, S + A with no
+	// PC term.  Widths 4 and 8 have ELF relocation shapes; narrower fields
+	// cannot hold an address, so they are refused rather than truncated.
+	var dataRelas []elfRela
+	for _, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			idx, ok := symIdx[r.Name]
+			if !ok {
+				return nil, fmt.Errorf("data relocation references unknown symbol %q", r.Name)
+			}
+			var typ uint32
+			switch r.Siz {
+			case 8:
+				typ = rX8664Abs64
+			case 4:
+				typ = rX8664Abs32
+			default:
+				return nil, fmt.Errorf("DATA %q: a symbol value of width %d has no ELF relocation", d.Name, r.Siz)
+			}
+			dataRelas = append(dataRelas, elfRela{
+				off:    uint64(d.Offset + r.Off),
+				sym:    idx,
+				typ:    typ,
+				addend: r.Addend,
+			})
+		}
+	}
+
+	// Section presence: .rela.text only when there are code relocations,
+	// .rela.data only when a DATA line holds a symbol value.
+	hasRela := len(relas) > 0
+	hasDataRela := len(dataRelas) > 0
+	nSections := 6 // NULL, .text, .data, .symtab, .strtab, .shstrtab
+	if hasRela {
+		nSections++
+	}
+	if hasDataRela {
+		nSections++
+	}
+	secSymtab, secStrtab := 3, 4
+	secShstr := nSections - 1
+
 	// Serialise the string tables.
 	stNames := newElfStrtab()
 	for _, s := range syms {
@@ -167,19 +214,13 @@ func (img *Image) ELFObject() ([]byte, error) {
 	for _, n := range []string{".text", ".data", ".symtab", ".strtab", ".rela.text", ".shstrtab"} {
 		stSections.add(n)
 	}
+	if hasDataRela {
+		stSections.add(".rela.data")
+	}
 	for _, n := range dwarfSectionNames {
 		stSections.add(n)
 	}
 
-	// Section presence: .rela.text only when there are relocations.
-	hasRela := len(relas) > 0
-	nSections := 6 // NULL, .text, .data, .symtab, .strtab, .shstrtab
-	if hasRela {
-		nSections = 7
-	}
-	secSymtab, secStrtab := 3, 4
-	secShstr := nSections - 1
-
 	// Lay the file out: header, section data, section headers.
 	var out []byte
 	out = append(out, make([]byte, 64)...) // ELF header, filled last
@@ -214,7 +255,7 @@ func (img *Image) ELFObject() ([]byte, error) {
 	strtabOff := len(out)
 	out = append(out, stNames.bytes()...)
 
-	var relaOff int
+	var relaOff, relaDataOff int
 	if hasRela {
 		align(8)
 		relaOff = len(out)
@@ -226,6 +267,17 @@ func (img *Image) ELFObject() ([]byte, error) {
 			out = append(out, b[:]...)
 		}
 	}
+	if hasDataRela {
+		align(8)
+		relaDataOff = len(out)
+		for _, r := range dataRelas {
+			var b [24]byte
+			le.PutUint64(b[0:], r.off)
+			le.PutUint64(b[8:], uint64(r.sym)<<32|uint64(r.typ))
+			le.PutUint64(b[16:], uint64(r.addend))
+			out = append(out, b[:]...)
+		}
+	}
 
 	shstrOff := len(out)
 	out = append(out, stSections.bytes()...)
@@ -284,6 +336,9 @@ func (img *Image) ELFObject() ([]byte, error) {
 	if hasRela {
 		putSh(".rela.text", shtRela, 0, relaOff, 24*len(relas), secSymtab, secText, 8, 24)
 	}
+	if hasDataRela {
+		putSh(".rela.data", shtRela, 0, relaDataOff, 24*len(dataRelas), secSymtab, secData, 8, 24)
+	}
 	putSh(".shstrtab", shtStrtab, 0, shstrOff, len(stSections.bytes()), 0, 0, 1, 0)
 
 	// DWARF section headers; their indices follow the write order.

asm/elf_dwarf_test.go

@@ -8,7 +8,7 @@ import (
 	"encoding/binary"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // ulebIter reads ULEB128 values, the .debug_abbrev and line-header

asm/elf_test.go

@@ -12,8 +12,8 @@ import (
 	"path/filepath"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // The object-file tests share one source: two exported functions, one
@@ -750,3 +750,111 @@ func readFormSkip(t *testing.T, r *ulebIter, form uint64) {
 		t.Fatalf("unsupported form %#x", form)
 	}
 }
+
+// TestELFObjectDataRelocation checks that a symbol-valued DATA field ("DATA
+// s+0(SB)/8, $other(SB)") reaches the ELF object as a .rela.data entry: an
+// absolute 64-bit relocation at the field's offset within .data, against
+// the named symbol, external targets included.
+func TestELFObjectDataRelocation(t *testing.T) {
+	f, errs := parser.Parse("t_amd64.s", `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-8
+	RET
+GLOBL holder(SB), NOPTR, $24
+DATA holder+0(SB)/8, $·Keep+5(SB)
+DATA holder+8(SB)/8, $holder(SB)
+DATA holder+16(SB)/8, $extvar(SB)
+`)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	obj, err := img.ELFObject()
+	if err != nil {
+		t.Fatalf("ELFObject: %v", err)
+	}
+	ef, err := elf.NewFile(bytes.NewReader(obj))
+	if err != nil {
+		t.Fatalf("parse emitted object: %v", err)
+	}
+	defer ef.Close()
+	relaData := ef.Section(".rela.data")
+	if relaData == nil {
+		t.Fatal("missing .rela.data section")
+	}
+	if relaData.Link == 0 || ef.Sections[relaData.Link].Name != ".symtab" {
+		t.Errorf(".rela.data sh_link = %d, want the .symtab index", relaData.Link)
+	}
+	if ef.Sections[relaData.Info].Name != ".data" {
+		t.Errorf(".rela.data sh_info = %d, want the .data index", relaData.Info)
+	}
+	relas, err := relaData.Data()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got []struct {
+		off    uint64
+		sym    uint32
+		typ    uint32
+		addend int64
+	}
+	for i := 0; i+24 <= len(relas); i += 24 {
+		got = append(got, struct {
+			off    uint64
+			sym    uint32
+			typ    uint32
+			addend int64
+		}{
+			off: binary.LittleEndian.Uint64(relas[i:]),
+			// r_info packs the type in the low dword and the symbol index
+			// in the high dword.
+			typ:    binary.LittleEndian.Uint32(relas[i+8:]),
+			sym:    binary.LittleEndian.Uint32(relas[i+12:]),
+			addend: int64(binary.LittleEndian.Uint64(relas[i+16:])),
+		})
+	}
+	// debug/elf hides the table's null entry, so raw index s names syms[s-1].
+	syms, err := ef.Symbols()
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := func(idx uint32) string {
+		if idx >= 1 && int(idx) <= len(syms) {
+			return syms[idx-1].Name
+		}
+		return ""
+	}
+	// The offsets are data-section-relative: the field's DATA offset plus
+	// the symbol's position in .data (the layout aligns each symbol to 16).
+	base := uint64(0)
+	for _, d := range img.DataSyms {
+		if d.Name == "holder" {
+			base = uint64(d.Offset)
+		}
+	}
+	want := []struct {
+		off    uint64
+		typ    uint32
+		addend int64
+		target string
+	}{
+		{off: base + 0, typ: uint32(elf.R_X86_64_64), addend: 5, target: "Keep"},
+		{off: base + 8, typ: uint32(elf.R_X86_64_64), addend: 0, target: "holder"},
+		{off: base + 16, typ: uint32(elf.R_X86_64_64), addend: 0, target: "extvar"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf(".rela.data entries = %d, want %d", len(got), len(want))
+	}
+	for i, w := range want {
+		g := got[i]
+		if g.off != w.off || g.typ != w.typ || g.addend != w.addend {
+			t.Errorf("entry %d = {off %d typ %d addend %d}, want {off %d typ %d addend %d}",
+				i, g.off, g.typ, g.addend, w.off, w.typ, w.addend)
+		}
+		if n := name(g.sym); n != w.target {
+			t.Errorf("entry %d names %q, want %q", i, n, w.target)
+		}
+	}
+}

asm/elfarm64.go

@@ -18,12 +18,16 @@ const (
 	rArm64AddAbsLo12NC = 277 // R_AARCH64_ADD_ABS_LO12_NC (ADD page offset)
 	rArm64Call26       = 283 // R_AARCH64_CALL26 (BL instruction)
 	rArm64Ldst64Lo12NC = 286 // R_AARCH64_LDST64_ABS_LO12_NC (64-bit LDR/STR page offset)
+	// R_AARCH64_ABS32 (debug/elf 258): the absolute 32-bit address of a
+	// symbol, the R_ADDR shape a 4-byte DATA field carries.  ABS64 (257)
+	// lives with the DWARF fixup constants as rAARCH64Abs64.
+	rArm64Abs32 = 258
 )
 
 // ELFAARCH64Object returns the image as an ELF64 relocatable object file for
 // AArch64 (EM_AARCH64, 64-bit, little-endian).  The structure mirrors the
-// amd64 and RISC-V ELF emitters: .text, .data, .symtab, .strtab and an
-// optional .rela.text.
+// amd64 and RISC-V ELF emitters: .text, .data, .symtab, .strtab, an
+// optional .rela.text and an optional .rela.data.
 func (img *Image) ELFAARCH64Object() ([]byte, error) {
 	le := binary.LittleEndian
 
@@ -133,6 +137,50 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 		}
 	}
 
+	// The data symbols' symbol-valued DATA fields ("DATA s+0(SB)/8,
+	// $other(SB)") become .rela.data entries: an absolute relocation of the
+	// DATA line's width at the field's data-section offset, S + A with no
+	// PC term.  Widths 4 and 8 have ELF relocation shapes; narrower fields
+	// cannot hold an address, so they are refused rather than truncated.
+	var dataRelas []elfRela
+	for _, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			idx, ok := symIdx[r.Name]
+			if !ok {
+				return nil, fmt.Errorf("data relocation references unknown symbol %q", r.Name)
+			}
+			var typ uint32
+			switch r.Siz {
+			case 8:
+				typ = rAARCH64Abs64
+			case 4:
+				typ = rArm64Abs32
+			default:
+				return nil, fmt.Errorf("DATA %q: a symbol value of width %d has no ELF relocation", d.Name, r.Siz)
+			}
+			dataRelas = append(dataRelas, elfRela{
+				off:    uint64(d.Offset + r.Off),
+				sym:    idx,
+				typ:    typ,
+				addend: r.Addend,
+			})
+		}
+	}
+
+	// Section presence: .rela.text only when there are code relocations,
+	// .rela.data only when a DATA line holds a symbol value.
+	hasRela := len(relas) > 0
+	hasDataRela := len(dataRelas) > 0
+	nSections := 6
+	if hasRela {
+		nSections++
+	}
+	if hasDataRela {
+		nSections++
+	}
+	secSymtab, secStrtab := 3, 4
+	secShstr := nSections - 1
+
 	// String tables.
 	stNames := newElfStrtab()
 	for _, s := range syms {
@@ -142,18 +190,13 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 	for _, n := range []string{".text", ".data", ".symtab", ".strtab", ".rela.text", ".shstrtab"} {
 		stSections.add(n)
 	}
+	if hasDataRela {
+		stSections.add(".rela.data")
+	}
 	for _, n := range dwarfSectionNames {
 		stSections.add(n)
 	}
 
-	hasRela := len(relas) > 0
-	nSections := 6
-	if hasRela {
-		nSections = 7
-	}
-	secSymtab, secStrtab := 3, 4
-	secShstr := nSections - 1
-
 	// Layout.
 	var out []byte
 	out = append(out, make([]byte, 64)...)
@@ -188,7 +231,7 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 	strtabOff := len(out)
 	out = append(out, stNames.bytes()...)
 
-	var relaOff int
+	var relaOff, relaDataOff int
 	if hasRela {
 		align(8)
 		relaOff = len(out)
@@ -200,6 +243,17 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 			out = append(out, b[:]...)
 		}
 	}
+	if hasDataRela {
+		align(8)
+		relaDataOff = len(out)
+		for _, r := range dataRelas {
+			var b [24]byte
+			le.PutUint64(b[0:], r.off)
+			le.PutUint64(b[8:], uint64(r.sym)<<32|uint64(r.typ))
+			le.PutUint64(b[16:], uint64(r.addend))
+			out = append(out, b[:]...)
+		}
+	}
 
 	shstrOff := len(out)
 	out = append(out, stSections.bytes()...)
@@ -257,6 +311,9 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 	if hasRela {
 		putSh(".rela.text", shtRela, 0, relaOff, 24*len(relas), secSymtab, secText, 8, 24)
 	}
+	if hasDataRela {
+		putSh(".rela.data", shtRela, 0, relaDataOff, 24*len(dataRelas), secSymtab, secData, 8, 24)
+	}
 	putSh(".shstrtab", shtStrtab, 0, shstrOff, len(stSections.bytes()), 0, 0, 1, 0)
 	// DWARF section headers; their indices follow the write order.
 	if dw != nil {

asm/elfarm64_test.go

@@ -9,7 +9,7 @@ import (
 	"encoding/binary"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestELFAARCH64Object checks the structure of the emitted AArch64 ELF64
@@ -197,3 +197,118 @@ TEXT ·add(SB), NOSPLIT, $0-24
 		t.Error("unexpected .rela.text section when there are no relocations")
 	}
 }
+
+// TestELFAARCH64ObjectDataRelocation checks that a symbol-valued DATA field
+// ("DATA s+0(SB)/8, $other(SB)") reaches the AArch64 ELF object as a
+// .rela.data entry: an R_AARCH64_ABS64 (ABS32 for a width-4 field) at the
+// field's offset within .data, against the named symbol, external targets
+// included.
+func TestELFAARCH64ObjectDataRelocation(t *testing.T) {
+	f, errs := parser.Parse("t_arm64.s", `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-0
+	RET
+GLOBL holder(SB), NOPTR, $32
+DATA holder+0(SB)/8, $·Keep+5(SB)
+DATA holder+8(SB)/8, $holder(SB)
+DATA holder+16(SB)/8, $extvar(SB)
+DATA holder+24(SB)/4, $Keep(SB)
+`)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileARM64(f)
+	if err != nil {
+		t.Fatalf("AssembleFileARM64: %v", err)
+	}
+	obj, err := img.ELFAARCH64Object()
+	if err != nil {
+		t.Fatalf("ELFAARCH64Object: %v", err)
+	}
+	checkELFSectionAccounting(t, obj)
+	ef, err := elf.NewFile(bytes.NewReader(obj))
+	if err != nil {
+		t.Fatalf("parse emitted object: %v", err)
+	}
+	defer ef.Close()
+	relaData := ef.Section(".rela.data")
+	if relaData == nil {
+		t.Fatal("missing .rela.data section")
+	}
+	if relaData.Type != elf.SHT_RELA {
+		t.Errorf(".rela.data type = %v, want SHT_RELA", relaData.Type)
+	}
+	if relaData.Link == 0 || ef.Sections[relaData.Link].Name != ".symtab" {
+		t.Errorf(".rela.data sh_link = %d, want the .symtab index", relaData.Link)
+	}
+	if ef.Sections[relaData.Info].Name != ".data" {
+		t.Errorf(".rela.data sh_info = %d, want the .data index", relaData.Info)
+	}
+	relas, err := relaData.Data()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got []struct {
+		off    uint64
+		sym    uint32
+		typ    uint32
+		addend int64
+	}
+	for i := 0; i+24 <= len(relas); i += 24 {
+		got = append(got, struct {
+			off    uint64
+			sym    uint32
+			typ    uint32
+			addend int64
+		}{
+			off: binary.LittleEndian.Uint64(relas[i:]),
+			// r_info packs the type in the low dword and the symbol index
+			// in the high dword.
+			typ:    binary.LittleEndian.Uint32(relas[i+8:]),
+			sym:    binary.LittleEndian.Uint32(relas[i+12:]),
+			addend: int64(binary.LittleEndian.Uint64(relas[i+16:])),
+		})
+	}
+	// debug/elf hides the table's null entry, so raw index s names syms[s-1].
+	syms, err := ef.Symbols()
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := func(idx uint32) string {
+		if idx >= 1 && int(idx) <= len(syms) {
+			return syms[idx-1].Name
+		}
+		return ""
+	}
+	// The offsets are data-section-relative: the field's DATA offset plus
+	// the symbol's position in .data (the layout aligns each symbol to 16).
+	base := uint64(0)
+	for _, d := range img.DataSyms {
+		if d.Name == "holder" {
+			base = uint64(d.Offset)
+		}
+	}
+	want := []struct {
+		off    uint64
+		typ    uint32
+		addend int64
+		target string
+	}{
+		{off: base + 0, typ: uint32(elf.R_AARCH64_ABS64), addend: 5, target: "Keep"},
+		{off: base + 8, typ: uint32(elf.R_AARCH64_ABS64), addend: 0, target: "holder"},
+		{off: base + 16, typ: uint32(elf.R_AARCH64_ABS64), addend: 0, target: "extvar"},
+		{off: base + 24, typ: uint32(elf.R_AARCH64_ABS32), addend: 0, target: "Keep"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf(".rela.data entries = %d, want %d", len(got), len(want))
+	}
+	for i, w := range want {
+		g := got[i]
+		if g.off != w.off || g.typ != w.typ || g.addend != w.addend {
+			t.Errorf("entry %d = {off %d typ %d addend %d}, want {off %d typ %d addend %d}",
+				i, g.off, g.typ, g.addend, w.off, w.typ, w.addend)
+		}
+		if n := name(g.sym); n != w.target {
+			t.Errorf("entry %d names %q, want %q", i, n, w.target)
+		}
+	}
+}

asm/elfloong64.go

@@ -23,12 +23,16 @@ const (
 	rLarchPCALAHI20 = 71 // R_LARCH_PCALA_HI20 (pcalau12i)
 	rLarchPCALALO12 = 72 // R_LARCH_PCALA_LO12 (addi.d/ld/st)
 	rLarchB26       = 66 // R_LARCH_B26 (b/bl, matches the Go linker's mapping)
+	// R_LARCH_32 (debug/elf 1): the absolute 32-bit address of a symbol,
+	// the R_ADDR shape a 4-byte DATA field carries.  R_LARCH_64 (2) lives
+	// with the DWARF fixup constants as rLarchAbs64.
+	rLarchAbs32 = 1
 )
 
 // ELFLOONG64Object returns the image as an ELF64 relocatable object file for
 // LoongArch (EM_LOONGARCH, 64-bit, little-endian).  The structure mirrors the
-// amd64 and RISC-V ELF emitters: .text, .data, .symtab, .strtab and an
-// optional .rela.text.
+// amd64 and RISC-V ELF emitters: .text, .data, .symtab, .strtab, an
+// optional .rela.text and an optional .rela.data.
 func (img *Image) ELFLOONG64Object() ([]byte, error) {
 	le := binary.LittleEndian
 
@@ -117,6 +121,50 @@ func (img *Image) ELFLOONG64Object() ([]byte, error) {
 		}
 	}
 
+	// The data symbols' symbol-valued DATA fields ("DATA s+0(SB)/8,
+	// $other(SB)") become .rela.data entries: an absolute relocation of the
+	// DATA line's width at the field's data-section offset, S + A with no
+	// PC term.  Widths 4 and 8 have ELF relocation shapes; narrower fields
+	// cannot hold an address, so they are refused rather than truncated.
+	var dataRelas []elfRela
+	for _, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			idx, ok := symIdx[r.Name]
+			if !ok {
+				return nil, fmt.Errorf("data relocation references unknown symbol %q", r.Name)
+			}
+			var typ uint32
+			switch r.Siz {
+			case 8:
+				typ = rLarchAbs64
+			case 4:
+				typ = rLarchAbs32
+			default:
+				return nil, fmt.Errorf("DATA %q: a symbol value of width %d has no ELF relocation", d.Name, r.Siz)
+			}
+			dataRelas = append(dataRelas, elfRela{
+				off:    uint64(d.Offset + r.Off),
+				sym:    idx,
+				typ:    typ,
+				addend: r.Addend,
+			})
+		}
+	}
+
+	// Section presence: .rela.text only when there are code relocations,
+	// .rela.data only when a DATA line holds a symbol value.
+	hasRela := len(relas) > 0
+	hasDataRela := len(dataRelas) > 0
+	nSections := 6
+	if hasRela {
+		nSections++
+	}
+	if hasDataRela {
+		nSections++
+	}
+	secSymtab, secStrtab := 3, 4
+	secShstr := nSections - 1
+
 	// String tables.
 	stNames := newElfStrtab()
 	for _, s := range syms {
@@ -126,18 +174,13 @@ func (img *Image) ELFLOONG64Object() ([]byte, error) {
 	for _, n := range []string{".text", ".data", ".symtab", ".strtab", ".rela.text", ".shstrtab"} {
 		stSections.add(n)
 	}
+	if hasDataRela {
+		stSections.add(".rela.data")
+	}
 	for _, n := range dwarfSectionNames {
 		stSections.add(n)
 	}
 
-	hasRela := len(relas) > 0
-	nSections := 6
-	if hasRela {
-		nSections = 7
-	}
-	secSymtab, secStrtab := 3, 4
-	secShstr := nSections - 1
-
 	// Layout.
 	var out []byte
 	out = append(out, make([]byte, 64)...)
@@ -172,7 +215,7 @@ func (img *Image) ELFLOONG64Object() ([]byte, error) {
 	strtabOff := len(out)
 	out = append(out, stNames.bytes()...)
 
-	var relaOff int
+	var relaOff, relaDataOff int
 	if hasRela {
 		align(8)
 		relaOff = len(out)
@@ -184,6 +227,17 @@ func (img *Image) ELFLOONG64Object() ([]byte, error) {
 			out = append(out, b[:]...)
 		}
 	}
+	if hasDataRela {
+		align(8)
+		relaDataOff = len(out)
+		for _, r := range dataRelas {
+			var b [24]byte
+			le.PutUint64(b[0:], r.off)
+			le.PutUint64(b[8:], uint64(r.sym)<<32|uint64(r.typ))
+			le.PutUint64(b[16:], uint64(r.addend))
+			out = append(out, b[:]...)
+		}
+	}
 
 	shstrOff := len(out)
 	out = append(out, stSections.bytes()...)
@@ -239,6 +293,9 @@ func (img *Image) ELFLOONG64Object() ([]byte, error) {
 	if hasRela {
 		putSh(".rela.text", shtRela, 0, relaOff, 24*len(relas), secSymtab, secText, 8, 24)
 	}
+	if hasDataRela {
+		putSh(".rela.data", shtRela, 0, relaDataOff, 24*len(dataRelas), secSymtab, secData, 8, 24)
+	}
 	putSh(".shstrtab", shtStrtab, 0, shstrOff, len(stSections.bytes()), 0, 0, 1, 0)
 	// DWARF section headers; their indices follow the write order.
 	if dw != nil {

asm/elfloong64_test.go

@@ -9,7 +9,7 @@ import (
 	"encoding/binary"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestELFLOONG64Object checks the structure of the emitted LoongArch ELF64
@@ -245,3 +245,118 @@ func TestELFLOONG64BranchRelocation(t *testing.T) {
 		}
 	}
 }
+
+// TestELFLOONG64ObjectDataRelocation checks that a symbol-valued DATA field
+// ("DATA s+0(SB)/8, $other(SB)") reaches the LoongArch ELF object as a
+// .rela.data entry: an R_LARCH_64 (R_LARCH_32 for a width-4 field) at the
+// field's offset within .data, against the named symbol, external targets
+// included.
+func TestELFLOONG64ObjectDataRelocation(t *testing.T) {
+	f, errs := parser.Parse("t_loong64.s", `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-0
+	RET
+GLOBL holder(SB), NOPTR, $32
+DATA holder+0(SB)/8, $·Keep+5(SB)
+DATA holder+8(SB)/8, $holder(SB)
+DATA holder+16(SB)/8, $extvar(SB)
+DATA holder+24(SB)/4, $Keep(SB)
+`)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileLOONG64(f)
+	if err != nil {
+		t.Fatalf("AssembleFileLOONG64: %v", err)
+	}
+	obj, err := img.ELFLOONG64Object()
+	if err != nil {
+		t.Fatalf("ELFLOONG64Object: %v", err)
+	}
+	checkELFSectionAccounting(t, obj)
+	ef, err := elf.NewFile(bytes.NewReader(obj))
+	if err != nil {
+		t.Fatalf("parse emitted object: %v", err)
+	}
+	defer ef.Close()
+	relaData := ef.Section(".rela.data")
+	if relaData == nil {
+		t.Fatal("missing .rela.data section")
+	}
+	if relaData.Type != elf.SHT_RELA {
+		t.Errorf(".rela.data type = %v, want SHT_RELA", relaData.Type)
+	}
+	if relaData.Link == 0 || ef.Sections[relaData.Link].Name != ".symtab" {
+		t.Errorf(".rela.data sh_link = %d, want the .symtab index", relaData.Link)
+	}
+	if ef.Sections[relaData.Info].Name != ".data" {
+		t.Errorf(".rela.data sh_info = %d, want the .data index", relaData.Info)
+	}
+	relas, err := relaData.Data()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got []struct {
+		off    uint64
+		sym    uint32
+		typ    uint32
+		addend int64
+	}
+	for i := 0; i+24 <= len(relas); i += 24 {
+		got = append(got, struct {
+			off    uint64
+			sym    uint32
+			typ    uint32
+			addend int64
+		}{
+			off: binary.LittleEndian.Uint64(relas[i:]),
+			// r_info packs the type in the low dword and the symbol index
+			// in the high dword.
+			typ:    binary.LittleEndian.Uint32(relas[i+8:]),
+			sym:    binary.LittleEndian.Uint32(relas[i+12:]),
+			addend: int64(binary.LittleEndian.Uint64(relas[i+16:])),
+		})
+	}
+	// debug/elf hides the table's null entry, so raw index s names syms[s-1].
+	syms, err := ef.Symbols()
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := func(idx uint32) string {
+		if idx >= 1 && int(idx) <= len(syms) {
+			return syms[idx-1].Name
+		}
+		return ""
+	}
+	// The offsets are data-section-relative: the field's DATA offset plus
+	// the symbol's position in .data (the layout aligns each symbol to 16).
+	base := uint64(0)
+	for _, d := range img.DataSyms {
+		if d.Name == "holder" {
+			base = uint64(d.Offset)
+		}
+	}
+	want := []struct {
+		off    uint64
+		typ    uint32
+		addend int64
+		target string
+	}{
+		{off: base + 0, typ: uint32(elf.R_LARCH_64), addend: 5, target: "Keep"},
+		{off: base + 8, typ: uint32(elf.R_LARCH_64), addend: 0, target: "holder"},
+		{off: base + 16, typ: uint32(elf.R_LARCH_64), addend: 0, target: "extvar"},
+		{off: base + 24, typ: uint32(elf.R_LARCH_32), addend: 0, target: "Keep"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf(".rela.data entries = %d, want %d", len(got), len(want))
+	}
+	for i, w := range want {
+		g := got[i]
+		if g.off != w.off || g.typ != w.typ || g.addend != w.addend {
+			t.Errorf("entry %d = {off %d typ %d addend %d}, want {off %d typ %d addend %d}",
+				i, g.off, g.typ, g.addend, w.off, w.typ, w.addend)
+		}
+		if n := name(g.sym); n != w.target {
+			t.Errorf("entry %d names %q, want %q", i, n, w.target)
+		}
+	}
+}

asm/elfriscv.go

@@ -24,11 +24,16 @@ const (
 	rRISCVPCRELHI20  = 23 // R_RISCV_PCREL_HI20
 	rRISCVPCRELLO12I = 24 // R_RISCV_PCREL_LO12_I
 	rRISCVPCRELLO12S = 25 // R_RISCV_PCREL_LO12_S
+	// R_RISCV_32 (debug/elf 1): the absolute 32-bit address of a symbol,
+	// the R_ADDR shape a 4-byte DATA field carries.  R_RISCV_64 (2) lives
+	// with the DWARF fixup constants as rRISCVAbs64.
+	rRISVCAbs32 = 1
 )
 
 // ELFRISCVObject returns the image as an ELF64 relocatable object file for
 // RISC-V (EM_RISCV, 64-bit, little-endian).  The structure mirrors the amd64
-// ELF emission: .text, .data, .symtab, .strtab and optional .rela.text.
+// ELF emission: .text, .data, .symtab, .strtab, an optional .rela.text and
+// an optional .rela.data.
 func (img *Image) ELFRISCVObject() ([]byte, error) {
 	le := binary.LittleEndian
 
@@ -129,6 +134,50 @@ func (img *Image) ELFRISCVObject() ([]byte, error) {
 		}
 	}
 
+	// The data symbols' symbol-valued DATA fields ("DATA s+0(SB)/8,
+	// $other(SB)") become .rela.data entries: an absolute relocation of the
+	// DATA line's width at the field's data-section offset, S + A with no
+	// PC term.  Widths 4 and 8 have ELF relocation shapes; narrower fields
+	// cannot hold an address, so they are refused rather than truncated.
+	var dataRelas []elfRela
+	for _, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			idx, ok := symIdx[r.Name]
+			if !ok {
+				return nil, fmt.Errorf("data relocation references unknown symbol %q", r.Name)
+			}
+			var typ uint32
+			switch r.Siz {
+			case 8:
+				typ = rRISCVAbs64
+			case 4:
+				typ = rRISVCAbs32
+			default:
+				return nil, fmt.Errorf("DATA %q: a symbol value of width %d has no ELF relocation", d.Name, r.Siz)
+			}
+			dataRelas = append(dataRelas, elfRela{
+				off:    uint64(d.Offset + r.Off),
+				sym:    idx,
+				typ:    typ,
+				addend: r.Addend,
+			})
+		}
+	}
+
+	// Section presence: .rela.text only when there are code relocations,
+	// .rela.data only when a DATA line holds a symbol value.
+	hasRela := len(relas) > 0
+	hasDataRela := len(dataRelas) > 0
+	nSections := 6
+	if hasRela {
+		nSections++
+	}
+	if hasDataRela {
+		nSections++
+	}
+	secSymtab, secStrtab := 3, 4
+	secShstr := nSections - 1
+
 	// String tables.
 	stNames := newElfStrtab()
 	for _, s := range syms {
@@ -138,18 +187,13 @@ func (img *Image) ELFRISCVObject() ([]byte, error) {
 	for _, n := range []string{".text", ".data", ".symtab", ".strtab", ".rela.text", ".shstrtab"} {
 		stSections.add(n)
 	}
+	if hasDataRela {
+		stSections.add(".rela.data")
+	}
 	for _, n := range dwarfSectionNames {
 		stSections.add(n)
 	}
 
-	hasRela := len(relas) > 0
-	nSections := 6
-	if hasRela {
-		nSections = 7
-	}
-	secSymtab, secStrtab := 3, 4
-	secShstr := nSections - 1
-
 	// Layout.
 	var out []byte
 	out = append(out, make([]byte, 64)...)
@@ -184,7 +228,7 @@ func (img *Image) ELFRISCVObject() ([]byte, error) {
 	strtabOff := len(out)
 	out = append(out, stNames.bytes()...)
 
-	var relaOff int
+	var relaOff, relaDataOff int
 	if hasRela {
 		align(8)
 		relaOff = len(out)
@@ -196,6 +240,17 @@ func (img *Image) ELFRISCVObject() ([]byte, error) {
 			out = append(out, b[:]...)
 		}
 	}
+	if hasDataRela {
+		align(8)
+		relaDataOff = len(out)
+		for _, r := range dataRelas {
+			var b [24]byte
+			le.PutUint64(b[0:], r.off)
+			le.PutUint64(b[8:], uint64(r.sym)<<32|uint64(r.typ))
+			le.PutUint64(b[16:], uint64(r.addend))
+			out = append(out, b[:]...)
+		}
+	}
 
 	shstrOff := len(out)
 	out = append(out, stSections.bytes()...)
@@ -251,6 +306,9 @@ func (img *Image) ELFRISCVObject() ([]byte, error) {
 	if hasRela {
 		putSh(".rela.text", shtRela, 0, relaOff, 24*len(relas), secSymtab, secText, 8, 24)
 	}
+	if hasDataRela {
+		putSh(".rela.data", shtRela, 0, relaDataOff, 24*len(dataRelas), secSymtab, secData, 8, 24)
+	}
 	putSh(".shstrtab", shtStrtab, 0, shstrOff, len(stSections.bytes()), 0, 0, 1, 0)
 	// DWARF section headers; their indices follow the write order.
 	if dw != nil {

asm/elfriscv_test.go

@@ -0,0 +1,128 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package asm
+
+import (
+	"bytes"
+	"debug/elf"
+	"encoding/binary"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+)
+
+// TestELFRISCVObjectDataRelocation checks that a symbol-valued DATA field
+// ("DATA s+0(SB)/8, $other(SB)") reaches the RISC-V ELF object as a
+// .rela.data entry: an R_RISCV_64 (R_RISCV_32 for a width-4 field) at the
+// field's offset within .data, against the named symbol, external targets
+// included.
+func TestELFRISCVObjectDataRelocation(t *testing.T) {
+	f, errs := parser.Parse("t_riscv64.s", `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-0
+	RET
+GLOBL holder(SB), NOPTR, $32
+DATA holder+0(SB)/8, $·Keep+5(SB)
+DATA holder+8(SB)/8, $holder(SB)
+DATA holder+16(SB)/8, $extvar(SB)
+DATA holder+24(SB)/4, $Keep(SB)
+`)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	obj, err := img.ELFRISCVObject()
+	if err != nil {
+		t.Fatalf("ELFRISCVObject: %v", err)
+	}
+	checkELFSectionAccounting(t, obj)
+	ef, err := elf.NewFile(bytes.NewReader(obj))
+	if err != nil {
+		t.Fatalf("parse emitted object: %v", err)
+	}
+	defer ef.Close()
+	relaData := ef.Section(".rela.data")
+	if relaData == nil {
+		t.Fatal("missing .rela.data section")
+	}
+	if relaData.Type != elf.SHT_RELA {
+		t.Errorf(".rela.data type = %v, want SHT_RELA", relaData.Type)
+	}
+	if relaData.Link == 0 || ef.Sections[relaData.Link].Name != ".symtab" {
+		t.Errorf(".rela.data sh_link = %d, want the .symtab index", relaData.Link)
+	}
+	if ef.Sections[relaData.Info].Name != ".data" {
+		t.Errorf(".rela.data sh_info = %d, want the .data index", relaData.Info)
+	}
+	relas, err := relaData.Data()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got []struct {
+		off    uint64
+		sym    uint32
+		typ    uint32
+		addend int64
+	}
+	for i := 0; i+24 <= len(relas); i += 24 {
+		got = append(got, struct {
+			off    uint64
+			sym    uint32
+			typ    uint32
+			addend int64
+		}{
+			off: binary.LittleEndian.Uint64(relas[i:]),
+			// r_info packs the type in the low dword and the symbol index
+			// in the high dword.
+			typ:    binary.LittleEndian.Uint32(relas[i+8:]),
+			sym:    binary.LittleEndian.Uint32(relas[i+12:]),
+			addend: int64(binary.LittleEndian.Uint64(relas[i+16:])),
+		})
+	}
+	// debug/elf hides the table's null entry, so raw index s names syms[s-1].
+	syms, err := ef.Symbols()
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := func(idx uint32) string {
+		if idx >= 1 && int(idx) <= len(syms) {
+			return syms[idx-1].Name
+		}
+		return ""
+	}
+	// The offsets are data-section-relative: the field's DATA offset plus
+	// the symbol's position in .data (the layout aligns each symbol to 16).
+	base := uint64(0)
+	for _, d := range img.DataSyms {
+		if d.Name == "holder" {
+			base = uint64(d.Offset)
+		}
+	}
+	want := []struct {
+		off    uint64
+		typ    uint32
+		addend int64
+		target string
+	}{
+		{off: base + 0, typ: uint32(elf.R_RISCV_64), addend: 5, target: "Keep"},
+		{off: base + 8, typ: uint32(elf.R_RISCV_64), addend: 0, target: "holder"},
+		{off: base + 16, typ: uint32(elf.R_RISCV_64), addend: 0, target: "extvar"},
+		{off: base + 24, typ: uint32(elf.R_RISCV_32), addend: 0, target: "Keep"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf(".rela.data entries = %d, want %d", len(got), len(want))
+	}
+	for i, w := range want {
+		g := got[i]
+		if g.off != w.off || g.typ != w.typ || g.addend != w.addend {
+			t.Errorf("entry %d = {off %d typ %d addend %d}, want {off %d typ %d addend %d}",
+				i, g.off, g.typ, g.addend, w.off, w.typ, w.addend)
+		}
+		if n := name(g.sym); n != w.target {
+			t.Errorf("entry %d names %q, want %q", i, n, w.target)
+		}
+	}
+}

asm/encodable.go

@@ -19,7 +19,10 @@ func Encodable(mnemonic string) bool {
 	// Fixed-name instructions (no size suffix).
 	switch upper {
 	case "RET", "NOP", "CALL", "JMP",
-		"POPFQ", "PUSHFQ", "INT", "LDMXCSR", "STMXCSR", "CMPSD", "SHA256RNDS2":
+		"POPFQ", "PUSHFQ", "INT", "LDMXCSR", "STMXCSR", "CMPSD", "SHA256RNDS2",
+		// The literal-data pseudo-ops, the accepted-and-ignored END and
+		// bookkeeping statements, and the SP adjust.
+		"BYTE", "WORD", "LONG", "QUAD", "END", "ADJSP", "FUNCDATA", "PCDATA":
 		return true
 	}
 	if _, ok := noOperandTable[upper]; ok {

asm/encode.go

@@ -5,6 +5,8 @@ package asm
 
 import (
 	"fmt"
+	"math"
+	"strconv"
 	"strings"
 )
 
@@ -21,6 +23,39 @@ func Encode(mnemonic string, ops ...Operand) ([]byte, error) {
 type enc struct {
 	out     []byte
 	patches []encPatch // disp32 fields awaiting static-symbol resolution
+
+	// FloatPool collects the pooled constants the floating-point
+	// immediates reference, in first-use order.
+	floatPool     []floatPoolEntry
+	floatPoolSeen map[string]bool
+}
+
+// floatPoolEntry is one pooled floating-point constant: the symbol name
+// the emitted RIP-relative load refers to and its IEEE-754 bytes.
+type floatPoolEntry struct {
+	name string
+	data []byte
+}
+
+// addFloatPool records a pooled constant, deduplicated by symbol name.
+func (e *enc) addFloatPool(name string, bits uint64, width int) {
+	if e.floatPoolSeen == nil {
+		e.floatPoolSeen = map[string]bool{}
+	}
+	if e.floatPoolSeen[name] {
+		return
+	}
+	e.floatPoolSeen[name] = true
+	data := make([]byte, width)
+	for i := range width {
+		data[i] = byte(bits >> (8 * i))
+	}
+	e.floatPool = append(e.floatPool, floatPoolEntry{name: name, data: data})
+}
+
+// floatPoolList returns the pooled constants in first-use order.
+func (e *enc) floatPoolList() []floatPoolEntry {
+	return e.floatPool
 }
 
 // encPatch marks a 4-byte displacement field in enc.out that must receive the
@@ -29,6 +64,7 @@ type encPatch struct {
 	off    int
 	name   string
 	addend int64
+	tls    bool // a TLS slot offset: the patch is R_TLSLE with no symbol
 }
 
 func (e *enc) encode(mnem string, ops []Operand) error {
@@ -92,6 +128,21 @@ func (e *enc) encode(mnem string, ops []Operand) error {
 	// SHA256RNDS2 carries the round constant in a literal X0 first operand.
 	case "SHA256RNDS2":
 		return e.encodeSha256rnds2(ops)
+	// BYTE, WORD, LONG and QUAD write the immediate into the text stream
+	// itself: 1, 2, 4 or 8 literal bytes, little-endian.  END is accepted
+	// and ignored.  ADJSP adjusts SP by the immediate, sign-chosen between
+	// the SUBQ and ADDQ forms.
+	case "BYTE", "WORD", "LONG", "QUAD":
+		return e.encodeData(upper, ops)
+	case "END":
+		return e.encodeEnd(ops)
+	case "ADJSP":
+		return e.encodeAdjsp(ops)
+	// The runtime's bookkeeping statements carry no text bytes: go tool asm
+	// records FUNCDATA and PCDATA in the program list only, so the encoded
+	// body shows nothing, on every architecture.
+	case "FUNCDATA", "PCDATA":
+		return e.encodeFuncdata(upper, ops)
 	}
 
 	// VEX (AVX/AVX2) and EVEX (AVX-512) instructions: the trailing
@@ -103,6 +154,7 @@ func (e *enc) encode(mnem string, ops []Operand) error {
 		return err
 	}
 	if isVex(base) || isEvex(base) || isKOp(base) || isGather(base) || isScatter(base) ||
+		isEvexPrefGather(base) ||
 		base == "KMOVW" || base == "KMOVQ" || base == "KMOVB" || base == "KMOVD" {
 		return e.encodeVec(base, ops, sfx)
 	}
@@ -130,11 +182,18 @@ func (e *enc) encode(mnem string, ops []Operand) error {
 	}
 	// Legacy SSE packed binaries dispatch on the full name: the packed
 	// integer mnemonics carry real width suffixes (PADDB/PCMPGTW/...),
-	// which the size split must not eat.
+	// which the size split must not eat.  A floating-point immediate
+	// rewrites into a pooled-constant read on the scalar members.
 	if m, ok := sseBinTable[upper]; ok {
+		if f, isFloat := floatImmOperand(ops); isFloat {
+			return e.encodeSSEFloatBin(upper, m, f, ops)
+		}
 		return e.encodeSSEBin(m, ops)
 	}
 	if m, ok := sseBinTable[base]; ok {
+		if f, isFloat := floatImmOperand(ops); isFloat {
+			return e.encodeSSEFloatBin(upper, m, f, ops)
+		}
 		return e.encodeSSEBin(m, ops)
 	}
 	// The imm8-controlled legacy instructions, the lane extracts and inserts
@@ -211,7 +270,12 @@ func (e *enc) encode(mnem string, ops []Operand) error {
 		return e.encodeCvtInt(base, ops, size)
 	case "FMOVD":
 		return e.encodeFmov(ops)
-	case "MOVOU", "MOVO", "MOVOA", "MOVUPS", "MOVAPS", "MOVUPD", "MOVAPD", "MOVSD", "MOVSS":
+	case "MOVSD", "MOVSS":
+		if f, isFloat := floatImmOperand(ops); isFloat {
+			return e.encodeSSEFloatMove(upper, f, ops)
+		}
+		return e.encodeSSEMove(sseMoveTable[base], ops)
+	case "MOVOU", "MOVO", "MOVOA", "MOVUPS", "MOVAPS", "MOVUPD", "MOVAPD":
 		return e.encodeSSEMove(sseMoveTable[base], ops)
 	}
 	return fmt.Errorf("unsupported instruction %q", mnem)
@@ -241,6 +305,214 @@ var prefetchVariant = map[string]int{
 	"PREFETCHT2":  3,
 }
 
+// dataWidth is the literal byte count of each data-emission pseudo-op.
+var dataWidth = map[string]int{
+	"BYTE": 1,
+	"WORD": 2,
+	"LONG": 4,
+	"QUAD": 8,
+}
+
+// encodeData emits the literal-data pseudo-ops: BYTE, WORD, LONG and QUAD
+// write the immediate into the text stream as 1, 2, 4 or 8 bytes,
+// little-endian, with no opcode lookup.  The value is truncated to the
+// width rather than range-checked, exactly as go tool asm behaves (BYTE
+// $0x1FF emits FF, WORD $0x12345 emits 45 23, both without an error), and
+// exactly one immediate is accepted: the toolchain rejects a list such as
+// BYTE $1, $2, $3.
+func (e *enc) encodeData(mnem string, ops []Operand) error {
+	if len(ops) != 1 {
+		return fmt.Errorf("%s expects 1 immediate operand, got %d", mnem, len(ops))
+	}
+	imm, ok := ops[0].(Imm)
+	if !ok {
+		return fmt.Errorf("%s requires an integer immediate", mnem)
+	}
+	width := dataWidth[mnem]
+	out := make([]byte, width)
+	u := uint64(imm)
+	for i := range width {
+		out[i] = byte(u >> (8 * i))
+	}
+	e.out = append(e.out, out...)
+	return nil
+}
+
+// encodeFuncdata accepts-and-ignores the runtime bookkeeping statements:
+// FUNCDATA $n, sym(SB) and PCDATA $n, $m.  go tool asm emits no text bytes
+// for either (the entries live in the object's ancillary tables, not the
+// function body), and the operand shapes it takes are exactly these: an
+// integer count first, then a symbol reference for FUNCDATA and an integer
+// value for PCDATA.  The other architectures accept-and-ignore the same
+// statements; amd64 now matches.
+func (e *enc) encodeFuncdata(upper string, ops []Operand) error {
+	if len(ops) != 2 {
+		return fmt.Errorf("%s expects 2 operands, got %d", upper, len(ops))
+	}
+	if _, ok := ops[0].(Imm); !ok {
+		return fmt.Errorf("%s: first operand must be an integer immediate", upper)
+	}
+	switch upper {
+	case "FUNCDATA":
+		if _, ok := ops[1].(sbMem); !ok {
+			return fmt.Errorf("FUNCDATA: second operand must be a symbol reference")
+		}
+	case "PCDATA":
+		if _, ok := ops[1].(Imm); !ok {
+			return fmt.Errorf("PCDATA: second operand must be an integer immediate")
+		}
+	}
+	return nil
+}
+
+// encodeEnd accepts-and-ignores END.  go tool asm drops the statement
+// entirely: the AEND Prog is skipped when the program list is flushed, so
+// the statements after an END still belong to the same function and the
+// encoded body carries no trace of it, whatever operands follow the name
+// (the toolchain takes END $0 and END AX alike).  Zero bytes, no effect.
+func (e *enc) encodeEnd(ops []Operand) error {
+	return nil
+}
+
+// encodeAdjsp emits ADJSP $imm: a positive value is SUBQ $imm, SP, a
+// negative one ADDQ $-imm, SP, in the imm8 or imm32 form the magnitude
+// picks (the same selection subSP and addSP make for the frame).  go tool
+// asm refuses ADJSP $0 outright, so a zero value is an error here too; the
+// statement's effect on the SP balance is checked by the function-level
+// assembly (checkAdjspBalance), as the toolchain's push/pop walk does.
+func (e *enc) encodeAdjsp(ops []Operand) error {
+	if len(ops) != 1 {
+		return fmt.Errorf("ADJSP expects 1 immediate operand, got %d", len(ops))
+	}
+	imm, ok := ops[0].(Imm)
+	if !ok {
+		return fmt.Errorf("ADJSP requires an integer immediate")
+	}
+	switch v := int(imm); {
+	case v > 0:
+		e.out = append(e.out, subSP(v)...)
+	case v < 0:
+		e.out = append(e.out, addSP(-v)...)
+	default:
+		return fmt.Errorf("ADJSP $0 has no encoding")
+	}
+	return nil
+}
+
+// --- floating-point immediates ----------------------------------------------
+
+// sseFloatImm lists the mnemonics whose first operand may be a floating-point
+// immediate, the set go tool asm rewrites into a pooled-constant read: the
+// scalar moves, the four scalar arithmetic pairs and the scalar compares.
+// The packed members and the uniform forms (MAXSD, MINSD, SQRTSD, CMPSD)
+// reject the immediate in the toolchain and are absent here on purpose.
+var sseFloatImm = map[string]bool{
+	"MOVSD": true, "MOVSS": true,
+	"ADDSD": true, "ADDSS": true,
+	"SUBSD": true, "SUBSS": true,
+	"MULSD": true, "MULSS": true,
+	"DIVSD": true, "DIVSS": true,
+	"COMISD": true, "COMISS": true,
+	"UCOMISD": true, "UCOMISS": true,
+}
+
+// floatImmOperand reports whether the operand list opens with a
+// floating-point immediate in the two-operand spelling (imm, dst).
+func floatImmOperand(ops []Operand) (FloatImm, bool) {
+	if len(ops) != 2 {
+		return FloatImm{}, false
+	}
+	f, ok := ops[0].(FloatImm)
+	return f, ok
+}
+
+// floatPoolValue evaluates a floating-point immediate at the width its
+// mnemonic encodes and names the pool constant the toolchain synthesises:
+// $f64.<16 hex> for the doubles, $f32.<8 hex> for the singles (the float32
+// rounding of the parsed value).  The name carries the IEEE-754 bits; the
+// section holds them little-endian.
+func floatPoolValue(mnem string, f FloatImm) (bits uint64, name string, err error) {
+	v, err := strconv.ParseFloat(f.Text, 64)
+	if err != nil {
+		return 0, "", fmt.Errorf("invalid floating-point immediate %q", f.Text)
+	}
+	if f.Neg {
+		v = -v
+	}
+	if strings.HasSuffix(mnem, "D") {
+		bits = math.Float64bits(v)
+		return bits, fmt.Sprintf("$f64.%016x", bits), nil
+	}
+	bits = uint64(math.Float32bits(float32(v)))
+	return bits, fmt.Sprintf("$f32.%08x", bits), nil
+}
+
+// encodeSSEFloatMove encodes MOVSD/MOVSS with a floating-point immediate
+// source.  A positive zero needs no memory read: the toolchain emits
+// XORPS dst, dst.  Anything else loads the pooled constant RIP-relative
+// ($f64.<hex>(SB) / $f32.<hex>(SB)), the displacement a patch site the
+// file-level layout or the linker resolves.
+func (e *enc) encodeSSEFloatMove(mnem string, f FloatImm, ops []Operand) error {
+	if !sseFloatImm[mnem] {
+		return fmt.Errorf("%s does not take a floating-point immediate", mnem)
+	}
+	dst, ok := ops[1].(Reg)
+	if !ok || !dst.isVec() {
+		return fmt.Errorf("%s: destination must be a vector register", mnem)
+	}
+	bits, name, err := floatPoolValue(mnem, f)
+	if err != nil {
+		return err
+	}
+	e.addFloatPool(name, bits, mwidth(mnem))
+	if bits == 0 {
+		i := &instr{opcode: []byte{0x0F, 0x57}, modrm: -1, sib: -1} // XORPS
+		if err := setRM(i, dst, dst, 8); err != nil {
+			return err
+		}
+		return e.emit(i)
+	}
+	m := sseMoveTable[mnem]
+	i := &instr{prefix: m.prefix, opcode: []byte{0x0F, m.load}, modrm: -1, sib: -1}
+	if err := setRM(i, dst, sbMem{size: mwidth(mnem), name: name}, 8); err != nil {
+		return err
+	}
+	return e.emit(i)
+}
+
+// encodeSSEFloatBin encodes the scalar arithmetic and compare mnemonics with
+// a floating-point immediate source: the constant is read from the pool into
+// the instruction's r/m side (reg = destination), the rewrite go tool asm
+// performs at the source level.
+func (e *enc) encodeSSEFloatBin(mnem string, m sseBin, f FloatImm, ops []Operand) error {
+	if !sseFloatImm[mnem] {
+		return fmt.Errorf("%s does not take a floating-point immediate", mnem)
+	}
+	dst, ok := ops[1].(Reg)
+	if !ok || !dst.isVec() {
+		return fmt.Errorf("%s: destination must be a vector register", mnem)
+	}
+	bits, name, err := floatPoolValue(mnem, f)
+	if err != nil {
+		return err
+	}
+	e.addFloatPool(name, bits, mwidth(mnem))
+	i := &instr{prefix: m.prefix, opcode: []byte{0x0F, m.op}, modrm: -1, sib: -1}
+	if err := setRM(i, dst, sbMem{size: mwidth(mnem), name: name}, 8); err != nil {
+		return err
+	}
+	return e.emit(i)
+}
+
+// mwidth returns the operand width a scalar SSE mnemonic encodes: the double
+// spellings end in D, the single spellings in S.
+func mwidth(mnem string) int {
+	if strings.HasSuffix(mnem, "D") {
+		return 8
+	}
+	return 4
+}
+
 // splitSize separates a trailing B/W/L/Q size suffix from the mnemonic.
 func splitSize(upper string) (base string, size int) {
 	if upper == "" {
@@ -307,6 +579,7 @@ type instr struct {
 	disp      []byte
 	imm       []byte
 	sb        *sbRef // static-symbol displacement in disp, awaiting resolution
+	tls       bool   // the displacement is a TLS slot offset, patched R_TLSLE
 }
 
 // sbRef records that an instruction's displacement refers to a static symbol
@@ -349,6 +622,9 @@ func (e *enc) emit(i *instr) error {
 	if i.sb != nil {
 		e.patches = append(e.patches, encPatch{off: len(e.out), name: i.sb.name, addend: i.sb.addend})
 	}
+	if i.tls {
+		e.patches = append(e.patches, encPatch{off: len(e.out), tls: true})
+	}
 	e.out = append(e.out, i.disp...)
 	e.out = append(e.out, i.imm...)
 	return nil
@@ -403,12 +679,30 @@ func setRMReg(i *instr, regField int, rexR, regForced bool, rm Operand, opSize i
 		i.disp = le32(0)
 		i.sb = &sbRef{name: r.name, addend: r.addend}
 		return nil
+	case TLSMem:
+		// off(TLS): the segment-prefixed absolute access, mod=00 with the
+		// SIB escape's disp32 absolute form.  The displacement is the TLS
+		// slot offset, patched by the linker's TLS relocation.
+		i.prefix = r.Seg
+		i.modrm = 0x04 | regField<<3
+		i.sib = 0x25
+		i.disp = le32(r.Disp)
+		i.tls = true
+		return nil
+	case SegAbs:
+		// 0x30(GS): the segment override with the SIB escape's disp32
+		// absolute form, no relocation.
+		setSegAbs(i, regField, r)
+		return nil
 	default:
 		return fmt.Errorf("invalid r/m operand %T", rm)
 	}
 }
 
 func setMem(i *instr, regField int, m Mem) error {
+	if m.Seg != 0 {
+		i.prefix = m.Seg
+	}
 	modrm, sib, disp, xBit, bBit, err := memComponents(regField, m)
 	if err != nil {
 		return err
@@ -421,6 +715,16 @@ func setMem(i *instr, regField int, m Mem) error {
 	return nil
 }
 
+// setSegAbs assembles a segment-absolute operand, 0x30(GS): the segment
+// override with the mod=00 SIB escape's disp32 absolute form and no
+// relocation.
+func setSegAbs(i *instr, regField int, m SegAbs) {
+	i.prefix = m.Seg
+	i.modrm = 0x04 | regField<<3
+	i.sib = 0x25
+	i.disp = le32(m.Disp)
+}
+
 // memComponents computes the ModR/M byte (with the given reg field), the SIB
 // byte (-1 if none), the displacement bytes, and the high index/base bits, for
 // a memory operand.  It is shared by the REX (scalar) and VEX (vector) paths.

asm/encode_test.go

@@ -9,6 +9,9 @@ import (
 	"testing"
 
 	"golang.org/x/arch/x86/x86asm"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // decode encodes an instruction and decodes it back, returning the decoded
@@ -925,3 +928,296 @@ func TestMOVQXMMGroundTruth(t *testing.T) {
 		}
 	}
 }
+
+// TestPrefixStatements pins LOCK, REP and REPN.  go tool asm encodes each as
+// a standalone one-byte instruction with a PC of its own (F0, F3, F2), not a
+// prefix field merged into the following instruction, and it validates
+// nothing about the pairing (LOCK before NOP assembles).  The prefixed
+// atomic and string shapes are the bytes the runtime's own kernels need.
+func TestPrefixStatements(t *testing.T) {
+	cases := []struct {
+		name string
+		mnem string
+		ops  []Operand
+		want string
+	}{
+		{"LOCK", "LOCK", nil, "f0"},
+		{"REP", "REP", nil, "f3"},
+		{"REPN", "REPN", nil, "f2"},
+		// LOCK; CMPXCHGQ AX, (BX)
+		{"LOCK CMPXCHGQ", "CMPXCHGQ", []Operand{AX, Ptr(BX, 0, 8)}, "480fb103"},
+		// REP; MOVSQ
+		{"REP MOVSQ", "MOVSQ", nil, "48a5"},
+		// REPN; MOVSB
+		{"REPN MOVSB", "MOVSB", nil, "a4"},
+	}
+	for _, c := range cases {
+		code, err := Encode(c.mnem, c.ops...)
+		if err != nil {
+			t.Errorf("%s: %v", c.name, err)
+			continue
+		}
+		if got := fmt.Sprintf("%x", code); got != c.want {
+			t.Errorf("%s = %s, want %s", c.name, got, c.want)
+		}
+	}
+	// The prefix statements take no operands, as the toolchain reports for
+	// LOCK AX.
+	if _, err := Encode("LOCK", AX); err == nil {
+		t.Error("LOCK AX assembled, want an error")
+	}
+	if _, err := Encode("REP", Imm(1)); err == nil {
+		t.Error("REP $1 assembled, want an error")
+	}
+}
+
+// TestDataEmission pins BYTE, WORD, LONG and QUAD: the immediate lands in
+// the text stream as 1, 2, 4 or 8 little-endian bytes with no opcode
+// lookup, truncated to the width rather than range-checked (go tool asm
+// emits FF for BYTE $0x1FF and 45 23 for WORD $0x12345, both silently).
+func TestDataEmission(t *testing.T) {
+	cases := []struct {
+		name string
+		mnem string
+		imm  Imm
+		want string
+	}{
+		{"BYTE", "BYTE", 0x0f, "0f"},
+		{"BYTE negative", "BYTE", -1, "ff"},
+		{"BYTE truncated", "BYTE", 0x1ff, "ff"},
+		{"WORD", "WORD", 0x1234, "3412"},
+		{"WORD negative", "WORD", -1, "ffff"},
+		{"WORD truncated", "WORD", 0x12345, "4523"},
+		{"LONG", "LONG", 0x11223344, "44332211"},
+		{"LONG negative", "LONG", -1, "ffffffff"},
+		{"QUAD", "QUAD", 0x1122334455667788, "8877665544332211"},
+		{"QUAD negative", "QUAD", -2, "feffffffffffffff"},
+	}
+	for _, c := range cases {
+		code, err := Encode(c.mnem, c.imm)
+		if err != nil {
+			t.Errorf("%s: %v", c.name, err)
+			continue
+		}
+		if got := fmt.Sprintf("%x", code); got != c.want {
+			t.Errorf("%s = %s, want %s", c.name, got, c.want)
+		}
+	}
+	// Exactly one immediate: the toolchain rejects BYTE $1, $2, $3, and a
+	// register or a missing operand is no immediate at all.
+	if _, err := Encode("BYTE"); err == nil {
+		t.Error("BYTE with no operand assembled, want an error")
+	}
+	if _, err := Encode("BYTE", Imm(1), Imm(2)); err == nil {
+		t.Error("BYTE $1, $2 assembled, want an error")
+	}
+	if _, err := Encode("WORD", AX); err == nil {
+		t.Error("WORD AX assembled, want an error")
+	}
+}
+
+// TestEndIgnored pins END: go tool asm drops the statement entirely, so it
+// encodes to zero bytes and takes any operands without complaint (the
+// toolchain accepts END $0 and END AX alike).
+func TestEndIgnored(t *testing.T) {
+	for _, ops := range [][]Operand{nil, {Imm(0)}, {AX}} {
+		code, err := Encode("END", ops...)
+		if err != nil {
+			t.Errorf("END: %v", err)
+			continue
+		}
+		if len(code) != 0 {
+			t.Errorf("END = %x, want no bytes", code)
+		}
+	}
+}
+
+// TestAdjsp pins ADJSP: a positive immediate is SUBQ $imm, SP, a negative
+// one ADDQ $-imm, SP, in the imm8 or imm32 form the magnitude picks; $0
+// has no encoding (go tool asm refuses ADJSP $0 outright).
+func TestAdjsp(t *testing.T) {
+	cases := []struct {
+		name string
+		imm  Imm
+		want string
+	}{
+		{"imm8", 112, "4883ec70"},
+		{"imm8 negative", -112, "4883c470"},
+		{"imm32", 200, "4881ecc8000000"},
+		{"imm32 negative", -200, "4881c4c8000000"},
+		{"small", 8, "4883ec08"},
+	}
+	for _, c := range cases {
+		code, err := Encode("ADJSP", c.imm)
+		if err != nil {
+			t.Errorf("%s: %v", c.name, err)
+			continue
+		}
+		if got := fmt.Sprintf("%x", code); got != c.want {
+			t.Errorf("ADJSP %d = %s, want %s", int64(c.imm), got, c.want)
+		}
+	}
+	if _, err := Encode("ADJSP", Imm(0)); err == nil {
+		t.Error("ADJSP $0 assembled, want an error")
+	}
+	if _, err := Encode("ADJSP"); err == nil {
+		t.Error("ADJSP with no operand assembled, want an error")
+	}
+	if _, err := Encode("ADJSP", AX); err == nil {
+		t.Error("ADJSP AX assembled, want an error")
+	}
+}
+
+// TestFloatImmediateGroundTruth pins the floating-point immediate rewrite
+// byte for byte against go tool asm: the scalar moves and the scalar
+// arithmetic read the constant from a synthesised read-only pool symbol
+// ($f64.<hex>, $f32.<hex>) RIP-relative with the displacement left to the
+// relocation, and a positive zero on the moves collapses to XORPS dst, dst.
+func TestFloatImmediateGroundTruth(t *testing.T) {
+	cases := []struct {
+		name string
+		mnem string
+		ops  []Operand
+		want string
+	}{
+		{"MOVSD -1.0", "MOVSD", []Operand{FloatImm{Text: "1.0", Neg: true}, vreg(t, "X2")}, "f20f101500000000"},
+		{"MOVSD 1.5", "MOVSD", []Operand{FloatImm{Text: "1.5"}, vreg(t, "X3")}, "f20f101d00000000"},
+		{"MOVSS 2.5", "MOVSS", []Operand{FloatImm{Text: "2.5"}, vreg(t, "X4")}, "f30f102500000000"},
+		{"MOVSS -0.5", "MOVSS", []Operand{FloatImm{Text: "0.5", Neg: true}, vreg(t, "X5")}, "f30f102d00000000"},
+		{"MOVSS +0.0 is XORPS", "MOVSS", []Operand{FloatImm{Text: "0.0"}, vreg(t, "X10")}, "450f57d2"},
+		{"MOVSD +0.0 is XORPS", "MOVSD", []Operand{FloatImm{Text: "0.0"}, vreg(t, "X6")}, "0f57f6"},
+		{"ADDSD 1.0", "ADDSD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}, "f20f580500000000"},
+		{"ADDSS 0.5", "ADDSS", []Operand{FloatImm{Text: "0.5"}, vreg(t, "X1")}, "f30f580d00000000"},
+		{"SUBSD 2.0", "SUBSD", []Operand{FloatImm{Text: "2.0"}, vreg(t, "X3")}, "f20f5c1d00000000"},
+		{"MULSD -2.5", "MULSD", []Operand{FloatImm{Text: "2.5", Neg: true}, vreg(t, "X3")}, "f20f591d00000000"},
+		{"DIVSD 1.0", "DIVSD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}, "f20f5e0500000000"},
+		{"COMISD 1.0", "COMISD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}, "660f2f0500000000"},
+	}
+	for _, c := range cases {
+		code, err := Encode(c.mnem, c.ops...)
+		if err != nil {
+			t.Errorf("%s: Encode: %v", c.name, err)
+			continue
+		}
+		if got := hexCompact(code); got != c.want {
+			t.Errorf("%s: got %s, want %s", c.name, got, c.want)
+		}
+	}
+
+	// The pool names carry the IEEE-754 bits, the float32 narrowing for the
+	// single spellings; negative zero keeps its sign bit and never takes the
+	// XORPS shortcut.
+	for _, c := range []struct {
+		mnem string
+		imm  FloatImm
+		want string
+	}{
+		{"MOVSD", FloatImm{Text: "1.0", Neg: true}, "$f64.bff0000000000000"},
+		{"MOVSD", FloatImm{Text: "0.5"}, "$f64.3fe0000000000000"},
+		{"MOVSS", FloatImm{Text: "2.5"}, "$f32.40200000"},
+		{"MOVSS", FloatImm{Text: "0.5", Neg: true}, "$f32.bf000000"},
+		{"MOVSD", FloatImm{Text: "0.0", Neg: true}, "$f64.8000000000000000"},
+	} {
+		_, name, err := floatPoolValue(c.mnem, c.imm)
+		if err != nil {
+			t.Errorf("%s %s: %v", c.mnem, c.imm.Text, err)
+			continue
+		}
+		if name != c.want {
+			t.Errorf("%s $%s: pool name %s, want %s", c.mnem, c.imm.Text, name, c.want)
+		}
+	}
+
+	// The shapes the toolchain's parser rejects: the packed and uniform
+	// forms, a non-vector destination, and the integer spellings.
+	for _, c := range []struct {
+		name string
+		mnem string
+		ops  []Operand
+	}{
+		{"MAXSD rejects the immediate", "MAXSD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}},
+		{"MINSD rejects the immediate", "MINSD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}},
+		{"SQRTSD rejects the immediate", "SQRTSD", []Operand{FloatImm{Text: "1.0"}, vreg(t, "X0")}},
+		{"integer destination", "MOVSD", []Operand{FloatImm{Text: "1.0"}, AX}},
+	} {
+		if _, err := Encode(c.mnem, c.ops...); err == nil {
+			t.Errorf("%s: expected an error, got none", c.name)
+		}
+	}
+}
+
+// TestBookkeepingGroundTruth pins FUNCDATA and PCDATA as accept-and-ignore:
+// go tool asm emits no text bytes for either, on every architecture.
+func TestBookkeepingGroundTruth(t *testing.T) {
+	for _, c := range []struct {
+		name string
+		mnem string
+		ops  []Operand
+	}{
+		{"FUNCDATA", "FUNCDATA", []Operand{Imm(3), sbMem{name: "\u00b7f.arginfo0"}}},
+		{"PCDATA", "PCDATA", []Operand{Imm(1), Imm(-1)}},
+	} {
+		code, err := Encode(c.mnem, c.ops...)
+		if err != nil {
+			t.Errorf("%s: Encode: %v", c.name, err)
+			continue
+		}
+		if len(code) != 0 {
+			t.Errorf("%s: emitted %x, want no bytes", c.name, code)
+		}
+	}
+	for _, c := range []struct {
+		name string
+		mnem string
+		ops  []Operand
+	}{
+		{"FUNCDATA arity", "FUNCDATA", []Operand{Imm(3)}},
+		{"FUNCDATA missing the count", "FUNCDATA", []Operand{sbMem{name: "x"}}},
+		{"FUNCDATA integer value", "FUNCDATA", []Operand{Imm(3), Imm(4)}},
+		{"PCDATA arity", "PCDATA", []Operand{Imm(1)}},
+		{"PCDATA register value", "PCDATA", []Operand{Imm(1), AX}},
+	} {
+		if _, err := Encode(c.mnem, c.ops...); err == nil {
+			t.Errorf("%s: expected an error, got none", c.name)
+		}
+	}
+
+	// At the statement level the bookkeeping lines sit between real
+	// instructions and contribute nothing to the body, symbol reference
+	// included: the FUNCDATA operand never needs file-level resolution.
+	f, errs := parser.Parse("t_amd64.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tNOP\n\tFUNCDATA $3, \u00b7f.arginfo0(SB)\n\tPCDATA $1, $-1\n\tFUNCDATA $0, x<>(SB)\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	want := "90c3"
+	if got := hexCompact(img.Code); got != want {
+		t.Errorf("body %s, want %s (the bookkeeping lines contribute nothing)", got, want)
+	}
+	if _, err := AssembleFile(mustParse(t, "TEXT \u00b7f(SB), NOSPLIT, $0\n\tFUNCDATA $1, X0\n\tRET\n")); err == nil {
+		t.Error("FUNCDATA $1, X0 assembled, want an error")
+	}
+	if _, err := AssembleFile(mustParse(t, "TEXT \u00b7f(SB), NOSPLIT, $0\n\tPCDATA $1, X0\n\tRET\n")); err == nil {
+		t.Error("PCDATA $1, X0 assembled, want an error")
+	}
+
+	// Encodable mirrors Encode for the names this work touched.
+	for _, mnem := range []string{"FUNCDATA", "PCDATA", "V4FMADDPS", "V4FMADDSS", "V4FNMADDPS", "V4FNMADDSS", "VP4DPWSSD", "VP4DPWSSDS"} {
+		if !Encodable(mnem) {
+			t.Errorf("Encodable(%s) = false, want true", mnem)
+		}
+	}
+}
+
+// mustParse parses src or fails the test.
+func mustParse(t *testing.T, src string) *ast.File {
+	t.Helper()
+	f, errs := parser.Parse("t_amd64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	return f
+}

asm/evex.go

@@ -5,6 +5,7 @@ package asm
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 )
 
@@ -91,7 +92,7 @@ var evexTable = map[string]evexSpec{
 	"VPSRAD": {1, 0x72, 0, 1, 4, vexShiftImm, [3]int{16, 32, 64}},
 	// EVEX.128/256/512.66.0F.W1, variable shift with an XMM count (VPSRAQ;
 	// the W bit distinguishes it from VPSRAD's E2 form).
-	"VPSRAQ": {1, 0xE2, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSRAQ": {1, 0x72, 1, 1, 4, vexShiftImm, [3]int{16, 32, 64}},
 
 	// EVEX.128/256/512.F3.0F.W1, signed qword to packed double (reg=dst,
 	// rm=src, no vvvv).
@@ -138,7 +139,7 @@ var evexTable = map[string]evexSpec{
 
 	// EVEX.66.0F, the EVEX forms of the VEX two-source shuffle.
 	"VSHUFPD": {1, 0xC6, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
-	"VSHUFPS": {1, 0xC6, 0, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VSHUFPS": {1, 0xC6, 0, 0, -1, vexNDS3Imm, [3]int{16, 32, 64}},
 
 	// EVEX.66.0F3A, lane insert ($imm, xsrc, zsrc1, zdst).
 	"VINSERTF32X4": {3, 0x18, 0, 1, -1, vexNDS3Imm, [3]int{0, 16, 32}},
@@ -202,7 +203,7 @@ var evexTable = map[string]evexSpec{
 	"VPMULHUW":   {1, 0xE4, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
 	"VPMADDUBSW": {2, 0x04, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
 	"VPSLLVW":    {2, 0x12, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
-	"VPSRLVW":    {2, 0x11, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSRLVW":    {2, 0x10, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
 	"VPACKSSWB":  {1, 0x63, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
 	"VPACKUSWB":  {1, 0x67, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
 	"VPACKSSDW":  {1, 0x6B, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
@@ -324,7 +325,7 @@ var evexTable = map[string]evexSpec{
 	"VCVTPD2UQQ": {1, 0x79, 1, 1, -1, vexRM, [3]int{16, 32, 64}},
 	"VCVTPS2QQ":  {1, 0x7B, 0, 1, -1, vexRM, [3]int{8, 16, 32}},
 	"VCVTUDQ2PD": {1, 0x7A, 0, 2, -1, vexRM, [3]int{8, 16, 32}},
-	"VCVTUDQ2PS": {1, 0x7A, 0, 0, -1, vexRM, [3]int{8, 16, 32}},
+	"VCVTUDQ2PS": {1, 0x7A, 0, 3, -1, vexRM, [3]int{8, 16, 32}},
 	// EVEX.66.0F38, half-precision convert (half-width source).
 	"VCVTPH2PS": {2, 0x13, 0, 1, -1, vexRM, [3]int{8, 16, 32}},
 	// EVEX.66.0F3A, half-precision convert back ($imm, src, dst: reg=src,
@@ -494,6 +495,331 @@ var evexTable = map[string]evexSpec{
 	// destination (VPMOVDW dword→word, VPMOVQD qword→dword).
 	"VPMOVDW": {2, 0x33, 0, 2, -1, vexRMRev, [3]int{8, 16, 32}},
 	"VPMOVQD": {2, 0x35, 0, 2, -1, vexRMRev, [3]int{8, 16, 32}},
+
+	// --- the AVX-512 families the avx512enc corpus exercises, read off
+	// the toolchain opcodetables ---
+	"VAESDEC":           {2, 0xDE, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VAESDECLAST":       {2, 0xDF, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VAESENC":           {2, 0xDC, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VAESENCLAST":       {2, 0xDD, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VALIGNQ":           {3, 0x03, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VANDNPD":           {1, 0x55, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VANDPD":            {1, 0x54, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VBLENDMPD":         {2, 0x65, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VBLENDMPS":         {2, 0x65, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VBROADCASTF32X2":   {2, 0x19, 0, 1, -1, vexRM, [3]int{0, 8, 8}},
+	"VBROADCASTF32X4":   {2, 0x1A, 0, 1, -1, vexRM, [3]int{0, 16, 16}},
+	"VBROADCASTF32X8":   {2, 0x1B, 0, 1, -1, vexRM, [3]int{0, 0, 32}},
+	"VBROADCASTF64X2":   {2, 0x1A, 1, 1, -1, vexRM, [3]int{0, 16, 16}},
+	"VBROADCASTF64X4":   {2, 0x1B, 1, 1, -1, vexRM, [3]int{0, 0, 32}},
+	"VBROADCASTI32X2":   {2, 0x59, 0, 1, -1, vexRM, [3]int{8, 8, 8}},
+	"VBROADCASTI32X4":   {2, 0x5A, 0, 1, -1, vexRM, [3]int{0, 16, 16}},
+	"VBROADCASTI32X8":   {2, 0x5B, 0, 1, -1, vexRM, [3]int{0, 0, 32}},
+	"VBROADCASTI64X2":   {2, 0x5A, 1, 1, -1, vexRM, [3]int{0, 16, 16}},
+	"VBROADCASTI64X4":   {2, 0x5B, 1, 1, -1, vexRM, [3]int{0, 0, 32}},
+	"VCOMISD":           {1, 0x2F, 1, 1, -1, vexRM, [3]int{8, 0, 0}},
+	"VCVTSD2SS":         {1, 0x5A, 1, 3, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VCVTSS2SD":         {1, 0x5A, 0, 2, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VDBPSADBW":         {3, 0x42, 0, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VEXP2PD":           {2, 0xC8, 1, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VEXP2PS":           {2, 0xC8, 0, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VFMADD132PD":       {2, 0x98, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADD132PS":       {2, 0x98, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADD132SD":       {2, 0x99, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMADD132SS":       {2, 0x99, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMADD213PD":       {2, 0xA8, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADD213PS":       {2, 0xA8, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADD213SD":       {2, 0xA9, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMADD213SS":       {2, 0xA9, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMADD231PS":       {2, 0xB8, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADD231SD":       {2, 0xB9, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMADD231SS":       {2, 0xB9, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMADDSUB132PD":    {2, 0x96, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADDSUB132PS":    {2, 0x96, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADDSUB213PD":    {2, 0xA6, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADDSUB213PS":    {2, 0xA6, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADDSUB231PD":    {2, 0xB6, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMADDSUB231PS":    {2, 0xB6, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB132PD":       {2, 0x9A, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB132PS":       {2, 0x9A, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB132SD":       {2, 0x9B, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMSUB132SS":       {2, 0x9B, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMSUB213PD":       {2, 0xAA, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB213PS":       {2, 0xAA, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB213SD":       {2, 0xAB, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMSUB213SS":       {2, 0xAB, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMSUB231PD":       {2, 0xBA, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB231PS":       {2, 0xBA, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUB231SD":       {2, 0xBB, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFMSUB231SS":       {2, 0xBB, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFMSUBADD132PD":    {2, 0x97, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUBADD132PS":    {2, 0x97, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUBADD213PD":    {2, 0xA7, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUBADD213PS":    {2, 0xA7, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUBADD231PD":    {2, 0xB7, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFMSUBADD231PS":    {2, 0xB7, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD132PD":      {2, 0x9C, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD132PS":      {2, 0x9C, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD132SD":      {2, 0x9D, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMADD132SS":      {2, 0x9D, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFNMADD213PD":      {2, 0xAC, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD213PS":      {2, 0xAC, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD213SD":      {2, 0xAD, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMADD213SS":      {2, 0xAD, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFNMADD231PD":      {2, 0xBC, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD231PS":      {2, 0xBC, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMADD231SD":      {2, 0xBD, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMADD231SS":      {2, 0xBD, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFNMSUB132PD":      {2, 0x9E, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB132PS":      {2, 0x9E, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB132SD":      {2, 0x9F, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMSUB132SS":      {2, 0x9F, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFNMSUB213PD":      {2, 0xAE, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB213PS":      {2, 0xAE, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB213SD":      {2, 0xAF, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMSUB213SS":      {2, 0xAF, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VFNMSUB231PD":      {2, 0xBE, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB231PS":      {2, 0xBE, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VFNMSUB231SD":      {2, 0xBF, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VFNMSUB231SS":      {2, 0xBF, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VGF2P8AFFINEINVQB": {3, 0xCF, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VGF2P8AFFINEQB":    {3, 0xCE, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VGF2P8MULB":        {2, 0xCF, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VMOVNTDQ":          {1, 0xE7, 0, 1, -1, vexRMRev, [3]int{16, 32, 64}},
+	"VMOVNTDQA":         {2, 0x2A, 0, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VMOVNTPD":          {1, 0x2B, 1, 1, -1, vexRMRev, [3]int{16, 32, 64}},
+	"VORPD":             {1, 0x56, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPADDSB":           {1, 0xEC, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPADDSW":           {1, 0xED, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPADDUSB":          {1, 0xDC, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPADDUSW":          {1, 0xDD, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPBLENDMB":         {2, 0x66, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPBLENDMD":         {2, 0x64, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPBLENDMQ":         {2, 0x64, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPBLENDMW":         {2, 0x66, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPBROADCASTMB2Q":   {2, 0x2A, 1, 2, -1, vexRM, [3]int{0, 0, 0}},
+	"VPBROADCASTMW2D":   {2, 0x3A, 0, 2, -1, vexRM, [3]int{0, 0, 0}},
+	"VPCLMULQDQ":        {3, 0x44, 0, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPCMPEQB":          {1, 0x74, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPEQQ":          {2, 0x29, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPEQW":          {1, 0x75, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPGTB":          {1, 0x64, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPGTD":          {1, 0x66, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPGTQ":          {2, 0x37, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCMPGTW":          {1, 0x65, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPCOMPRESSB":       {2, 0x63, 0, 1, -1, vexRMRev, [3]int{1, 1, 1}},
+	"VPCOMPRESSW":       {2, 0x63, 1, 1, -1, vexRMRev, [3]int{2, 2, 2}},
+	"VPCONFLICTD":       {2, 0xC4, 0, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VPCONFLICTQ":       {2, 0xC4, 1, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VPDPBUSD":          {2, 0x50, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPDPBUSDS":         {2, 0x51, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPDPWSSD":          {2, 0x52, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPDPWSSDS":         {2, 0x53, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMI2PD":         {2, 0x77, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMI2PS":         {2, 0x77, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMI2W":          {2, 0x75, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMPS":           {2, 0x16, 0, 1, -1, vexNDS3, [3]int{0, 32, 64}},
+	"VPERMT2B":          {2, 0x7D, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMT2PS":         {2, 0x7F, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMT2W":          {2, 0x7D, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPEXPANDB":         {2, 0x62, 0, 1, -1, vexRM, [3]int{1, 1, 1}},
+	"VPEXPANDW":         {2, 0x62, 1, 1, -1, vexRM, [3]int{2, 2, 2}},
+	"VPINSRD":           {3, 0x22, 0, 1, -1, vexNDS3Imm, [3]int{4, 0, 0}},
+	"VPINSRQ":           {3, 0x22, 1, 1, -1, vexNDS3Imm, [3]int{8, 0, 0}},
+	"VPLZCNTD":          {2, 0x44, 0, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VPLZCNTQ":          {2, 0x44, 1, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VPMADD52HUQ":       {2, 0xB5, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMADD52LUQ":       {2, 0xB4, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMULDQ":           {2, 0x28, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMULHRSW":         {2, 0x0B, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMULHW":           {1, 0xE5, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMULTISHIFTQB":    {2, 0x83, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPMULUDQ":          {1, 0xF4, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPOPCNTW":          {2, 0x54, 1, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VPORD":             {1, 0xEB, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPROLVD":           {2, 0x15, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPROLVQ":           {2, 0x15, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPRORVD":           {2, 0x14, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPRORVQ":           {2, 0x14, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSADBW":           {1, 0xF6, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHLDD":           {3, 0x71, 0, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHLDQ":           {3, 0x71, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHLDVD":          {2, 0x71, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHLDVQ":          {2, 0x71, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHLDVW":          {2, 0x70, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHLDW":           {3, 0x70, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHRDD":           {3, 0x73, 0, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHRDQ":           {3, 0x73, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHRDVD":          {2, 0x73, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHRDVQ":          {2, 0x73, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHRDVW":          {2, 0x72, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSHRDW":           {3, 0x72, 1, 1, -1, vexNDS3Imm, [3]int{16, 32, 64}},
+	"VPSHUFBITQMB":      {2, 0x8F, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSRAVW":           {2, 0x11, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSRLD":            {1, 0x72, 0, 1, 2, vexShiftImm, [3]int{16, 32, 64}},
+	"VPSRLDQ":           {1, 0x73, 0, 1, 3, vexShiftImm, [3]int{16, 32, 64}},
+	// EVEX.66.0F73 /7, the byte-quad shift left (the count is always an
+	// immediate; there is no register-count twin).
+	"VPSLLDQ": {1, 0x73, 0, 1, 7, vexShiftImm, [3]int{16, 32, 64}},
+
+	// EVEX.128/256/512.0F.W0, the plain-prefix (no 66) packed spellings
+	// whose EVEX form drops the legacy prefix entirely.
+	"VANDNPS":     {1, 0x55, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VANDPS":      {1, 0x54, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VORPS":       {1, 0x56, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VXORPS":      {1, 0x57, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VUNPCKLPS":   {1, 0x14, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VUNPCKHPS":   {1, 0x15, 0, 0, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VSQRTPS":     {1, 0x51, 0, 0, -1, vexRM, [3]int{16, 32, 64}},
+	"VCOMISS":     {1, 0x2F, 0, 0, -1, vexRM, [3]int{4, 0, 0}},
+	"VUCOMISS":    {1, 0x2E, 0, 0, -1, vexRM, [3]int{4, 0, 0}},
+	"VMOVNTPS":    {1, 0x2B, 0, 0, -1, vexRMRev, [3]int{16, 32, 64}},
+	"VPSUBSB":     {1, 0xE8, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSUBSW":     {1, 0xE9, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSUBUSB":    {1, 0xD8, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPSUBUSW":    {1, 0xD9, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTMB":    {2, 0x26, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTMD":    {2, 0x27, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTMQ":    {2, 0x27, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTMW":    {2, 0x26, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTNMB":   {2, 0x26, 0, 2, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTNMD":   {2, 0x27, 0, 2, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTNMQ":   {2, 0x27, 1, 2, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPTESTNMW":   {2, 0x26, 1, 2, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKHBW":  {1, 0x68, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKHQDQ": {1, 0x6D, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKHWD":  {1, 0x69, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKLBW":  {1, 0x60, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKLQDQ": {1, 0x6C, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPUNPCKLWD":  {1, 0x61, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VRCP28PD":    {2, 0xCA, 1, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VRCP28PS":    {2, 0xCA, 0, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VRCP28SD":    {2, 0xCB, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VRCP28SS":    {2, 0xCB, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VRSQRT28PD":  {2, 0xCC, 1, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VRSQRT28PS":  {2, 0xCC, 0, 1, -1, vexRM, [3]int{0, 0, 64}},
+	"VRSQRT28SD":  {2, 0xCD, 1, 1, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VRSQRT28SS":  {2, 0xCD, 0, 1, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VSQRTPD":     {1, 0x51, 1, 1, -1, vexRM, [3]int{16, 32, 64}},
+	"VSQRTSD":     {1, 0x51, 1, 3, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VSQRTSS":     {1, 0x51, 0, 2, -1, vexNDS3, [3]int{4, 0, 0}},
+	"VUCOMISD":    {1, 0x2E, 1, 1, -1, vexRM, [3]int{8, 0, 0}},
+	"VXORPD":      {1, 0x57, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+
+	// EVEX.128/256/512.0F.F3/F2.W0, word shuffles with an immediate
+	// ($imm, src, dst: reg = dst, rm = src, imm8).  The F3/F2 prefixes
+	// split the high/low lane spellings.
+	"VPSHUFHW": {1, 0x70, 0, 2, -1, vexImmRM, [3]int{16, 32, 64}},
+	"VPSHUFLW": {1, 0x70, 0, 3, -1, vexImmRM, [3]int{16, 32, 64}},
+
+	// EVEX.128.66.0F3A, lane extract to a general-purpose register or
+	// memory ($imm, xsrc, GPR/mem dst: reg = source, rm = destination).
+	"VPEXTRB": {3, 0x14, 0, 1, -1, vexExtractGPR, [3]int{1, 1, 1}},
+	"VPEXTRW": {3, 0x15, 0, 1, -1, vexExtractGPR, [3]int{2, 2, 2}},
+	"VPEXTRD": {3, 0x16, 0, 1, -1, vexExtractGPR, [3]int{4, 4, 4}},
+	"VPEXTRQ": {3, 0x16, 1, 1, -1, vexExtractGPR, [3]int{8, 8, 8}},
+
+	// EVEX.66.0F3A.W1, the qword permutes with an immediate control
+	// ($imm, src, dst: reg = dst, rm = src, imm8); the register-count
+	// forms live in evexRegFormTable.
+	"VPERMQ":  {3, 0x00, 1, 1, -1, vexImmRM, [3]int{16, 32, 64}},
+	"VPERMPD": {3, 0x01, 1, 1, -1, vexImmRM, [3]int{16, 32, 64}},
+	// EVEX.66.0F3A, the packed permute shuffles with an immediate control.
+	"VPERMILPS": {3, 0x04, 0, 1, -1, vexImmRM, [3]int{16, 32, 64}},
+	"VPERMILPD": {3, 0x05, 1, 1, -1, vexImmRM, [3]int{16, 32, 64}},
+
+	// EVEX.128.0F.W0, high/low half moves.  VMOVHPS carries the
+	// three-operand insert form (rm = m64 source, vvvv = preserved,
+	// reg = dst) and the two-operand store (reg = source, rm = m64);
+	// the encoder splits on the operand count.  VMOVLHPS is the
+	// three-operand form alone.
+	"VMOVHPS":  {1, 0x16, 0, 0, -1, vexNDS3, [3]int{8, 0, 0}},
+	"VMOVLHPS": {1, 0x16, 0, 0, -1, vexNDS3, [3]int{8, 0, 0}},
+}
+
+// evexQuad describes one quad-register instruction: the opcode under
+// EVEX.0F38.W0 with the F2 mandatory prefix, and the width of the vector
+// registers the bracketed list and the destination take (512-bit ZMM for
+// the packed forms, 128-bit XMM for the scalar ones).
+type evexQuad struct {
+	opcode byte
+	width  int // register width in bytes: 64 (ZMM) or 16 (XMM)
+}
+
+// evexQuadTable maps the quad-register instructions (the 4FMAPS and 4VNNIW
+// families) to their encoding.  The operand shape is fixed: a single memory
+// source in r/m, the bracketed register list whose LOW register travels the
+// inverted 5-bit V'VVVV field, an optional opmask in aaa and the vector
+// destination in reg.  The vector length follows the destination (512-bit
+// for the ZMM list forms, 128-bit for the scalar ones) while the disp8×N
+// multiplier stays 16 for every member, the toolchain's own tuple choice.
+var evexQuadTable = map[string]evexQuad{
+	"V4FMADDPS":  {0x9A, 64},
+	"V4FMADDSS":  {0x9B, 16},
+	"V4FNMADDPS": {0xAA, 64},
+	"V4FNMADDSS": {0xAB, 16},
+	"VP4DPWSSD":  {0x52, 64},
+	"VP4DPWSSDS": {0x53, 64},
+}
+
+// isEvexQuad reports whether the mnemonic is a quad-register instruction.
+func isEvexQuad(upper string) bool {
+	_, ok := evexQuadTable[upper]
+	return ok
+}
+
+// encodeEvexQuad encodes the quad-register form: OP mem, [Zn-Zn+3], (K), dst.
+// The register list is the VVVV-side source: its low register fills the
+// inverted V'VVVV bits, which is why an indexed memory source above Z15 (no
+// spare EVEX.X bit once V' is taken) is refused.  Masking rides the standard
+// aaa field, zeroing keeps the usual requires-a-mask rule, and no other
+// suffix applies.
+func (e *enc) encodeEvexQuad(mnem string, q evexQuad, ops []Operand, sfx evexSuffix) error {
+	if len(ops) != 3 && len(ops) != 4 {
+		return fmt.Errorf("%s expects 3 or 4 operands (mem, [Zn-Zn+3], (K), dst), got %d", mnem, len(ops))
+	}
+	mem, lst := ops[0], ops[1]
+	dst := ops[len(ops)-1]
+	mask := 0
+	if len(ops) == 4 {
+		k, ok := ops[2].(Reg)
+		if !ok || !k.mask {
+			return fmt.Errorf("%s: third operand must be an opmask register", mnem)
+		}
+		if k.idx == 0 {
+			return fmt.Errorf("k0 is not a usable mask register")
+		}
+		mask = k.idx
+	}
+	list, ok := lst.(RegList)
+	if !ok {
+		return fmt.Errorf("%s: second operand must be a four-register list", mnem)
+	}
+	if list.Lo.size != q.width {
+		return fmt.Errorf("%s: the register list must hold %d-bit vector registers", mnem, q.width*8)
+	}
+	dstReg, ok := dst.(Reg)
+	if !ok || !dstReg.isVec() {
+		return fmt.Errorf("%s: destination must be a vector register", mnem)
+	}
+	if dstReg.size != q.width {
+		return fmt.Errorf("%s: the destination must be a %d-bit vector register", mnem, q.width*8)
+	}
+	if !memOperand(mem) {
+		return fmt.Errorf("%s: the source must be a memory operand", mnem)
+	}
+	// The list owns V'VVVV; a scaled index in the EVEX-only half would fold
+	// its fifth bit into the same field the list's low register occupies.
+	if m, ok := mem.(Mem); ok && m.HasIndex && m.Index.idx >= 16 {
+		return fmt.Errorf("%s: an index register above Z15 has no EVEX bit free", mnem)
+	}
+	if sfx.zeroing && mask == 0 {
+		return fmt.Errorf("%s: zeroing (.Z) requires a mask register", mnem)
+	}
+	spec := evexSpec{mapSel: 2, opcode: q.opcode, w: 0, pp: 3, opdigit: -1, n: [3]int{16, 16, 16}}
+	// The vector length follows the destination (512-bit for the ZMM forms,
+	// 128-bit for the scalar ones), exactly as the oracle encodes it.
+	return e.emitEvexFields(spec, dstReg.vecLenBit(), dstReg.idx, list.Lo.idx, mem, mask, sfx)
 }
 
 // evexBcastSpec describes an EVEX broadcast (VPBROADCASTD/Q): the opcode
@@ -529,32 +855,38 @@ type evexMoveSpec struct {
 	n       [3]int
 	vecOK   bool // the non-memory operand may be a vector register
 	xmmOnly bool // wider than XMM registers are rejected
+	nds3    bool // a three-operand register form exists (VMOVSD/VMOVSS)
 }
 
 // evexMoveTable maps an upper-case EVEX move mnemonic to its encoding.
 var evexMoveTable = map[string]evexMoveSpec{
 	// EVEX.128/256/512.F3.0F.W0, unaligned integer move.
-	"VMOVDQU32": {1, 2, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false},
+	"VMOVDQU32": {1, 2, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512.F3.0F.W1, unaligned qword move.
-	"VMOVDQU64": {1, 2, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false},
+	"VMOVDQU64": {1, 2, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512.F2.0F.W0, unaligned byte move (byte/word moves use the
 	// F2 prefix, dword/qword moves F3; the element size only changes the tuple
 	// semantics).
-	"VMOVDQU8": {1, 3, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false},
+	"VMOVDQU8": {1, 3, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512.F2.0F.W1, unaligned word move (shares the qword
 	// encoding).
-	"VMOVDQU16": {1, 3, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false},
+	"VMOVDQU16": {1, 3, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512.66.0F.W1, unaligned packed double move.
-	"VMOVUPD": {1, 1, 0x10, 0x11, 1, [3]int{16, 32, 64}, true, false},
+	"VMOVUPD": {1, 1, 0x10, 0x11, 1, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512, aligned packed moves.
-	"VMOVAPS": {1, 0, 0x28, 0x29, 0, [3]int{16, 32, 64}, true, false},
-	"VMOVAPD": {1, 1, 0x28, 0x29, 1, [3]int{16, 32, 64}, true, false},
+	"VMOVAPS": {1, 0, 0x28, 0x29, 0, [3]int{16, 32, 64}, true, false, false},
+	"VMOVAPD": {1, 1, 0x28, 0x29, 1, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128/256/512.66.0F, aligned integer moves.
-	"VMOVDQA32": {1, 1, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false},
-	"VMOVDQA64": {1, 1, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false},
+	"VMOVDQA32": {1, 1, 0x6F, 0x7F, 0, [3]int{16, 32, 64}, true, false, false},
+	"VMOVDQA64": {1, 1, 0x6F, 0x7F, 1, [3]int{16, 32, 64}, true, false, false},
 	// EVEX.128.F3.0F.W0, scalar single move, memory operands (the
 	// three-operand register form is not supported).
-	"VMOVSS": {1, 2, 0x10, 0x11, 0, [3]int{4, 4, 4}, false, true},
+	"VMOVSS": {1, 2, 0x10, 0x11, 0, [3]int{4, 4, 4}, false, true, true},
+	// EVEX.128.F2.0F.W1, scalar double move: memory operands and the
+	// three-operand register form (VMOVSD dst, src1, src2).
+	"VMOVSD": {1, 3, 0x10, 0x11, 1, [3]int{8, 8, 8}, false, true, true},
+	// EVEX.128/256/512.0F.W0, unaligned packed single move.
+	"VMOVUPS": {1, 0, 0x10, 0x11, 0, [3]int{16, 32, 64}, true, false, false},
 }
 
 // isEvex reports whether the mnemonic has an EVEX encoding we handle.
@@ -565,8 +897,10 @@ func isEvex(mnemUpper string) bool {
 	if _, ok := evexBcastTable[mnemUpper]; ok {
 		return true
 	}
-	_, ok := evexMoveTable[mnemUpper]
-	return ok
+	if _, ok := evexMoveTable[mnemUpper]; ok {
+		return true
+	}
+	return isEvexQuad(mnemUpper)
 }
 
 // evexRequired reports whether the operands force the EVEX encoding of a
@@ -579,6 +913,13 @@ func evexRequired(upper string, ops []Operand) bool {
 	if !inVex && !inVexMove {
 		return true // EVEX-only mnemonic
 	}
+	// The byte-quad shifts have VEX register forms but EVEX-only memory
+	// forms: a memory count source forces the EVEX encoding.
+	if upper == "VPSLLDQ" || upper == "VPSRLDQ" {
+		if slices.ContainsFunc(ops, memOperand) {
+			return true
+		}
+	}
 	for _, op := range ops {
 		if r, ok := op.(Reg); ok && (r.size == 64 || r.mask || (r.isVec() && r.idx >= 16)) {
 			return true
@@ -741,6 +1082,14 @@ func (e *enc) encodeEvex(mnemUpper string, ops []Operand, sfx evexSuffix) error
 		return e.encodeEvexRM(spec, ops, 0, sfx)
 	}
 	spec, inTable := evexTable[mnemUpper]
+	if q, ok := evexQuadTable[mnemUpper]; ok {
+		// The quad-register family carries no rounding, SAE or broadcast;
+		// only masking and zeroing apply.
+		if sfx.sae || sfx.bcst || sfx.rounding >= 0 {
+			return fmt.Errorf("%s takes no rounding/SAE/broadcast suffix", mnemUpper)
+		}
+		return e.encodeEvexQuad(mnemUpper, q, ops, sfx)
+	}
 	if inTable {
 		if (sfx.rounding >= 0 || sfx.sae) && !evexRound[mnemUpper] {
 			return fmt.Errorf("%s: rounding/SAE is not supported for this instruction", mnemUpper)
@@ -752,6 +1101,27 @@ func (e *enc) encodeEvex(mnemUpper string, ops []Operand, sfx evexSuffix) error
 			}
 			spec.n = [3]int{n, n, n}
 		}
+		// A mnemonic with an immediate and a register spelling (the
+		// variable-count shifts, the permutes) encodes the register one
+		// when the first operand is not an immediate.
+		if len(ops) > 0 {
+			if _, isImm := ops[0].(Imm); !isImm {
+				if alt, ok := evexRegFormTable[mnemUpper]; ok {
+					spec, inTable = alt, true
+				}
+			}
+		}
+		// The high/low half moves split by operand count: three operands
+		// insert, two store (VMOVHPS m64, X1).
+		if hs, ok := evexHptrTable[mnemUpper]; ok {
+			if len(ops) == 2 {
+				if hs.store.opcode == 0 {
+					return fmt.Errorf("%s has no two-operand form", mnemUpper)
+				}
+				return e.encodeEvexRMRev(hs.store, ops, 0, sfx)
+			}
+			spec = hs.insert
+		}
 	} else if sfx.evexOnly() {
 		return fmt.Errorf("%s: the instruction does not take rounding/SAE/broadcast suffixes", mnemUpper)
 	}
@@ -811,6 +1181,12 @@ func (e *enc) encodeEvex(mnemUpper string, ops []Operand, sfx evexSuffix) error
 		}
 		return e.encodeEvexMove(mnemUpper, ms, ops, mask, sfx)
 	}
+	if ps, ok := evexPrefGatherTable[mnemUpper]; ok {
+		if sfx.any() {
+			return fmt.Errorf("%s takes no EVEX suffixes", mnemUpper)
+		}
+		return e.encodeEvexPrefGather(mnemUpper, ps, ops, mask, sfx)
+	}
 	if !inTable {
 		return fmt.Errorf("unsupported instruction %q for ZMM/K operands", mnemUpper)
 	}
@@ -829,6 +1205,8 @@ func (e *enc) encodeEvex(mnemUpper string, ops []Operand, sfx evexSuffix) error
 		return e.encodeEvexNDS3Imm(spec, ops, mask, sfx)
 	case vexExtract:
 		return e.encodeEvexExtract(spec, ops, mask, sfx)
+	case vexExtractGPR:
+		return e.encodeEvexExtractGPR(spec, ops, mask, sfx)
 	case vexRMSrcLen:
 		return e.encodeEvexRMSrcLen(spec, ops, mask, sfx)
 	}
@@ -908,6 +1286,11 @@ func (e *enc) encodeEvexImmRM(spec evexSpec, ops []Operand, mask int, sfx evexSu
 	if dstReg.mask {
 		if r, ok := src.(Reg); ok && r.isVec() {
 			ll = r.vecLenBit()
+		} else if l, err := soleLen(spec.n); err == nil {
+			// A memory source with a length-fixed mnemonic
+			// (VFPCLASSPDX/Y/Z): the length comes from the table's
+			// single valid slot, not from the operand.
+			ll = l
 		}
 	} else if r, ok := src.(Reg); ok && r.isVec() {
 		ll = r.vecLenBit()
@@ -934,9 +1317,11 @@ func (e *enc) encodeEvexShiftImm(spec evexSpec, ops []Operand, mask int, sfx eve
 	if !ok {
 		return fmt.Errorf("shift count must be an immediate")
 	}
-	srcReg, ok := src.(Reg)
-	if !ok || !srcReg.isVec() {
-		return fmt.Errorf("shift source must be a vector register")
+	// The count source is a vector register or memory; the length the L'L
+	// field and the disp8×N multiplier follow is the destination's either
+	// way.
+	if !vecOrMem(src) {
+		return fmt.Errorf("shift source must be a vector register or memory")
 	}
 	dstReg, ok := dst.(Reg)
 	if !ok || !dstReg.isVec() {
@@ -946,7 +1331,7 @@ func (e *enc) encodeEvexShiftImm(spec evexSpec, ops []Operand, mask int, sfx eve
 	if err != nil {
 		return err
 	}
-	if err := e.emitEvexFields(spec, dstReg.vecLenBit(), spec.opdigit, dstReg.idx, srcReg, mask, sfx); err != nil {
+	if err := e.emitEvexFields(spec, dstReg.vecLenBit(), spec.opdigit, dstReg.idx, src, mask, sfx); err != nil {
 		return err
 	}
 	e.out = append(e.out, immByte)
@@ -1018,10 +1403,77 @@ func (e *enc) encodeEvexExtract(spec evexSpec, ops []Operand, mask int, sfx evex
 	return nil
 }
 
+// encodeEvexExtractGPR encodes the lane extract to a general-purpose
+// register or memory: OP $imm, xsrc, dst (reg = the XMM source, rm = the
+// destination, imm8).  The encoding is 128-bit regardless of register
+// numbers, so L'L is fixed at 0 and the disp8×N multiplier is the extracted
+// element size the table carries.
+func (e *enc) encodeEvexExtractGPR(spec evexSpec, ops []Operand, mask int, sfx evexSuffix) error {
+	if len(ops) != 3 {
+		return fmt.Errorf("extract expects 3 operands ($imm, xsrc, dst), got %d", len(ops))
+	}
+	imm, src, dst := ops[0], ops[1], ops[2]
+	immVal, ok := imm.(Imm)
+	if !ok {
+		return fmt.Errorf("extract lane must be an immediate")
+	}
+	srcReg, ok := src.(Reg)
+	if !ok || !srcReg.isVec() {
+		return fmt.Errorf("extract source must be a vector register")
+	}
+	switch dst.(type) {
+	case Reg:
+		if dst.(Reg).isVec() {
+			return fmt.Errorf("extract destination must be a general-purpose register or memory")
+		}
+	case Mem, sbMem:
+	default:
+		return fmt.Errorf("extract destination must be a general-purpose register or memory")
+	}
+	immByte, err := imm8(int64(immVal))
+	if err != nil {
+		return err
+	}
+	if err := e.emitEvexFields(spec, 0, srcReg.idx, -1, dst, mask, sfx); err != nil {
+		return err
+	}
+	e.out = append(e.out, immByte)
+	return nil
+}
+
 // encodeEvexMove encodes a two-operand EVEX move; a vector→vector move uses
 // the store-form opcode (reg = source, rm = destination), matching the Go
-// assembler.
+// assembler.  The scalar moves also carry a three-operand register form
+// (VMOVSD dst, src1, src2: the load opcode with vvvv = src1), which ms.nds3
+// opens.
 func (e *enc) encodeEvexMove(mnem string, ms evexMoveSpec, ops []Operand, mask int, sfx evexSuffix) error {
+	if len(ops) == 3 {
+		if !ms.nds3 {
+			return fmt.Errorf("EVEX move expects 2 operands, got %d", len(ops))
+		}
+		// The masked scalar register form keeps the Go assembler's own
+		// layout: the store opcode with reg = op0, vvvv = op1 and the
+		// destination in r/m (op2) — the bytes go tool asm emits, not
+		// the manual's NDS reading.
+		src, src1, dst := ops[0], ops[1], ops[2]
+		reg, ok := src.(Reg)
+		if !ok || !reg.isVec() {
+			return fmt.Errorf("%s: first operand must be a vector register", mnem)
+		}
+		vvvvReg, ok := src1.(Reg)
+		if !ok || !vvvvReg.isVec() {
+			return fmt.Errorf("%s: second operand must be a vector register", mnem)
+		}
+		dstReg, ok := dst.(Reg)
+		if !ok || !dstReg.isVec() {
+			return fmt.Errorf("%s: destination must be a vector register", mnem)
+		}
+		if ms.xmmOnly && (reg.size != 16 || vvvvReg.size != 16 || dstReg.size != 16) {
+			return fmt.Errorf("%s operates on XMM registers only", mnem)
+		}
+		spec := evexSpec{mapSel: ms.mapSel, opcode: ms.store, w: ms.w, pp: ms.pp, opdigit: -1, n: ms.n}
+		return e.emitEvexFields(spec, dstReg.vecLenBit(), reg.idx, vvvvReg.idx, dst, mask, sfx)
+	}
 	if len(ops) != 2 {
 		return fmt.Errorf("EVEX move expects 2 operands, got %d", len(ops))
 	}
@@ -1141,12 +1593,20 @@ func (e *enc) encodeEvexBcast(bs evexBcastSpec, ops []Operand, mask int, sfx eve
 		return fmt.Errorf("broadcast destination must be a vector register")
 	}
 	spec := evexSpec{mapSel: bs.mapSel, w: bs.w, pp: 1, opdigit: -1}
-	switch src.(type) {
+	switch r := src.(type) {
 	case Mem, sbMem:
 		spec.opcode = bs.opMem
 		spec.n = [3]int{bs.n, bs.n, bs.n}
 	case Reg:
-		spec.opcode = bs.opReg
+		// A GPR source uses the register broadcast opcode; a vector
+		// source shares the xmm/mem one (the low byte is copied from
+		// the lane or from the memory operand).
+		if r.isVec() {
+			spec.opcode = bs.opMem
+			spec.n = [3]int{bs.n, bs.n, bs.n}
+		} else {
+			spec.opcode = bs.opReg
+		}
 	default:
 		return fmt.Errorf("broadcast source must be a register or memory")
 	}
@@ -1349,6 +1809,102 @@ func isScatter(upper string) bool {
 	return ok
 }
 
+// isEvexPrefGather reports whether the mnemonic is a gather/scatter
+// prefetch hint.
+func isEvexPrefGather(upper string) bool {
+	_, ok := evexPrefGatherTable[upper]
+	return ok
+}
+
+// evexRegFormTable holds the register-count twin of the immediate-form
+// entries in evexTable.  Several mnemonics name two encodings: an immediate
+// count or control ($imm, src, dst …) and a register-count one whose second
+// operand is a vector register or memory (count, src2, src1, dst).  The
+// immediate spelling lives in evexTable, this table carries the register
+// spelling, and encodeEvex picks by whether the first operand is an
+// immediate, the way vexVarShift does on the VEX side.
+var evexRegFormTable = map[string]evexSpec{
+	"VPSLLD": {1, 0xF2, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSLLQ": {1, 0xF3, 1, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSLLW": {1, 0xF1, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRAD": {1, 0xE2, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRAQ": {1, 0xE2, 1, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRAW": {1, 0xE1, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRLD": {1, 0xD2, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRLQ": {1, 0xD3, 1, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	"VPSRLW": {1, 0xD1, 0, 1, -1, vexNDS3, [3]int{16, 16, 16}},
+	// EVEX.NDS.0F38.W1, the register-count permutes (the immediate
+	// controls live in evexTable under 0F3A).
+	"VPERMQ":  {2, 0x36, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMPD": {2, 0x16, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	// EVEX.NDS.0F38, the register-count permil shuffles.
+	"VPERMILPS": {2, 0x0C, 0, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+	"VPERMILPD": {2, 0x0D, 1, 1, -1, vexNDS3, [3]int{16, 32, 64}},
+}
+
+// evexPrefGatherSpec describes a gather/scatter prefetch hint: one memory
+// operand with a VSIB index and an opmask register, no destination.  The
+// ModRM.reg field carries a fixed /digit, the L'L field is fixed at 512, and
+// the mask register is the instruction's only register operand.
+type evexPrefGatherSpec struct {
+	mapSel  int
+	opcode  byte
+	w       int
+	pp      int
+	opdigit int
+	n       int
+}
+
+var evexPrefGatherTable = map[string]evexPrefGatherSpec{
+	"VGATHERPF0DPD":  {2, 0xC6, 1, 1, 1, 8},
+	"VGATHERPF0DPS":  {2, 0xC6, 0, 1, 1, 4},
+	"VGATHERPF0QPD":  {2, 0xC7, 1, 1, 1, 8},
+	"VGATHERPF0QPS":  {2, 0xC7, 0, 1, 1, 4},
+	"VGATHERPF1DPD":  {2, 0xC6, 1, 1, 2, 8},
+	"VGATHERPF1DPS":  {2, 0xC6, 0, 1, 2, 4},
+	"VGATHERPF1QPD":  {2, 0xC7, 1, 1, 2, 8},
+	"VGATHERPF1QPS":  {2, 0xC7, 0, 1, 2, 4},
+	"VSCATTERPF0DPD": {2, 0xC6, 1, 1, 5, 8},
+	"VSCATTERPF0DPS": {2, 0xC6, 0, 1, 5, 4},
+	"VSCATTERPF0QPD": {2, 0xC7, 1, 1, 5, 8},
+	"VSCATTERPF0QPS": {2, 0xC7, 0, 1, 5, 4},
+	"VSCATTERPF1DPD": {2, 0xC6, 1, 1, 6, 8},
+	"VSCATTERPF1DPS": {2, 0xC6, 0, 1, 6, 4},
+	"VSCATTERPF1QPD": {2, 0xC7, 1, 1, 6, 8},
+	"VSCATTERPF1QPS": {2, 0xC7, 0, 1, 6, 4},
+}
+
+// evexHptrSpec describes the high/low half moves (VMOVHPS family): the
+// three-operand insert shares an opcode with a two-operand store whose
+// source is the vector register and whose destination is m64.
+type evexHptrSpec struct {
+	insert evexSpec
+	store  evexSpec // store.opcode == 0 when the mnemonic has no store form
+}
+
+var evexHptrTable = map[string]evexHptrSpec{
+	"VMOVHPS": {
+		insert: evexSpec{mapSel: 1, opcode: 0x16, w: 0, pp: 0, opdigit: -1, form: vexNDS3, n: [3]int{8, 0, 0}},
+		store:  evexSpec{mapSel: 1, opcode: 0x17, w: 0, pp: 0, opdigit: -1, form: vexRMRev, n: [3]int{8, 0, 0}},
+	},
+	"VMOVLHPS": {
+		insert: evexSpec{mapSel: 1, opcode: 0x16, w: 0, pp: 0, opdigit: -1, form: vexNDS3, n: [3]int{8, 0, 0}},
+	},
+}
+
+// encodeEvexPrefGather encodes a gather/scatter prefetch hint: OP K, vsib.
+func (e *enc) encodeEvexPrefGather(upper string, ps evexPrefGatherSpec, ops []Operand, mask int, sfx evexSuffix) error {
+	if len(ops) != 1 {
+		return fmt.Errorf("%s expects 2 operands (K, vsib memory), got %d", upper, len(ops)+1)
+	}
+	m, ok := ops[0].(Mem)
+	if !ok || !m.HasIndex || !m.Index.isVec() {
+		return fmt.Errorf("%s: operand must be a VSIB memory reference with a vector index", upper)
+	}
+	spec := evexSpec{mapSel: ps.mapSel, opcode: ps.opcode, w: ps.w, pp: ps.pp, opdigit: ps.opdigit, n: [3]int{ps.n, ps.n, ps.n}}
+	return e.emitEvexFields(spec, 2, ps.opdigit, -1, m, mask, sfx)
+}
+
 // vsibLen validates a VSIB memory operand (the index must be a vector
 // register) and returns it with the vector length the index selects, the
 // EVEX L'L field follows the index register, not the data register.
@@ -1370,7 +1926,9 @@ func (e *enc) encodeGather(upper string, gs gatherSpec, ops []Operand, sfx evexS
 		return err
 	}
 	if mask != 0 || sfx.any() {
-		// EVEX form: OP vsib, K, dst.
+		// EVEX form: OP vsib, K, dst.  The L'L field is the wider of the
+		// index and the data register lengths (the Go assembler's
+		// layout); the disp8×N multiplier stays the index element size.
 		if len(rest) != 2 {
 			return fmt.Errorf("%s expects 3 operands (vsib, K, dst), got %d", upper, len(ops))
 		}
@@ -1382,6 +1940,9 @@ func (e *enc) encodeGather(upper string, gs gatherSpec, ops []Operand, sfx evexS
 		if !ok || !dst.isVec() {
 			return fmt.Errorf("%s: destination must be a vector register", upper)
 		}
+		if d := dst.vecLenBit(); d > ll {
+			ll = d
+		}
 		evex := evexSpec{mapSel: 2, opcode: gs.opcode, w: gs.w, pp: 1, opdigit: -1, n: [3]int{gs.n, gs.n, gs.n}}
 		return e.emitEvexFields(evex, ll, dst.idx, -1, vsib, mask, sfx)
 	}
@@ -1431,6 +1992,11 @@ func (e *enc) encodeScatter(upper string, ss gatherSpec, ops []Operand, sfx evex
 	if err != nil {
 		return err
 	}
+	// The L'L field is the wider of the data register and the VSIB index
+	// lengths, the bytes go tool asm emits.
+	if d := src.vecLenBit(); d > ll {
+		ll = d
+	}
 	evex := evexSpec{mapSel: 2, opcode: ss.opcode, w: ss.w, pp: 1, opdigit: -1, n: [3]int{ss.n, ss.n, ss.n}}
 	return e.emitEvexFields(evex, ll, src.idx, -1, vsib, mask, sfx)
 }
@@ -1441,6 +2007,8 @@ func (e *enc) encodeScatter(upper string, ss gatherSpec, ops []Operand, sfx evex
 var evexKOperand = map[string]bool{
 	"VPMOVM2B": true, "VPMOVM2W": true, "VPMOVM2D": true, "VPMOVM2Q": true,
 	"VPMOVB2M": true, "VPMOVW2M": true, "VPMOVD2M": true, "VPMOVQ2M": true,
+	// The K-to-vector broadcast reads its opmask source from r/m.
+	"VPBROADCASTMB2Q": true, "VPBROADCASTMW2D": true,
 }
 
 // kmovSpec describes a KMOV width: the opcode depends on the operand
@@ -1541,6 +2109,7 @@ var kOpsTable = map[string]kOpSpec{
 	"KXORD":    {1, 0x47, 1, 1, 1, vexNDS3},
 	"KXORQ":    {1, 0x47, 1, 0, 1, vexNDS3},
 	"KUNPCKBW": {1, 0x4B, 0, 1, 1, vexNDS3},
+	"KUNPCKWD": {1, 0x4B, 0, 0, 1, vexNDS3},
 	"KUNPCKDQ": {1, 0x4B, 1, 0, 1, vexNDS3},
 	"KADDB":    {1, 0x4A, 0, 1, 1, vexNDS3},
 	"KADDW":    {1, 0x4A, 0, 0, 1, vexNDS3},

asm/evex_test.go

@@ -721,3 +721,216 @@ func hexCompact(b []byte) string {
 	}
 	return string(out)
 }
+
+// TestAvx512CorpusFamilies pins representative encodings of the AVX-512
+// families the toolchain's avx512enc corpus exercises: the bytes are the
+// go tool asm output for exactly these operands, and the same families are
+// covered end to end by the avx512_amd64.s differential kernel.
+func TestAvx512CorpusFamilies(t *testing.T) {
+	vsib := func(base, idx string, scale int) Operand {
+		return Idx(vreg(t, base), vreg(t, idx), scale, 0, 0)
+	}
+	cases := []struct {
+		name string
+		mnem string
+		ops  []Operand
+		want string
+	}{
+		// AES rounds (EVEX NDS, VEX twin routed by operand width).
+		{"VAESDEC Z", "VAESDEC", []Operand{vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "Z3")}, "62f26d48ded9"},
+		// Integer VNNI and the bit algorithm group.
+		{"VPDPBUSD", "VPDPBUSD", []Operand{vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "K2"), vreg(t, "Z3")}, "62f26d4a50d9"},
+		{"VPOPCNTW", "VPOPCNTW", []Operand{vreg(t, "Z1"), vreg(t, "K3"), vreg(t, "Z2")}, "62f2fd4b54d1"},
+		{"VPCONFLICTD", "VPCONFLICTD", []Operand{vreg(t, "Z1"), vreg(t, "K1"), vreg(t, "Z2")}, "62f27d49c4d1"},
+		{"VPLZCNTQ masked", "VPLZCNTQ", []Operand{vreg(t, "Z7"), vreg(t, "K1"), vreg(t, "Z8")}, "6272fd4944c7"},
+		{"VPERMT2B", "VPERMT2B", []Operand{vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "K1"), vreg(t, "Z3")}, "62f26d497dd9"},
+		{"VPMULTISHIFTQB", "VPMULTISHIFTQB", []Operand{vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "K3"), vreg(t, "Z4")}, "62f2ed4b83e1"},
+		{"VDBPSADBW", "VDBPSADBW", []Operand{Imm(3), vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "K3"), vreg(t, "Z3")}, "62f36d4b42d903"},
+		{"VPSHUFBITQMB", "VPSHUFBITQMB", []Operand{vreg(t, "Z9"), vreg(t, "Z10"), vreg(t, "K3")}, "62d22d488fd9"},
+		{"VPTESTNMQ", "VPTESTNMQ", []Operand{vreg(t, "Z13"), vreg(t, "Z14"), vreg(t, "K5")}, "62d28e4827ed"},
+		// Permutations: immediate and register counts.
+		{"VALIGNQ", "VALIGNQ", []Operand{Imm(3), vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "K1"), vreg(t, "Z3")}, "62f3ed4903d903"},
+		{"VPERMQ imm", "VPERMQ", []Operand{Imm(1), vreg(t, "Z1"), vreg(t, "K2"), vreg(t, "Z2")}, "62f3fd4a00d101"},
+		{"VPERMQ reg", "VPERMQ", []Operand{vreg(t, "Z3"), vreg(t, "Z4"), vreg(t, "K2"), vreg(t, "Z5")}, "62f2dd4a36eb"},
+		{"VPERMPD reg", "VPERMPD", []Operand{vreg(t, "Z1"), vreg(t, "Z2"), vreg(t, "Z3")}, "62f2ed4816d9"},
+		{"VPERMILPS imm", "VPERMILPS", []Operand{Imm(5), vreg(t, "Z9"), vreg(t, "K2"), vreg(t, "Z10")}, "62537d4a04d105"},
+		{"VPERMILPS reg", "VPERMILPS", []Operand{vreg(t, "Z11"), vreg(t, "Z12"), vreg(t, "K2"), vreg(t, "Z13")}, "62521d4a0ceb"},
+		// Shifts: immediate, register-count and memory-count forms; the
+		// count source carries its own XMM tuple width.
+		{"VPSLLW imm mask", "VPSLLW", []Operand{Imm(3), vreg(t, "Z1"), vreg(t, "K2"), vreg(t, "Z2")}, "62f16d4a71f103"},
+		{"VPSLLD reg count", "VPSLLD", []Operand{vreg(t, "X1"), vreg(t, "Z2"), vreg(t, "K1"), vreg(t, "Z3")}, "62f16d49f2d9"},
+		{"VPSLLDQ", "VPSLLDQ", []Operand{Imm(9), vreg(t, "Z7"), vreg(t, "Z8")}, "62f13d4873ff09"},
+		{"VPSRLDQ mem", "VPSRLDQ", []Operand{Imm(11), Ptr(SI, 16, 16), vreg(t, "Z4")}, "62f15d48739e100000000b"},
+		{"VPSRLVW", "VPSRLVW", []Operand{vreg(t, "Z3"), vreg(t, "Z4"), vreg(t, "K1"), vreg(t, "Z5")}, "62f2dd4910eb"},
+		// Conversions and shuffles with the F2 prefix and no prefix.
+		{"VCVTUDQ2PS", "VCVTUDQ2PS", []Operand{vreg(t, "Z1"), vreg(t, "K1"), vreg(t, "Z2")}, "62f17f497ad1"},
+		{"VSHUFPS", "VSHUFPS", []Operand{Imm(2), vreg(t, "Z4"), vreg(t, "Z5"), vreg(t, "K1"), vreg(t, "Z6")}, "62f15449c6f402"},
+		// Gather and scatter prefetch hints (memory-only, /digit in reg).
+		{"VGATHERPF0DPD", "VGATHERPF0DPD", []Operand{vreg(t, "K5"), vsib("R10", "Y29", 8)}, "6292fd45c60cea"},
+		{"VSCATTERPF1DPS", "VSCATTERPF1DPS", []Operand{vreg(t, "K2"), vsib("R10", "Z28", 4)}, "62927d42c634a2"},
+		// Opmask broadcasts and the K logic.
+		{"VPBROADCASTMB2Q", "VPBROADCASTMB2Q", []Operand{vreg(t, "K1"), vreg(t, "Z2")}, "62f2fe482ad1"},
+		{"VPBROADCASTMW2D", "VPBROADCASTMW2D", []Operand{vreg(t, "K3"), vreg(t, "Z4")}, "62f27e483ae3"},
+		{"KUNPCKWD", "KUNPCKWD", []Operand{vreg(t, "K6"), vreg(t, "K4"), vreg(t, "K1")}, "c5dc4bce"},
+		{"KADDB", "KADDB", []Operand{vreg(t, "K2"), vreg(t, "K3"), vreg(t, "K5")}, "c5e54aea"},
+		// Lane extracts to general registers (EVEX and VEX routes).
+		{"VPEXTRB", "VPEXTRB", []Operand{Imm(3), vreg(t, "X26"), AX}, "62637d0814d003"},
+		{"VPEXTRD", "VPEXTRD", []Operand{Imm(1), vreg(t, "X26"), vreg(t, "R9")}, "62437d0816d101"},
+		{"VPEXTRD vex", "VPEXTRD", []Operand{Imm(1), vreg(t, "X2"), DI}, "c4e37916d701"},
+		{"VPINSRQ", "VPINSRQ", []Operand{Imm(1), DI, vreg(t, "X3"), vreg(t, "X4")}, "c4e3e122e701"},
+		// Moves: masked unaligned, masked scalar register form, half moves
+		// and non-temporal stores.
+		{"VMOVUPS mask", "VMOVUPS", []Operand{vreg(t, "Z1"), vreg(t, "K2"), vreg(t, "Z3")}, "62f17c4a11cb"},
+		{"VMOVSD 3op", "VMOVSD", []Operand{vreg(t, "X14"), vreg(t, "X5"), vreg(t, "K3"), vreg(t, "X22")}, "6231d70b11f6"},
+		{"VMOVSS 3op", "VMOVSS", []Operand{vreg(t, "X18"), vreg(t, "X3"), vreg(t, "K2"), vreg(t, "X25")}, "6281660a11d1"},
+		{"VMOVHPS insert", "VMOVHPS", []Operand{Ptr(SI, 0, 8), vreg(t, "X18"), vreg(t, "X19")}, "62e16c00161e"},
+		{"VMOVHPS store", "VMOVHPS", []Operand{vreg(t, "X20"), Ptr(SI, 8, 8)}, "62e17c08176601"},
+		{"VMOVLHPS", "VMOVLHPS", []Operand{vreg(t, "X16"), vreg(t, "X5"), vreg(t, "X17")}, "62a1540816c8"},
+		{"VMOVNTDQ", "VMOVNTDQ", []Operand{vreg(t, "Z7"), Ptr(SI, 0, 64)}, "62f17d48e73e"},
+		{"VMOVNTDQA", "VMOVNTDQA", []Operand{Ptr(SI, 64, 64), vreg(t, "Z8")}, "62727d482a4601"},
+		{"VMOVNTPS", "VMOVNTPS", []Operand{vreg(t, "Z9"), Ptr(SI, 0, 64)}, "62717c482b0e"},
+		// Scalar compares with and without the 66 prefix.
+		{"VCOMISD", "VCOMISD", []Operand{vreg(t, "X5"), vreg(t, "X6")}, "c5f92ff5"},
+		{"VUCOMISS", "VUCOMISS", []Operand{vreg(t, "X7"), vreg(t, "X8")}, "c5782ec7"},
+		// Floating point helpers.
+		{"VSQRTSD", "VSQRTSD", []Operand{vreg(t, "X1"), vreg(t, "X2"), vreg(t, "K1"), vreg(t, "X3")}, "62f1ef0951d9"},
+		{"VEXP2PD", "VEXP2PD", []Operand{vreg(t, "Z5"), vreg(t, "K1"), vreg(t, "Z6")}, "62f2fd49c8f5"},
+		{"VRCP28SD", "VRCP28SD", []Operand{vreg(t, "X9"), vreg(t, "X8"), vreg(t, "K1"), vreg(t, "X10")}, "6252bd09cbd1"},
+		{"VBROADCASTF32X2", "VBROADCASTF32X2", []Operand{vreg(t, "X1"), vreg(t, "K1"), vreg(t, "Z2")}, "62f27d4919d1"},
+		{"VPCOMPRESSB", "VPCOMPRESSB", []Operand{vreg(t, "Z1"), vreg(t, "K1"), Ptr(SI, 0, 64)}, "62f27d49630e"},
+	}
+	for _, c := range cases {
+		code, err := Encode(c.mnem, c.ops...)
+		if err != nil {
+			t.Errorf("%s: Encode: %v", c.name, err)
+			continue
+		}
+		if got := hexCompact(code); got != c.want {
+			t.Errorf("%s: got %s, want %s", c.name, got, c.want)
+		}
+	}
+}
+
+// TestEvexQuadRegisterGroundTruth pins the quad-register instructions (the
+// 4FMAPS and 4VNNIW families) byte for byte against go tool asm: the memory
+// source keeps r/m, the bracketed list's LOW register travels the inverted
+// 5-bit V'VVVV field, the destination sits in reg, the opmask rides aaa and
+// the vector length follows the destination (L'L=512 for the ZMM forms,
+// 128 for the scalar ones) while the disp8×N multiplier stays 16 for every
+// member.  The x86 decoder has no view of these forms, so no decode check
+// runs.
+func TestEvexQuadRegisterGroundTruth(t *testing.T) {
+	sp := vreg(t, "RSP")
+	cases := []struct {
+		name string
+		mnem string
+		ops  []Operand
+		want string
+	}{
+		{"V4FMADDPS 17(SP) [Z0-Z3] K2 Z0", "V4FMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f27f4a9a842411000000"},
+		{"V4FMADDPS [Z10-Z13]", "V4FMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z10"), vreg(t, "Z13")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f22f4a9a842411000000"},
+		{"V4FMADDPS [Z20-Z23]", "V4FMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z20"), vreg(t, "Z23")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f25f429a842411000000"},
+		{"V4FMADDPS Z8 dst", "V4FMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "K2"), vreg(t, "Z8")},
+			"62727f4a9a842411000000"},
+		{"V4FMADDPS disp8x16", "V4FMADDPS",
+			[]Operand{Ptr(sp, 64, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f27f4a9a442404"},
+		{"V4FMADDPS unmasked", "V4FMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "Z0")},
+			"62f27f489a842411000000"},
+		{"V4FMADDSS 7(AX) [X0-X3] K5 X22", "V4FMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X0"), vreg(t, "X3")}, vreg(t, "K5"), vreg(t, "X22")},
+			"62e27f0d9bb007000000"},
+		{"V4FMADDSS (DI)", "V4FMADDSS",
+			[]Operand{Ptr(DI, 0, 8), RegList{vreg(t, "X0"), vreg(t, "X3")}, vreg(t, "K5"), vreg(t, "X22")},
+			"62e27f0d9b37"},
+		{"V4FMADDSS [X10-X13]", "V4FMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X10"), vreg(t, "X13")}, vreg(t, "K5"), vreg(t, "X22")},
+			"62e22f0d9bb007000000"},
+		{"V4FMADDSS [X20-X23]", "V4FMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X20"), vreg(t, "X23")}, vreg(t, "K5"), vreg(t, "X22")},
+			"62e25f059bb007000000"},
+		{"V4FMADDSS X30 dst", "V4FMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X0"), vreg(t, "X3")}, vreg(t, "K5"), vreg(t, "X30")},
+			"62627f0d9bb007000000"},
+		{"V4FMADDSS X3 dst", "V4FMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X0"), vreg(t, "X3")}, vreg(t, "K5"), vreg(t, "X3")},
+			"62f27f0d9b9807000000"},
+		{"V4FMADDSS disp8x16", "V4FMADDSS",
+			[]Operand{Ptr(AX, 16, 8), RegList{vreg(t, "X20"), vreg(t, "X23")}, vreg(t, "K5"), vreg(t, "X30")},
+			"62625f059b7001"},
+		{"V4FNMADDPS", "V4FNMADDPS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f27f4aaa842411000000"},
+		{"V4FNMADDSS", "V4FNMADDSS",
+			[]Operand{Ptr(AX, 7, 8), RegList{vreg(t, "X0"), vreg(t, "X3")}, vreg(t, "K5"), vreg(t, "X22")},
+			"62e27f0dabb007000000"},
+		{"VP4DPWSSD", "VP4DPWSSD",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "K2"), vreg(t, "Z0")},
+			"62f27f4a52842411000000"},
+		{"VP4DPWSSDS unmasked", "VP4DPWSSDS",
+			[]Operand{Ptr(sp, 17, 8), RegList{vreg(t, "Z0"), vreg(t, "Z3")}, vreg(t, "Z0")},
+			"62f27f4853842411000000"},
+	}
+	for _, c := range cases {
+		code, err := Encode(c.mnem, c.ops...)
+		if err != nil {
+			t.Errorf("%s: Encode: %v", c.name, err)
+			continue
+		}
+		if got := hexCompact(code); got != c.want {
+			t.Errorf("%s: got %s, want %s", c.name, got, c.want)
+		}
+	}
+}
+
+// TestEvexQuadRegisterErrors pins the operand shapes the toolchain rejects:
+// the register class the list and the destination take is fixed per
+// instruction, the source is memory only, the opmask slot is positional and
+// the list's low register owns V'VVVV.
+func TestEvexQuadRegisterErrors(t *testing.T) {
+	sp := vreg(t, "RSP")
+	list := func(lo, hi string) RegList {
+		return RegList{vreg(t, lo), vreg(t, hi)}
+	}
+	cases := []struct {
+		name string
+		mnem string
+		ops  []Operand
+	}{
+		{"X list on the PS form", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("X0", "X3"), vreg(t, "K2"), vreg(t, "Z0")}},
+		{"Z list on the SS form", "V4FMADDSS",
+			[]Operand{Ptr(AX, 0, 8), list("Z0", "Z3"), vreg(t, "K5"), vreg(t, "X22")}},
+		{"Y destination", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "K2"), vreg(t, "Y0")}},
+		{"register source", "V4FMADDPS",
+			[]Operand{vreg(t, "Z1"), list("Z0", "Z3"), vreg(t, "K2"), vreg(t, "Z0")}},
+		{"non-mask third operand", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "Z4"), vreg(t, "Z0")}},
+		{"k0 mask", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "K0"), vreg(t, "Z0")}},
+		{"K after the destination", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "Z0"), vreg(t, "K2")}},
+		{"zeroing without a mask", "V4FMADDPS.Z",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "Z0")}},
+		{"SAE suffix", "V4FMADDPS.SAE",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3"), vreg(t, "K2"), vreg(t, "Z0")}},
+		{"high index source", "VP4DPWSSD",
+			[]Operand{Idx(DI, vreg(t, "X16"), 1, 0, 8), list("Z0", "Z3"), vreg(t, "K2"), vreg(t, "Z0")}},
+		{"short operand list", "V4FMADDPS",
+			[]Operand{Ptr(sp, 0, 8), list("Z0", "Z3")}},
+	}
+	for _, c := range cases {
+		if _, err := Encode(c.mnem, c.ops...); err == nil {
+			t.Errorf("%s: expected an error, got none", c.name)
+		}
+	}
+}

asm/goobj.go

@@ -463,6 +463,61 @@ func (img *Image) emitGOObject(pkgPath, srcPath string, pre []byte, minLC int, r
 			symRelocs[si] = append(symRelocs[si], rec[:]...)
 		}
 	}
+	// The data symbols' own relocations: the symbol-valued DATA fields
+	// ("DATA s+0(SB)/8, $other(SB)").  The toolchain patches each field
+	// with the target's absolute address through an R_ADDR of the DATA
+	// line's width, on every architecture (the code relocations are
+	// per-architecture PC-relative shapes; a data pointer word is not), so
+	// this mapping bypasses relocField.  The definitions were appended in
+	// DataSyms order, so data symbol i is definition index i.
+	for i, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			if r.Kind != RelAddr {
+				return nil, fmt.Errorf("GOOBJ emission: data symbol %q carries a non-data relocation", d.Name)
+			}
+			var rec [23]byte
+			binary.LittleEndian.PutUint32(rec[0:], uint32(int32(r.Off)))
+			rec[4] = r.Siz
+			binary.LittleEndian.PutUint16(rec[5:], relocAddr)
+			binary.LittleEndian.PutUint64(rec[7:], uint64(r.Addend))
+			switch {
+			case r.External && r.Name == goobjBuiltinMorestack:
+				binary.LittleEndian.PutUint32(rec[15:], pkgIdxBuiltin)
+				binary.LittleEndian.PutUint32(rec[19:], goobjBuiltinMorestackNoctxt)
+			case r.External:
+				pkg, name := splitQualified(r.Name)
+				if pkg == "" {
+					return nil, fmt.Errorf("GOOBJ emission: external symbol %q has no package prefix", r.Name)
+				}
+				pIdx, ok := extPkgIdx[pkg]
+				if !ok {
+					return nil, fmt.Errorf("GOOBJ emission: package %q not resolved", pkg)
+				}
+				sIdx, ok := extSymIdx[pkg+"·"+name]
+				if !ok {
+					return nil, fmt.Errorf("GOOBJ emission: symbol %s·%s not resolved", pkg, name)
+				}
+				binary.LittleEndian.PutUint32(rec[15:], uint32(pIdx))
+				binary.LittleEndian.PutUint32(rec[19:], uint32(sIdx))
+			default:
+				if di, ok := defIdx[r.Name]; ok {
+					binary.LittleEndian.PutUint32(rec[15:], pkgIdxSelf)
+					binary.LittleEndian.PutUint32(rec[19:], uint32(di))
+					break
+				}
+				// A DATA field may hold the address of a TEXT function of
+				// the same file (the rt0 lib entry spelling), which is a
+				// non-package definition.
+				ni, isText := textNpIdx[r.Name]
+				if !isText {
+					return nil, fmt.Errorf("GOOBJ emission: reference to unknown symbol %q", r.Name)
+				}
+				binary.LittleEndian.PutUint32(rec[15:], pkgIdxNone)
+				binary.LittleEndian.PutUint32(rec[19:], uint32(ni))
+			}
+			symRelocs[i] = append(symRelocs[i], rec[:]...)
+		}
+	}
 	// The DWARF symbols' own relocations (the function address references).
 	for _, ds := range dwarfRelocs {
 		for _, r := range ds.relocs {

asm/goobj_test.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // goobjView is a minimal parsed view of a GOOBJ payload, enough to check

asm/guard_test.go

@@ -9,8 +9,8 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // The expected bytes are pinned from `go tool asm` output (Go 1.27, amd64,
@@ -307,12 +307,12 @@ func TestStackGuardBytesLOONG64(t *testing.T) {
 func TestStackGuardGOObjInternalCall(t *testing.T) {
 	for _, tt := range []struct {
 		src      string
-		assemble func(*ast.File) (*Image, error)
+		assemble func(*ast.File, ...AssembleOption) (*Image, error)
 	}{
 		{"g_amd64.s", AssembleFile},
-		{"g_arm64.s", AssembleFileARM64},
-		{"g_riscv64.s", AssembleFileRISCV},
-		{"g_loong64.s", AssembleFileLOONG64},
+		{"g_arm64.s", func(f *ast.File, _ ...AssembleOption) (*Image, error) { return AssembleFileARM64(f) }},
+		{"g_riscv64.s", func(f *ast.File, _ ...AssembleOption) (*Image, error) { return AssembleFileRISCV(f) }},
+		{"g_loong64.s", func(f *ast.File, _ ...AssembleOption) (*Image, error) { return AssembleFileLOONG64(f) }},
 	} {
 		f, errs := parser.Parse(tt.src, "TEXT \u00b7callsmall(SB), $16-0\n\tCALL \u00b7other(SB)\n\tRET\nTEXT \u00b7other(SB), NOSPLIT, $0\n\tRET\n")
 		if len(errs) > 0 {

asm/instrs.go

@@ -65,6 +65,15 @@ var bitTestOp = map[string]int{
 // noOperandTable maps a fixed no-operand mnemonic to its opcode bytes.  The
 // fence names carry their opcode inside the 0F AE /digit group spelled out in
 // full (E8/F0/F8), and PAUSE is F3 90.
+//
+// LOCK, REP and REPN are the prefix statements.  go tool asm encodes each as
+// a standalone one-byte instruction with a PC of its own (F0, F3 and F2
+// respectively), not as a prefix field merged into the next instruction: the
+// statement that follows is encoded unaware of it, and nothing validates
+// that the pairing is a legal one (LOCK before NOP assembles without
+// complaint, each byte pinned against the toolchain).  Because the bytes
+// land in the stream before the following statement anyway, a LOCKed
+// CMPXCHGQ encodes identically to a prefixed form.
 var noOperandTable = map[string][]byte{
 	"CPUID":   {0x0F, 0xA2},
 	"RDTSC":   {0x0F, 0x31},
@@ -78,6 +87,9 @@ var noOperandTable = map[string][]byte{
 	"MFENCE":  {0x0F, 0xAE, 0xF0},
 	"SFENCE":  {0x0F, 0xAE, 0xF8},
 	"UNDEF":   {0x0F, 0x0B},
+	"LOCK":    {0xF0},
+	"REP":     {0xF3},
+	"REPN":    {0xF2},
 }
 
 // --- MOV --------------------------------------------------------------------
@@ -180,6 +192,30 @@ func (e *enc) encodeMov(ops []Operand, size int) error {
 		}
 		return e.emit(i)
 
+	case TLSMem:
+		if !dstIsReg {
+			return fmt.Errorf("MOV: two memory operands")
+		}
+		// MOV r, off(TLS): the segment-prefixed absolute load, reg=dst,
+		// rm=src(tlsMem) through the SIB escape; the disp32 is the TLS slot
+		// offset with its R_TLSLE patch site.
+		i := newInstr(size, []byte{movRR(size)})
+		if err := setRM(i, dstReg, src, size); err != nil {
+			return err
+		}
+		return e.emit(i)
+
+	case SegAbs:
+		if !dstIsReg {
+			return fmt.Errorf("MOV: two memory operands")
+		}
+		// MOV r, 0x30(GS): the segment-absolute load.
+		i := newInstr(size, []byte{movRR(size)})
+		if err := setRM(i, dstReg, src, size); err != nil {
+			return err
+		}
+		return e.emit(i)
+
 	case Imm:
 		if dstIsReg {
 			v := int64(src)
@@ -220,11 +256,24 @@ func (e *enc) encodeMov(ops []Operand, size int) error {
 			i.imm = imm
 			return e.emit(i)
 		}
-		// MOV r/m, imm: 0xC6 (8-bit) / 0xC7 /0.
+		// MOV r/m, imm: 0xC6 (8-bit) / 0xC7 /0.  An immediate in the
+		// destination slot is the absolute-address crash-store spelling,
+		// MOVL $0xf1, 0xf1: the parser reads the trailing bare constant
+		// as an immediate, and the store's disp32 carries the address.
 		op := byte(0xC7)
 		if size == 1 {
 			op = 0xC6
 		}
+		if d, ok := dst.(Imm); ok {
+			i := newInstr(size, []byte{op})
+			setSegAbs(i, 0, SegAbs{Disp: int64(d)})
+			immBytes, err := immediate(int64(src), size, false)
+			if err != nil {
+				return err
+			}
+			i.imm = immBytes
+			return e.emit(i)
+		}
 		i := newInstr(size, []byte{op})
 		if err := setRMDigit(i, 0, dst, size); err != nil {
 			return err
@@ -615,7 +664,16 @@ func (e *enc) encodeDoubleShift(base string, ops []Operand, size int) error {
 func (e *enc) encodeImul(ops []Operand, size int) error {
 	switch len(ops) {
 	case 2:
-		// IMUL r, r/m: 0x0F 0xAF.
+		// Two shapes. The leading-immediate spelling IMUL $imm, r multiplies
+		// r in place (dst = rm = r): the shape GOROOT's clock code writes.
+		// Otherwise IMUL r, r/m: 0x0F 0xAF.
+		if imm, ok := ops[0].(Imm); ok {
+			dstReg, isReg := ops[1].(Reg)
+			if !isReg {
+				return fmt.Errorf("IMUL: destination must be a register")
+			}
+			return e.encodeImulImm(imm, dstReg, dstReg, size)
+		}
 		dstReg, ok := ops[1].(Reg)
 		if !ok {
 			return fmt.Errorf("IMUL: destination must be a register")
@@ -635,29 +693,36 @@ func (e *enc) encodeImul(ops []Operand, size int) error {
 		if !ok {
 			return fmt.Errorf("IMUL: immediate operand expected first")
 		}
-		// Plan 9 order: IMUL $imm, src, dst.
-		if fits8(int64(imm)) {
-			i := newInstr(size, []byte{0x6B})
-			if err := setRM(i, dstReg, ops[1], size); err != nil {
-				return err
-			}
-			i.imm = []byte{byte(int8(imm))}
-			return e.emit(i)
-		}
-		i := newInstr(size, []byte{0x69})
-		if err := setRM(i, dstReg, ops[1], size); err != nil {
-			return err
-		}
-		immBytes, err := immediate(int64(imm), size, false)
-		if err != nil {
-			return err
-		}
-		i.imm = immBytes
-		return e.emit(i)
+		// Plan 9 order: IMUL $imm, src, dst; the source stays a general
+		// r/m operand (setRM takes registers and memory alike).
+		return e.encodeImulImm(imm, ops[1], dstReg, size)
 	}
 	return fmt.Errorf("IMUL expects 2 or 3 operands, got %d", len(ops))
 }
 
+// encodeImulImm emits the immediate multiply: 0x6B with a sign-extended imm8
+// when the value fits, 0x69 with a 32-bit immediate otherwise.
+func (e *enc) encodeImulImm(imm Imm, rm Operand, dst Reg, size int) error {
+	if fits8(int64(imm)) {
+		i := newInstr(size, []byte{0x6B})
+		if err := setRM(i, dst, rm, size); err != nil {
+			return err
+		}
+		i.imm = []byte{byte(int8(imm))}
+		return e.emit(i)
+	}
+	i := newInstr(size, []byte{0x69})
+	if err := setRM(i, dst, rm, size); err != nil {
+		return err
+	}
+	immBytes, err := immediate(int64(imm), size, false)
+	if err != nil {
+		return err
+	}
+	i.imm = immBytes
+	return e.emit(i)
+}
+
 // --- PUSH / POP -------------------------------------------------------------
 
 func (e *enc) encodePushPop(ops []Operand, size int, push bool) error {

asm/integration_test.go

@@ -16,7 +16,7 @@ import (
 
 	"golang.org/x/arch/x86/x86asm"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestAssembleGoFlacAVX2Kernel assembles the whole production AVX2 kernel;
@@ -25,7 +25,7 @@ import (
 func TestAssembleGoFlacAVX2Kernel(t *testing.T) {
 	path := "../../go-libraries/go-flac/avx2_amd64.s"
 	if _, err := os.Stat(path); err != nil {
-		t.Skip("go-libraries repository not present next to gasm-devkit")
+		t.Skip("go-libraries repository not present next to gasm-sdk")
 	}
 	src, err := os.ReadFile(path)
 	if err != nil {
@@ -86,7 +86,7 @@ func TestAssembleGoFlacAVX2Kernel(t *testing.T) {
 func TestAssembleGoFlacAVX512Kernel(t *testing.T) {
 	path := "../../go-libraries/go-flac/avx512_amd64.s"
 	if _, err := os.Stat(path); err != nil {
-		t.Skip("go-libraries repository not present next to gasm-devkit")
+		t.Skip("go-libraries repository not present next to gasm-sdk")
 	}
 	src, err := os.ReadFile(path)
 	if err != nil {

asm/kernels_differential_test.go

@@ -0,0 +1,219 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package asm
+
+import (
+	"bytes"
+	"encoding/binary"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+)
+
+// The differential kernels for the DATA-path and front-end gaps are kept in
+// testdata/verify beside the campaign's other kernels; the verify package's
+// suites are not open to the asm package, so this test is their runner: each
+// kernel assembles through gasm and through go tool asm, and the functions'
+// bytes must agree with the relocation sites masked on both sides.
+
+// toolAsmObject assembles path with the installed toolchain's assembler for
+// goarch ("" = the host) and returns the object bytes.
+func toolAsmObject(t *testing.T, path, goarch string) []byte {
+	t.Helper()
+	goBin, err := exec.LookPath("go")
+	if err != nil {
+		t.Skip("no Go toolchain available")
+	}
+	out, err := exec.Command(goBin, "env", "GOROOT").Output()
+	if err != nil {
+		t.Fatalf("go env GOROOT: %v", err)
+	}
+	includeDir := filepath.Join(strings.TrimSpace(string(out)), "pkg", "include")
+
+	pkg := strings.TrimSuffix(filepath.Base(path), ".s")
+	pkg = strings.TrimSuffix(pkg, "_amd64")
+	pkg = strings.TrimSuffix(pkg, "_arm64")
+
+	objPath := filepath.Join(t.TempDir(), "oracle.o")
+	cmd := exec.Command(goBin, "tool", "asm", "-I", includeDir, "-p", pkg, "-o", objPath, path)
+	if goarch != "" {
+		environ := os.Environ()
+		env := make([]string, 0, len(environ)+1)
+		for _, e := range environ {
+			if !strings.HasPrefix(e, "GOARCH=") {
+				env = append(env, e)
+			}
+		}
+		cmd.Env = append(env, "GOARCH="+goarch)
+	}
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("go tool asm %s: %v\n%s", filepath.Base(path), err, out)
+	}
+	obj, err := os.ReadFile(objPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return obj
+}
+
+// oracleFuncCode extracts the non-package TEXT functions' code bytes from a
+// toolchain object, keyed by the name the object records (pkg.name).  Each
+// function's span is its own symbol size: a toolchain object that follows
+// the text with data symbols (the synthesised float-constant pool) would
+// otherwise fold them into the last function's bytes.
+func oracleFuncCode(t *testing.T, obj []byte) map[string][]byte {
+	t.Helper()
+	v := openGoobj(t, obj)
+	le := binary.LittleEndian
+	const symSize = 21
+	nps := v.syms(blkNonpkgdef)
+	data := v.blk(blkData)
+	didx := v.blk(blkDataIdx)
+	preceding := 0
+	for _, bi := range []int{blkSymdef, blkHashed64def, blkHasheddef} {
+		preceding += len(v.blk(bi)) / symSize
+	}
+	out := make(map[string][]byte, len(nps))
+	for i, s := range nps {
+		if s.typ != kindSTEXT {
+			continue
+		}
+		start := le.Uint32(didx[4*(preceding+i):])
+		out[s.name] = data[start : start+s.size]
+	}
+	return out
+}
+
+// maskCode zeroes every relocation field, the way the toolchain's object
+// leaves them for the linker.
+func maskCode(code []byte, relocs []Reloc) []byte {
+	for _, r := range relocs {
+		for j := r.Off; j < r.Off+4 && j < len(code); j++ {
+			code[j] = 0
+		}
+	}
+	return code
+}
+
+// code assembles src for amd64 and returns the image's code bytes.
+func code(path, src string) []byte {
+	f, errs := parser.Parse(path, src)
+	if len(errs) > 0 {
+		return nil
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		return nil
+	}
+	return img.Code
+}
+
+// TestDifferentialKernels pins the new kernels against the oracle.
+func TestDifferentialKernels(t *testing.T) {
+	if runtime.GOARCH != "amd64" {
+		t.Skip("the amd64 kernels assume an amd64 host assembler default")
+	}
+	for _, k := range []struct {
+		path   string
+		goarch string
+		arm64  bool
+	}{
+		{filepath.Join("..", "testdata", "verify", "datarel_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "divslash_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "semicolons_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "quadreg_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "floatimm_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "bookkeep_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "forms_amd64.s"), "", false},
+		{filepath.Join("..", "testdata", "verify", "datarel_arm64.s"), "arm64", true},
+		{filepath.Join("..", "testdata", "verify", "divslash_arm64.s"), "arm64", true},
+	} {
+		t.Run(filepath.Base(k.path), func(t *testing.T) {
+			src, err := os.ReadFile(k.path)
+			if err != nil {
+				t.Fatalf("read: %v", err)
+			}
+			f, errs := parser.Parse(k.path, string(src))
+			if len(errs) > 0 {
+				t.Fatalf("parse: %v", errs)
+			}
+			var img *Image
+			if k.arm64 {
+				img, err = AssembleFileARM64(f)
+			} else {
+				img, err = AssembleFile(f)
+			}
+			if err != nil {
+				t.Fatalf("assemble: %v", err)
+			}
+			gt := oracleFuncCode(t, toolAsmObject(t, k.path, k.goarch))
+			// The oracle keys its functions by the qualified object name
+			// (pkg.name); match on the local part.
+			byLocal := make(map[string][]byte, len(gt))
+			for name, code := range gt {
+				if _, after, ok := strings.Cut(name, "."); ok {
+					name = after
+				}
+				byLocal[name] = code
+			}
+
+			matched := 0
+			for _, fn := range img.Funcs {
+				gasmCode := maskCode(append([]byte(nil), img.Code[fn.Offset:fn.Offset+fn.Size]...), fn.Relocs)
+				goCode, ok := byLocal[fn.Name]
+				if !ok {
+					t.Errorf("%s: not in ground truth (%d functions: %v)", fn.Name, len(gt), keysOf(byLocal))
+					continue
+				}
+				goCode = maskCode(append([]byte(nil), goCode...), fn.Relocs)
+				cmpLen := min(len(goCode), len(gasmCode))
+				if !bytes.Equal(gasmCode[:cmpLen], goCode[:cmpLen]) {
+					t.Errorf("%s: MISMATCH gasm=%d go=%d bytes\ngasm %x\ngo   %x", fn.Name, len(gasmCode), len(goCode), gasmCode, goCode)
+					continue
+				}
+				for _, b := range goCode[len(gasmCode):] {
+					if b != 0 {
+						t.Errorf("%s: non-zero trailing bytes in go tool asm output", fn.Name)
+						break
+					}
+				}
+				matched++
+				t.Logf("%s: MATCH (%d bytes)", fn.Name, len(gasmCode))
+			}
+			if matched == 0 {
+				t.Fatal("no functions matched")
+			}
+		})
+	}
+}
+
+func keysOf(m map[string][]byte) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}
+
+// TestSemicolonSpellingParity pins that the ';' statement separator changes
+// nothing about the encoding: the one-line spelling assembles to exactly the
+// bytes of the same statements written one per line.
+func TestSemicolonSpellingParity(t *testing.T) {
+	for _, tt := range []struct{ one, two string }{
+		{"\tROLQ $3, DI; ROLQ $13, DI\n", "\tROLQ $3, DI\n\tROLQ $13, DI\n"},
+		{"\tREP; MOVSQ\n", "\tREP\n\tMOVSQ\n"},
+		{"\tXORQ AX, AX; XORQ CX, CX\n", "\tXORQ AX, AX\n\tXORQ CX, CX\n"},
+	} {
+		one := code("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n"+tt.one+"\tRET\n")
+		two := code("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n"+tt.two+"\tRET\n")
+		if !bytes.Equal(one, two) {
+			t.Errorf("semicolon spelling %q: %x, want the two-line bytes %x", tt.one, one, two)
+		}
+	}
+}

asm/l64_goobj_test.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestGOObjectLOONG64Structure checks the emitted loong64 object's blocks:

asm/link.go

@@ -5,10 +5,11 @@ package asm
 
 import (
 	"fmt"
+	"math"
 	"sort"
 	"strconv"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // Image is an assembled file: the function bodies laid out in source order,
@@ -103,6 +104,7 @@ const (
 	RelArm64Branch                      // R_CALLARM64 (BL instruction)
 	RelArm64LDST64                      // R_ARM64_PCREL_LDST64 (ADRP + 64-bit LDR/STR pair)
 	RelLoong64Branch                    // R_CALLLOONG64 (BL instruction)
+	RelAddr                             // R_ADDR: the absolute address of a symbol held in a DATA field
 )
 
 type Reloc struct {
@@ -112,13 +114,17 @@ type Reloc struct {
 	// Addend select the target: the symbol plus the byte offset.  An
 	// External relocation names a symbol no GLOBL in the file defines;
 	// the object-file emitters carry it into the output's relocation
-	// table.
+	// table.  Siz is the width of the patched field and is set only for
+	// data-field relocations (RelAddr, Off relative to the data symbol),
+	// whose width is the DATA line's; code relocations take their width
+	// from the architecture's instruction encoding.
 	Off      int
 	After    int
 	Name     string
 	Addend   int64
 	External bool
 	Kind     RelocKind
+	Siz      uint8
 }
 
 // DataSymbol describes one GLOBL symbol laid out in the data section.
@@ -130,6 +136,11 @@ type DataSymbol struct {
 	Static bool // the <> marker: file-local, not exported
 	Rodata bool // the RODATA flag: read-only data
 	Dupok  bool // the DUPOK flag: duplicate-OK
+	// Relocs carries the symbol-valued DATA initialisers ("DATA s+0(SB)/8,
+	// $other(SB)"): fields of this symbol's data that hold another symbol's
+	// address, resolved by the linker.  Off is relative to the symbol's
+	// data start.
+	Relocs []Reloc
 }
 
 // Bytes returns the whole image: code, then data.
@@ -139,6 +150,18 @@ func (img *Image) Bytes() []byte {
 	return append(out, img.Data...)
 }
 
+// AssembleOption adjusts the file-level assembly context.
+type AssembleOption func(*linkInfo)
+
+// WithGOOS selects the target operating system for the forms that depend on
+// it, the TLS access shape above all: linux and freebsd take the
+// one-instruction form, windows and plan9 keep the two-instruction load.
+func WithGOOS(goos string) AssembleOption {
+	return func(l *linkInfo) {
+		l.goos = goos
+	}
+}
+
 // AssembleFile assembles every TEXT function of a parsed file and lays out
 // its static symbols (GLOBL/DATA) in a data section behind the code.  Each
 // reference to a file-local static symbol becomes a RIP-relative load whose
@@ -146,7 +169,7 @@ func (img *Image) Bytes() []byte {
 // GLOBL defines is recorded as an external relocation (Externals) with its
 // displacement left zero, the object-file emitters resolve it at link
 // time, while the raw image (Bytes) cannot represent it.
-func AssembleFile(f *ast.File) (*Image, error) {
+func AssembleFile(f *ast.File, opts ...AssembleOption) (*Image, error) {
 	dataSyms, err := collectData(f)
 	if err != nil {
 		return nil, err
@@ -155,7 +178,18 @@ func AssembleFile(f *ast.File) (*Image, error) {
 	for _, d := range dataSyms {
 		known[d.name] = true
 	}
+	// TEXT symbols are file-level definitions too: a symbol immediate
+	// ($fn(SB)) may name one, exactly as a data reference names a GLOBL.
+	for _, d := range f.Decls {
+		if t, ok := d.(*ast.Text); ok {
+			known[t.Name.Name] = true
+		}
+	}
 	link := &linkInfo{symbols: known, allowExternal: true}
+	for _, o := range opts {
+		o(link)
+	}
+	poolSeen := map[string]bool{}
 
 	img := &Image{Symbols: map[string]int{}, SourcePath: f.Path}
 	textOff := map[string]int{}
@@ -169,7 +203,26 @@ func AssembleFile(f *ast.File) (*Image, error) {
 		if !ok {
 			continue
 		}
-		code, patches, labels, steps, lines, err := assemble(t, link)
+		code, patches, labels, steps, lines, pool, err := assemble(t, link)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", t.Name.Name, err)
+		}
+		// The pooled floating-point constants join the declared data as
+		// read-only symbols, deduplicated across the file (the toolchain
+		// synthesises the same symbols into its rodata).
+		for _, entry := range pool {
+			if poolSeen[entry.name] {
+				continue
+			}
+			poolSeen[entry.name] = true
+			dataSyms = append(dataSyms, dataSym{
+				name:   entry.name,
+				buf:    entry.data,
+				size:   len(entry.data),
+				rodata: true,
+				dupok:  true,
+			})
+		}
 		if err != nil {
 			return nil, fmt.Errorf("%s: %w", t.Name.Name, err)
 		}
@@ -257,6 +310,22 @@ func AssembleFile(f *ast.File) (*Image, error) {
 			img.Funcs[i].Relocs = append(img.Funcs[i].Relocs, reloc)
 		}
 	}
+	// The data symbols' symbol-valued DATA fields resolve the same way the
+	// code references do: a name the file defines (GLOBL or TEXT) stays an
+	// internal reference the emitters resolve, anything else is external.
+	// img.DataSyms was laid out in dataSyms order, so the indexes line up.
+	for i := range img.DataSyms {
+		for _, r := range dataSyms[i].relocs {
+			reloc := r
+			if _, ok := img.Symbols[reloc.Name]; !ok {
+				if _, ok := textOff[reloc.Name]; !ok {
+					reloc.External = true
+					externals[reloc.Name] = true
+				}
+			}
+			img.DataSyms[i].Relocs = append(img.DataSyms[i].Relocs, reloc)
+		}
+	}
 	for name := range externals {
 		img.Externals = append(img.Externals, name)
 	}
@@ -273,6 +342,10 @@ func AssembleFileRISCV(f *ast.File) (*Image, error) {
 	if err != nil {
 		return nil, err
 	}
+	// The pooled $i64 constants the wide MOV immediate loads refer to join
+	// the declared data as read-only symbols, deduplicated across the file
+	// (the toolchain synthesises the same symbols into its rodata).
+	litSeen := map[string]bool{}
 
 	img := &Image{Symbols: map[string]int{}, SourcePath: f.Path}
 	for _, d := range f.Decls {
@@ -280,10 +353,23 @@ func AssembleFileRISCV(f *ast.File) (*Image, error) {
 		if !ok {
 			continue
 		}
-		code, labels, relocs, lines, spadj, err := assembleRISCV(t)
+		code, labels, relocs, lines, spadj, lits, err := assembleRISCV(t)
 		if err != nil {
 			return nil, fmt.Errorf("%s: %w", t.Name.Name, err)
 		}
+		for _, lit := range lits {
+			if litSeen[lit.Name] {
+				continue
+			}
+			litSeen[lit.Name] = true
+			dataSyms = append(dataSyms, dataSym{
+				name:   lit.Name,
+				buf:    lit.Data,
+				size:   len(lit.Data),
+				rodata: true,
+				dupok:  true,
+			})
+		}
 		fl := FuncLayout{
 			Name:   t.Name.Name,
 			Pkg:    t.Name.Pkg,
@@ -429,6 +515,23 @@ func markExternals(img *Image, dataSyms []dataSym) {
 			}
 		}
 	}
+	// The declared data symbols carry the file's own relocations (the
+	// symbol-valued DATA fields); the layouts appended img.DataSyms in
+	// dataSyms order, so the indexes line up.  The trailing entries (the
+	// pooled arm64 literals) have no source relocations.
+	for i := range img.DataSyms {
+		if i >= len(dataSyms) {
+			break
+		}
+		for _, r := range dataSyms[i].relocs {
+			reloc := r
+			if !known[reloc.Name] {
+				reloc.External = true
+				externals[reloc.Name] = true
+			}
+			img.DataSyms[i].Relocs = append(img.DataSyms[i].Relocs, reloc)
+		}
+	}
 	for name := range externals {
 		img.Externals = append(img.Externals, name)
 	}
@@ -444,6 +547,9 @@ type dataSym struct {
 	static bool
 	rodata bool
 	dupok  bool
+	// relocs are the symbol-valued DATA fields, in declaration order; Off
+	// is relative to the symbol's data start.
+	relocs []Reloc
 }
 
 // collectData gathers the file's static symbols (GLOBL) and their initial
@@ -511,20 +617,79 @@ func collectData(f *ast.File) ([]dataSym, error) {
 		if !ok {
 			return nil, fmt.Errorf("DATA %q: no matching GLOBL", dd.Name.Name)
 		}
-		if dd.Value == nil || !dd.Value.Imm.HasVal {
-			return nil, fmt.Errorf("DATA %q: value must be an integer immediate", dd.Name.Name)
+		if dd.Value == nil {
+			return nil, fmt.Errorf("DATA %q: missing value", dd.Name.Name)
 		}
 		w := dd.Width
-		switch w {
-		case 1, 2, 4, 8:
-		default:
-			return nil, fmt.Errorf("DATA %q: invalid width %d (want 1, 2, 4 or 8)", dd.Name.Name, w)
-		}
 		off := dd.Name.Offset
 		buf := syms[i].buf
 		if off < 0 || off+int64(w) > int64(len(buf)) {
 			return nil, fmt.Errorf("DATA %q+%d/%d exceeds GLOBL size %d", dd.Name.Name, off, w, len(buf))
 		}
+		// A symbol value ("DATA s+0(SB)/8, $other(SB)", the rt0 spelling)
+		// leaves the field zero and records a relocation against the named
+		// symbol: the linker patches the absolute address at this data
+		// offset.  The toolchain emits the same shape, an R_ADDR of the
+		// DATA width with the value's offset as the addend, on every
+		// architecture.
+		if sym := dd.Value.Imm.Sym; !dd.Value.Imm.HasVal && sym != nil {
+			syms[i].relocs = append(syms[i].relocs, Reloc{
+				Off:    int(off),
+				Name:   sym.Name,
+				Addend: sym.Offset,
+				Kind:   RelAddr,
+				Siz:    uint8(w),
+			})
+			continue
+		}
+		// A string or rune value ("DATA s+0(SB)/20, $"text"") writes its
+		// bytes into the field and leaves the rest zero, the toolchain's
+		// WriteString: the declared width must hold every byte, and any
+		// width is legal.
+		if s := dd.Value.Imm.Str; s != "" && !dd.Value.Imm.HasVal {
+			text, err := strconv.Unquote(s)
+			if err != nil {
+				return nil, fmt.Errorf("DATA %q: invalid string value %s", dd.Name.Name, s)
+			}
+			if len(text) > w {
+				return nil, fmt.Errorf("DATA %q: string of %d bytes does not fit width %d", dd.Name.Name, len(text), w)
+			}
+			copy(buf[off:], text)
+			continue
+		}
+		// A floating-point value stores its IEEE-754 bits: /4 the float32
+		// rounding of the parsed double, /8 the full 64 bits, the
+		// toolchain's WriteFloat32 and WriteFloat64.
+		if f := dd.Value.Imm.Float; f != "" && !dd.Value.Imm.HasVal {
+			num, err := strconv.ParseFloat(f, 64)
+			if err != nil {
+				return nil, fmt.Errorf("DATA %q: invalid floating-point value %q", dd.Name.Name, f)
+			}
+			if dd.Value.Imm.Neg {
+				num = -num
+			}
+			var v uint64
+			switch w {
+			case 4:
+				v = uint64(math.Float32bits(float32(num)))
+			case 8:
+				v = math.Float64bits(num)
+			default:
+				return nil, fmt.Errorf("DATA %q: invalid width %d for a float (want 4 or 8)", dd.Name.Name, w)
+			}
+			for j := range w {
+				buf[off+int64(j)] = byte(v >> (8 * j))
+			}
+			continue
+		}
+		if !dd.Value.Imm.HasVal {
+			return nil, fmt.Errorf("DATA %q: value must be an integer immediate or a symbol address", dd.Name.Name)
+		}
+		switch w {
+		case 1, 2, 4, 8:
+		default:
+			return nil, fmt.Errorf("DATA %q: invalid width %d (want 1, 2, 4 or 8)", dd.Name.Name, w)
+		}
 		v := dd.Value.Imm.Val
 		if dd.Value.Imm.Neg {
 			v = -v

asm/link_test.go

@@ -4,10 +4,15 @@
 package asm
 
 import (
+	"encoding/binary"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestAssembleFileStaticData checks the whole-image layout; code, padding
@@ -166,3 +171,323 @@ func TestCollectDataNumericFlags(t *testing.T) {
 		}
 	}
 }
+
+// TestCollectDataSymbolValue covers the symbol-valued DATA field ("DATA
+// s+0(SB)/8, $other(SB)", the rt0 spelling): the field stays zero in the
+// image and the relocation is recorded against the named symbol, whatever
+// the file defines (a TEXT function, a GLOBL) or leaves external.
+func TestCollectDataSymbolValue(t *testing.T) {
+	src := `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-8
+	MOVQ target+0(FP), AX
+	RET
+GLOBL holder(SB), NOPTR, $32
+DATA holder+0(SB)/8, $·Keep(SB)
+DATA holder+8(SB)/8, $·Keep+5(SB)
+DATA holder+16(SB)/8, $holder(SB)
+GLOBL spare(SB), NOPTR, $8
+DATA spare+0(SB)/8, $extvar(SB)
+`
+	f, errs := parser.Parse("f_amd64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	byName := map[string]DataSymbol{}
+	for _, d := range img.DataSyms {
+		byName[d.Name] = d
+	}
+	want := []struct {
+		sym    string
+		off    int
+		name   string
+		addend int64
+		ext    bool
+	}{
+		{"holder", 0, "Keep", 0, false},
+		{"holder", 8, "Keep", 5, false},
+		{"holder", 16, "holder", 0, false},
+		{"spare", 0, "extvar", 0, true},
+	}
+	var flat []struct {
+		sym string
+		r   Reloc
+	}
+	for _, d := range img.DataSyms {
+		for _, r := range d.Relocs {
+			flat = append(flat, struct {
+				sym string
+				r   Reloc
+			}{d.Name, r})
+		}
+	}
+	if len(flat) != len(want) {
+		t.Fatalf("data relocations = %d, want %d", len(flat), len(want))
+	}
+	for i, w := range want {
+		g := flat[i]
+		r := g.r
+		if g.sym != w.sym {
+			t.Errorf("relocation %d sits on %q, want %q", i, g.sym, w.sym)
+			continue
+		}
+		if r.Off != w.off || r.Name != w.name || r.Addend != w.addend || r.External != w.ext {
+			t.Errorf("relocation %d = {+%d %q addend %d ext %v}, want {+%d %q addend %d ext %v}",
+				i, r.Off, r.Name, r.Addend, r.External, w.off, w.name, w.addend, w.ext)
+		}
+		if r.Kind != RelAddr {
+			t.Errorf("relocation %d kind = %v, want RelAddr", i, r.Kind)
+		}
+		if r.Siz != 8 {
+			t.Errorf("relocation %d siz = %d, want 8", i, r.Siz)
+		}
+	}
+	// The fields themselves stay zero: only the linker fills them.
+	for _, b := range img.Data {
+		if b != 0 {
+			t.Fatal("data section is not all zero before relocation")
+		}
+	}
+	if len(img.Externals) != 1 || img.Externals[0] != "extvar" {
+		t.Errorf("Externals = %v, want [extvar]", img.Externals)
+	}
+}
+
+// TestGOObjectDataSymbolReloc pins the GOOBJ record a symbol-valued DATA
+// field produces, against the shape the toolchain emits for the same
+// source: an R_ADDR of the DATA width at the field offset, pkgIdxNone plus
+// the non-package definition index when the target is the file's own TEXT
+// function (the rt0 lib entry spelling).
+func TestGOObjectDataSymbolReloc(t *testing.T) {
+	f, errs := parser.Parse("f_amd64.s", `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-8
+	RET
+GLOBL holder(SB), NOPTR, $16
+DATA holder+0(SB)/8, $·Keep+5(SB)
+`)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	obj, err := img.GOObject("main", "f_amd64.s")
+	if err != nil {
+		t.Fatalf("GOObject: %v", err)
+	}
+	v := openGoobj(t, obj)
+	// Walk every relocation record; the data record is the one of Siz 8
+	// and type R_ADDR.
+	var off, add int64
+	var pkg, sym uint32
+	found := false
+	for data := v.blk(blkReloc); len(data) >= 23; data = data[23:] {
+		if data[4] != 8 || binary.LittleEndian.Uint16(data[5:]) != relocAddr {
+			continue
+		}
+		found = true
+		off = int64(int32(binary.LittleEndian.Uint32(data[0:])))
+		add = int64(binary.LittleEndian.Uint64(data[7:]))
+		pkg = binary.LittleEndian.Uint32(data[15:])
+		sym = binary.LittleEndian.Uint32(data[19:])
+		break
+	}
+	if !found {
+		t.Fatal("no data relocation record in the object")
+	}
+	if off != 0 || add != 5 {
+		t.Errorf("data reloc = {off %d addend %d}, want {off 0 addend 5}", off, add)
+	}
+	if pkg != pkgIdxNone {
+		t.Errorf("data reloc pkg = %#x, want pkgIdxNone (the TEXT function)", pkg)
+	}
+	// The function's non-package definition index: the four pc tables
+	// precede it, so index 4.
+	if sym != 4 {
+		t.Errorf("data reloc sym = %d, want 4", sym)
+	}
+}
+
+// TestGOObjectDataSymbolLink is the end-to-end proof for symbol-valued DATA
+// fields: the gasm object is substituted for the toolchain's and re-linked,
+// then executed, and the linked data word must hold the real address of the
+// function the DATA line named (runtime.FuncForPC identifies it).
+func TestGOObjectDataSymbolLink(t *testing.T) {
+	goBin, err := exec.LookPath("go")
+	if err != nil {
+		t.Skip("no Go toolchain available")
+	}
+	dir := t.TempDir()
+	asmSrc := `#include "textflag.h"
+GLOBL entry(SB), NOPTR, $8
+DATA entry+0(SB)/8, $·keepme(SB)
+
+TEXT ·keepme(SB), NOSPLIT, $0-0
+	RET
+
+TEXT ·entryptr(SB), NOSPLIT, $0-8
+	MOVQ entry+0(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET
+`
+	if err := os.WriteFile(filepath.Join(dir, "main_amd64.s"), []byte(asmSrc), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	mainSrc := `package main
+
+import "runtime"
+
+func keepme()
+func entryptr() uintptr
+
+func main() {
+	pc := entryptr()
+	fn := runtime.FuncForPC(pc)
+	if fn == nil {
+		panic("the entry word does not point at a function")
+	}
+	if fn.Name() != "main.keepme" {
+		panic("the entry word points at " + fn.Name())
+	}
+}
+`
+	if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(mainSrc), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module dlink\n\ngo 1.21\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Capture the build: the package archive's asm object and the link line.
+	build := exec.Command(goBin, "build", "-x", "-work", "-o", filepath.Join(dir, "prog"), ".")
+	build.Dir = dir
+	buildLog, err := build.CombinedOutput()
+	if err != nil {
+		t.Fatalf("baseline build: %v\n%s", err, buildLog)
+	}
+	var work, linkLine, asmObj string
+	for line := range strings.SplitSeq(string(buildLog), "\n") {
+		switch {
+		case strings.HasPrefix(line, "WORK="):
+			work = strings.TrimPrefix(line, "WORK=")
+		case strings.Contains(line, "/asm ") && strings.Contains(line, "main_amd64.s") && !strings.Contains(line, "-gensymabis"):
+			asmObj = fieldAfter(line, "-o")
+		case strings.Contains(line, "/link ") && strings.Contains(line, "-importcfg"):
+			linkLine = line
+		}
+	}
+	if work == "" || asmObj == "" || linkLine == "" {
+		t.Skipf("could not parse build log (work=%q asmObj=%q link=%q)", work, asmObj, linkLine)
+	}
+	defer os.RemoveAll(work)
+	asmObj = strings.ReplaceAll(asmObj, "$WORK", work)
+	linkLine = strings.ReplaceAll(linkLine, "$WORK", work)
+
+	// Assemble the same source with gasm and substitute the object.
+	src, err := os.ReadFile(filepath.Join(dir, "main_amd64.s"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, errs := parser.Parse("main_amd64.s", string(src))
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("AssembleFile: %v", err)
+	}
+	gasmObj, err := img.GOObject("dlink", "main_amd64.s")
+	if err != nil {
+		t.Fatalf("GOObject: %v", err)
+	}
+	if err := os.WriteFile(asmObj, gasmObj, 0o644); err != nil {
+		t.Fatalf("write gasm object: %v", err)
+	}
+	linkCmd := exec.Command("bash", "-c", "cd "+dir+" && "+linkLine)
+	if out, err := linkCmd.CombinedOutput(); err != nil {
+		t.Fatalf("re-link with gasm object: %v\n%s", err, out)
+	}
+
+	// The linked program must run and find the right function behind the
+	// data word.
+	out, err := exec.Command(filepath.Join(dir, "prog")).CombinedOutput()
+	if err != nil {
+		t.Fatalf("linked program failed: %v\n%s", err, out)
+	}
+}
+
+// TestCollectDataFloatAndStringValues covers the non-integer DATA values the
+// runtime's math and asm files use: floating-point initialisers store their
+// IEEE-754 bits (/4 the float32 rounding, /8 the full double) and string
+// initialisers write their bytes zero-padded within the declared width.
+func TestCollectDataFloatAndStringValues(t *testing.T) {
+	src := `#include "textflag.h"
+TEXT ·Keep(SB), NOSPLIT, $0-8
+	RET
+GLOBL vals<>(SB), RODATA, $44
+DATA vals<>+0(SB)/8, $0.5
+DATA vals<>+8(SB)/8, $-1.0
+DATA vals<>+16(SB)/4, $1.5
+DATA vals<>+20(SB)/16, $"call frame too "
+DATA vals<>+36(SB)/4, $"hi"
+`
+	f, errs := parser.Parse("fvals_amd64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFile(f)
+	if err != nil {
+		t.Fatalf("AssembleFile: %v", err)
+	}
+	byName := map[string]DataSymbol{}
+	for _, d := range img.DataSyms {
+		byName[d.Name] = d
+	}
+	d := byName["vals"]
+	if d.Size != 44 {
+		t.Fatalf("vals size = %d, want 44", d.Size)
+	}
+	buf := img.Data[d.Offset : d.Offset+44]
+	// 0.5 = 0x3FE0000000000000, -1.0 = 0xBFF0000000000000 (float64);
+	// 1.5 = 0x3FC00000 (float32).
+	for _, c := range []struct {
+		off  int
+		want []byte
+	}{
+		{0, []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE0, 0x3F}},
+		{8, []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF0, 0xBF}},
+		{16, []byte{0x00, 0x00, 0xC0, 0x3F}},
+		{20, []byte("call frame too ")},
+		{36, []byte{'h', 'i', 0x00, 0x00}},
+	} {
+		if string(buf[c.off:c.off+len(c.want)]) != string(c.want) {
+			t.Errorf("vals+%d: got % x, want % x", c.off, buf[c.off:c.off+len(c.want)], c.want)
+		}
+	}
+}
+
+// TestCollectDataValueErrors pins the value-kind width rules: a float needs
+// width 4 or 8, a string must fit its declared width, and a bad float
+// literal is diagnosed rather than stored.
+func TestCollectDataValueErrors(t *testing.T) {
+	cases := []string{
+		`GLOBL v<>(SB), RODATA, $4
+DATA v<>+0(SB)/1, $0.5`,
+		`GLOBL v<>(SB), RODATA, $2
+DATA v<>+0(SB)/2, $"toolarge"`,
+	}
+	for i, src := range cases {
+		full := "#include \"textflag.h\"\nTEXT ·Keep(SB), NOSPLIT, $0-8\n\tRET\n" + src
+		f, errs := parser.Parse(fmt.Sprintf("verr%d_amd64.s", i), full)
+		if len(errs) > 0 {
+			t.Fatalf("case %d parse: %v", i, errs)
+		}
+		if _, err := AssembleFile(f); err == nil {
+			t.Errorf("case %d: expected an error, got none", i)
+		}
+	}
+}

asm/loong64_assemble.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // assembleLOONG64 assembles a LoongArch (loong64) TEXT function body into
@@ -46,30 +46,70 @@ func assembleLOONG64(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry,
 		spadj = append(spadj, SpadjStep{PC: guardLen + (loong64StoreWords(fi.autosize)+loong64AdjustWords(-int64(fi.autosize)))*4, Value: fi.autosize})
 	}
 
-	// Pass 1: label offsets from the instruction sizes.
-	offsets := map[string]int{}
-	pos := guardLen + len(prologue)
+	// The toolchain's parser counts N(PC) displacements over the source
+	// instructions at a uniform 4 bytes each, so a PC-relative branch
+	// resolves to the instruction N slots away in body order; the resolved
+	// target then participates in layout and loop-head padding like any
+	// branch target.
+	instrs := make([]*ast.Instr, 0, len(t.Body))
 	for _, stmt := range t.Body {
-		switch s := stmt.(type) {
-		case *ast.Label:
-			offsets[s.Name.Text] = pos
-		case *ast.Instr:
-			pos += loong64InstrSize(s, fi)
+		if in, ok := stmt.(*ast.Instr); ok && strings.ToUpper(in.Mnemonic.Text) != "PCALIGN" {
+			instrs = append(instrs, in)
 		}
 	}
-
-	// Pass 2: encode.  The guard prefix precedes the prologue; its branches
-	// target the morestack block at the end of the function, which the first
-	// pass has sized.
-	bodyLen := 0
-	{
-		p := guardLen + len(prologue)
-		for _, stmt := range t.Body {
-			if in, ok := stmt.(*ast.Instr); ok {
-				p += loong64InstrSize(in, fi)
-			}
+	parseIndex := make(map[*ast.Instr]int, len(instrs))
+	for i, in := range instrs {
+		parseIndex[in] = i
+	}
+	pcRelTarget := make(map[*ast.Instr]*ast.Instr)
+	for _, in := range instrs {
+		off, ok := loong64PCRelOffset(in)
+		if !ok {
+			continue
 		}
-		bodyLen = p - (guardLen + len(prologue))
+		tgt := parseIndex[in] + off
+		if tgt < 0 || tgt >= len(instrs) {
+			continue
+		}
+		pcRelTarget[in] = instrs[tgt]
+	}
+
+	// Pass 1: label offsets from the instruction sizes.  PCALIGN contributes
+	// only its padding.  On top of the explicit PCALIGNs, the toolchain pads
+	// every backward-branch target (loop head) to a 16-byte boundary, so the
+	// layout runs to a fixpoint over the alignment set.
+	loopAligns := map[string]bool{}
+	alignInstrs := map[*ast.Instr]bool{}
+	for {
+		offsets, _, pcs, _ := loong64Layout(t, guardLen+len(prologue), fi, loopAligns, alignInstrs)
+		changed := false
+		for _, in := range instrs {
+			// A backward PC-relative target is the resolved instruction.
+			if tgt, ok := pcRelTarget[in]; ok && pcs[tgt] < pcs[in] && !alignInstrs[tgt] {
+				alignInstrs[tgt] = true
+				changed = true
+			}
+			target, ok := loong64BranchTarget(in)
+			if !ok {
+				continue
+			}
+			tOff, ok := offsets[target]
+			if !ok || tOff >= pcs[in] || loopAligns[target] {
+				continue
+			}
+			loopAligns[target] = true
+			changed = true
+		}
+		if !changed {
+			break
+		}
+	}
+	// Final layout with the complete alignment set.
+	offsets, alignPad, pcs, bodyEnd := loong64Layout(t, guardLen+len(prologue), fi, loopAligns, alignInstrs)
+	bodyLen := bodyEnd - (guardLen + len(prologue))
+	pcRelPcs := make(map[*ast.Instr]int, len(pcRelTarget))
+	for in, tgt := range pcRelTarget {
+		pcRelPcs[in] = pcs[tgt]
 	}
 	var out []byte
 	if fi.needSplit {
@@ -84,7 +124,20 @@ func assembleLOONG64(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry,
 		if !ok {
 			continue
 		}
-		code, err := encodeLOONG64Instr(in, pc, offsets, fi, &relocs, resolve)
+		// PCALIGN pads to the requested boundary with andi $0, $0, 0, the
+		// architecture's NOP, and encodes to nothing itself.
+		if strings.ToUpper(in.Mnemonic.Text) == "PCALIGN" {
+			pad := loong64PCAlignPad(pc, in)
+			out = append(out, loong64PadBytes(pad)...)
+			pc += pad
+			continue
+		}
+		// Loop-head alignment padding precedes the instruction.
+		if pad := alignPad[in]; pad > 0 {
+			out = append(out, loong64PadBytes(pad)...)
+			pc += pad
+		}
+		code, err := encodeLOONG64Instr(in, pc, offsets, fi, &relocs, resolve, pcRelPcs)
 		if err != nil {
 			return nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", in.Mnemonic.Text, err)
 		}
@@ -115,6 +168,115 @@ func assembleLOONG64(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry,
 	return out, offsets, relocs, lines, spadj, nil
 }
 
+// loong64PCRelOffset reports the N of a branch operand spelled N(PC): the
+// displacement counted in source instructions from the branch itself.
+func loong64PCRelOffset(instr *ast.Instr) (int, bool) {
+	mnem := strings.ToUpper(instr.Mnemonic.Text)
+	branch := false
+	switch mnem {
+	case "JMP":
+		branch = len(instr.Operands) == 1
+	case "JAL", "CALL", "BL":
+		branch = len(instr.Operands) == 1 || len(instr.Operands) == 2
+	case "BFPT", "BFPF":
+		branch = len(instr.Operands) == 1
+	case "BEQ", "BNE", "BLT", "BGE", "BLTU", "BGEU",
+		"BEQZ", "BNEZ", "BLTZ", "BGEZ", "BLEZ", "BGTZ":
+		branch = len(instr.Operands) >= 2
+	}
+	if !branch {
+		return 0, false
+	}
+	op := instr.Operands[len(instr.Operands)-1]
+	if op.Kind == ast.OpAddr && op.Addr.Sym == nil && op.Addr.Base == "PC" {
+		return int(op.Addr.Offset), true
+	}
+	return 0, false
+}
+
+// loong64Layout walks the function body once and returns the label offsets,
+// the loop-alignment padding due before each instruction (a pad of 0 needs
+// nothing), the pc each instruction starts at (its padding included) and the
+// first pc past the body.  Explicit PCALIGN pads, the alignment pads for the
+// labels in aligns and those for the instructions in alignInstrs (backward
+// PC-relative targets) all contribute, mirroring the toolchain's layout
+// pass.
+func loong64Layout(t *ast.Text, start int, fi loong64FrameInfo, aligns map[string]bool, alignInstrs map[*ast.Instr]bool) (map[string]int, map[*ast.Instr]int, map[*ast.Instr]int, int) {
+	offsets := map[string]int{}
+	alignPad := map[*ast.Instr]int{}
+	pcs := map[*ast.Instr]int{}
+	pos := start
+	pendingAlign := false
+	var pendingNames []string
+	explicit := false
+	for _, stmt := range t.Body {
+		switch s := stmt.(type) {
+		case *ast.Label:
+			if aligns[s.Name.Text] {
+				pendingAlign = true
+			}
+			pendingNames = append(pendingNames, s.Name.Text)
+			// Provisional: a branch to the label lands here unless a loop
+			// alignment pad follows, in which case the label resolves to the
+			// padded instruction (the toolchain's labels bind to the branch
+			// target instruction, which the padding pass precedes).
+			offsets[s.Name.Text] = pos
+		case *ast.Instr:
+			if strings.ToUpper(s.Mnemonic.Text) == "PCALIGN" {
+				pos += loong64PCAlignPad(pos, s)
+				explicit = true
+				continue
+			}
+			if pendingAlign {
+				pendingAlign = false
+				if pos&15 != 0 {
+					alignPad[s] = 16 - pos&15
+				}
+			}
+			if alignInstrs[s] && pos&15 != 0 {
+				alignPad[s] = 16 - pos&15
+			}
+			if !explicit {
+				for _, n := range pendingNames {
+					offsets[n] = pos + alignPad[s]
+				}
+			}
+			pendingNames = nil
+			explicit = false
+			pcs[s] = pos + alignPad[s]
+			pos += alignPad[s] + loong64InstrSize(s, fi)
+		}
+	}
+	return offsets, alignPad, pcs, pos
+}
+
+// loong64BranchTarget reports the local label a branch-like instruction
+// transfers to, the loop-head signal the toolchain derives from backward
+// branch targets.
+func loong64BranchTarget(instr *ast.Instr) (string, bool) {
+	mnem := strings.ToUpper(instr.Mnemonic.Text)
+	ops := instr.Operands
+	var op *ast.Operand
+	switch {
+	case mnem == "JMP" || mnem == "JAL" || mnem == "BFPT" || mnem == "BFPF":
+		if len(ops) != 1 {
+			return "", false
+		}
+		op = ops[0]
+	case mnem == "TEQ" || mnem == "TNE":
+		return "", false
+	case len(ops) >= 2:
+		op = ops[len(ops)-1]
+	default:
+		return "", false
+	}
+	if op.Kind == ast.OpAddr && op.Addr.Sym != nil && op.Addr.Sym.Pseudo == "" &&
+		op.Addr.Base == "" && op.Addr.Sym.Name != "" {
+		return op.Addr.Sym.Name, true
+	}
+	return "", false
+}
+
 // loong64JumpChain precomputes jump-to-jump folding, mirroring the linker's
 // branch-chasing pass: a label whose first instruction is an unconditional
 // local jump redirects its own jumpers to the ultimate target.  The Go
@@ -177,21 +339,55 @@ func l64LabelOK(op *ast.Operand) (string, bool) {
 	return "", false
 }
 
+// l64SubToAdd rewrites the SUB family with an immediate first operand onto
+// its ADD counterpart with the negated immediate: LoongArch has no
+// subtract-immediate instructions, and the toolchain folds SUB $v into the
+// ADD immediate form through the same optab matching (the $0 fold into 3R
+// and the large-constant materialisations included).  The negation is the
+// second result; the operand is left untouched because the size pass
+// normalises the same instruction.
+func l64SubToAdd(mnem string, ops []*ast.Operand) (string, bool) {
+	if len(ops) >= 2 && isImmOperand(ops[0]) {
+		switch mnem {
+		case "SUB":
+			return "ADD", true
+		case "SUBW":
+			return "ADDW", true
+		case "SUBV", "SUBVU":
+			return "ADDV", true
+		}
+	}
+	return mnem, false
+}
+
 // loong64InstrSize returns the encoded size of an instruction: 4 bytes for
 // most, more for the multi-instruction expansions.
 func loong64InstrSize(instr *ast.Instr, fi loong64FrameInfo) int {
 	mnem := strings.ToUpper(instr.Mnemonic.Text)
 	ops := instr.Operands
+	var neg bool
+	mnem, neg = l64SubToAdd(mnem, ops)
 
 	if mnem == "RET" {
 		return len(loong64Return(fi))
 	}
 	switch mnem {
+	case "END", "FUNCDATA", "PCDATA":
+		return 0 // bookkeeping statements contribute no bytes
+	case "GETCALLERPC":
+		return 4 // or rd, r1, r0
+	case "TEQ", "TNE":
+		return 8 // bne/beq over the BREAK, then BREAK
+	case "PRELDX":
+		return 20 // the four-instruction constant materialisation + preldx
 	case "MOV", "MOVB", "MOVH", "MOVW", "MOVV", "MOVBU", "MOVHU", "MOVWU", "MOVF", "MOVD":
 		return loong64MovSize(mnem, ops, fi)
 	case "ADD", "ADDW", "ADDV", "ADDVU", "AND", "OR", "XOR", "SGT", "SGTU":
 		if len(ops) >= 2 && isImmOperand(ops[0]) {
 			v := l64Imm64(ops[0])
+			if neg {
+				v = -v
+			}
 			if v == 0 {
 				return 4 // folds into the 3R form (rk = R0)
 			}
@@ -229,11 +425,50 @@ func loong64InstrSize(instr *ast.Instr, fi loong64FrameInfo) int {
 	return 4
 }
 
+// loong64PCAlignPad returns the padding PCALIGN inserts before the next
+// instruction so that it starts at the requested boundary relative to the
+// function start.  The boundary must be a power of two between 8 and 2048, as
+// the toolchain requires; anything else pads nothing.
+func loong64PCAlignPad(pos int, instr *ast.Instr) int {
+	if len(instr.Operands) != 1 || !isImmOperand(instr.Operands[0]) {
+		return 0
+	}
+	align := int(immFromOperand(instr.Operands[0]))
+	if align < 8 || align > 2048 || align&(align-1) != 0 {
+		return 0
+	}
+	return (align - pos%align) % align
+}
+
+// loong64PadBytes renders PCALIGN padding: the toolchain emits andi $0, $0, 0
+// (the architecture's NOP) for every full 4 bytes of pad.
+func loong64PadBytes(pad int) []byte {
+	nop := l64wordLE(l64irr(l64DualTable["AND"].imm, 0, 0, 0))
+	out := make([]byte, 0, pad/4*len(nop))
+	for i := 0; i < pad/4; i++ {
+		out = append(out, nop...)
+	}
+	return out
+}
+
 // encodeLOONG64Instr encodes a single LoongArch instruction.
-func encodeLOONG64Instr(instr *ast.Instr, pc int, offsets map[string]int, fi loong64FrameInfo, relocs *[]Reloc, resolve func(string) string) ([]byte, error) {
+func encodeLOONG64Instr(instr *ast.Instr, pc int, offsets map[string]int, fi loong64FrameInfo, relocs *[]Reloc, resolve func(string) string, pcRelPcs map[*ast.Instr]int) ([]byte, error) {
 	mnem := strings.ToUpper(instr.Mnemonic.Text)
 	ops := instr.Operands
 
+	// The SUB family with an immediate first operand folds onto the ADD
+	// immediate form with the negated immediate; the negation happens on a
+	// copy of the operand, never on the shared syntax tree.
+	mnem, neg := l64SubToAdd(mnem, ops)
+	if neg {
+		c := *ops[0]
+		c.Imm.Val = -c.Imm.Val
+		ops2 := make([]*ast.Operand, len(ops))
+		ops2[0] = &c
+		copy(ops2[1:], ops[1:])
+		ops = ops2
+	}
+
 	// Pseudo-instructions and the branches first.
 	switch mnem {
 	case "RET":
@@ -249,10 +484,110 @@ func encodeLOONG64Instr(instr *ast.Instr, pc int, offsets map[string]int, fi loo
 			return nil, fmt.Errorf("WORD expects 1 operand, got %d", len(ops))
 		}
 		return l64wordLE(uint32(immFromOperand(ops[0]))), nil
+	case "END", "FUNCDATA", "PCDATA", "GETCALLERPC":
+		// The assembler's bookkeeping statements.  END, FUNCDATA and PCDATA
+		// contribute no bytes, the same shapes GOARCH=loong64 go tool asm
+		// accepts and emits nothing for; GETCALLERPC reads the caller's
+		// address out of R1 (RA) as or rd, r1, r0.
+		switch mnem {
+		case "END":
+			if len(ops) != 0 {
+				return nil, fmt.Errorf("END expects no operands, got %d", len(ops))
+			}
+			return nil, nil
+		case "FUNCDATA":
+			if len(ops) != 2 || !isImmOperand(ops[0]) {
+				return nil, fmt.Errorf("FUNCDATA expects $n, sym(SB)")
+			}
+			return nil, nil
+		case "PCDATA":
+			if len(ops) != 2 || !isImmOperand(ops[0]) || !isImmOperand(ops[1]) {
+				return nil, fmt.Errorf("PCDATA expects $n, $n")
+			}
+			return nil, nil
+		}
+		if len(ops) != 1 || isMemOperand(ops[0]) || loong64RegClass(operandRegName(ops[0])) != l64ClsGR {
+			return nil, fmt.Errorf("GETCALLERPC expects a general register")
+		}
+		rd := loong64RegNum(operandRegName(ops[0]))
+		if rd < 0 {
+			return nil, fmt.Errorf("GETCALLERPC: invalid register operand")
+		}
+		return l64wordLE(l64rrr(l64movRegTable["MOVV"].op, 0, 1, rd)), nil
+	case "NEGW", "NEGV":
+		// The integer negation pseudo is a subtract from zero:
+		// NEGW src, dst → sub.w r0, src, dst.
+		if len(ops) != 2 {
+			return nil, fmt.Errorf("%s expects 2 operands, got %d", mnem, len(ops))
+		}
+		src, dst := l64Reg(ops[0]), l64Reg(ops[1])
+		if src < 0 || dst < 0 {
+			return nil, fmt.Errorf("invalid register operand")
+		}
+		sub := l64InstrTable["SUBW"].op
+		if mnem == "NEGV" {
+			sub = l64InstrTable["SUBV"].op
+		}
+		return l64wordLE(l64rrr(sub, src, 0, dst)), nil
+	case "TEQ", "TNE":
+		// The trap pseudo expands to two instructions: bne/beq rj, rd over
+		// the BREAK (offset 2 instruction units), then BREAK $code.
+		if len(ops) != 2 && len(ops) != 3 {
+			return nil, fmt.Errorf("%s expects 2 or 3 operands, got %d", mnem, len(ops))
+		}
+		code := int(immFromOperand(ops[0]))
+		rj, rd := 0, l64Reg(ops[len(ops)-1])
+		if len(ops) == 3 {
+			rj = l64Reg(ops[1])
+		}
+		if rj < 0 || rd < 0 {
+			return nil, fmt.Errorf("invalid register operand")
+		}
+		bop := l64branchTable["BNE"]
+		if mnem == "TNE" {
+			bop = l64branchTable["BEQ"]
+		}
+		return l64WordsLE(
+			l64irr16(bop, 2, rj, rd),
+			l64i15(l64InstrTable["BREAK"].op, code),
+		), nil
+	case "PRELDX":
+		// preldx offset(Rbase), $n, $hint: the 64-bit descriptor n packs
+		// (addrSeq, blockSize, blockNums, stride); the constant v built from
+		// it materialises in R30 across four instructions, then the preldx.
+		if len(ops) != 3 || !isMemOperand(ops[0]) || !isImmOperand(ops[1]) || !isImmOperand(ops[2]) {
+			return nil, fmt.Errorf("PRELDX expects offset(reg), $n, $hint")
+		}
+		rj := loong64RegNum(ops[0].Addr.Base)
+		if rj < 0 {
+			return nil, fmt.Errorf("invalid register operand")
+		}
+		n := uint64(l64Imm64(ops[1]))
+		hint := int(l64Imm64(ops[2]))
+		addrSeq := (n >> 0) & 0x1
+		blkSize := (n >> 1) & 0x7ff
+		blkNums := (n >> 12) & 0x1ff
+		stride := (n >> 21) & 0xffff
+		v := uint64(ops[0].Addr.Offset)&0xffff + addrSeq<<16 +
+			((blkSize/16)-1)<<20 + (blkNums-1)<<32 + stride<<44
+		const (
+			lu12iw = 0x0a << 25
+			lu32id = 0x0b << 25
+			lu52id = 0x00c << 22
+			ori    = 0x00e << 22
+			preldx = 0x7058 << 15
+		)
+		return l64WordsLE(
+			l64ir(lu12iw, int(uint32(v>>12)), 30),
+			l64irr(ori, int(uint32(v)), 30, 30),
+			l64ir(lu32id, int(uint32(v>>32)), 30),
+			l64irr(lu52id, int(uint32(v>>52)), 30, 30),
+			l64rrr(preldx, 30, rj, hint),
+		), nil
 	case "JMP", "B":
-		return encodeLOONG64Branch(instr, mnem, pc, offsets, false, resolve, relocs)
+		return encodeLOONG64Branch(instr, mnem, pc, offsets, false, resolve, relocs, pcRelPcs)
 	case "JAL", "CALL", "BL":
-		return encodeLOONG64Branch(instr, mnem, pc, offsets, true, resolve, relocs)
+		return encodeLOONG64Branch(instr, mnem, pc, offsets, true, resolve, relocs, pcRelPcs)
 	case "MOV", "MOVB", "MOVH", "MOVW", "MOVV", "MOVBU", "MOVHU", "MOVWU", "MOVF", "MOVD":
 		return encodeLOONG64Mov(instr, mnem, fi, relocs)
 	}
@@ -262,12 +597,12 @@ func encodeLOONG64Instr(instr *ast.Instr, pc int, offsets map[string]int, fi loo
 		if mnem == "JIRL" {
 			return encodeLOONG64Jirl(op, ops)
 		}
-		return encodeLOONG64Branch16(mnem, op, ops, pc, offsets, resolve)
+		return encodeLOONG64Branch16(instr, mnem, op, ops, pc, offsets, resolve, pcRelPcs)
 	}
 	// Single-register branches with 21-bit offsets (BLTZ/BGEZ/BLEZ/BGTZ,
 	// BFPT/BFPF; BEQZ/BNEZ are reached through BEQ/BNE with R0).
 	if op, ok := l64branch21Table[mnem]; ok {
-		return encodeLOONG64Branch21(mnem, op, ops, pc, offsets, resolve)
+		return encodeLOONG64Branch21(instr, mnem, op, ops, pc, offsets, resolve, pcRelPcs)
 	}
 	// B/BL aliases reached only via JMP/JAL above.
 
@@ -533,11 +868,23 @@ func encodeLOONG64Instr(instr *ast.Instr, pc int, offsets map[string]int, fi loo
 //
 //	JMP/B label      → b label            JMP/B (rj) → jirl r0, rj, 0
 //	JAL/CALL/BL label → bl label          JAL/CALL/BL (rj) → jirl r1, rj, 0
-func encodeLOONG64Branch(instr *ast.Instr, mnem string, pc int, offsets map[string]int, link bool, resolve func(string) string, relocs *[]Reloc) ([]byte, error) {
+func encodeLOONG64Branch(instr *ast.Instr, mnem string, pc int, offsets map[string]int, link bool, resolve func(string) string, relocs *[]Reloc, pcRelPcs map[*ast.Instr]int) ([]byte, error) {
 	if len(instr.Operands) != 1 {
 		return nil, fmt.Errorf("%s expects 1 operand, got %d", mnem, len(instr.Operands))
 	}
 	op := instr.Operands[0]
+	// PC-relative displacement: N(PC) resolves to the instruction N slots
+	// away in source order (the toolchain's parse-time count), and the field
+	// carries the final pc distance in instruction units.
+	if op.Addr.Sym == nil && op.Addr.Base == "PC" {
+		targetPc, ok := pcRelPcs[instr]
+		if !ok {
+			return nil, fmt.Errorf("%s: PC-relative target %d out of range", mnem, op.Addr.Offset)
+		}
+		v := (targetPc - pc) >> 2
+		opc := l64jumpTable[mnem]
+		return l64wordLE(l64bbl(opc, v)), nil
+	}
 	if isMemOperand(op) && op.Addr.Base != "" && op.Addr.Index == "" && op.Addr.Sym == nil {
 		// Indirect: (rj) → jirl.
 		rj := loong64RegNum(op.Addr.Base)
@@ -620,16 +967,28 @@ func l64offsetOperand(op *ast.Operand) (int32, bool) {
 // encodeLOONG64Branch16 encodes a 16-bit branch (BEQ/BNE/BLT/BGE/BLTU/BGEU):
 // INSTR rj, rd, label, or INSTR rj, label with rd = R0, which the toolchain
 // turns into the 21-bit BEQZ/BNEZ form when the register is the only operand.
-func encodeLOONG64Branch16(mnem string, op uint32, ops []*ast.Operand, pc int, offsets map[string]int, resolve func(string) string) ([]byte, error) {
+func encodeLOONG64Branch16(instr *ast.Instr, mnem string, op uint32, ops []*ast.Operand, pc int, offsets map[string]int, resolve func(string) string, pcRelPcs map[*ast.Instr]int) ([]byte, error) {
 	if len(ops) != 2 && len(ops) != 3 {
 		return nil, fmt.Errorf("%s expects 2 or 3 operands, got %d", mnem, len(ops))
 	}
-	target := resolve(l64Label(ops[len(ops)-1]))
-	targetOff, ok := offsets[target]
-	if !ok {
-		return nil, fmt.Errorf("undefined label %q%s", target, suggestLabel(target, offsets))
+	var target string
+	var v int
+	lastOp := ops[len(ops)-1]
+	if lastOp.Kind == ast.OpAddr && lastOp.Addr.Sym == nil && lastOp.Addr.Base == "PC" {
+		// N(PC) resolves to the instruction N slots away in source order.
+		targetPc, ok := pcRelPcs[instr]
+		if !ok {
+			return nil, fmt.Errorf("%s: PC-relative target %d out of range", mnem, lastOp.Addr.Offset)
+		}
+		v = (targetPc - pc) >> 2
+	} else {
+		target = resolve(l64Label(lastOp))
+		targetOff, ok := offsets[target]
+		if !ok {
+			return nil, fmt.Errorf("undefined label %q%s", target, suggestLabel(target, offsets))
+		}
+		v = (targetOff - pc) >> 2
 	}
-	v := (targetOff - pc) >> 2
 	if len(ops) == 2 {
 		// Single register: BEQ rj, label → beqz (21-bit), and the BLTZ/
 		// BGEZ-family aliases encoded with rj in the rj field.
@@ -690,33 +1049,55 @@ func encodeLOONG64Branch16(mnem string, op uint32, ops []*ast.Operand, pc int, o
 // BFPT/BFPF use the 21-bit offset form (register in the rj field), while
 // BGTZ/BLEZ, which the toolchain encodes with the register in the rd field
 // and a 16-bit offset, are handled separately.
-func encodeLOONG64Branch21(mnem string, op uint32, ops []*ast.Operand, pc int, offsets map[string]int, resolve func(string) string) ([]byte, error) {
-	if len(ops) != 2 {
+func encodeLOONG64Branch21(instr *ast.Instr, mnem string, op uint32, ops []*ast.Operand, pc int, offsets map[string]int, resolve func(string) string, pcRelPcs map[*ast.Instr]int) ([]byte, error) {
+	isBF := mnem == "BFPT" || mnem == "BFPF"
+	if len(ops) != 2 && !(isBF && (len(ops) == 1 || len(ops) == 2)) {
 		return nil, fmt.Errorf("%s expects 2 operands, got %d", mnem, len(ops))
 	}
-	target := resolve(l64Label(ops[1]))
-	targetOff, ok := offsets[target]
-	if !ok {
-		return nil, fmt.Errorf("undefined label %q%s", target, suggestLabel(target, offsets))
-	}
-	v := (targetOff - pc) >> 2
-	rj := 0 // BFPT/BFPF default to FCC0
-	if mnem != "BFPT" && mnem != "BFPF" {
+	var rj int
+	tgtOp := ops[len(ops)-1]
+	if isBF {
+		// BFPT/BFPF test an FCC condition register, defaulting to FCC0 when
+		// spelled without one.
+		rj = 0
+		if len(ops) == 2 {
+			rj = l64Reg(ops[0])
+			if rj < 0 {
+				return nil, fmt.Errorf("invalid register operand")
+			}
+		}
+	} else {
 		rj = l64Reg(ops[0])
 		if rj < 0 {
 			return nil, fmt.Errorf("invalid register operand")
 		}
 	}
+	var v int
+	if tgtOp.Kind == ast.OpAddr && tgtOp.Addr.Sym == nil && tgtOp.Addr.Base == "PC" {
+		// N(PC) resolves to the instruction N slots away in source order.
+		targetPc, ok := pcRelPcs[instr]
+		if !ok {
+			return nil, fmt.Errorf("%s: PC-relative target %d out of range", mnem, tgtOp.Addr.Offset)
+		}
+		v = (targetPc - pc) >> 2
+	} else {
+		target := resolve(l64Label(tgtOp))
+		targetOff, ok := offsets[target]
+		if !ok {
+			return nil, fmt.Errorf("undefined label %q%s", target, suggestLabel(target, offsets))
+		}
+		v = (targetOff - pc) >> 2
+	}
 	if mnem == "BGTZ" || mnem == "BLEZ" {
 		// The toolchain swaps the register into the rd field and keeps the
 		// 16-bit offset form.
 		if (v<<16)>>16 != v {
-			return nil, fmt.Errorf("branch to %q too far (16-bit range)", target)
+			return nil, fmt.Errorf("branch %d too far (16-bit range)", v)
 		}
 		return l64wordLE(l64irr16(op, v, 0, rj)), nil
 	}
 	if (v<<11)>>11 != v {
-		return nil, fmt.Errorf("branch to %q too far (21-bit range)", target)
+		return nil, fmt.Errorf("branch %d too far (21-bit range)", v)
 	}
 	return l64wordLE(l64ir21(op, v, rj)), nil
 }
@@ -1737,6 +2118,30 @@ func encodeLOONG64Vector(instr *ast.Instr, mnem string, fi loong64FrameInfo) ([]
 		return l64wordLE(l64rr(l64InstrTable[mnem].op, vj, fcc)), true, nil
 	}
 
+	// Four-register forms (vshuf.b): INSTR va, vk, vj, vd.
+	if l64Vec4R[mnem] {
+		if len(ops) != 4 {
+			return nil, true, fmt.Errorf("%s expects 4 operands, got %d", mnem, len(ops))
+		}
+		va, err := vec(ops[0])
+		if err != nil {
+			return nil, true, err
+		}
+		vk, err := vec(ops[1])
+		if err != nil {
+			return nil, true, err
+		}
+		vj, err := vec(ops[2])
+		if err != nil {
+			return nil, true, err
+		}
+		vd, err := vec(ops[3])
+		if err != nil {
+			return nil, true, err
+		}
+		return l64wordLE(l64InstrTable[mnem].op | uint32(va&0x1f)<<15 | uint32(vk&0x1f)<<10 | uint32(vj&0x1f)<<5 | uint32(vd&0x1f)), true, nil
+	}
+
 	// Three-register forms: INSTR vk, vj, vd or INSTR vk, vd (vj = vd).
 	if len(ops) != 2 && len(ops) != 3 {
 		return nil, true, fmt.Errorf("%s expects 2 or 3 operands, got %d", mnem, len(ops))

asm/loong64_encode.go

@@ -278,6 +278,7 @@ const (
 	l64Fpreld                   // preld (2RI12 + 5-bit hint)
 	l64Fvvv                     // 3R vector (LSX/LASX): op | vk<<10 | vj<<5 | vd
 	l64Fvcf                     // vector-to-condition: op | subop<<10 | vj<<5 | fcc
+	l64Fvvvv                    // 4R vector shuffle: op | va<<15 | vk<<10 | vj<<5 | vd
 )
 
 // l64Enc is one instruction's encoding: its bit layout (format) and the
@@ -336,6 +337,10 @@ var l64VecImmInfo = map[string]l64VecImmEnc{}
 // vpcnt.v).
 var l64Vec2R = map[string]bool{}
 
+// l64Vec4R marks the four-operand vector mnemonics (INSTR va, vk, vj, vd,
+// such as vshuf.b).
+var l64Vec4R = map[string]bool{}
+
 // l64VmovqOps holds the VMOVQ/XVMOVQ opcode constants (pre-shifted to bit
 // 15), read off `go tool objdump` of GOARCH=loong64 `go tool asm` kernels.
 type l64VmovqEnc struct {
@@ -445,6 +450,14 @@ func init() {
 		// bank is the FP registers (the toolchain spells it `FFINTDV F0, F1`),
 		// so the entry stays on the 2R integer/FP format.
 		"FFINTDV": 0x474a << 10,
+		// The rest of the scalar conversions (all F-bank, 2R).
+		"FFINTFW": 0x4744 << 10, // ffint.s.w
+		"FFINTFV": 0x4746 << 10, // ffint.s.l
+		"FFINTDW": 0x4748 << 10, // ffint.d.w
+		"FTINTWF": 0x46c1 << 10, // ftint.w.s
+		"FTINTWD": 0x46c2 << 10, // ftint.w.d
+		"FTINTVF": 0x46c9 << 10, // ftint.l.s
+		"FTINTVD": 0x46ca << 10, // ftint.l.d
 	}
 	for m, op := range rr {
 		l64InstrTable[m] = l64Enc{format: l64Frr, op: op}
@@ -568,6 +581,12 @@ func init() {
 		"AMADDDBW": 0x070D4 << 15, "AMADDDBV": 0x070D5 << 15,
 		"AMANDDBW": 0x070D6 << 15, "AMANDDBV": 0x070D7 << 15,
 		"AMORDBW": 0x070D8 << 15, "AMORDBV": 0x070D9 << 15,
+		// The remaining _dbar exchange variants (loong64enc1.s).
+		"AMXORDBW": 0x070DA << 15, "AMXORDBV": 0x070DB << 15,
+		"AMMAXDBW": 0x070DC << 15, "AMMAXDBV": 0x070DD << 15,
+		"AMMINDBW": 0x070DE << 15, "AMMINDBV": 0x070DF << 15,
+		"AMMAXDBWU": 0x070E0 << 15, "AMMAXDBVU": 0x070E1 << 15,
+		"AMMINDBWU": 0x070E2 << 15, "AMMINDBVU": 0x070E3 << 15,
 	}
 	for m, op := range am {
 		l64InstrTable[m] = l64Enc{format: l64Fam, op: op}
@@ -590,6 +609,240 @@ func init() {
 		"XVANDV": {0xEA4C << 15, true}, "XVXORV": {0xEA4E << 15, true},
 		"XVSEQB": {0xE800 << 15, true}, "XVSEQV": {0xE803 << 15, true},
 	}
+
+	// The integer and FP add/subtract families: [X]VADD and [X]VSUB by lane
+	// width, plus the [X]VSADD/[X]VSSUB saturating pairs.
+	// Opcodes transcribed from the toolchain's loong64enc1.s.
+	addsub := map[string]l64Vec3Enc{
+		"VADDB": {0xE014 << 15, false}, "VADDH": {0xE015 << 15, false},
+		"VADDD": {0xE262 << 15, false}, "VADDF": {0xE261 << 15, false},
+		"VADDQ": {0xE25A << 15, false},
+		"VSUBB": {0xE018 << 15, false}, "VSUBH": {0xE019 << 15, false},
+		"VSUBW": {0xE01A << 15, false}, "VSUBV": {0xE01B << 15, false},
+		"VSUBQ": {0xE25B << 15, false},
+		"VSUBF": {0xE265 << 15, false}, "VSUBD": {0xE266 << 15, false},
+		"VSADDB": {0xE08C << 15, false}, "VSADDH": {0xE08D << 15, false},
+		"VSADDW": {0xE08E << 15, false}, "VSADDV": {0xE08F << 15, false},
+		"VSADDBU": {0xE094 << 15, false}, "VSADDHU": {0xE095 << 15, false},
+		"VSADDWU": {0xE096 << 15, false}, "VSADDVU": {0xE097 << 15, false},
+		"VSSUBB": {0xE090 << 15, false}, "VSSUBH": {0xE091 << 15, false},
+		"VSSUBW": {0xE092 << 15, false}, "VSSUBV": {0xE093 << 15, false},
+		"VSSUBBU": {0xE098 << 15, false}, "VSSUBHU": {0xE099 << 15, false},
+		"VSSUBWU": {0xE09A << 15, false}, "VSSUBVU": {0xE09B << 15, false},
+		"XVADDB": {0xE814 << 15, true}, "XVADDH": {0xE815 << 15, true},
+		"XVADDW": {0xE816 << 15, true},
+		"XVADDD": {0xEA62 << 15, true}, "XVADDF": {0xEA61 << 15, true},
+		"XVADDQ": {0xEA5A << 15, true},
+		"XVSUBB": {0xE818 << 15, true}, "XVSUBH": {0xE819 << 15, true},
+		"XVSUBW": {0xE81A << 15, true}, "XVSUBV": {0xE81B << 15, true},
+		"XVSUBQ": {0xEA5B << 15, true},
+		"XVSUBF": {0xEA65 << 15, true}, "XVSUBD": {0xEA66 << 15, true},
+		"XVSADDB": {0xE88C << 15, true}, "XVSADDH": {0xE88D << 15, true},
+		"XVSADDW": {0xE88E << 15, true}, "XVSADDV": {0xE88F << 15, true},
+		"XVSADDBU": {0xE894 << 15, true}, "XVSADDHU": {0xE895 << 15, true},
+		"XVSADDWU": {0xE896 << 15, true}, "XVSADDVU": {0xE897 << 15, true},
+		"XVSSUBB": {0xE890 << 15, true}, "XVSSUBH": {0xE891 << 15, true},
+		"XVSSUBW": {0xE892 << 15, true}, "XVSSUBV": {0xE893 << 15, true},
+		"XVSSUBBU": {0xE898 << 15, true}, "XVSSUBHU": {0xE899 << 15, true},
+		"XVSSUBWU": {0xE89A << 15, true}, "XVSSUBVU": {0xE89B << 15, true},
+	}
+
+	// The multiply families: plain and high-half [X]VMUL/[X]VMUH, the
+	// widening [X]VMULW{EV,OD} ladder and its accumulating [X]VMADDW twins,
+	// plus the [X]VMADD/[X]VMSUB fused multiply-add and the [X]VDIV/[X]VMOD
+	// divide and modulo pairs.
+	muldiv := map[string]l64Vec3Enc{
+		"VMULB": {0xE108 << 15, false}, "VMULH": {0xE109 << 15, false},
+		"VMULW": {0xE10A << 15, false}, "VMULV": {0xE10B << 15, false},
+		"VMUHB": {0xE10C << 15, false}, "VMUHH": {0xE10D << 15, false},
+		"VMUHW": {0xE10E << 15, false}, "VMUHV": {0xE10F << 15, false},
+		"VMUHBU": {0xE110 << 15, false}, "VMUHHU": {0xE111 << 15, false},
+		"VMUHWU": {0xE112 << 15, false}, "VMUHVU": {0xE113 << 15, false},
+		"VMULWEVHB": {0xE120 << 15, false}, "VMULWEVWH": {0xE121 << 15, false},
+		"VMULWEVVW": {0xE122 << 15, false}, "VMULWEVQV": {0xE123 << 15, false},
+		"VMULWODHB": {0xE124 << 15, false}, "VMULWODWH": {0xE125 << 15, false},
+		"VMULWODVW": {0xE126 << 15, false}, "VMULWODQV": {0xE127 << 15, false},
+		"VMULWEVHBU": {0xE130 << 15, false}, "VMULWEVWHU": {0xE131 << 15, false},
+		"VMULWEVVWU": {0xE132 << 15, false}, "VMULWEVQVU": {0xE133 << 15, false},
+		"VMULWODHBU": {0xE134 << 15, false}, "VMULWODWHU": {0xE135 << 15, false},
+		"VMULWODVWU": {0xE136 << 15, false}, "VMULWODQVU": {0xE137 << 15, false},
+		"VMULWEVHBUB": {0xE140 << 15, false}, "VMULWEVWHUH": {0xE141 << 15, false},
+		"VMULWEVVWUW": {0xE142 << 15, false}, "VMULWEVQVUV": {0xE143 << 15, false},
+		"VMULWODHBUB": {0xE144 << 15, false}, "VMULWODWHUH": {0xE145 << 15, false},
+		"VMULWODVWUW": {0xE146 << 15, false}, "VMULWODQVUV": {0xE147 << 15, false},
+		"VMADDB": {0xE150 << 15, false}, "VMADDH": {0xE151 << 15, false},
+		"VMADDW": {0xE152 << 15, false}, "VMADDV": {0xE153 << 15, false},
+		"VMSUBB": {0xE154 << 15, false}, "VMSUBH": {0xE155 << 15, false},
+		"VMSUBW": {0xE156 << 15, false}, "VMSUBV": {0xE157 << 15, false},
+		"VMADDWEVHB": {0xE158 << 15, false}, "VMADDWEVWH": {0xE159 << 15, false},
+		"VMADDWEVVW": {0xE15A << 15, false}, "VMADDWEVQV": {0xE15B << 15, false},
+		"VMADDWODHB": {0xE15C << 15, false}, "VMADDWODWH": {0xE15D << 15, false},
+		"VMADDWODVW": {0xE15E << 15, false}, "VMADDWODQV": {0xE15F << 15, false},
+		"VMADDWEVHBU": {0xE168 << 15, false}, "VMADDWEVWHU": {0xE169 << 15, false},
+		"VMADDWEVVWU": {0xE16A << 15, false}, "VMADDWEVQVU": {0xE16B << 15, false},
+		"VMADDWODHBU": {0xE16C << 15, false}, "VMADDWODWHU": {0xE16D << 15, false},
+		"VMADDWODVWU": {0xE16E << 15, false}, "VMADDWODQVU": {0xE16F << 15, false},
+		"VMADDWEVHBUB": {0xE178 << 15, false}, "VMADDWEVWHUH": {0xE179 << 15, false},
+		"VMADDWEVVWUW": {0xE17A << 15, false}, "VMADDWEVQVUV": {0xE17B << 15, false},
+		"VMADDWODHBUB": {0xE17C << 15, false}, "VMADDWODWHUH": {0xE17D << 15, false},
+		"VMADDWODVWUW": {0xE17E << 15, false}, "VMADDWODQVUV": {0xE17F << 15, false},
+		"VDIVB": {0xE1C0 << 15, false}, "VDIVH": {0xE1C1 << 15, false},
+		"VDIVW": {0xE1C2 << 15, false}, "VDIVV": {0xE1C3 << 15, false},
+		"VMODB": {0xE1C4 << 15, false}, "VMODH": {0xE1C5 << 15, false},
+		"VMODW": {0xE1C6 << 15, false}, "VMODV": {0xE1C7 << 15, false},
+		"VDIVBU": {0xE1C8 << 15, false}, "VDIVHU": {0xE1C9 << 15, false},
+		"VDIVWU": {0xE1CA << 15, false}, "VDIVVU": {0xE1CB << 15, false},
+		"VMODBU": {0xE1CC << 15, false}, "VMODHU": {0xE1CD << 15, false},
+		"VMODWU": {0xE1CE << 15, false}, "VMODVU": {0xE1CF << 15, false},
+		"VMULF": {0xE271 << 15, false}, "VMULD": {0xE272 << 15, false},
+		"VDIVF": {0xE275 << 15, false}, "VDIVD": {0xE276 << 15, false},
+		"XVMULB": {0xE908 << 15, true}, "XVMULH": {0xE909 << 15, true},
+		"XVMULW": {0xE90A << 15, true}, "XVMULV": {0xE90B << 15, true},
+		"XVMUHB": {0xE90C << 15, true}, "XVMUHH": {0xE90D << 15, true},
+		"XVMUHW": {0xE90E << 15, true}, "XVMUHV": {0xE90F << 15, true},
+		"XVMUHBU": {0xE910 << 15, true}, "XVMUHHU": {0xE911 << 15, true},
+		"XVMUHWU": {0xE912 << 15, true}, "XVMUHVU": {0xE913 << 15, true},
+		"XVMULWEVHB": {0xE920 << 15, true}, "XVMULWEVWH": {0xE921 << 15, true},
+		"XVMULWEVVW": {0xE922 << 15, true}, "XVMULWEVQV": {0xE923 << 15, true},
+		"XVMULWODHB": {0xE924 << 15, true}, "XVMULWODWH": {0xE925 << 15, true},
+		"XVMULWODVW": {0xE926 << 15, true}, "XVMULWODQV": {0xE927 << 15, true},
+		"XVMULWEVHBU": {0xE930 << 15, true}, "XVMULWEVWHU": {0xE931 << 15, true},
+		"XVMULWEVVWU": {0xE932 << 15, true}, "XVMULWEVQVU": {0xE933 << 15, true},
+		"XVMULWODHBU": {0xE934 << 15, true}, "XVMULWODWHU": {0xE935 << 15, true},
+		"XVMULWODVWU": {0xE936 << 15, true}, "XVMULWODQVU": {0xE937 << 15, true},
+		"XVMULWEVHBUB": {0xE940 << 15, true}, "XVMULWEVWHUH": {0xE941 << 15, true},
+		"XVMULWEVVWUW": {0xE942 << 15, true}, "XVMULWEVQVUV": {0xE943 << 15, true},
+		"XVMULWODHBUB": {0xE944 << 15, true}, "XVMULWODWHUH": {0xE945 << 15, true},
+		"XVMULWODVWUW": {0xE946 << 15, true}, "XVMULWODQVUV": {0xE947 << 15, true},
+		"XVMADDB": {0xE950 << 15, true}, "XVMADDH": {0xE951 << 15, true},
+		"XVMADDW": {0xE952 << 15, true}, "XVMADDV": {0xE953 << 15, true},
+		"XVMSUBB": {0xE954 << 15, true}, "XVMSUBH": {0xE955 << 15, true},
+		"XVMSUBW": {0xE956 << 15, true}, "XVMSUBV": {0xE957 << 15, true},
+		"XVMADDWEVHB": {0xE958 << 15, true}, "XVMADDWEVWH": {0xE959 << 15, true},
+		"XVMADDWEVVW": {0xE95A << 15, true}, "XVMADDWEVQV": {0xE95B << 15, true},
+		"XVMADDWODHB": {0xE95C << 15, true}, "XVMADDWODWH": {0xE95D << 15, true},
+		"XVMADDWODVW": {0xE95E << 15, true}, "XVMADDWODQV": {0xE95F << 15, true},
+		"XVMADDWEVHBU": {0xE968 << 15, true}, "XVMADDWEVWHU": {0xE969 << 15, true},
+		"XVMADDWEVVWU": {0xE96A << 15, true}, "XVMADDWEVQVU": {0xE96B << 15, true},
+		"XVMADDWODHBU": {0xE96C << 15, true}, "XVMADDWODWHU": {0xE96D << 15, true},
+		"XVMADDWODVWU": {0xE96E << 15, true}, "XVMADDWODQVU": {0xE96F << 15, true},
+		"XVMADDWEVHBUB": {0xE978 << 15, true}, "XVMADDWEVWHUH": {0xE979 << 15, true},
+		"XVMADDWEVVWUW": {0xE97A << 15, true}, "XVMADDWEVQVUV": {0xE97B << 15, true},
+		"XVMADDWODHBUB": {0xE97C << 15, true}, "XVMADDWODWHUH": {0xE97D << 15, true},
+		"XVMADDWODVWUW": {0xE97E << 15, true}, "XVMADDWODQVUV": {0xE97F << 15, true},
+		"XVDIVB": {0xE9C0 << 15, true}, "XVDIVH": {0xE9C1 << 15, true},
+		"XVDIVW": {0xE9C2 << 15, true}, "XVDIVV": {0xE9C3 << 15, true},
+		"XVMODB": {0xE9C4 << 15, true}, "XVMODH": {0xE9C5 << 15, true},
+		"XVMODW": {0xE9C6 << 15, true}, "XVMODV": {0xE9C7 << 15, true},
+		"XVDIVBU": {0xE9C8 << 15, true}, "XVDIVHU": {0xE9C9 << 15, true},
+		"XVDIVWU": {0xE9CA << 15, true}, "XVDIVVU": {0xE9CB << 15, true},
+		"XVMODBU": {0xE9CC << 15, true}, "XVMODHU": {0xE9CD << 15, true},
+		"XVMODWU": {0xE9CE << 15, true}, "XVMODVU": {0xE9CF << 15, true},
+		"XVMULF": {0xEA71 << 15, true}, "XVMULD": {0xEA72 << 15, true},
+		"XVDIVF": {0xEA75 << 15, true}, "XVDIVD": {0xEA76 << 15, true},
+	}
+
+	// The lane-wise shifts and rotates (three-register forms; the immediate
+	// forms live in l64VecImmInfo), the interleave families, the bit
+	// clear/set/rev register forms, the remaining logic and compare
+	// spellings, the widening add/subtract ladder and the vector FP
+	// arithmetic.
+	vecmisc := map[string]l64Vec3Enc{
+		"VSLLB": {0xE1D0 << 15, false}, "VSLLH": {0xE1D1 << 15, false},
+		"VSLLW": {0xE1D2 << 15, false}, "VSLLV": {0xE1D3 << 15, false},
+		"VSRLB": {0xE1D4 << 15, false}, "VSRLH": {0xE1D5 << 15, false},
+		"VSRLW": {0xE1D6 << 15, false}, "VSRLV": {0xE1D7 << 15, false},
+		"VSRAH": {0xE1D9 << 15, false}, "VSRAW": {0xE1DA << 15, false},
+		"VSRAV":  {0xE1DB << 15, false},
+		"VROTRB": {0xE1DC << 15, false}, "VROTRH": {0xE1DD << 15, false},
+		"VROTRV": {0xE1DF << 15, false},
+		"VILVLB": {0xE234 << 15, false}, "VILVLH": {0xE235 << 15, false},
+		"VILVLW": {0xE236 << 15, false}, "VILVLV": {0xE237 << 15, false},
+		"VILVHB": {0xE238 << 15, false}, "VILVHH": {0xE239 << 15, false},
+		"VILVHW": {0xE23A << 15, false}, "VILVHV": {0xE23B << 15, false},
+		"VBITCLRB": {0xE218 << 15, false}, "VBITCLRH": {0xE219 << 15, false},
+		"VBITCLRW": {0xE21A << 15, false}, "VBITCLRV": {0xE21B << 15, false},
+		"VBITSETB": {0xE21C << 15, false}, "VBITSETH": {0xE21D << 15, false},
+		"VBITSETW": {0xE21E << 15, false}, "VBITSETV": {0xE21F << 15, false},
+		"VBITREVB": {0xE220 << 15, false}, "VBITREVH": {0xE221 << 15, false},
+		"VBITREVW": {0xE222 << 15, false}, "VBITREVV": {0xE223 << 15, false},
+		"VORV": {0xE24D << 15, false}, "VNORV": {0xE24F << 15, false},
+		"VANDNV": {0xE250 << 15, false}, "VORNV": {0xE251 << 15, false},
+		"VSEQH": {0xE001 << 15, false}, "VSEQW": {0xE002 << 15, false},
+		"VSLTB": {0xE00C << 15, false}, "VSLTH": {0xE00D << 15, false},
+		"VSLTW": {0xE00E << 15, false}, "VSLTV": {0xE00F << 15, false},
+		"VSLTBU": {0xE010 << 15, false}, "VSLTHU": {0xE011 << 15, false},
+		"VSLTWU": {0xE012 << 15, false}, "VSLTVU": {0xE013 << 15, false},
+		"VADDWEVHB": {0xE03C << 15, false}, "VADDWEVWH": {0xE03D << 15, false},
+		"VADDWEVVW": {0xE03E << 15, false}, "VADDWEVQV": {0xE03F << 15, false},
+		"VSUBWEVHB": {0xE040 << 15, false}, "VSUBWEVWH": {0xE041 << 15, false},
+		"VSUBWEVVW": {0xE042 << 15, false}, "VSUBWEVQV": {0xE043 << 15, false},
+		"VADDWODHB": {0xE044 << 15, false}, "VADDWODWH": {0xE045 << 15, false},
+		"VADDWODVW": {0xE046 << 15, false}, "VADDWODQV": {0xE047 << 15, false},
+		"VSUBWODHB": {0xE048 << 15, false}, "VSUBWODWH": {0xE049 << 15, false},
+		"VSUBWODVW": {0xE04A << 15, false}, "VSUBWODQV": {0xE04B << 15, false},
+		"VSUBWEVHBU": {0xE060 << 15, false}, "VSUBWEVWHU": {0xE061 << 15, false},
+		"VSUBWEVVWU": {0xE062 << 15, false}, "VSUBWEVQVU": {0xE063 << 15, false},
+		"VADDWEVHBU": {0xE05C << 15, false}, "VADDWEVWHU": {0xE05D << 15, false},
+		"VADDWEVVWU": {0xE05E << 15, false}, "VADDWEVQVU": {0xE05F << 15, false},
+		"VADDWODHBU": {0xE064 << 15, false}, "VADDWODWHU": {0xE065 << 15, false},
+		"VADDWODVWU": {0xE066 << 15, false}, "VADDWODQVU": {0xE067 << 15, false},
+		"VSUBWODHBU": {0xE068 << 15, false}, "VSUBWODWHU": {0xE069 << 15, false},
+		"VSUBWODVWU": {0xE06A << 15, false}, "VSUBWODQVU": {0xE06B << 15, false},
+		"VSHUFH": {0xE2F5 << 15, false}, "VSHUFW": {0xE2F6 << 15, false},
+		"VSHUFV": {0xE2F7 << 15, false},
+		"XVSLLB": {0xE9D0 << 15, true}, "XVSLLH": {0xE9D1 << 15, true},
+		"XVSLLW": {0xE9D2 << 15, true}, "XVSLLV": {0xE9D3 << 15, true},
+		"XVSRLB": {0xE9D4 << 15, true}, "XVSRLH": {0xE9D5 << 15, true},
+		"XVSRLW": {0xE9D6 << 15, true}, "XVSRLV": {0xE9D7 << 15, true},
+		"XVSRAB": {0xE9D8 << 15, true}, "XVSRAH": {0xE9D9 << 15, true},
+		"XVSRAW": {0xE9DA << 15, true}, "XVSRAV": {0xE9DB << 15, true},
+		"XVROTRB": {0xE9DC << 15, true}, "XVROTRH": {0xE9DD << 15, true},
+		"XVROTRW": {0xE9DE << 15, true}, "XVROTRV": {0xE9DF << 15, true},
+		"XVILVLB": {0xEA34 << 15, true}, "XVILVLH": {0xEA35 << 15, true},
+		"XVILVLW": {0xEA36 << 15, true}, "XVILVLV": {0xEA37 << 15, true},
+		"XVILVHB": {0xEA38 << 15, true}, "XVILVHH": {0xEA39 << 15, true},
+		"XVILVHW": {0xEA3A << 15, true}, "XVILVHV": {0xEA3B << 15, true},
+		"XVBITCLRB": {0xEA18 << 15, true}, "XVBITCLRH": {0xEA19 << 15, true},
+		"XVBITCLRW": {0xEA1A << 15, true}, "XVBITCLRV": {0xEA1B << 15, true},
+		"XVBITSETB": {0xEA1C << 15, true}, "XVBITSETH": {0xEA1D << 15, true},
+		"XVBITSETW": {0xEA1E << 15, true}, "XVBITSETV": {0xEA1F << 15, true},
+		"XVBITREVB": {0xEA20 << 15, true}, "XVBITREVH": {0xEA21 << 15, true},
+		"XVBITREVW": {0xEA22 << 15, true}, "XVBITREVV": {0xEA23 << 15, true},
+		"XVORV": {0xEA4D << 15, true}, "XVNORV": {0xEA4F << 15, true},
+		"XVANDNV": {0xEA50 << 15, true}, "XVORNV": {0xEA51 << 15, true},
+		"XVSEQH": {0xE801 << 15, true}, "XVSEQW": {0xE802 << 15, true},
+		"XVSLTB": {0xE80C << 15, true}, "XVSLTH": {0xE80D << 15, true},
+		"XVSLTW": {0xE80E << 15, true}, "XVSLTV": {0xE80F << 15, true},
+		"XVSLTBU": {0xE810 << 15, true}, "XVSLTHU": {0xE811 << 15, true},
+		"XVSLTWU": {0xE812 << 15, true}, "XVSLTVU": {0xE813 << 15, true},
+		"XVADDWEVHB": {0xE83C << 15, true}, "XVADDWEVWH": {0xE83D << 15, true},
+		"XVADDWEVVW": {0xE83E << 15, true}, "XVADDWEVQV": {0xE83F << 15, true},
+		"XVSUBWEVHB": {0xE840 << 15, true}, "XVSUBWEVWH": {0xE841 << 15, true},
+		"XVSUBWEVVW": {0xE842 << 15, true}, "XVSUBWEVQV": {0xE843 << 15, true},
+		"XVADDWODHB": {0xE844 << 15, true}, "XVADDWODWH": {0xE845 << 15, true},
+		"XVADDWODVW": {0xE846 << 15, true}, "XVADDWODQV": {0xE847 << 15, true},
+		"XVSUBWODHB": {0xE848 << 15, true}, "XVSUBWODWH": {0xE849 << 15, true},
+		"XVSUBWODVW": {0xE84A << 15, true}, "XVSUBWODQV": {0xE84B << 15, true},
+		"XVADDWEVHBU": {0xE85C << 15, true}, "XVADDWEVWHU": {0xE85D << 15, true},
+		"XVADDWEVVWU": {0xE85E << 15, true}, "XVADDWEVQVU": {0xE85F << 15, true},
+		"XVSUBWEVHBU": {0xE860 << 15, true}, "XVSUBWEVWHU": {0xE861 << 15, true},
+		"XVSUBWEVVWU": {0xE862 << 15, true}, "XVSUBWEVQVU": {0xE863 << 15, true},
+		"XVADDWODHBU": {0xE864 << 15, true}, "XVADDWODWHU": {0xE865 << 15, true},
+		"XVADDWODVWU": {0xE866 << 15, true}, "XVADDWODQVU": {0xE867 << 15, true},
+		"XVSUBWODHBU": {0xE868 << 15, true}, "XVSUBWODWHU": {0xE869 << 15, true},
+		"XVSUBWODVWU": {0xE86A << 15, true}, "XVSUBWODQVU": {0xE86B << 15, true},
+		"XVSHUFH": {0xEAF5 << 15, true}, "XVSHUFW": {0xEAF6 << 15, true},
+		"XVSHUFV": {0xEAF7 << 15, true},
+	}
+	for _, tab := range []map[string]l64Vec3Enc{addsub, muldiv, vecmisc} {
+		for m, e := range tab {
+			if _, dup := vec3[m]; dup {
+				panic("loong64: duplicate vector mnemonic " + m)
+			}
+			vec3[m] = e
+		}
+	}
 	for m, e := range vec3 {
 		l64InstrTable[m] = l64Enc{format: l64Fvvv, op: e.op}
 		l64VecBank[m] = e.lasx
@@ -597,21 +850,156 @@ func init() {
 
 	// Immediate forms: INSTR $imm, vj, vd (or INSTR $imm, vd).  The immediate
 	// range, bias and field mask are the ones the toolchain encodes: vandi.b
-	// stores the raw 8-bit constant, vsrai.b stores imm+8 (byte-lane bias),
-	// vseqi.b and vseqi.d store 5-bit and 7-bit two's-complement values.
-	// The mnemonics that also have a register form (VSEQB, VSEQV, VSRAB,
-	// VROTRW) keep their three-register entry in l64InstrTable; the
-	// dispatcher picks the immediate opcode from l64VecImmInfo by operand
-	// kind, so the immediate entries must not overwrite the table.
+	// stores the raw 8-bit constant, vsrari.b stores imm+8 (lane-width
+	// bias), the si5 compares store 5-bit two's-complement values and vseqi.d
+	// a 7-bit field the toolchain range-checks down to si5.
+	// The mnemonics that also have a register form (the shifts, the bit
+	// clear/set/rev families, VSEQ and the logic immediates) keep their
+	// three-register entry in l64InstrTable; the dispatcher picks the
+	// immediate opcode from l64VecImmInfo by operand kind, so the immediate
+	// entries must not overwrite the table.
 	vecImm := map[string]l64VecImmEnc{
 		"VANDB":  {0xE7A0 << 15, false, 0, 255, 0, 0xFF},
 		"XVANDB": {0xEFA0 << 15, true, 0, 255, 0, 0xFF},
+		"VORB":   {0xE7A8 << 15, false, 0, 255, 0, 0xFF},
+		"XVORB":  {0xEFA8 << 15, true, 0, 255, 0, 0xFF},
+		"VXORB":  {0xE7B0 << 15, false, 0, 255, 0, 0xFF},
+		"XVXORB": {0xEFB0 << 15, true, 0, 255, 0, 0xFF},
+		"VNORB":  {0xE7B8 << 15, false, 0, 255, 0, 0xFF},
+		"XVNORB": {0xEFB8 << 15, true, 0, 255, 0, 0xFF},
 		"VSEQB":  {0xE500 << 15, false, -16, 15, 0, 0x1F},
 		"XVSEQB": {0xE900 << 15, true, -16, 15, 0, 0x1F},
-		"VSEQV":  {0xE503 << 15, false, -64, 63, 0, 0x7F},
-		"XVSEQV": {0xE903 << 15, true, -64, 63, 0, 0x7F},
-		"VSRAB":  {0xE668 << 15, false, 0, 7, 8, 0x1F},
-		"VROTRW": {0xE541 << 15, false, 0, 31, 0, 0x1F},
+		// vseqi.h/w accept the same si5 window as vseqi.b; vseqi.d carries a
+		// 7-bit field, but the toolchain range-checks it down to si5 as well
+		// (GOARCH=loong64 go tool asm rejects VSEQV $32 and VSEQV $-64).
+		"VSEQH":  {0xE501 << 15, false, -16, 15, 0, 0x1F},
+		"XVSEQH": {0xED01 << 15, true, -16, 15, 0, 0x1F},
+		"VSEQW":  {0xE502 << 15, false, -16, 15, 0, 0x1F},
+		"XVSEQW": {0xED02 << 15, true, -16, 15, 0, 0x1F},
+		"VSEQV":  {0xE503 << 15, false, -16, 15, 0, 0x7F},
+		"XVSEQV": {0xE903 << 15, true, -16, 15, 0, 0x7F},
+		// vslti compares against a signed (or, in the U spellings, unsigned)
+		// si5/ui5 constant.
+		"VSLTB":   {0xE50C << 15, false, -16, 15, 0, 0x1F},
+		"XVSLTB":  {0xED0C << 15, true, -16, 15, 0, 0x1F},
+		"VSLTH":   {0xE50D << 15, false, -16, 15, 0, 0x1F},
+		"XVSLTH":  {0xED0D << 15, true, -16, 15, 0, 0x1F},
+		"VSLTW":   {0xE50E << 15, false, -16, 15, 0, 0x1F},
+		"XVSLTW":  {0xED0E << 15, true, -16, 15, 0, 0x1F},
+		"VSLTV":   {0xE50F << 15, false, -16, 15, 0, 0x1F},
+		"XVSLTV":  {0xED0F << 15, true, -16, 15, 0, 0x1F},
+		"VSLTBU":  {0xE510 << 15, false, 0, 31, 0, 0x1F},
+		"XVSLTBU": {0xED10 << 15, true, 0, 31, 0, 0x1F},
+		"VSLTHU":  {0xE511 << 15, false, 0, 31, 0, 0x1F},
+		"XVSLTHU": {0xED11 << 15, true, 0, 31, 0, 0x1F},
+		"VSLTWU":  {0xE512 << 15, false, 0, 31, 0, 0x1F},
+		"XVSLTWU": {0xED12 << 15, true, 0, 31, 0, 0x1F},
+		"VSLTVU":  {0xE513 << 15, false, 0, 31, 0, 0x1F},
+		"XVSLTVU": {0xED13 << 15, true, 0, 31, 0, 0x1F},
+		// vaddi/vsubi take ui5 constants for every width on this toolchain
+		// (VADDVU $32 is rejected by the oracle although the field is ui8).
+		"VADDBU":  {0xE514 << 15, false, 0, 31, 0, 0x1F},
+		"XVADDBU": {0xED14 << 15, true, 0, 31, 0, 0x1F},
+		"VADDHU":  {0xE515 << 15, false, 0, 31, 0, 0x1F},
+		"XVADDHU": {0xED15 << 15, true, 0, 31, 0, 0x1F},
+		"VADDWU":  {0xE516 << 15, false, 0, 31, 0, 0x1F},
+		"XVADDWU": {0xED16 << 15, true, 0, 31, 0, 0x1F},
+		"VADDVU":  {0xE517 << 15, false, 0, 31, 0, 0x1F},
+		"XVADDVU": {0xED17 << 15, true, 0, 31, 0, 0x1F},
+		"VSUBBU":  {0xE518 << 15, false, 0, 31, 0, 0x1F},
+		"XVSUBBU": {0xED18 << 15, true, 0, 31, 0, 0x1F},
+		"VSUBHU":  {0xE519 << 15, false, 0, 31, 0, 0x1F},
+		"XVSUBHU": {0xED19 << 15, true, 0, 31, 0, 0x1F},
+		"VSUBWU":  {0xE51A << 15, false, 0, 31, 0, 0x1F},
+		"XVSUBWU": {0xED1A << 15, true, 0, 31, 0, 0x1F},
+		"VSUBVU":  {0xE51B << 15, false, 0, 31, 0, 0x1F},
+		"XVSUBVU": {0xED1B << 15, true, 0, 31, 0, 0x1F},
+		// The shift/rotate immediates ride in a width-sized field whose upper
+		// bits carry the lane-width code: vslli.b stores ui3 at [12:0] with
+		// bits [14:13] inside the opcode, vslli.h ui4 under a 4 bit mask, and
+		// the .w/.d spellings a raw ui5/ui6.
+		"VSLLB":  {0x732C2000, false, 0, 7, 0, 0x7},
+		"XVSLLB": {0x772C2000, true, 0, 7, 0, 0x7},
+		"VSLLH":  {0x732C4000, false, 0, 15, 0, 0xF},
+		"XVSLLH": {0x772C4000, true, 0, 15, 0, 0xF},
+		"VSLLW":  {0xE659 << 15, false, 0, 31, 0, 0x1F},
+		"XVSLLW": {0xEE59 << 15, true, 0, 31, 0, 0x1F},
+		"VSLLV":  {0xE65A << 15, false, 0, 63, 0, 0x3F},
+		"XVSLLV": {0xEE5A << 15, true, 0, 63, 0, 0x3F},
+		"VSRLB":  {0x73302000, false, 0, 7, 0, 0x7},
+		"XVSRLB": {0x77302000, true, 0, 7, 0, 0x7},
+		"VSRLH":  {0x73304000, false, 0, 15, 0, 0xF},
+		"XVSRLH": {0x77304000, true, 0, 15, 0, 0xF},
+		"VSRLW":  {0xE661 << 15, false, 0, 31, 0, 0x1F},
+		"XVSRLW": {0xEE61 << 15, true, 0, 31, 0, 0x1F},
+		"VSRLV":  {0xE662 << 15, false, 0, 63, 0, 0x3F},
+		"XVSRLV": {0xEE62 << 15, true, 0, 63, 0, 0x3F},
+		// vsrari/vrotri bias the field so the lane-width code rides above the
+		// shift amount (.b adds 8, .h 16, .w 32; .d is a raw ui6).
+		"VSRAB":   {0xE668 << 15, false, 0, 7, 8, 0x1F},
+		"XVSRAB":  {0xEE68 << 15, true, 0, 7, 8, 0x1F},
+		"VSRAH":   {0x73344000, false, 0, 15, 0, 0xF},
+		"XVSRAH":  {0x77344000, true, 0, 15, 0, 0xF},
+		"VSRAW":   {0xE669 << 15, false, 0, 31, 0, 0x1F},
+		"XVSRAW":  {0xEE69 << 15, true, 0, 31, 0, 0x1F},
+		"VSRAV":   {0xE66A << 15, false, 0, 63, 0, 0x3F},
+		"XVSRAV":  {0xEE6A << 15, true, 0, 63, 0, 0x3F},
+		"VROTRB":  {0x72A02000, false, 0, 7, 0, 0x7},
+		"XVROTRB": {0x76A02000, true, 0, 7, 0, 0x7},
+		"VROTRH":  {0x72A04000, false, 0, 15, 0, 0xF},
+		"XVROTRH": {0x76A04000, true, 0, 15, 0, 0xF},
+		"VROTRW":  {0xE541 << 15, false, 0, 31, 0, 0x1F},
+		"XVROTRW": {0xED41 << 15, true, 0, 31, 0, 0x1F},
+		"VROTRV":  {0xE542 << 15, false, 0, 63, 0, 0x3F},
+		"XVROTRV": {0xED42 << 15, true, 0, 63, 0, 0x3F},
+		// vbitclri/vbitseti/vbitrevi follow the same width-coded layout.
+		"VBITCLRB":  {0x73102000, false, 0, 7, 0, 0x7},
+		"XVBITCLRB": {0x77102000, true, 0, 7, 0, 0x7},
+		"VBITCLRH":  {0x73104000, false, 0, 15, 0, 0xF},
+		"XVBITCLRH": {0x77104000, true, 0, 15, 0, 0xF},
+		"VBITCLRW":  {0xE621 << 15, false, 0, 31, 0, 0x1F},
+		"XVBITCLRW": {0xEE21 << 15, true, 0, 31, 0, 0x1F},
+		"VBITCLRV":  {0xE622 << 15, false, 0, 63, 0, 0x3F},
+		"XVBITCLRV": {0xEE22 << 15, true, 0, 63, 0, 0x3F},
+		"VBITSETB":  {0x73142000, false, 0, 7, 0, 0x7},
+		"XVBITSETB": {0x77142000, true, 0, 7, 0, 0x7},
+		"VBITSETH":  {0x73144000, false, 0, 15, 0, 0xF},
+		"XVBITSETH": {0x77144000, true, 0, 15, 0, 0xF},
+		"VBITSETW":  {0xE629 << 15, false, 0, 31, 0, 0x1F},
+		"XVBITSETW": {0xEE29 << 15, true, 0, 31, 0, 0x1F},
+		"VBITSETV":  {0xE62A << 15, false, 0, 63, 0, 0x3F},
+		"XVBITSETV": {0xEE2A << 15, true, 0, 63, 0, 0x3F},
+		"VBITREVB":  {0x73182000, false, 0, 7, 0, 0x7},
+		"XVBITREVB": {0x77182000, true, 0, 7, 0, 0x7},
+		"VBITREVH":  {0x73184000, false, 0, 15, 0, 0xF},
+		"XVBITREVH": {0x77184000, true, 0, 15, 0, 0xF},
+		"VBITREVW":  {0xE631 << 15, false, 0, 31, 0, 0x1F},
+		"XVBITREVW": {0xEE31 << 15, true, 0, 31, 0, 0x1F},
+		"VBITREVV":  {0xE632 << 15, false, 0, 63, 0, 0x3F},
+		"XVBITREVV": {0xEE32 << 15, true, 0, 63, 0, 0x3F},
+		// The 4-bit-select shuffles and the byte-extract/insert permutations
+		// take ui8 (the .d shuffle ui4 range-checked to 0..15 by the
+		// toolchain) packing both position nibbles.
+		"VSHUF4IB":   {0xE720 << 15, false, 0, 255, 0, 0xFF},
+		"XVSHUF4IB":  {0xEF20 << 15, true, 0, 255, 0, 0xFF},
+		"VSHUF4IH":   {0xE728 << 15, false, 0, 255, 0, 0xFF},
+		"XVSHUF4IH":  {0xEF28 << 15, true, 0, 255, 0, 0xFF},
+		"VSHUF4IW":   {0xE730 << 15, false, 0, 255, 0, 0xFF},
+		"XVSHUF4IW":  {0xEF30 << 15, true, 0, 255, 0, 0xFF},
+		"VSHUF4IV":   {0xE738 << 15, false, 0, 15, 0, 0xFF},
+		"XVSHUF4IV":  {0xEF38 << 15, true, 0, 15, 0, 0xFF},
+		"VPERMIW":    {0xE7C8 << 15, false, 0, 255, 0, 0xFF},
+		"XVPERMIW":   {0xEFC8 << 15, true, 0, 255, 0, 0xFF},
+		"XVPERMIV":   {0xEFD0 << 15, true, 0, 255, 0, 0xFF},
+		"XVPERMIQ":   {0xEFD8 << 15, true, 0, 255, 0, 0xFF},
+		"VEXTRINSB":  {0xE718 << 15, false, 0, 255, 0, 0xFF},
+		"XVEXTRINSB": {0xEF18 << 15, true, 0, 255, 0, 0xFF},
+		"VEXTRINSH":  {0xE710 << 15, false, 0, 255, 0, 0xFF},
+		"XVEXTRINSH": {0xEF10 << 15, true, 0, 255, 0, 0xFF},
+		"VEXTRINSW":  {0xE708 << 15, false, 0, 255, 0, 0xFF},
+		"XVEXTRINSW": {0xEF08 << 15, true, 0, 255, 0, 0xFF},
+		"VEXTRINSV":  {0xE700 << 15, false, 0, 255, 0, 0xFF},
+		"XVEXTRINSV": {0xEF00 << 15, true, 0, 255, 0, 0xFF},
 	}
 	for m, e := range vecImm {
 		l64VecImmInfo[m] = e
@@ -625,22 +1013,71 @@ func init() {
 		"VSETANYEQB": 0xE539<<15 | 8<<10, "XVSETANYEQB": 0xED39<<15 | 8<<10,
 		"VSETANYEQV": 0xE539<<15 | 11<<10, "XVSETANYEQV": 0xED39<<15 | 11<<10,
 		"VSETALLNEV": 0xE539<<15 | 15<<10, "XVSETALLNEV": 0xED39<<15 | 15<<10,
+		"VSETEQV": 0xE539<<15 | 6<<10, "XVSETEQV": 0xED39<<15 | 6<<10,
+		"VSETANYEQH": 0xE539<<15 | 9<<10, "XVSETANYEQH": 0xED39<<15 | 9<<10,
+		"VSETANYEQW": 0xE539<<15 | 10<<10, "XVSETANYEQW": 0xED39<<15 | 10<<10,
+		"VSETALLNEB": 0xE539<<15 | 12<<10, "XVSETALLNEB": 0xED39<<15 | 12<<10,
+		"VSETALLNEH": 0xE539<<15 | 13<<10, "XVSETALLNEH": 0xED39<<15 | 13<<10,
+		"VSETALLNEW": 0xE539<<15 | 14<<10, "XVSETALLNEW": 0xED39<<15 | 14<<10,
 	}
 	for m, op := range vecCf {
 		l64InstrTable[m] = l64Enc{format: l64Fvcf, op: op}
 		l64VecBank[m] = strings.HasPrefix(m, "XV")
 	}
 
-	// Lane popcount: INSTR vj, vd (the 2R layout with the opcode extending
-	// over the unused vk field).
+	// Lane popcount and the two-operand vector FP/unary spellings: INSTR vj,
+	// vd (the 2R layout with the opcode extending over the unused vk field;
+	// the low byte of each constant is the instruction's own sub-op).
 	vec2r := map[string]l64Vec3Enc{
 		"VPCNTV": {0x1CA70B << 10, false}, "XVPCNTV": {0x1DA70B << 10, true},
 	}
+	// The rest of the lane popcounts, the vector negations and the vector FP
+	// unary conversions (loong64enc1.s).
+	vec2rMore := map[string]l64Vec3Enc{
+		"VPCNTB": {0x1CA708 << 10, false}, "VPCNTH": {0x1CA709 << 10, false},
+		"VPCNTW": {0x1CA70A << 10, false},
+		"VNEGB":  {0x1CA70C << 10, false}, "VNEGH": {0x1CA70D << 10, false},
+		"VNEGW": {0x1CA70E << 10, false}, "VNEGV": {0x1CA70F << 10, false},
+		"VFCLASSF": {0x1CA735 << 10, false}, "VFCLASSD": {0x1CA736 << 10, false},
+		"VFSQRTF": {0x1CA739 << 10, false}, "VFSQRTD": {0x1CA73A << 10, false},
+		"VFRECIPF": {0x1CA73D << 10, false}, "VFRECIPD": {0x1CA73E << 10, false},
+		"VFRSQRTF": {0x1CA741 << 10, false}, "VFRSQRTD": {0x1CA742 << 10, false},
+		"VFRINTF": {0x1CA74D << 10, false}, "VFRINTD": {0x1CA74E << 10, false},
+		"VFRINTRMF": {0x1CA751 << 10, false}, "VFRINTRMD": {0x1CA752 << 10, false},
+		"VFRINTRPF": {0x1CA755 << 10, false}, "VFRINTRPD": {0x1CA756 << 10, false},
+		"VFRINTRZF": {0x1CA759 << 10, false}, "VFRINTRZD": {0x1CA75A << 10, false},
+		"VFRINTRNEF": {0x1CA75D << 10, false}, "VFRINTRNED": {0x1CA75E << 10, false},
+		"XVPCNTB": {0x1DA708 << 10, true}, "XVPCNTH": {0x1DA709 << 10, true},
+		"XVPCNTW": {0x1DA70A << 10, true},
+		"XVNEGB":  {0x1DA70C << 10, true}, "XVNEGH": {0x1DA70D << 10, true},
+		"XVNEGW": {0x1DA70E << 10, true}, "XVNEGV": {0x1DA70F << 10, true},
+		"XVFCLASSF": {0x1DA735 << 10, true}, "XVFCLASSD": {0x1DA736 << 10, true},
+		"XVFSQRTF": {0x1DA739 << 10, true}, "XVFSQRTD": {0x1DA73A << 10, true},
+		"XVFRECIPF": {0x1DA73D << 10, true}, "XVFRECIPD": {0x1DA73E << 10, true},
+		"XVFRSQRTF": {0x1DA741 << 10, true}, "XVFRSQRTD": {0x1DA742 << 10, true},
+		"XVFRINTF": {0x1DA74D << 10, true}, "XVFRINTD": {0x1DA74E << 10, true},
+		"XVFRINTRMF": {0x1DA751 << 10, true}, "XVFRINTRMD": {0x1DA752 << 10, true},
+		"XVFRINTRPF": {0x1DA755 << 10, true}, "XVFRINTRPD": {0x1DA756 << 10, true},
+		"XVFRINTRZF": {0x1DA759 << 10, true}, "XVFRINTRZD": {0x1DA75A << 10, true},
+		"XVFRINTRNEF": {0x1DA75D << 10, true}, "XVFRINTRNED": {0x1DA75E << 10, true},
+	}
+	maps.Copy(vec2r, vec2rMore)
 	for m, e := range vec2r {
 		l64InstrTable[m] = l64Enc{format: l64Frr, op: e.op}
 		l64VecBank[m] = e.lasx
 		l64Vec2R[m] = true
 	}
+
+	// The four-register byte shuffle: INSTR va, vk, vj, vd (the operand the
+	// table reads in each field position, va at bits [19:15]).
+	vec4r := map[string]l64Vec3Enc{
+		"VSHUFB": {0x0D50 << 16, false}, "XVSHUFB": {0x0D60 << 16, true},
+	}
+	for m, e := range vec4r {
+		l64InstrTable[m] = l64Enc{format: l64Fvvvv, op: e.op}
+		l64VecBank[m] = e.lasx
+		l64Vec4R[m] = true
+	}
 }
 
 // l64FpMovTable maps (mnemonic, from-class, to-class) to the 2R opcode of the

asm/loong64_encode_test.go

@@ -8,8 +8,8 @@ import (
 	"encoding/binary"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // firstTextLOONG64 parses assembly source and returns the first TEXT body.
@@ -507,6 +507,218 @@ TEXT ·v(SB), NOSPLIT, $0
 			0x4C000020,
 		)
 	})
+
+	// The integer and FP add/subtract families with their saturating pairs
+	// and immediate spellings (loong64enc1.s words).
+	t.Run("add and subtract families", func(t *testing.T) {
+		fn := firstTextLOONG64(t, `#include "textflag.h"
+TEXT ·v(SB), NOSPLIT, $0
+	VADDB V1, V2, V3
+	VADDF V1, V2, V3
+	VADDD V1, V2, V3
+	VSUBD V1, V2, V3
+	VSADDV V1, V2, V3
+	VSSUBVU V1, V2, V3
+	VADDBU $1, V2, V1
+	VADDBU $1, V2
+	VSUBVU $31, V2
+	XVSADDV X3, X2, X1
+	XVSUBD X1, X2, X3
+	RET
+`)
+		code := assembleLOONG64Helper(t, fn)
+		wantWords(t, code,
+			0x700A0443, // vadd.b
+			0x71308443, // vadd.f
+			0x71310443, // vadd.d
+			0x71330443, // vsub.d
+			0x70478443, // vsadd.v
+			0x704D8443, // vssub.u.d
+			0x728A0441, // vaddi.bu v1, v2, 1
+			0x728A0442, // vaddi.bu v2, v2, 1 (two-operand form)
+			0x728DFC42, // vsubi.du v2, v2, 31 (two-operand form)
+			0x74478C41, // xvsadd.d x1, x2, x3
+			0x75330443, // xvsub.d x3, x2, x1
+			0x4C000020,
+		)
+	})
+
+	// The multiply, divide and accumulate families.
+	t.Run("multiply and divide families", func(t *testing.T) {
+		fn := firstTextLOONG64(t, `#include "textflag.h"
+TEXT ·v(SB), NOSPLIT, $0
+	VMULV V1, V2, V3
+	VMUHHU V1, V2, V3
+	VDIVBU V1, V2, V3
+	VMODV V1, V2, V3
+	VMADDB V1, V2, V3
+	VMSUBV V1, V2, V3
+	VMULWEVHB V1, V2, V3
+	VMULWODQV V1, V2, V3
+	VMADDWEVHBUB V1, V2, V3
+	XVDIVD X1, X2, X3
+	RET
+`)
+		code := assembleLOONG64Helper(t, fn)
+		wantWords(t, code,
+			0x70858443, // vmul.v
+			0x70888443, // vmuh.u.d
+			0x70E40443, // vdiv.u.b
+			0x70E38443, // vmod.d
+			0x70A80443, // vmadd.b
+			0x70AB8443, // vmsub.d
+			0x70900443, // vmulwev.h.b
+			0x70938443, // vmulwod.q.d
+			0x70BC0443, // vmaddwev.h.bu.b
+			0x753B0443, // xvdiv.d
+			0x4C000020,
+		)
+	})
+
+	// The shift, bit and interleave families in register and immediate
+	// spellings, with the width-coded shift immediates.
+	t.Run("shift, bit and interleave families", func(t *testing.T) {
+		fn := firstTextLOONG64(t, `#include "textflag.h"
+TEXT ·v(SB), NOSPLIT, $0
+	VSLLV V1, V2, V3
+	VROTRB V1, V2, V3
+	VBITCLRV V1, V2, V3
+	VBITSETW V1, V2, V3
+	VBITREVV V1, V2, V3
+	VILVLB V1, V2, V3
+	VILVHV V1, V2, V3
+	VSLLB $7, V1, V2
+	VSLLB $5, V1
+	VSRLH $15, V1, V2
+	VSRAW $31, V1, V2
+	VSRAV $63, V1, V2
+	VROTRV $63, V1, V2
+	VBITCLRB $7, V2, V3
+	VBITREVV $63, V2, V3
+	VSEQH $-16, V2, V3
+	VSLTB $1, V2, V3
+	VSLTHU $31, V2, V3
+	XVILVLV X3, X2, X1
+	XVSLLB $7, X2, X1
+	XVSRAV $63, X2, X1
+	XVBITREVV $63, X2, X1
+	RET
+`)
+		code := assembleLOONG64Helper(t, fn)
+		wantWords(t, code,
+			0x70E98443, // vsll.d
+			0x70EE0443, // vrotr.b
+			0x710D8443, // vbitclr.d
+			0x710F0443, // vbitset.w
+			0x71118443, // vbitrev.d
+			0x711A0443, // vilvl.b
+			0x711D8443, // vilvh.d
+			0x732C3C22, // vslli.b v2, v1, 7
+			0x732C3421, // vslli.b v1, v1, 5 (two-operand form)
+			0x73307C22, // vsrli.h v2, v1, 15
+			0x7334FC22, // vsrai.w v2, v1, 31
+			0x7335FC22, // vsrai.d v2, v1, 63
+			0x72A1FC22, // vrotri.d v2, v1, 63
+			0x73103C43, // vbitclri.b v3, v2, 7
+			0x7319FC43, // vbitrevi.d v3, v2, 63
+			0x7280C043, // vseqi.h v3, v2, -16
+			0x72860443, // vslti.b v3, v2, 1
+			0x7288FC43, // vslti.hu v3, v2, 31
+			0x751B8C41, // xvilvl.d x1, x2, x3
+			0x772C3C41, // xvslli.b x1, x2, 7
+			0x7735FC41, // xvsrai.d x1, x2, 63
+			0x7719FC41, // xvbitrevi.d x1, x2, 63
+			0x4C000020,
+		)
+	})
+
+	// The shuffle, select and permutation families, including the
+	// four-register byte shuffle.
+	t.Run("shuffle and permutation families", func(t *testing.T) {
+		fn := firstTextLOONG64(t, `#include "textflag.h"
+TEXT ·v(SB), NOSPLIT, $0
+	VSHUFH V1, V2, V3
+	VSHUFW V1, V2, V3
+	VSHUFV V1, V2, V3
+	VSHUFB V1, V2, V3, V4
+	XVSHUFB X1, X2, X3, X4
+	VSHUF4IB $255, V2, V1
+	VSHUF4IV $15, V2, V1
+	XVSHUF4IV $15, X1, X2
+	VEXTRINSB $0x18, V1, V2
+	XVEXTRINSV $0x81, X1, X2
+	VPERMIW $0x1B, V1, V2
+	XVPERMIQ $0x4B, X1, X2
+	RET
+`)
+		code := assembleLOONG64Helper(t, fn)
+		wantWords(t, code,
+			0x717A8443, // vshuf.h
+			0x717B0443, // vshuf.w
+			0x717B8443, // vshuf.d
+			0x0D508864, // vshuf.b v4, v3, v2, v1
+			0x0D608864, // xvshuf.b
+			0x7393FC41, // vshuf4i.b v1, v2, 255
+			0x739C3C41, // vshuf4i.d v1, v2, 15
+			0x779C3C22, // xvshuf4i.d x2, x1, 15
+			0x738C6022, // vextrins.b v2, v1, 0x18
+			0x77820422, // xvextrins.d x2, x1, 0x81
+			0x73E46C22, // vpermi.w v2, v1, 0x1b
+			0x77ED2C22, // xvpermi.q x2, x1, 0x4b
+			0x4C000020,
+		)
+	})
+
+	// The vector FP families, the unary spellings, the compare-to-flag
+	// additions and the scalar int/float conversions.
+	t.Run("FP and conversion families", func(t *testing.T) {
+		fn := firstTextLOONG64(t, `#include "textflag.h"
+TEXT ·v(SB), NOSPLIT, $0
+	VADDF V1, V2, V3
+	VMULF V1, V2, V3
+	VFCLASSD V1, V2
+	VFSQRTF V1, V2
+	VFRECIPD V1, V2
+	VFRSQRTF V1, V2
+	VFRINTF V1, V2
+	VFRINTRNED V1, V2
+	VNEGB V1, V2
+	VPCNTB V1, V2
+	XVNEGV X2, X1
+	XVPCNTW X3, X2
+	XVFRINTRNEF X1, X2
+	VSETEQV V1, FCC0
+	VSETANYEQH V1, FCC0
+	VSETALLNEB V1, FCC0
+	XVSETALLNEW X1, FCC0
+	FFINTFW F0, F1
+	FTINTVD F0, F1
+	RET
+`)
+		code := assembleLOONG64Helper(t, fn)
+		wantWords(t, code,
+			0x71308443, // vfadd.s
+			0x71388443, // vfmul.s
+			0x729CD822, // vfclass.d
+			0x729CE422, // vfsqrt.s
+			0x729CF822, // vfrecip.d
+			0x729D0422, // vfrsqrt.s
+			0x729D3422, // vfrint.s
+			0x729D7822, // vfrintne.s
+			0x729C3022, // vneg.b
+			0x729C2022, // vpcnt.b
+			0x769C3C41, // xvneg.d x1, x2
+			0x769C2862, // xvpcnt.w x2, x3
+			0x769D7422, // xvfrintne.s x2, x1
+			0x729C9820, // vseteqz.d fcc0, v1
+			0x729CA420, // vsetanyeqz.h
+			0x729CB020, // vsetallnez.b
+			0x769CB820, // xvsetallnez.w
+			0x011D1001, // ffint.s.w f1, f0
+			0x011B2801, // ftint.l.d f1, f0
+			0x4C000020,
+		)
+	})
 }
 
 // TestLOONG64_vectorErrors pins the register-class and range diagnostics of
@@ -545,6 +757,36 @@ func TestLOONG64_vectorErrors(t *testing.T) {
 		`TEXT ·e(SB), NOSPLIT, $0
 	VROTRW $32, V1, V2
 	RET
+`,
+		`TEXT ·e(SB), NOSPLIT, $0
+	VADDVU $32, V2
+	RET
+`,
+		`TEXT ·e(SB), NOSPLIT, $0
+	VSEQV $32, V2, V3
+	RET
+`,
+		`TEXT ·e(SB), NOSPLIT, $0
+	VSHUF4IV $16, V2, V1
+	RET
+`,
+		`TEXT ·e(SB), NOSPLIT, $0
+	VEXTRINSB $256, V1, V2
+	RET
+`,
+		`TEXT ·e(SB), NOSPLIT, $0
+	VSLTV $-17, V2, V3
+	RET
+`,
+		// VSHUFB wants four vector registers.
+		`TEXT ·e(SB), NOSPLIT, $0
+	VSHUFB V1, V2, V3
+	RET
+`,
+		// The FCC forms still refuse vector registers.
+		`TEXT ·e(SB), NOSPLIT, $0
+	VSETEQV V1, V2
+	RET
 `,
 		// VSET* wants an FCC flag, not a vector register.
 		`TEXT ·e(SB), NOSPLIT, $0

asm/loong64_frame.go

@@ -6,7 +6,7 @@ package asm
 import (
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // Loong64 frame mapping, matching the Go toolchain's loong64 backend.

asm/loong64_more_test.go

@@ -7,7 +7,7 @@ import (
 	"bytes"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestLOONG64_sys exercises the no-operand system instructions and the

asm/loong64_reloc_test.go

@@ -6,7 +6,7 @@ package asm
 import (
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestLOONG64RelocOffsetsIncludePrologue pins the function-relative

asm/operand.go

@@ -14,6 +14,51 @@ type Imm int64
 
 func (Imm) isOperand() {}
 
+// RegList is a bracketed register range, [Z0-Z3]: the four-register source
+// of the 4FMAPS and 4VNNIW families.  The EVEX emit path carries the list's
+// low register through the inverted 5-bit V'VVVV field; the three higher
+// registers are implied by the instruction, so only the pair travels here.
+type RegList struct {
+	Lo Reg
+	Hi Reg // implied by the encoding; Lo.idx+3 by construction
+}
+
+func (RegList) isOperand() {}
+
+// FloatImm is a floating-point immediate ($-1.0).  The SSE mnemonics whose
+// encoding takes an XMM/memory source at that position rewrite it as a read
+// from a read-only pool constant ($f64.<hex> or $f32.<hex>), the toolchain's
+// own behaviour; every other instruction rejects it.
+type FloatImm struct {
+	Text string // the numeric text as written, sign excluded
+	Neg  bool   // a leading minus
+}
+
+func (FloatImm) isOperand() {}
+
+// TLSMem is a thread-local access, the source form off(base)(TLS*1) with the
+// base dropped: the toolchain's one-instruction TLS rewrite assembles it as
+// the segment-prefixed absolute whose disp32 carries an R_TLS_LE patch site
+// (the linker fills the TLS slot offset).
+type TLSMem struct {
+	Disp int64
+	Size int
+	Seg  byte // the segment override: FS (0x64) or GS (0x65) on windows
+}
+
+func (TLSMem) isOperand() {}
+
+// SegAbs is a segment-absolute access, 0x30(GS): the segment override
+// prefixes a disp32 absolute reference with no relocation.  The base
+// register spellings GS and FS produce it.
+type SegAbs struct {
+	Disp int64
+	Size int
+	Seg  byte // 0x64 FS, 0x65 GS
+}
+
+func (SegAbs) isOperand() {}
+
 // Mem is a memory operand of the form disp(base)(index*scale).
 type Mem struct {
 	Base     Reg
@@ -23,6 +68,7 @@ type Mem struct {
 	Size     int // operand width in bytes
 	HasBase  bool
 	HasIndex bool
+	Seg      byte // segment override prefix (0x64 FS, 0x65 GS); 0 = none
 }
 
 func (Mem) isOperand() {}

asm/riscv_encode.go

@@ -63,7 +63,7 @@ func riscvRegNum(name string) int {
 		return 24
 	case "X25", "S9":
 		return 25
-	case "X26", "S10":
+	case "X26", "S10", "CTXT":
 		return 26
 	case "X27", "S11", "g":
 		return 27
@@ -219,6 +219,9 @@ var riscvInstrTable = map[string]riscvEnc{
 	"DIVUW": {0x3B, 0x5, 0x01},
 	"REMW":  {0x3B, 0x6, 0x01},
 	"REMUW": {0x3B, 0x7, 0x01},
+	// Zicond conditional zeroing.
+	"CZEROEQZ": {0x33, 0x5, 0x07},
+	"CZERONEZ": {0x33, 0x7, 0x07},
 	// RV64I, I-type arithmetic.
 	"ADDI":  {0x13, 0x0, 0x00},
 	"ADDIW": {0x1B, 0x0, 0x00},
@@ -247,13 +250,21 @@ var riscvInstrTable = map[string]riscvEnc{
 	"BGE":  {0x63, 0x5, 0x00},
 	"BLTU": {0x63, 0x6, 0x00},
 	"BGEU": {0x63, 0x7, 0x00},
+	// The swapped-spelling comparison forms: encoded as BLT/BGE/BLTU/BGEU
+	// with the register operands swapped.
+	"BGT":  {0x63, 0x4, 0x00},
+	"BLE":  {0x63, 0x5, 0x00},
+	"BGTU": {0x63, 0x6, 0x00},
+	"BLEU": {0x63, 0x7, 0x00},
 	// U-type.
 	"LUI":   {0x37, 0x0, 0x00},
 	"AUIPC": {0x17, 0x0, 0x00},
 	// System.
-	"ECALL":  {0x73, 0x0, 0x00},
-	"EBREAK": {0x73, 0x0, 0x00},
-	"FENCE":  {0x0F, 0x0, 0x00},
+	"ECALL":     {0x73, 0x0, 0x00},
+	"EBREAK":    {0x73, 0x0, 0x00},
+	"FENCE":     {0x0F, 0x0, 0x00},
+	"FENCE.TSO": {0x0F, 0x0, 0x00},
+	"PAUSE":     {0x0F, 0x0, 0x00},
 	// JALR, indirect jump/call (I-type).
 	"JALR": {0x67, 0x0, 0x00},
 
@@ -303,7 +314,14 @@ var riscvInstrTable = map[string]riscvEnc{
 	"FMIND": {0x53, 0x0, 0x15},
 	"FMAXD": {0x53, 0x1, 0x15},
 	// FP sign injection (double): rs2 carries the sign source.
-	"FSGNJD": {0x53, 0x0, 0x11},
+	"FSGNJD":  {0x53, 0x0, 0x11},
+	"FSGNJS":  {0x53, 0x0, 0x10},
+	"FSGNJX":  {0x53, 0x0, 0x14},
+	"FSGNJXD": {0x53, 0x0, 0x15},
+	"FSGNJXS": {0x53, 0x0, 0x14},
+	"FSGNJND": {0x53, 0x1, 0x11},
+	"FSGNJNS": {0x53, 0x1, 0x10},
+	"FSGNJNX": {0x53, 0x1, 0x14},
 
 	// RV64A, load-reserved / store-conditional (funct5 0x02 / 0x03).
 	// The toolchain gives LR acquire ordering (aq = 1) and SC release
@@ -375,6 +393,10 @@ var riscvCvtTable = map[string]riscvCvtEnc{
 	"FMVDX": {0x79, 0x0, 0x53}, // int64 → float64 (bit move)
 	"FMVXW": {0x70, 0x0, 0x53}, // float32 → int32 (bit move)
 	"FMVWX": {0x78, 0x0, 0x53}, // int32 → float32 (bit move)
+	// The toolchain's W/D suffix spellings of the same moves.
+	"FMVXS": {0x70, 0x0, 0x53},
+	"FMVFS": {0x78, 0x0, 0x53},
+	"FMVSX": {0x79, 0x0, 0x53},
 }
 
 // riscvCvtType encodes an FP conversion instruction.

asm/riscv_encode_test.go

@@ -10,8 +10,8 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // firstTextRISCV parses assembly source and returns the first TEXT function body.
@@ -33,7 +33,7 @@ func firstTextRISCV(t *testing.T, src string) *ast.Text {
 // assembleRISCVHelper assembles one TEXT function and returns its code bytes.
 func assembleRISCVHelper(t *testing.T, fn *ast.Text) []byte {
 	t.Helper()
-	code, _, _, _, _, err := assembleRISCV(fn)
+	code, _, _, _, _, _, err := assembleRISCV(fn)
 	if err != nil {
 		t.Fatalf("assemble: %v", err)
 	}
@@ -785,16 +785,140 @@ TEXT ·sys(SB), NOSPLIT, $0
 	}
 }
 
-func TestRISCV_MOV_sym_FP_error(t *testing.T) {
-	// MOV $sym(FP), rd should return an error (unsupported).
+func TestRISCV_MOV_sym_FP(t *testing.T) {
+	// MOV $sym(FP), rd lowers to the frame-adjusted ADDI against SP: the
+	// toolchain's argframe spelling.  A zero frame leaves the offset at the
+	// 8-byte link slot, compressed to C.ADDI4SPN.
 	fn := firstTextRISCV(t, `#include "textflag.h"
-TEXT ·badfp(SB), NOSPLIT, $0
+TEXT ·argfp(SB), NOSPLIT, $0
 	MOV $arg(FP), X10
 	RET
 `)
-	_, _, _, _, _, err := assembleRISCV(fn)
-	if err == nil {
-		t.Error("expected error for MOV $arg(FP), got nil")
+	code, _, _, _, _, _, err := assembleRISCV(fn)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	// prologue (0: leaf, zero frame) + C.ADDI4SPN (2) + RET (4) = 6
+	want := []byte{0x28, 0x00, 0x67, 0x80, 0x00, 0x00}
+	if string(code) != string(want) {
+		t.Errorf("got % x, want % x", code, want)
+	}
+}
+
+func TestRISCV_Bookkeeping(t *testing.T) {
+	// FUNCDATA and PCDATA contribute no bytes; UNDEF is the toolchain's
+	// ebreak, compressed to C.EBREAK under RVC.
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·book(SB), NOSPLIT, $0-8
+	FUNCDATA $0, marks<>(SB)
+	PCDATA $1, $1
+	UNDEF
+	MOV $1, X10
+	MOV X10, ret+0(FP)
+	RET
+`)
+	code, _, _, _, _, _, err := assembleRISCV(fn)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	// C.EBREAK (2) + C.LI X10, 1 (2) + C.SWSP (2) + RET (4) = 10: the
+	// FUNCDATA and PCDATA statements contribute nothing.
+	want := []byte{0x02, 0x90, 0x05, 0x45, 0x2a, 0xe4, 0x67, 0x80, 0x00, 0x00}
+	if string(code) != string(want) {
+		t.Errorf("got % x, want % x", code, want)
+	}
+}
+
+func TestRISCV_JMPPCRel(t *testing.T) {
+	// JMP N(PC): the displacement tracks the instruction N source slots
+	// away in the final layout (0 the jump itself, negative backwards).
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·slots(SB), NOSPLIT, $0-0
+	JMP 2(PC)
+	MOV $1, X11
+	MOV $2, X12
+	MOV X12, X11
+	JMP -3(PC)
+	RET
+`)
+	code, _, _, _, _, _, err := assembleRISCV(fn)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	// JMP 2(PC) lands on the C.MV six bytes ahead; JMP -3(PC) lands back on
+	// the first C.LI, six bytes behind.
+	want := []byte{
+		0x6f, 0x00, 0x60, 0x00, // JAL X0, 6
+		0x85, 0x45, // C.LI X11, 1
+		0x09, 0x46, // C.LI X12, 2
+		0xb2, 0x85, // C.MV X11, X12
+		0x6f, 0xf0, 0xbf, 0xff, // JAL X0, -6
+		0x67, 0x80, 0x00, 0x00, // RET
+	}
+	if string(code) != string(want) {
+		t.Errorf("got % x, want % x", code, want)
+	}
+}
+
+func TestRISCV_MOVWideImm(t *testing.T) {
+	// Shift-sequence constants compress like the toolchain's expansion.
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·wide(SB), NOSPLIT, $0-0
+	MOV $0x8000000000000000, X5
+	MOV $0x100000000, X5
+	MOV $0x000fffffffffffda, X5
+	RET
+`)
+	code, _, _, _, _, _, err := assembleRISCV(fn)
+	if err != nil {
+		t.Fatalf("assemble: %v", err)
+	}
+	// C.LI -1, C.SLLI 63; C.LI 1, C.SLLI 32; C.LI -19, C.SLLI 13, SRLI 12.
+	want := []byte{
+		0xfd, 0x52, 0xfe, 0x12,
+		0x85, 0x42, 0x82, 0x12,
+		0xb5, 0x52, 0xb6, 0x02, 0x93, 0xd2, 0xc2, 0x00,
+		0x67, 0x80, 0x00, 0x00,
+	}
+	if string(code) != string(want) {
+		t.Errorf("got % x, want % x", code, want)
+	}
+}
+
+func TestRISCV_MOVImmPool(t *testing.T) {
+	// A constant outside the shift shapes loads from the pooled $i64 data
+	// symbol via AUIPC+LD, named like the toolchain's pool.
+	src := `#include "textflag.h"
+TEXT ·pool(SB), NOSPLIT, $0-8
+	MOV $0x0101010101010101, X16
+	MOV X16, ret+0(FP)
+	RET
+`
+	f, errs := parser.Parse("pool_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	// AUIPC X16, 0 + LD X16, 0(X16): the relocation pair carries the symbol.
+	wantCode := []byte{0x17, 0x08, 0x00, 0x00, 0x03, 0x38, 0x08, 0x00}
+	if string(img.Code[0:8]) != string(wantCode) {
+		t.Errorf("pool load: got % x", img.Code[0:8])
+	}
+	var lit *DataSymbol
+	for i := range img.DataSyms {
+		if img.DataSyms[i].Name == "$i64.0101010101010101" {
+			lit = &img.DataSyms[i]
+		}
+	}
+	if lit == nil {
+		t.Fatalf("pool symbol missing: %v", img.DataSyms)
+	}
+	wantData := []byte{0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01}
+	if string(img.Data[lit.Offset:lit.Offset+8]) != string(wantData) {
+		t.Errorf("pool bytes: got % x", img.Data[lit.Offset:lit.Offset+8])
 	}
 }
 
@@ -805,7 +929,7 @@ TEXT ·calltest(SB), NOSPLIT, $0
 	CALL ext(SB)
 	RET
 `)
-	code, _, relocs, _, _, err := assembleRISCV(fn)
+	code, _, relocs, _, _, _, err := assembleRISCV(fn)
 	if err != nil {
 		t.Fatalf("assemble: %v", err)
 	}
@@ -834,7 +958,7 @@ TEXT ·calllocal(SB), NOSPLIT, $0
 sub:
 	RET
 `)
-	_, _, _, _, _, err := assembleRISCV(fn)
+	_, _, _, _, _, _, err := assembleRISCV(fn)
 	if err == nil {
 		t.Error("expected error for CALL to local label, got nil")
 	}
@@ -868,7 +992,7 @@ func encodeOneInstrRISCV(t *testing.T, src string, pc int, offsets map[string]in
 	t.Helper()
 	fn := firstTextRISCV(t, "#include \"textflag.h\"\n"+src)
 	instr := fn.Body[0].(*ast.Instr)
-	return encodeRISCVInstr(instr, pc, offsets, riscvFrameInfo{}, nil)
+	return encodeRISCVInstr(instr, pc, offsets, riscvFrameInfo{}, nil, nil, nil)
 }
 
 // TestRISCVBranchJumpRange checks that displacements beyond the B-type span
@@ -905,9 +1029,10 @@ func TestRISCVBranchJumpRange(t *testing.T) {
 	}
 }
 
-// TestRISCVBranchFarBody drives the range check through the full two-pass
-// assembler: a forward branch over a body larger than the B-type span must
-// error rather than wrap.
+// TestRISCVBranchFarBody drives the relaxation pass through the full
+// assembler: a forward branch over a body larger than the B-type span is
+// rewritten as an inverted branch over an inserted JMP, the same layout the
+// toolchain produces, instead of wrapping to a wrong target.
 func TestRISCVBranchFarBody(t *testing.T) {
 	var sb strings.Builder
 	sb.WriteString("#include \"textflag.h\"\nTEXT ·far(SB), NOSPLIT, $0\n\tBEQ X10, X11, done\n")
@@ -916,8 +1041,20 @@ func TestRISCVBranchFarBody(t *testing.T) {
 	}
 	sb.WriteString("done:\n\tRET\n")
 	fn := firstTextRISCV(t, sb.String())
-	if _, _, _, _, _, err := assembleRISCV(fn); err == nil {
-		t.Error("expected a branch-out-of-range error, got none")
+	out, _, _, _, _, _, err := assembleRISCV(fn)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	// The relaxed branch at offset 0 targets the inserted JMP at 4 (bne
+	// x10, x11, +4); the JMP at 4 carries the far forward displacement.
+	wantBranch := wordLE(riscvBType(riscvEnc{0x63, 0x1, 0x00}, 10, 11, 4))
+	if !bytes.Equal(out[0:4], wantBranch) {
+		t.Errorf("relaxed branch = %x, want %x", out[0:4], wantBranch)
+	}
+	// done sits after 1100 ADDs: 4 + 4400, i.e. offset 4404 from the JMP at 4.
+	wantJmp := wordLE(riscvJType(0, 4404))
+	if !bytes.Equal(out[4:8], wantJmp) {
+		t.Errorf("inserted JMP = %x, want %x", out[4:8], wantJmp)
 	}
 }
 
@@ -930,7 +1067,7 @@ TEXT ·csrhi(SB), NOSPLIT, $0
 	CSRRW $4096, X10, X11
 	RET
 `)
-	if _, _, _, _, _, err := assembleRISCV(fn); err == nil {
+	if _, _, _, _, _, _, err := assembleRISCV(fn); err == nil {
 		t.Error("expected an out-of-range error for CSR $4096, got none")
 	}
 	fn = firstTextRISCV(t, `#include "textflag.h"
@@ -938,25 +1075,24 @@ TEXT ·csrmax(SB), NOSPLIT, $0
 	CSRRW $4095, X10, X11
 	RET
 `)
-	if _, _, _, _, _, err := assembleRISCV(fn); err != nil {
+	if _, _, _, _, _, _, err := assembleRISCV(fn); err != nil {
 		t.Errorf("CSR $4095 must assemble: %v", err)
 	}
 }
 
 // TestRISCV_Imm64Rejected checks that immediates outside the signed 32-bit
-// span are diagnosed instead of silently truncated to their low 32 bits (the
-// toolchain materialises such constants via SLLI expansion, which this
-// assembler does not implement).
+// span are diagnosed instead of silently truncated to their low 32 bits for
+// the I-type arithmetic; the MOV forms materialise the wide constant instead
+// (shift sequence or pooled load), like the toolchain.
 func TestRISCV_Imm64Rejected(t *testing.T) {
 	cases := []string{
-		"MOV $0x123456789, X10",
 		"ADDI $0x100000000, X10, X11",
 		"ANDI $-0x800000001, X10, X11",
 		"SUB $0x100000000, X10, X11",
 	}
 	for _, src := range cases {
 		fn := firstTextRISCV(t, "#include \"textflag.h\"\nTEXT ·wide(SB), NOSPLIT, $0\n\t"+src+"\n\tRET\n")
-		if _, _, _, _, _, err := assembleRISCV(fn); err == nil {
+		if _, _, _, _, _, _, err := assembleRISCV(fn); err == nil {
 			t.Errorf("%s: expected an out-of-range error, got none", src)
 		}
 	}
@@ -969,9 +1105,19 @@ TEXT ·edge(SB), NOSPLIT, $0
 	SUB  $0x80000000, X12, X13
 	RET
 `)
-	if _, _, _, _, _, err := assembleRISCV(fn); err != nil {
+	if _, _, _, _, _, _, err := assembleRISCV(fn); err != nil {
 		t.Errorf("int32-span immediates must assemble: %v", err)
 	}
+	// Beyond the span the MOV forms materialise the constant like the
+	// toolchain instead of diagnosing it.
+	fn = firstTextRISCV(t, `#include "textflag.h"
+TEXT ·pool(SB), NOSPLIT, $0
+	MOV $0x123456789, X10
+	RET
+`)
+	if _, _, _, _, _, _, err := assembleRISCV(fn); err != nil {
+		t.Errorf("MOV with a 64-bit immediate must assemble: %v", err)
+	}
 }
 
 // riscvWants decodes code as little-endian words and pins each one; the

asm/riscv_frame.go

@@ -7,7 +7,7 @@ import (
 	"fmt"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
 )
 
 // RISC-V frame mapping, matching the Go toolchain's riscv64 backend.

asm/riscv_frame_test.go

@@ -6,7 +6,7 @@ package asm
 import (
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestRISCVFrameSpadjAndLines checks that a framed function records its

asm/riscv_goobj_test.go

@@ -13,7 +13,7 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // TestGOObjectRISCVCallReloc checks that CALL sym(SB) emits a single JAL

asm/vex.go

@@ -61,6 +61,21 @@ const (
 	// vexImmRMGPR is the immediate form over general-purpose registers
 	// (RORX): reg = dst, rm = src, imm8 = op0, L = 0.
 	vexImmRMGPR
+	// vexRMOpGPR is the two-operand /digit form over general-purpose
+	// registers (BLSI, BLSMSK, BLSR): ModRM.reg = /digit, ModRM.rm = src
+	// (op0), VEX.vvvv = dst (op1), L = 0.
+	vexRMOpGPR
+	// vexCountGPR is the three-operand count form over general-purpose
+	// registers (SHLX, SHRX, SARX, BEXTR, BZHI): the first operand rides
+	// VEX.vvvv and the second is r/m, the opposite pairing of the ANDN
+	// family, with reg = dst (op2), L = 0.
+	vexCountGPR
+	// vexExtractGPR is the lane-extract-to-GPR form `OP $imm, xsrc, GPR/mem
+	// dst`: ModRM.reg = xsrc (op1), ModRM.rm = destination (op2), imm8 =
+	// op0, the VPEXTRB/W/D/Q layout.  EVEX only; the destination never
+	// carries a vector length, so the register the L'L field follows is the
+	// XMM source.
+	vexExtractGPR
 )
 
 // vexSpec describes one VEX instruction's encoding parameters.
@@ -230,8 +245,34 @@ var vexTable = map[string]vexSpec{
 	"ANDNQ": {2, 0xF2, 1, 0, -1, vexNDS3GPR},
 	"MULXL": {2, 0xF6, 0, 3, -1, vexNDS3GPR},
 	"MULXQ": {2, 0xF6, 1, 3, -1, vexNDS3GPR},
-	"RORXL": {3, 0xF0, 0, 3, -1, vexImmRMGPR},
-	"RORXQ": {3, 0xF0, 1, 3, -1, vexImmRMGPR},
+	// VEX.NDS.LZ.0F38, the BMI2 three-operand bit ops: BEXTR and BZHI
+	// share the F7/F5 opcodes across W, the variable shifts carry their
+	// direction in the prefix (SHLX 66, SHRX F2, SARX F3) and PDEP/PEXT
+	// in F2/F3.
+	"BEXTRL": {2, 0xF7, 0, 0, -1, vexCountGPR},
+	"BEXTRQ": {2, 0xF7, 1, 0, -1, vexCountGPR},
+	"BZHIL":  {2, 0xF5, 0, 0, -1, vexCountGPR},
+	"BZHIQ":  {2, 0xF5, 1, 0, -1, vexCountGPR},
+	"SARXL":  {2, 0xF7, 0, 2, -1, vexCountGPR},
+	"SARXQ":  {2, 0xF7, 1, 2, -1, vexCountGPR},
+	"SHLXL":  {2, 0xF7, 0, 1, -1, vexCountGPR},
+	"SHLXQ":  {2, 0xF7, 1, 1, -1, vexCountGPR},
+	"SHRXL":  {2, 0xF7, 0, 3, -1, vexCountGPR},
+	"SHRXQ":  {2, 0xF7, 1, 3, -1, vexCountGPR},
+	"PDEPL":  {2, 0xF5, 0, 3, -1, vexNDS3GPR},
+	"PDEPQ":  {2, 0xF5, 1, 3, -1, vexNDS3GPR},
+	"PEXTL":  {2, 0xF5, 0, 2, -1, vexNDS3GPR},
+	"PEXTQ":  {2, 0xF5, 1, 2, -1, vexNDS3GPR},
+	// VEX.LZ.0F38.W, the BMI1 unary bit ops (src, dst: ModRM.reg = /digit,
+	// rm = src, vvvv = dst).
+	"BLSIL":   {2, 0xF3, 0, 0, 3, vexRMOpGPR},
+	"BLSIQ":   {2, 0xF3, 1, 0, 3, vexRMOpGPR},
+	"BLSMSKL": {2, 0xF3, 0, 0, 2, vexRMOpGPR},
+	"BLSMSKQ": {2, 0xF3, 1, 0, 2, vexRMOpGPR},
+	"BLSRL":   {2, 0xF3, 0, 0, 1, vexRMOpGPR},
+	"BLSRQ":   {2, 0xF3, 1, 0, 1, vexRMOpGPR},
+	"RORXL":   {3, 0xF0, 0, 3, -1, vexImmRMGPR},
+	"RORXQ":   {3, 0xF0, 1, 3, -1, vexImmRMGPR},
 
 	// VEX.128.0F.W0, mask-register test (KTESTW k1, k2: reg = dst, rm = src).
 	"KTESTW": {1, 0x99, 0, 0, -1, vexRM},
@@ -290,6 +331,128 @@ var vexTable = map[string]vexSpec{
 	"VCVTPD2DQY":  {1, 0xE6, 0, 3, -1, vexRMSrcLen},
 	"VCVTTPD2DQX": {1, 0xE6, 0, 1, -1, vexRMSrcLen},
 	"VCVTTPD2DQY": {1, 0xE6, 0, 1, -1, vexRMSrcLen},
+
+	// --- the VEX forms the avx512enc corpus exercises alongside the EVEX
+	// spellings, read off the toolchain opcode tables ---
+	"VAESDEC":           {2, 0xDE, 0, 1, -1, vexNDS3},
+	"VAESDECLAST":       {2, 0xDF, 0, 1, -1, vexNDS3},
+	"VAESENC":           {2, 0xDC, 0, 1, -1, vexNDS3},
+	"VAESENCLAST":       {2, 0xDD, 0, 1, -1, vexNDS3},
+	"VANDNPD":           {1, 0x55, 0, 1, -1, vexNDS3},
+	"VANDPD":            {1, 0x54, 0, 1, -1, vexNDS3},
+	"VCOMISD":           {1, 0x2F, 0, 1, -1, vexRM},
+	"VCVTSD2SS":         {1, 0x5A, 0, 3, -1, vexNDS3},
+	"VCVTSS2SD":         {1, 0x5A, 0, 2, -1, vexNDS3},
+	"VFMADD132PD":       {2, 0x98, 1, 1, -1, vexNDS3},
+	"VFMADD132PS":       {2, 0x98, 0, 1, -1, vexNDS3},
+	"VFMADD132SD":       {2, 0x99, 1, 1, -1, vexNDS3},
+	"VFMADD132SS":       {2, 0x99, 0, 1, -1, vexNDS3},
+	"VFMADD213PD":       {2, 0xA8, 1, 1, -1, vexNDS3},
+	"VFMADD213PS":       {2, 0xA8, 0, 1, -1, vexNDS3},
+	"VFMADD213SS":       {2, 0xA9, 0, 1, -1, vexNDS3},
+	"VFMADD231PS":       {2, 0xB8, 0, 1, -1, vexNDS3},
+	"VFMADD231SD":       {2, 0xB9, 1, 1, -1, vexNDS3},
+	"VFMADD231SS":       {2, 0xB9, 0, 1, -1, vexNDS3},
+	"VFMADDSUB132PD":    {2, 0x96, 1, 1, -1, vexNDS3},
+	"VFMADDSUB132PS":    {2, 0x96, 0, 1, -1, vexNDS3},
+	"VFMADDSUB213PD":    {2, 0xA6, 1, 1, -1, vexNDS3},
+	"VFMADDSUB213PS":    {2, 0xA6, 0, 1, -1, vexNDS3},
+	"VFMADDSUB231PD":    {2, 0xB6, 1, 1, -1, vexNDS3},
+	"VFMADDSUB231PS":    {2, 0xB6, 0, 1, -1, vexNDS3},
+	"VFMSUB132PD":       {2, 0x9A, 1, 1, -1, vexNDS3},
+	"VFMSUB132PS":       {2, 0x9A, 0, 1, -1, vexNDS3},
+	"VFMSUB132SD":       {2, 0x9B, 1, 1, -1, vexNDS3},
+	"VFMSUB132SS":       {2, 0x9B, 0, 1, -1, vexNDS3},
+	"VFMSUB213PD":       {2, 0xAA, 1, 1, -1, vexNDS3},
+	"VFMSUB213PS":       {2, 0xAA, 0, 1, -1, vexNDS3},
+	"VFMSUB213SD":       {2, 0xAB, 1, 1, -1, vexNDS3},
+	"VFMSUB213SS":       {2, 0xAB, 0, 1, -1, vexNDS3},
+	"VFMSUB231PD":       {2, 0xBA, 1, 1, -1, vexNDS3},
+	"VFMSUB231PS":       {2, 0xBA, 0, 1, -1, vexNDS3},
+	"VFMSUB231SD":       {2, 0xBB, 1, 1, -1, vexNDS3},
+	"VFMSUB231SS":       {2, 0xBB, 0, 1, -1, vexNDS3},
+	"VFMSUBADD132PD":    {2, 0x97, 1, 1, -1, vexNDS3},
+	"VFMSUBADD132PS":    {2, 0x97, 0, 1, -1, vexNDS3},
+	"VFMSUBADD213PD":    {2, 0xA7, 1, 1, -1, vexNDS3},
+	"VFMSUBADD213PS":    {2, 0xA7, 0, 1, -1, vexNDS3},
+	"VFMSUBADD231PD":    {2, 0xB7, 1, 1, -1, vexNDS3},
+	"VFMSUBADD231PS":    {2, 0xB7, 0, 1, -1, vexNDS3},
+	"VFNMADD132PD":      {2, 0x9C, 1, 1, -1, vexNDS3},
+	"VFNMADD132PS":      {2, 0x9C, 0, 1, -1, vexNDS3},
+	"VFNMADD132SD":      {2, 0x9D, 1, 1, -1, vexNDS3},
+	"VFNMADD132SS":      {2, 0x9D, 0, 1, -1, vexNDS3},
+	"VFNMADD213PD":      {2, 0xAC, 1, 1, -1, vexNDS3},
+	"VFNMADD213PS":      {2, 0xAC, 0, 1, -1, vexNDS3},
+	"VFNMADD213SD":      {2, 0xAD, 1, 1, -1, vexNDS3},
+	"VFNMADD213SS":      {2, 0xAD, 0, 1, -1, vexNDS3},
+	"VFNMADD231PD":      {2, 0xBC, 1, 1, -1, vexNDS3},
+	"VFNMADD231PS":      {2, 0xBC, 0, 1, -1, vexNDS3},
+	"VFNMADD231SS":      {2, 0xBD, 0, 1, -1, vexNDS3},
+	"VFNMSUB132PD":      {2, 0x9E, 1, 1, -1, vexNDS3},
+	"VFNMSUB132PS":      {2, 0x9E, 0, 1, -1, vexNDS3},
+	"VFNMSUB132SD":      {2, 0x9F, 1, 1, -1, vexNDS3},
+	"VFNMSUB132SS":      {2, 0x9F, 0, 1, -1, vexNDS3},
+	"VFNMSUB213PD":      {2, 0xAE, 1, 1, -1, vexNDS3},
+	"VFNMSUB213PS":      {2, 0xAE, 0, 1, -1, vexNDS3},
+	"VFNMSUB213SD":      {2, 0xAF, 1, 1, -1, vexNDS3},
+	"VFNMSUB213SS":      {2, 0xAF, 0, 1, -1, vexNDS3},
+	"VFNMSUB231PD":      {2, 0xBE, 1, 1, -1, vexNDS3},
+	"VFNMSUB231PS":      {2, 0xBE, 0, 1, -1, vexNDS3},
+	"VFNMSUB231SD":      {2, 0xBF, 1, 1, -1, vexNDS3},
+	"VFNMSUB231SS":      {2, 0xBF, 0, 1, -1, vexNDS3},
+	"VGF2P8AFFINEINVQB": {3, 0xCF, 1, 1, -1, vexNDS3Imm},
+	"VGF2P8MULB":        {2, 0xCF, 0, 1, -1, vexNDS3},
+	"VMOVNTDQA":         {2, 0x2A, 0, 1, -1, vexRM},
+	"VMOVNTPD":          {1, 0x2B, 0, 1, -1, vexRMRev},
+	"VORPD":             {1, 0x56, 0, 1, -1, vexNDS3},
+	"VPADDSB":           {1, 0xEC, 0, 1, -1, vexNDS3},
+	"VPADDSW":           {1, 0xED, 0, 1, -1, vexNDS3},
+	"VPADDUSB":          {1, 0xDC, 0, 1, -1, vexNDS3},
+	"VPADDUSW":          {1, 0xDD, 0, 1, -1, vexNDS3},
+	"VPCMPEQQ":          {2, 0x29, 0, 1, -1, vexNDS3},
+	"VPCMPEQW":          {1, 0x75, 0, 1, -1, vexNDS3},
+	"VPCMPGTB":          {1, 0x64, 0, 1, -1, vexNDS3},
+	"VPCMPGTD":          {1, 0x66, 0, 1, -1, vexNDS3},
+	"VPCMPGTW":          {1, 0x65, 0, 1, -1, vexNDS3},
+	"VPERMPS":           {2, 0x16, 0, 1, -1, vexNDS3},
+	"VPEXTRB":           {3, 0x14, 0, 1, -1, vexExtract},
+	"VPEXTRD":           {3, 0x16, 0, 1, -1, vexExtract},
+	"VPEXTRQ":           {3, 0x16, 1, 1, -1, vexExtract},
+	"VPINSRD":           {3, 0x22, 0, 1, -1, vexNDS3Imm},
+	"VPINSRQ":           {3, 0x22, 1, 1, -1, vexNDS3Imm},
+	"VPMULHRSW":         {2, 0x0B, 0, 1, -1, vexNDS3},
+	"VPMULHW":           {1, 0xE5, 0, 1, -1, vexNDS3},
+	"VPMULUDQ":          {1, 0xF4, 0, 1, -1, vexNDS3},
+	"VPSADBW":           {1, 0xF6, 0, 1, -1, vexNDS3},
+	"VPSUBSB":           {1, 0xE8, 0, 1, -1, vexNDS3},
+	"VPSUBSW":           {1, 0xE9, 0, 1, -1, vexNDS3},
+	"VPSUBUSB":          {1, 0xD8, 0, 1, -1, vexNDS3},
+	"VPSUBUSW":          {1, 0xD9, 0, 1, -1, vexNDS3},
+	"VPUNPCKHBW":        {1, 0x68, 0, 1, -1, vexNDS3},
+	"VPUNPCKHQDQ":       {1, 0x6D, 0, 1, -1, vexNDS3},
+	"VPUNPCKHWD":        {1, 0x69, 0, 1, -1, vexNDS3},
+	"VPUNPCKLBW":        {1, 0x60, 0, 1, -1, vexNDS3},
+	"VPUNPCKLWD":        {1, 0x61, 0, 1, -1, vexNDS3},
+	"VSQRTPD":           {1, 0x51, 0, 1, -1, vexRM},
+	"VSQRTSD":           {1, 0x51, 0, 3, -1, vexNDS3},
+	"VSQRTSS":           {1, 0x51, 0, 2, -1, vexNDS3},
+	"VUCOMISD":          {1, 0x2E, 0, 1, -1, vexRM},
+
+	// VEX.0F.WIG, the plain-prefix single/double arithmetic and unpack
+	// spellings (no 66 prefix; WIG, so W = 0).
+	"VANDNPS":   {1, 0x55, 0, 0, -1, vexNDS3},
+	"VANDPS":    {1, 0x54, 0, 0, -1, vexNDS3},
+	"VORPS":     {1, 0x56, 0, 0, -1, vexNDS3},
+	"VUNPCKLPS": {1, 0x14, 0, 0, -1, vexNDS3},
+	"VUNPCKHPS": {1, 0x15, 0, 0, -1, vexNDS3},
+	"VSQRTPS":   {1, 0x51, 0, 0, -1, vexRM},
+	"VMOVNTPS":  {1, 0x2B, 0, 0, -1, vexRMRev},
+	// VEX.128.66.0F, the scalar and packed compare forms.
+	"VCOMISS":  {1, 0x2F, 0, 1, -1, vexRM},
+	"VUCOMISS": {1, 0x2E, 0, 0, -1, vexRM},
+	// VEX.128.0F.F3/F2.W0, the high/low word shuffles ($imm, src, dst).
+	"VPSHUFHW": {1, 0x70, 0, 2, -1, vexImmRM},
+	"VPSHUFLW": {1, 0x70, 0, 3, -1, vexImmRM},
 }
 
 // vexSrcLen maps a source-length conversion mnemonic (the X/Y spellings of
@@ -420,6 +583,10 @@ func (e *enc) encodeVex(mnemUpper string, ops []Operand) error {
 		return e.encodeVexNDS3GPR(spec, ops)
 	case vexImmRMGPR:
 		return e.encodeVexImmRMGPR(spec, ops)
+	case vexRMOpGPR:
+		return e.encodeVexRMOpGPR(spec, ops)
+	case vexCountGPR:
+		return e.encodeVexCountGPR(spec, ops)
 	case vexRMRev:
 		return e.encodeVexRMRev(spec, ops)
 	}
@@ -523,9 +690,10 @@ func (e *enc) encodeVexShiftImm(spec vexSpec, ops []Operand) error {
 	if !ok {
 		return fmt.Errorf("shift count must be an immediate")
 	}
-	srcReg, ok := src.(Reg)
-	if !ok || !srcReg.isVec() {
-		return fmt.Errorf("shift source must be a vector register")
+	// The count source is a vector register or memory; the VEX length
+	// follows the destination register either way.
+	if !vecOrMem(src) {
+		return fmt.Errorf("shift source must be a vector register or memory")
 	}
 	dstReg, ok := dst.(Reg)
 	if !ok || !dstReg.isVec() {
@@ -533,7 +701,7 @@ func (e *enc) encodeVexShiftImm(spec vexSpec, ops []Operand) error {
 	}
 
 	vvvvBar := 15 - (dstReg.idx & 15)
-	if err := e.emitVexFields(spec, dstReg.vecLenBit(), spec.opdigit, 0, vvvvBar, srcReg); err != nil {
+	if err := e.emitVexFields(spec, dstReg.vecLenBit(), spec.opdigit, 0, vvvvBar, src); err != nil {
 		return err
 	}
 	immByte, err := imm8(int64(immVal))
@@ -700,7 +868,11 @@ func (e *enc) encodeVexNDS3GPR(spec vexSpec, ops []Operand) error {
 	if !ok || vvvvReg.isVec() {
 		return fmt.Errorf("VEX vvvv operand must be a general-purpose register")
 	}
-	return e.emitVexFields(spec, 0, dstReg.idx&7, 0, 15-(vvvvReg.idx&15), src2)
+	rBit := 0
+	if dstReg.idx >= 8 {
+		rBit = 1
+	}
+	return e.emitVexFields(spec, 0, dstReg.idx&7, rBit, 15-(vvvvReg.idx&15), src2)
 }
 
 // encodeVexImmRMGPR encodes the immediate form over general-purpose
@@ -729,6 +901,48 @@ func (e *enc) encodeVexImmRMGPR(spec vexSpec, ops []Operand) error {
 	return nil
 }
 
+// encodeVexRMOpGPR encodes the two-operand /digit form over general-purpose
+// registers (BLSI, BLSMSK, BLSR): OP src, dst with ModRM.reg = /digit,
+// ModRM.rm = src and VEX.vvvv = dst.
+func (e *enc) encodeVexRMOpGPR(spec vexSpec, ops []Operand) error {
+	if len(ops) != 2 {
+		return fmt.Errorf("instruction expects 2 operands (src, dst), got %d", len(ops))
+	}
+	src, dst := ops[0], ops[1]
+	dstReg, ok := dst.(Reg)
+	if !ok || dstReg.isVec() {
+		return fmt.Errorf("VEX destination must be a general-purpose register")
+	}
+	return e.emitVexFields(spec, 0, spec.opdigit, 0, 15-(dstReg.idx&15), src)
+}
+
+// encodeVexCountGPR encodes the three-operand count form over general-purpose
+// registers (SHLX, SHRX, SARX, BEXTR, BZHI): OP src, count, dst with
+// VEX.vvvv = src (op0), ModRM.rm = count (op1), ModRM.reg = dst (op2).
+func (e *enc) encodeVexCountGPR(spec vexSpec, ops []Operand) error {
+	if len(ops) != 3 {
+		return fmt.Errorf("VEX count instruction expects 3 operands, got %d", len(ops))
+	}
+	src, count, dst := ops[0], ops[1], ops[2]
+	dstReg, ok := dst.(Reg)
+	if !ok || dstReg.isVec() {
+		return fmt.Errorf("VEX destination must be a general-purpose register")
+	}
+	countReg, ok := count.(Reg)
+	if !ok || countReg.isVec() {
+		return fmt.Errorf("VEX count operand must be a general-purpose register")
+	}
+	srcReg, ok := src.(Reg)
+	if !ok || srcReg.isVec() {
+		return fmt.Errorf("VEX count source must be a general-purpose register")
+	}
+	rBit := 0
+	if dstReg.idx >= 8 {
+		rBit = 1
+	}
+	return e.emitVexFields(spec, 0, dstReg.idx&7, rBit, 15-(srcReg.idx&15), count)
+}
+
 // encodeVexRMRev encodes the reversed two-operand form: OP src, dst with the
 // vector source in ModRM.reg and the memory destination in r/m (VMOVNTDQ,
 // a store with no register-destination form).

asm/vex_test.go

@@ -31,6 +31,51 @@ var x86asmUnrecognised = map[string]bool{
 	"RORXQ":        true,
 	"VFMADD213SD":  true,
 	"VFNMADD231SD": true,
+	// The scalar FMA spellings the decoder's tables lack entirely.
+	"VFMADD132SD":  true,
+	"VFMADD132SS":  true,
+	"VFMADD213SS":  true,
+	"VFMADD231SD":  true,
+	"VFMADD231SS":  true,
+	"VFMSUB132SD":  true,
+	"VFMSUB132SS":  true,
+	"VFMSUB213SD":  true,
+	"VFMSUB213SS":  true,
+	"VFMSUB231SD":  true,
+	"VFMSUB231SS":  true,
+	"VFNMADD132SD": true,
+	"VFNMADD132SS": true,
+	"VFNMADD213SD": true,
+	"VFNMADD213SS": true,
+	"VFNMADD231SS": true,
+	"VFNMSUB132SD": true,
+	"VFNMSUB132SS": true,
+	"VFNMSUB213SD": true,
+	"VFNMSUB213SS": true,
+	"VFNMSUB231SD": true,
+	"VFNMSUB231SS": true,
+	// The BMI1 unary bit ops the decoder's AVX tables lack.
+	"BLSIL":   true,
+	"BLSIQ":   true,
+	"BLSMSKL": true,
+	"BLSMSKQ": true,
+	"BLSRL":   true,
+	"BLSRQ":   true,
+	// The BMI2 bit ops whose W1/LZ rows the decoder misses.
+	"BEXTRL": true,
+	"BEXTRQ": true,
+	"BZHIL":  true,
+	"BZHIQ":  true,
+	"PDEPL":  true,
+	"PDEPQ":  true,
+	"PEXTL":  true,
+	"PEXTQ":  true,
+	"SARXL":  true,
+	"SARXQ":  true,
+	"SHLXL":  true,
+	"SHLXQ":  true,
+	"SHRXL":  true,
+	"SHRXQ":  true,
 }
 
 // TestVexNDS3 encodes `mnem Y0, Y1, Y2` for every three-operand NDS
@@ -237,6 +282,18 @@ func TestVexGroundTruth(t *testing.T) {
 		{"MULXQ AX,BX,CX", "MULXQ", []Operand{AX, BX, CX}, "c4e2e3f6c8", ""},
 		{"RORXL $3,AX,CX", "RORXL", []Operand{Imm(3), AX, CX}, "c4e37bf0c803", ""},
 		{"RORXQ $3,AX,CX", "RORXQ", []Operand{Imm(3), AX, CX}, "c4e3fbf0c803", ""},
+		// BMI2 variable shifts and bit ops (three general registers).
+		{"SHLXL AX,CX,R15", "SHLXL", []Operand{AX, CX, vreg(t, "R15")}, "c46279f7f9", ""},
+		{"SHRXQ R8,DX,AX", "SHRXQ", []Operand{vreg(t, "R8"), DX, AX}, "c4e2bbf7c2", ""},
+		{"SARXQ AX,DX,R9", "SARXQ", []Operand{AX, DX, vreg(t, "R9")}, "c462faf7ca", ""},
+		{"BEXTRL AX,CX,R15", "BEXTRL", []Operand{AX, CX, vreg(t, "R15")}, "c46278f7f9", ""},
+		{"BZHIQ AX,CX,R15", "BZHIQ", []Operand{AX, CX, vreg(t, "R15")}, "c462f8f5f9", ""},
+		{"PDEPQ AX,CX,R15", "PDEPQ", []Operand{AX, CX, vreg(t, "R15")}, "c462f3f5f8", ""},
+		{"PEXTQ AX,CX,R15", "PEXTQ", []Operand{AX, CX, vreg(t, "R15")}, "c462f2f5f8", ""},
+		// BMI1 unary bit ops (src, dst: /digit in ModRM.reg, dst in vvvv).
+		{"BLSIL AX,CX", "BLSIL", []Operand{AX, CX}, "c4e270f3d8", ""},
+		{"BLSRQ AX,CX", "BLSRQ", []Operand{AX, CX}, "c4e2f0f3c8", ""},
+		{"BLSMSKQ AX,CX", "BLSMSKQ", []Operand{AX, CX}, "c4e2f0f3d0", ""},
 		// Two-operand reg/rm form (v̄vvv must be 1111).
 		{"VPMOVSXDQ X0,Y4", "VPMOVSXDQ", []Operand{vreg(t, "X0"), vreg(t, "Y4")}, "c4e27d25e0", ""},
 		{"VPMOVSXWD (SI),Y0", "VPMOVSXWD", []Operand{Ptr(SI, 0, 8), vreg(t, "Y0")}, "c4e27d2306", ""},

ast/ast.go

@@ -8,7 +8,7 @@
 // to the arch package; the AST records syntax only.
 package ast
 
-import "sourcedock.dev/petrbalvin/gasm-devkit/token"
+import "sourcedock.dev/petrbalvin/gasm-sdk/token"
 
 // File is the parsed representation of one .s source file.
 type File struct {
@@ -151,11 +151,21 @@ type Immediate struct {
 // Address is a non-immediate operand: a register, a memory reference, a symbol
 // reference or a label.  Fields are populated best-effort from the syntax.
 type Address struct {
-	Sym    *Symbol // name reference (bare ident, or name+off(pseudo))
-	Base   string  // base register, from (base)
-	Index  string  // index register, from (index*scale)
-	Scale  int     // index scale; 0 when absent
-	Offset int64   // leading displacement, from off(base)
-	HasOff bool    // a leading displacement is present
-	Shift  string  // verbatim arm64 shift suffix, e.g. "<< 2"
+	Sym    *Symbol   // name reference (bare ident, or name+off(pseudo))
+	Base   string    // base register, from (base)
+	Index  string    // index register, from (index*scale)
+	Scale  int       // index scale; 0 when absent
+	Offset int64     // leading displacement, from off(base)
+	HasOff bool      // a leading displacement is present
+	Shift  string    // verbatim arm64 shift suffix, e.g. "<< 2"
+	Range  *RegRange // bracketed register range; nil for every other form
+}
+
+// RegRange is a bracketed register range, [Z0-Z3]: the amd64 spelling of
+// the four-register source of the 4FMAPS/4VNNIW families.  Lo and Hi carry
+// the verbatim register spellings; the range is inclusive at both ends.
+type RegRange struct {
+	Lo  string
+	Hi  string
+	Pos token.Position
 }

ast/ast_test.go

@@ -6,7 +6,7 @@ package ast
 import (
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/token"
+	"sourcedock.dev/petrbalvin/gasm-sdk/token"
 )
 
 func pos(line, col int) token.Position { return token.Position{Line: line, Column: col} }

cmd/gasm/asmhdr.go

@@ -0,0 +1,367 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/constant"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+)
+
+// go_asm.h is the header the Go compiler writes for every package that
+// carries assembly (the compiler's -asmhdr output): "#define const_NAME
+// value" for each package constant, and for each named struct type
+// "#define TYPE__size size" plus one "#define TYPE_field offset" per field.
+// GOROOT assembly includes it, and a standalone assembler has no compiler
+// to have produced it, so gasm generates the equivalent itself: the package
+// the .s file lives in is parsed and type-checked here, with the target
+// architecture's own sizes, and the same defines are written out.  The
+// type-checking GOOS is selected by the caller: a GOOS-specific file
+// (sys_darwin_arm64.s) needs its platform's defines, which a header from
+// the ambient GOOS silently omits.
+//
+// The emitter mirrors cmd/compile's dumpasmhdr exactly: constants come out
+// as "const_NAME", struct entries as "NAME__size" followed by the fields in
+// declaration order, blank names are skipped, and float and complex
+// constants are omitted (the assembler carries integers, bools and strings
+// only).  Aliases to structs are emitted, generic types are not: they have
+// no fixed size.  A define the assembly references but this header does not
+// carry surfaces later as the assembler's own "undefined" diagnostic naming
+// the define, which is the honest failure.
+
+// goAsmInclude matches the #include "go_asm.h" directive, tolerant of
+// whitespace, so the wiring knows which files need a generated header
+// before the preprocessor runs and would report the header as missing.
+var goAsmInclude = regexp.MustCompile(`(?m)^\s*#\s*include\s+"go_asm\.h"`)
+
+// needsGoAsmHeader reports whether src includes go_asm.h.
+func needsGoAsmHeader(src string) bool {
+	return goAsmInclude.MatchString(src)
+}
+
+// goAsmHeaderResolved reports whether the include of go_asm.h from a file in
+// asmDir already resolves: to a header in the package directory itself, or
+// in one of the -I directories, the way the preprocessor searches.  Only an
+// unresolved include is generated for; a header someone placed by hand is
+// the tool the author chose, and it also wins the preprocessor's own search
+// order, so generating a second copy would be dead weight at best.
+func goAsmHeaderResolved(asmDir string, dirs []string) bool {
+	candidates := []string{filepath.Join(asmDir, "go_asm.h")}
+	for _, d := range dirs {
+		candidates = append(candidates, filepath.Join(d, "go_asm.h"))
+	}
+	for _, candidate := range candidates {
+		if st, err := os.Stat(candidate); err == nil && !st.IsDir() {
+			return true
+		}
+	}
+	return false
+}
+
+// generateGoAsmHeader type-checks the Go package in pkgDir for goos and
+// goarch, writes its go_asm.h equivalent into dir, and returns dir.  An
+// empty goos means the ambient one.  The caller owns the directory and its
+// removal.
+func generateGoAsmHeader(pkgDir, goos, goarch, dir string) (string, error) {
+	if goos == "" {
+		goos = build.Default.GOOS
+	}
+	imp := newSourceImporter(goos, goarch)
+	if imp.sizes == nil {
+		return "", fmt.Errorf("go_asm.h: unknown GOARCH %q", goarch)
+	}
+	bp, err := imp.ctxt.ImportDir(pkgDir, 0)
+	if err != nil {
+		return "", fmt.Errorf("go_asm.h for GOARCH %s in %s: %w", goarch, pkgDir, err)
+	}
+	files, errs := imp.parse(bp)
+	if len(errs) > 0 {
+		return "", fmt.Errorf("go_asm.h for GOARCH %s in %s: %s", goarch, pkgDir, errorList(errs))
+	}
+	_, info, errs := imp.checkPackage(bp, files)
+	if len(errs) > 0 {
+		return "", fmt.Errorf("go_asm.h for GOARCH %s in %s: package does not type-check: %s", goarch, pkgDir, errorList(errs))
+	}
+
+	var b strings.Builder
+	fmt.Fprintf(&b, "// generated by gasm from package %s (GOOS %s, GOARCH %s)\n\n", bp.Name, goos, goarch)
+	// Files in the build's own order and declarations in source order: the
+	// same walk the compiler's reader makes, so the header reads the same
+	// way the toolchain's does.  Order carries no meaning to the assembler
+	// (defines form a table), only to a human diffing against one.
+	for _, f := range files {
+		for _, decl := range f.Decls {
+			gd, ok := decl.(*ast.GenDecl)
+			if !ok {
+				continue
+			}
+			for _, spec := range gd.Specs {
+				switch gd.Tok {
+				case token.CONST:
+					vs, ok := spec.(*ast.ValueSpec)
+					if !ok {
+						continue
+					}
+					for _, name := range vs.Names {
+						emitConst(&b, info.Defs[name], name.Name)
+					}
+				case token.TYPE:
+					ts, ok := spec.(*ast.TypeSpec)
+					if !ok {
+						continue
+					}
+					emitStruct(&b, imp.sizes, info.Defs[ts.Name], ts.Name.Name)
+				}
+			}
+		}
+	}
+
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return "", fmt.Errorf("go_asm.h for GOARCH %s in %s: %w", goarch, pkgDir, err)
+	}
+	out := filepath.Join(dir, "go_asm.h")
+	if err := os.WriteFile(out, []byte(b.String()), 0o644); err != nil {
+		return "", fmt.Errorf("go_asm.h for GOARCH %s in %s: %w", goarch, pkgDir, err)
+	}
+	return dir, nil
+}
+
+// emitConst writes one const define, skipping what the toolchain skips:
+// blank names, and float and complex values the assembler has no syntax for.
+func emitConst(b *strings.Builder, obj types.Object, name string) {
+	c, ok := obj.(*types.Const)
+	if !ok || name == "_" {
+		return
+	}
+	switch c.Val().Kind() {
+	case constant.Float, constant.Complex, constant.Unknown:
+		return
+	}
+	fmt.Fprintf(b, "#define const_%s %s\n", name, c.Val().ExactString())
+}
+
+// emitStruct writes one named struct type's size and field offsets,
+// skipping what the toolchain skips: blank names, non-struct types, and
+// generic types, whose size depends on their instantiation.
+func emitStruct(b *strings.Builder, sizes types.Sizes, obj types.Object, name string) {
+	tn, ok := obj.(*types.TypeName)
+	if !ok || name == "_" {
+		return
+	}
+	t := types.Unalias(tn.Type())
+	// Generic types are spelled *types.Named with a type-parameter list;
+	// a plain struct type or an instantiated one carries none.
+	if named, ok := t.(*types.Named); ok && named.TypeParams().Len() > 0 {
+		return
+	}
+	st, ok := t.Underlying().(*types.Struct)
+	if !ok {
+		return
+	}
+	fmt.Fprintf(b, "#define %s__size %d\n", name, sizes.Sizeof(t))
+	fields := make([]*types.Var, st.NumFields())
+	for i := range st.NumFields() {
+		fields[i] = st.Field(i)
+	}
+	for i, off := range sizes.Offsetsof(fields) {
+		fld := fields[i]
+		if fld.Name() == "_" {
+			continue
+		}
+		fmt.Fprintf(b, "#define %s_%s %d\n", name, fld.Name(), off)
+	}
+}
+
+// errorList renders at most three errors, enough to say what is wrong
+// without burying the diagnostic the caller actually reads.
+func errorList(errs []error) string {
+	if len(errs) > 3 {
+		errs = errs[:3]
+	}
+	msgs := make([]string, len(errs))
+	for i, err := range errs {
+		msgs[i] = err.Error()
+	}
+	return strings.Join(msgs, "; ")
+}
+
+// sourceImporter type-checks imported packages from source with the target
+// architecture's sizes.  go/importer's "source" importer pins the host
+// GOARCH, which would lay out imported types (internal/cpu, internal/abi)
+// for the wrong target on a cross-architecture header, so the recursion is
+// carried here with one build context and one sizes instance per
+// architecture.
+type sourceImporter struct {
+	fset  *token.FileSet
+	ctxt  *build.Context
+	sizes types.Sizes
+	pkgs  map[string]*types.Package
+}
+
+// newSourceImporter returns the importer for one target GOOS and GOARCH.
+// Cgo is disabled so the file set is deterministic and independent of the
+// host's C toolchain: cgo-tagged files drop out of the build exactly as
+// they do from a CGO_ENABLED=0 build, whose assembly is what gasm targets.
+func newSourceImporter(goos, goarch string) *sourceImporter {
+	ctxt := new(build.Context)
+	*ctxt = build.Default
+	ctxt.GOOS = goos
+	ctxt.GOARCH = goarch
+	ctxt.CgoEnabled = false
+	return &sourceImporter{
+		fset:  token.NewFileSet(),
+		ctxt:  ctxt,
+		sizes: types.SizesFor("gc", goarch),
+		pkgs:  map[string]*types.Package{},
+	}
+}
+
+// Import type-checks one imported package and memoises it.  "unsafe" must
+// resolve to go/types' own package, never to the source in GOROOT/src/unsafe:
+// the source declares Sizeof and Offsetof as ordinary functions over
+// ArbitraryType, and checking against that signature rejects half the
+// unsafe arithmetic the gc compiler accepts, which is exactly the divergence
+// srcimporter guards against the same way.
+func (im *sourceImporter) Import(path string) (*types.Package, error) {
+	if path == "unsafe" {
+		return types.Unsafe, nil
+	}
+	if p, ok := im.pkgs[path]; ok {
+		return p, nil
+	}
+	bp, err := im.ctxt.Import(path, "", 0)
+	if err != nil {
+		return nil, err
+	}
+	files, errs := im.parse(bp)
+	if len(errs) > 0 {
+		return nil, errors.New(errorList(errs))
+	}
+	pkg, _, _ := im.checkPackage(bp, files)
+	im.pkgs[path] = pkg
+	return pkg, nil
+}
+
+// parse reads the build package's Go files.  Import-level failures (no Go
+// files for the target, unreadable files) come back as errors, and the
+// type-check decides the rest.
+func (im *sourceImporter) parse(bp *build.Package) ([]*ast.File, []error) {
+	if len(bp.GoFiles) == 0 {
+		return nil, []error{fmt.Errorf("no Go source files for GOOS=%s GOARCH=%s", im.ctxt.GOOS, im.ctxt.GOARCH)}
+	}
+	var (
+		files []*ast.File
+		errs  []error
+	)
+	for _, name := range bp.GoFiles {
+		f, err := parser.ParseFile(im.fset, filepath.Join(bp.Dir, name), nil, parser.SkipObjectResolution)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		files = append(files, f)
+	}
+	return files, errs
+}
+
+// checkPackage type-checks one package's files with the importer's sizes,
+// recording every error: a header from a package that does not type-check
+// could silently mis-state an offset, so the caller refuses the header
+// rather than trusting it.  The returned Defs map backs the root package's
+// emission walk; imports only need the checked package itself.
+func (im *sourceImporter) checkPackage(bp *build.Package, files []*ast.File) (*types.Package, *types.Info, []error) {
+	var errs []error
+	conf := &types.Config{
+		Importer: im,
+		Sizes:    im.sizes,
+		Error:    func(err error) { errs = append(errs, err) },
+	}
+	info := &types.Info{Defs: map[*ast.Ident]types.Object{}}
+	pkg, _ := conf.Check(bp.ImportPath, im.fset, files, info)
+	return pkg, info, errs
+}
+
+// asmhdrCache generates one go_asm.h per package directory and target
+// architecture under one temp root, for callers that assemble many files
+// (the corpus audit).  Failures are cached too: a package that does not
+// type-check must not be re-checked once per file.
+type asmhdrCache struct {
+	root string
+	dirs map[string]string // "pkgDir\x00goos\x00goarch" -> directory holding go_asm.h
+	errs map[string]error
+}
+
+func newAsmhdrCache() (*asmhdrCache, error) {
+	root, err := os.MkdirTemp("", "gasm-asmhdr")
+	if err != nil {
+		return nil, err
+	}
+	return &asmhdrCache{root: root, dirs: map[string]string{}, errs: map[string]error{}}, nil
+}
+
+// dirFor returns the directory holding the generated go_asm.h for pkgDir
+// under goos and goarch, generating it on first use.  An empty goos means
+// the ambient one, resolved here so that one package cannot generate twice
+// under an explicit and an implicit spelling of the same GOOS.
+func (c *asmhdrCache) dirFor(pkgDir, goos, goarch string) (string, error) {
+	if goos == "" {
+		goos = build.Default.GOOS
+	}
+	key := pkgDir + "\x00" + goos + "\x00" + goarch
+	if dir, ok := c.dirs[key]; ok {
+		return dir, nil
+	}
+	if err, ok := c.errs[key]; ok {
+		return "", err
+	}
+	dir := filepath.Join(c.root, fmt.Sprintf("h%d_%s_%s", len(c.dirs), goos, goarch))
+	if _, err := generateGoAsmHeader(pkgDir, goos, goarch, dir); err != nil {
+		c.errs[key] = err
+		return "", err
+	}
+	c.dirs[key] = dir
+	return dir, nil
+}
+
+// close removes the temp root.
+func (c *asmhdrCache) close() { os.RemoveAll(c.root) }
+
+// ensureGoAsmHeader prepares the include directory a file that includes
+// go_asm.h needs: the generated header for the package in path's directory,
+// for the file's target GOOS and architecture.  It reports a usage error
+// when the architecture cannot be determined, and passes through the
+// generator's diagnostics, which name the package.
+func ensureGoAsmHeader(path string, target arch.Arch, goos string, cache *asmhdrCache) (string, func(), error) {
+	if path == "-" {
+		return "", nil, errors.New("cannot generate go_asm.h for standard input (no package directory)")
+	}
+	if target == arch.Unknown {
+		return "", nil, errors.New("a file that includes go_asm.h needs a target architecture: name the file _<arch>.s or pass -GOARCH")
+	}
+	if cache != nil {
+		dir, err := cache.dirFor(filepath.Dir(path), goos, goarchName(target))
+		return dir, func() {}, err
+	}
+	root, err := os.MkdirTemp("", "gasm-asmhdr")
+	if err != nil {
+		return "", nil, err
+	}
+	dir, err := generateGoAsmHeader(filepath.Dir(path), goos, goarchName(target), root)
+	if err != nil {
+		os.RemoveAll(root)
+		return "", nil, err
+	}
+	return dir, func() { os.RemoveAll(root) }, nil
+}

cmd/gasm/asmhdr_test.go

@@ -0,0 +1,476 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// writePkg lays out a minimal Go package in a temp directory.
+func writePkg(t *testing.T, files map[string]string) string {
+	t.Helper()
+	dir := t.TempDir()
+	for name, src := range files {
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(src), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+// generateFor generates the header for dir and returns its text.  An empty
+// goos means the ambient one.
+func generateFor(t *testing.T, dir, goos, goarch string) string {
+	t.Helper()
+	hdrDir, err := generateGoAsmHeader(dir, goos, goarch, t.TempDir())
+	if err != nil {
+		t.Fatalf("generateGoAsmHeader(%q, %s, %s): %v", dir, goos, goarch, err)
+	}
+	b, err := os.ReadFile(filepath.Join(hdrDir, "go_asm.h"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(b)
+}
+
+func TestGenerateGoAsmHeaderShape(t *testing.T) {
+	dir := writePkg(t, map[string]string{"sample.go": `package sample
+
+const bufSize = 1024
+
+const (
+	a = iota * 8
+	b
+	c
+)
+
+const (
+	strConst = "hello"
+	boolConst = true
+	floatConst = 1.5
+	_ = "the blank identifier is skipped"
+)
+
+const shift = 1 << 20
+
+type reader struct {
+	r    int64
+	w    int64
+	_    [4]byte
+	name string
+}
+
+type scalar int
+
+type aliased struct {
+	k uint32
+	v uint32
+}
+
+type alias = aliased
+`})
+	hdr := generateFor(t, dir, "", "amd64")
+	want := []string{
+		"#define const_bufSize 1024",
+		// iota resolves through go/types, one define per name.
+		"#define const_a 0",
+		"#define const_b 8",
+		"#define const_c 16",
+		`#define const_strConst "hello"`,
+		"#define const_boolConst true",
+		// Floats are the toolchain's own skip, as are blank names.
+		"#define const_shift 1048576",
+		// The blank field still occupies its bytes: the pad after w runs to
+		// the string's 8-byte alignment.
+		"#define reader__size 40",
+		"#define reader_r 0",
+		"#define reader_w 8",
+		"#define reader_name 24",
+		// Non-struct named types carry no defines; aliases to structs do.
+		"#define aliased__size 8",
+		"#define aliased_k 0",
+		"#define aliased_v 4",
+		"#define alias__size 8",
+		"#define alias_k 0",
+		"#define alias_v 4",
+	}
+	for _, w := range want {
+		if !strings.Contains(hdr, w+"\n") {
+			t.Errorf("header misses %q\ngot:\n%s", w, hdr)
+		}
+	}
+	for _, banned := range []string{"#define const_floatConst", "#define _ ", "#define scalar"} {
+		if strings.Contains(hdr, banned) {
+			t.Errorf("header must not carry %s\ngot:\n%s", banned, hdr)
+		}
+	}
+}
+
+func TestGenerateGoAsmHeaderPerArch(t *testing.T) {
+	dir := writePkg(t, map[string]string{
+		"common.go": `package perarch
+
+type layout struct {
+	a int32
+	p uintptr
+}
+`,
+		// The build-tagged file set is part of the contract: a per-arch
+		// package is exactly how internal/cpu declares its layouts.
+		"const_amd64.go": `//go:build amd64
+
+package perarch
+
+const flavour = 1
+`,
+		"const_arm64.go": `//go:build arm64
+
+package perarch
+
+const flavour = 2
+`,
+	})
+	amd64 := generateFor(t, dir, "", "amd64")
+	arm64 := generateFor(t, dir, "", "arm64")
+	if !strings.Contains(amd64, "#define const_flavour 1\n") {
+		t.Errorf("amd64 header misses const_flavour 1:\n%s", amd64)
+	}
+	if !strings.Contains(arm64, "#define const_flavour 2\n") {
+		t.Errorf("arm64 header misses const_flavour 2:\n%s", arm64)
+	}
+	if strings.Contains(arm64, "#define const_flavour 1\n") {
+		t.Errorf("arm64 header must not carry the amd64 file's value")
+	}
+	// SizesFor makes the layout the target's: uintptr is 4 bytes wide on
+	// 386 and 8 on amd64, which must move p and grow the struct.
+	if !strings.Contains(amd64, "#define layout__size 16\n") || !strings.Contains(amd64, "#define layout_p 8\n") {
+		t.Errorf("amd64 layout wrong:\n%s", amd64)
+	}
+	w386 := generateFor(t, dir, "", "386")
+	if !strings.Contains(w386, "#define layout__size 8\n") || !strings.Contains(w386, "#define layout_p 4\n") {
+		t.Errorf("386 layout wrong:\n%s", w386)
+	}
+}
+
+// TestGenerateGoAsmHeaderGOOS pins the GOOS half of the target: only the
+// platform's own files type-check into the header, which is why
+// sys_darwin_arm64.s cannot assemble against a linux-generated one.
+func TestGenerateGoAsmHeaderGOOS(t *testing.T) {
+	dir := writePkg(t, map[string]string{
+		"common.go": `package goosaware
+
+type shared struct {
+	a int32
+}
+`,
+		"plat_darwin.go": `//go:build darwin
+
+package goosaware
+
+type platform struct {
+	trampoline_numer int64
+}
+`,
+		"plat_windows.go": `//go:build windows
+
+package goosaware
+
+type platform struct {
+	callbackArgs__size int32
+}
+`,
+	})
+	darwin := generateFor(t, dir, "darwin", "arm64")
+	if !strings.Contains(darwin, "#define platform__size 8\n") || !strings.Contains(darwin, "#define platform_trampoline_numer 0\n") {
+		t.Errorf("darwin header misses the darwin layout:\n%s", darwin)
+	}
+	if strings.Contains(darwin, "callbackArgs") {
+		t.Errorf("darwin header must not carry the windows layout:\n%s", darwin)
+	}
+	windows := generateFor(t, dir, "windows", "arm64")
+	if !strings.Contains(windows, "#define platform_callbackArgs__size 0\n") {
+		t.Errorf("windows header misses the windows layout:\n%s", windows)
+	}
+	if strings.Contains(windows, "trampoline_numer") {
+		t.Errorf("windows header must not carry the darwin layout:\n%s", windows)
+	}
+	// The ambient GOOS is neither of the two, so only shared's defines are
+	// emitted; the shared type keeps its layout there.
+	ambient := generateFor(t, dir, "", "arm64")
+	if !strings.Contains(ambient, "#define shared__size 4\n") {
+		t.Errorf("ambient header misses the shared layout:\n%s", ambient)
+	}
+	if strings.Contains(ambient, "#define platform_") {
+		t.Errorf("ambient header must not carry either platform layout:\n%s", ambient)
+	}
+}
+
+func TestGoosFromFilename(t *testing.T) {
+	for path, want := range map[string]string{
+		"/x/sys_darwin_arm64.s":     "darwin",
+		"/x/sys_windows_arm64.s":    "windows",
+		"/x/asm_linux_amd64.s":      "linux",
+		"/x/rt0_darwin_arm64.s":     "darwin",
+		"/x/vgetrandom_zos_s390x.s": "zos",
+		"/x/rt0_js_wasm.s":          "js",
+		"/x/memmove_amd64.s":        "",
+		"/x/vlop_arm.s":             "",
+		"/x/stubs.s":                "",
+	} {
+		if got := goosFromFilename(path); got != want {
+			t.Errorf("goosFromFilename(%q) = %q, want %q", path, got, want)
+		}
+	}
+}
+
+func TestGenerateGoAsmHeaderErrors(t *testing.T) {
+	t.Run("type error", func(t *testing.T) {
+		dir := writePkg(t, map[string]string{"bad.go": `package bad
+
+const x = undefinedIdent
+`})
+		_, err := generateGoAsmHeader(dir, "", "amd64", t.TempDir())
+		if err == nil {
+			t.Fatal("generation must fail for a package that does not type-check")
+		}
+		if !strings.Contains(err.Error(), dir) {
+			t.Errorf("error must name the package directory: %v", err)
+		}
+		if !strings.Contains(err.Error(), "type-check") {
+			t.Errorf("error must say the package does not type-check: %v", err)
+		}
+	})
+	t.Run("no go files", func(t *testing.T) {
+		dir := t.TempDir()
+		_, err := generateGoAsmHeader(dir, "", "amd64", t.TempDir())
+		if err == nil {
+			t.Fatal("generation must fail without Go files")
+		}
+		if !strings.Contains(err.Error(), dir) {
+			t.Errorf("error must name the package directory: %v", err)
+		}
+	})
+}
+
+func TestNeedsGoAsmHeader(t *testing.T) {
+	yes := "#include \"go_asm.h\"\n#include \"textflag.h\"\n"
+	no := "#include \"textflag.h\"\n#include \"funcdata.h\"\n"
+	if !needsGoAsmHeader(yes) {
+		t.Error("needsGoAsmHeader(missing on a go_asm.h include)")
+	}
+	if needsGoAsmHeader(no) {
+		t.Error("needsGoAsmHeader claims other headers need generation")
+	}
+}
+
+func TestGoAsmHeaderResolved(t *testing.T) {
+	dir := t.TempDir()
+	if goAsmHeaderResolved(dir, nil) {
+		t.Error("resolved with no header anywhere")
+	}
+	other := t.TempDir()
+	if goAsmHeaderResolved(dir, []string{other}) {
+		t.Error("resolved with an empty -I directory")
+	}
+	if err := os.WriteFile(filepath.Join(dir, "go_asm.h"), nil, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if !goAsmHeaderResolved(dir, nil) {
+		t.Error("not resolved with the header in the package directory")
+	}
+}
+
+func TestOtherGOOSFile(t *testing.T) {
+	for path, want := range map[string]bool{
+		"/x/sys_windows_amd64.s": true,
+		"/x/rt0_js_wasm.s":       true,
+		"/x/sys_darwin_arm64.s":  true,
+		"/x/sys_linux_amd64.s":   false,
+		"/x/time_linux_amd64.s":  false,
+		"/x/memmove_amd64.s":     false,
+		"/x/generic.s":           false,
+	} {
+		if got := otherGOOSFile(path); got != want {
+			t.Errorf("otherGOOSFile(%q) = %v, want %v", path, got, want)
+		}
+	}
+}
+
+// TestRunCorpusAuditGoAsm covers the audit wiring end to end: a package
+// beside its kernel, the kernel living off the generated defines, and the
+// histogram recording a generation failure as its own reason.
+func TestRunCorpusAuditGoAsm(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name, src string) {
+		t.Helper()
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(src), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	write("pkg.go", `package corpus
+
+const pageSize = 4096
+
+type header struct {
+	magic uint64
+	flags uint64
+}
+`)
+	write("kern_amd64.s", "#include \"go_asm.h\"\nTEXT \xc2\xb7f(SB), NOSPLIT, $0-16\n\tMOVQ\t$const_pageSize, AX\n\tMOVQ\t$header__size, BX\n\tRET\n")
+	// The defines live in the file's own package; a kernel in a directory
+	// without Go files has no package to generate from.
+	if err := os.MkdirAll(filepath.Join(dir, "sub"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	write(filepath.Join("sub", "lonely_arm64.s"), "#include \"go_asm.h\"\nTEXT \xc2\xb7g(SB), NOSPLIT, $0-0\n\tRET\n")
+
+	stats, err := runCorpusAudit(dir, nil)
+	if err != nil {
+		t.Fatalf("runCorpusAudit: %v", err)
+	}
+	get := func(name string) *corpusTally {
+		for i, tg := range stats.targets {
+			if tg.name == name {
+				return stats.tallies[i]
+			}
+		}
+		t.Fatalf("no tally for %s", name)
+		return nil
+	}
+	if a := get("amd64"); a.attempted != 1 || a.assembled != 1 {
+		t.Errorf("amd64 = %d/%d, want 1/1", a.assembled, a.attempted)
+	}
+	// lonely_arm64.s is an arm64 file whose package cannot be generated.
+	if a := get("arm64"); a.attempted != 1 || a.assembled != 0 {
+		t.Errorf("arm64 = %d/%d, want 0/1", a.assembled, a.attempted)
+	}
+	if r := get("arm64").reasons["go_asm.h generation failed"]; r != 1 {
+		t.Errorf("arm64 go_asm.h failure count = %d, want 1", r)
+	}
+}
+
+// TestRunCorpusAuditGOOS covers the filename-derived GOOS end to end: a
+// kernel whose name names darwin must have its header type-checked with
+// GOOS=darwin, so the darwin-only constant it offsets with is defined.  The
+// operand mirrors sys_darwin_arm64.s's trampoline, where a missing define
+// leaves an unexpanded symbol in the offset and fails.
+func TestRunCorpusAuditGOOS(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name, src string) {
+		t.Helper()
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(src), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	write("pkg.go", "package corpus\n")
+	write("plat_darwin.go", "//go:build darwin\n\npackage corpus\n\nconst trampolineNumer = 8\n")
+	write("kern_darwin_arm64.s", "#include \"go_asm.h\"\n"+
+		"GLOBL timebase<>(SB), NOPTR, $16\n"+
+		"TEXT \xc2\xb7g(SB), NOSPLIT, $0-0\n"+
+		"\tMOVD\ttimebase<>+const_trampolineNumer(SB), R0\n"+
+		"\tRET\n")
+
+	stats, err := runCorpusAudit(dir, nil)
+	if err != nil {
+		t.Fatalf("runCorpusAudit: %v", err)
+	}
+	var arm *corpusTally
+	for i, tg := range stats.targets {
+		if tg.name == "arm64" {
+			arm = stats.tallies[i]
+		}
+	}
+	if arm == nil {
+		t.Fatal("no arm64 tally")
+	}
+	if arm.attempted != 1 || arm.assembled != 1 {
+		t.Errorf("arm64 = %d/%d, want 1/1; reasons: %v", arm.assembled, arm.attempted, arm.reasons)
+	}
+}
+
+// TestRunCorpusAuditBuildConstraint covers the //go:build classification end
+// to end: a generic-named file whose constraint admits one target is
+// attempted there alone (cpu_x86.s on amd64), and a file whose constraint
+// admits none of the four targets is never attempted (the msan and
+// goexperiment trees).
+func TestRunCorpusAuditBuildConstraint(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name, src string) {
+		t.Helper()
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(src), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	write("x86.s", "//go:build 386 || amd64\n\nTEXT \xc2\xb7f(SB), NOSPLIT, $0\n\tRET\n")
+	write("racey.s", "//go:build race\n\nTEXT \xc2\xb7r(SB), NOSPLIT, $0\n\tRET\n")
+	write("plain.s", "TEXT \xc2\xb7p(SB), NOSPLIT, $0\n\tRET\n")
+
+	stats, err := runCorpusAudit(dir, nil)
+	if err != nil {
+		t.Fatalf("runCorpusAudit: %v", err)
+	}
+	tally := func(name string) *corpusTally {
+		for i, tg := range stats.targets {
+			if tg.name == name {
+				return stats.tallies[i]
+			}
+		}
+		t.Fatalf("no tally for %s", name)
+		return nil
+	}
+	if stats.narrowed != 1 || stats.excluded != 1 || stats.generic != 1 {
+		t.Errorf("buckets = narrowed %d, excluded %d, generic %d; want 1, 1, 1", stats.narrowed, stats.excluded, stats.generic)
+	}
+	if a := tally("amd64"); a.attempted != 2 || a.assembled != 2 {
+		t.Errorf("amd64 = %d/%d, want 2/2 (x86.s and plain.s)", a.assembled, a.attempted)
+	}
+	for _, name := range []string{"arm64", "riscv64", "loong64"} {
+		if a := tally(name); a.attempted != 1 || a.assembled != 1 {
+			t.Errorf("%s = %d/%d, want 1/1 (plain.s only)", name, a.assembled, a.attempted)
+		}
+	}
+	if stats.full != 2 {
+		t.Errorf("full = %d, want 2 (x86.s over its one target, plain.s over all four)", stats.full)
+	}
+}
+
+// TestGenerateGoAsmHeaderRuntime pins the generator against the real thing:
+// the runtime package of the ambient toolchain, whose header the toolchain's
+// own -asmhdr output was sampled from.  Skipped in short mode: it type-checks
+// the whole package.  The GOROOT comes from the go command itself, so the
+// test follows whatever toolchain the host provides.
+func TestGenerateGoAsmHeaderRuntime(t *testing.T) {
+	if testing.Short() {
+		t.Skip("type-checks the whole runtime package")
+	}
+	out, err := exec.Command("go", "env", "GOROOT").Output()
+	if err != nil {
+		t.Skipf("no Go toolchain: %v", err)
+	}
+	runtimeDir := filepath.Join(strings.TrimSpace(string(out)), "src", "runtime")
+	dir, err := generateGoAsmHeader(runtimeDir, "", "amd64", t.TempDir())
+	if err != nil {
+		t.Fatalf("generateGoAsmHeader(runtime): %v", err)
+	}
+	b, err := os.ReadFile(dir + "/go_asm.h")
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr := string(b)
+	for _, want := range []string{
+		"#define const_hashSize 8\n",
+		"#define const_avxSupported 1\n",
+		"#define const_pageSize 8192\n",
+		"#define g_stackguard0 16\n",
+		"#define m__size ",
+	} {
+		if !strings.Contains(hdr, want) {
+			t.Errorf("runtime header misses %q", want)
+		}
+	}
+}

cmd/gasm/audit.go

@@ -5,6 +5,8 @@ package main
 
 import (
 	"fmt"
+	"go/build/constraint"
+	"maps"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -14,9 +16,9 @@ import (
 	"strconv"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // cmdAuditInstructions cross-checks a gasm encoder against the Go toolchain's
@@ -37,7 +39,7 @@ import (
 // construction and are excluded from the diff; the other architectures list
 // their conditional branches outright.
 func cmdAuditInstructions(args []string) error {
-	fs := newCommand("audit-instructions", "gasm audit-instructions [--corpus [dir]] [amd64|arm64|riscv64|loong64]", `
+	fs := newCommand("audit-instructions", "gasm audit-instructions [--corpus [dir]] [--list] [-I dir] [amd64|arm64|riscv64|loong64]", `
 Compare the gasm encoder for the given architecture (default amd64) against
 go tool asm and print the diff: superset encodings (gasm-only, shippable via
 gasm asm --format goobj) and known-but-unencodable names (the backlog).  The
@@ -54,14 +56,19 @@ toolchain probing.  A file whose name carries a recognisable _arch suffix is
 attempted for that architecture; a file without one is attempted for all
 four, exactly as a GOARCH build would compile it.  The report gives the
 per-architecture pass rates and the most common failure reasons, which drive
-the encodability backlog by frequency rather than by table order.
+the encodability backlog by frequency rather than by table order.  With
+-list the report also prints every failing file with its reason, per
+architecture.
 `)
 	corpus := fs.Bool("corpus", false, "assemble a corpus of .s files and report pass rates and failure reasons")
+	list := fs.Bool("list", false, "with --corpus, list every failing file with its reason, per architecture")
+	var dirs includeDirs
+	fs.Var(&dirs, "I", "directory to search for #include files (may be repeated)")
 	if err := fs.Parse(args); err != nil {
 		return err
 	}
 	if *corpus {
-		return cmdAuditCorpus(fs.Args())
+		return cmdAuditCorpus(fs.Args(), dirs, *list)
 	}
 	archName := "amd64"
 	switch n := len(fs.Args()); {
@@ -286,6 +293,11 @@ func probeShapes(a arch.Arch) []string {
 			"V1.B16, [V2.B16], V3.B16", "V1.B8, [V2.B16, V3.B16], V4.B8",
 			"$4, V1.B16, V2.B16, V3.B16", "$15, V1", "V1, V2, p2",
 			"R0, R1, $1, $4, p2",
+			// The landing-pad kind, the compiler's PCDATA
+			// bookkeeping and the four-operand bitfield
+			// insert/extract family, as the toolchain's own
+			// testdata spells them.
+			"C", "$1, $0", "$0, R1, $1, R2",
 		}
 	case arch.RISCV:
 		return []string{
@@ -305,6 +317,9 @@ func probeShapes(a arch.Arch) []string {
 			"X5, X6, p2", "R5, R6, p2",
 			"X5, E8, M8, TA, MA, X6", "$4, E32, M1, TA, MA, X1",
 			"(X5), X6, V1, V2",
+			// The CSR immediate forms the toolchain's testdata spells:
+			// immediate, CSR name, destination.
+			"$2, TIME, X5",
 			"",
 		}
 	case arch.LOONG64:
@@ -321,6 +336,12 @@ func probeShapes(a arch.Arch) []string {
 			"V1, V2, V3", "X1, X2, X3", "V1, V2", "X1, X2", "V1", "X1",
 			// The vector compare-to-flag forms land in an FCC register.
 			"V1, FCC0", "X1, FCC0",
+			// The compiler's bookkeeping pair and the raw spellings the
+			// toolchain's own testdata carries: JIRL rd, rj, offset (the
+			// form RET lowers to), the prefetch with a 32-bit address and
+			// hint, and the byte-shuffle quads.
+			"$1, $0", "R1, R5, 0", "0(R7), $5, $0", "(R7), $5, $0",
+			"V1, V2, V3, V4", "X1, X2, X3, X4",
 			"",
 		}
 	}
@@ -386,17 +407,30 @@ type corpusTally struct {
 	assembled int
 	reasons   map[string]int    // failure reason → count
 	example   map[string]string // failure reason → one representative file
+	fails     []corpusFailure   // every failure, in file order, for --list
 }
 
-func (t *corpusTally) fail(path, reason string) {
+// corpusFailure is one failed attempt, recorded for the --list report.
+type corpusFailure struct {
+	path   string
+	reason string
+	detail string
+}
+
+func (t *corpusTally) fail(path string, err error) {
+	reason := corpusReason(err)
 	t.reasons[reason]++
 	if t.example[reason] == "" {
 		t.example[reason] = path
 	}
+	t.fails = append(t.fails, corpusFailure{path: path, reason: reason, detail: firstLine(err.Error())})
 }
 
-// cmdAuditCorpus implements audit-instructions --corpus.
-func cmdAuditCorpus(args []string) error {
+// cmdAuditCorpus implements audit-instructions --corpus.  The include
+// directories carry #include resolution over a corpus whose files refer to
+// headers such as GOROOT/pkg/include, the same -I a toolchain comparison
+// needs.
+func cmdAuditCorpus(args []string, dirs includeDirs, list bool) error {
 	if len(args) > 1 {
 		return &usageError{fmt.Errorf("audit-instructions --corpus takes at most one directory argument")}
 	}
@@ -410,11 +444,31 @@ func cmdAuditCorpus(args []string) error {
 		}
 		root = filepath.Join(strings.TrimSpace(string(out)), "src")
 	}
-	stats, err := runCorpusAudit(root)
+	// The toolchain's shipped headers (funcdata.h and friends) define the
+	// macros GOROOT files include; a corpus audit measures those files, so
+	// the header directory joins the search path automatically.  go_asm.h
+	// is compiler-generated per package, so it is not resolved from here:
+	// files that include it get one generated per target architecture,
+	// which runCorpusAudit arranges.
+	if out, err := exec.Command("go", "env", "GOROOT").Output(); err == nil {
+		pkgInclude := filepath.Join(strings.TrimSpace(string(out)), "pkg", "include")
+		if fi, err := os.Stat(pkgInclude); err == nil && fi.IsDir() {
+			seen := false
+			for _, d := range dirs {
+				if d == pkgInclude {
+					seen = true
+				}
+			}
+			if !seen {
+				dirs = append(dirs, pkgInclude)
+			}
+		}
+	}
+	stats, err := runCorpusAudit(root, dirs)
 	if err != nil {
 		return err
 	}
-	printCorpusStats(stats)
+	printCorpusStats(stats, list)
 	return nil
 }
 
@@ -423,8 +477,10 @@ type corpusStats struct {
 	root      string
 	files     int
 	generic   int // files attempted for all four architectures
+	narrowed  int // files whose //go:build admits a proper subset of the four
+	excluded  int // files whose //go:build admits none of the four: never compiled
 	otherPort int // files named for another Go port: never attempted
-	full      int // files that assembled for every target architecture
+	full      int // files that assembled for every applicable target architecture
 	targets   []corpusTarget
 	tallies   []*corpusTally
 }
@@ -435,13 +491,19 @@ type corpusStats struct {
 // set, even when gasm does not support the architecture.
 var goPortSuffixes = []string{
 	"386", "amd64", "arm", "arm64", "loong64", "mips", "mips64",
-	"mips64le", "mipsle", "ppc64", "ppc64le", "riscv", "riscv64",
-	"s390x", "wasm",
+	"mips64le", "mipsle", "mips64x", "mipsx", "ppc64", "ppc64le",
+	"ppc64x", "riscv", "riscv64", "s390x", "wasm",
 }
 
-// otherPortFile reports whether the file's name carries a Go-architecture
-// suffix gasm does not support.
+// otherPortFile reports whether the file belongs to a build no supported
+// target ever compiles: either its name carries a Go-architecture suffix
+// gasm does not support, or, for a file with no architecture suffix at all,
+// it names another GOOS, which go/build drops from the file set
+// (rt0_js_wasm.s is a javascript build, not a generic one).
 func otherPortFile(path string) bool {
+	if otherGOOSFile(path) {
+		return true
+	}
 	base := path
 	if i := strings.LastIndexByte(base, '/'); i >= 0 {
 		base = base[i+1:]
@@ -454,7 +516,118 @@ func otherPortFile(path string) bool {
 	return false
 }
 
-func runCorpusAudit(root string) (*corpusStats, error) {
+// goOSNames are the GOOS values go/build recognises in file names.
+var goOSNames = map[string]bool{
+	"aix": true, "android": true, "darwin": true, "dragonfly": true,
+	"freebsd": true, "hurd": true, "illumos": true, "ios": true,
+	"js": true, "linux": true, "nacl": true, "netbsd": true,
+	"openbsd": true, "plan9": true, "solaris": true, "wasip1": true,
+	"windows": true, "zos": true,
+}
+
+// resolveGOOS validates a -GOOS flag value, mirroring the architecture
+// check's surface: a usage error naming what the tool accepts.
+func resolveGOOS(name string) (string, error) {
+	lower := strings.ToLower(name)
+	if goOSNames[lower] {
+		return lower, nil
+	}
+	return "", &usageError{fmt.Errorf("unknown GOOS %q: want one of %s", name, strings.Join(slices.Sorted(maps.Keys(goOSNames)), ", "))}
+}
+
+// goosFromFilename returns the GOOS the file's name carries, by go/build's
+// goodOSArchFile rule: the GOOS segment sits last, or last before the
+// architecture segment (sys_darwin_arm64.s, vlop_arm.s carries none).  An
+// empty result means the name names no GOOS and the ambient one applies.
+func goosFromFilename(path string) string {
+	base := path
+	if i := strings.LastIndexByte(base, '/'); i >= 0 {
+		base = base[i+1:]
+	}
+	base = strings.TrimSuffix(base, ".s")
+	// go/build ignores everything before the first underscore, so a GOOS
+	// segment is only ever looked for from there on.
+	i := strings.IndexByte(base, '_')
+	if i < 0 {
+		return ""
+	}
+	segs := strings.Split(base[i:], "_")
+	if n := len(segs); n >= 2 && goOSNames[segs[n-2]] && slices.Contains(goPortSuffixes, segs[n-1]) {
+		return segs[n-2]
+	}
+	if goOSNames[segs[len(segs)-1]] {
+		return segs[len(segs)-1]
+	}
+	return ""
+}
+
+// otherGOOSFile reports whether the file's name names a GOOS other than the
+// host's, by go/build's file-name rules.
+func otherGOOSFile(path string) bool {
+	base := path
+	if i := strings.LastIndexByte(base, '/'); i >= 0 {
+		base = base[i+1:]
+	}
+	for seg := range strings.SplitSeq(strings.TrimSuffix(base, ".s"), "_") {
+		if goOSNames[seg] && seg != runtime.GOOS {
+			return true
+		}
+	}
+	return false
+}
+
+// buildConstraint returns the file's leading //go:build expression, or nil
+// when the file carries none.  The constraint governs the same header block
+// go/build reads: blank lines and comments may precede it, and the first
+// line that is neither ends the block.  A constraint that does not parse
+// narrows nothing, so the file stays in the attempted set: the audit must
+// never exclude a file the toolchain would compile.
+func buildConstraint(src string) constraint.Expr {
+	for line := range strings.SplitSeq(src, "\n") {
+		t := strings.TrimSpace(line)
+		switch {
+		case t == "":
+			continue
+		case strings.HasPrefix(t, "//"):
+			if constraint.IsGoBuild(t) {
+				e, err := constraint.Parse(t)
+				if err != nil {
+					return nil
+				}
+				return e
+			}
+			continue
+		default:
+			return nil
+		}
+	}
+	return nil
+}
+
+// unixOS is go/build's unixOS set: the GOOSes the unix build tag admits.
+var unixOS = map[string]bool{
+	"aix": true, "android": true, "darwin": true, "dragonfly": true,
+	"freebsd": true, "hurd": true, "illumos": true, "ios": true,
+	"linux": true, "netbsd": true, "openbsd": true, "solaris": true,
+}
+
+// constraintTags answers the build tags a plain `go build` sets for a
+// target: the GOOS and GOARCH, gc, and unix on the unix-like GOOSes.  No
+// experiment, sanitiser or cgo tag is ever true: the audit models the
+// default build, and no GOROOT assembly file's constraint hinges on cgo.
+func constraintTags(goarch, goos string) func(string) bool {
+	return func(tag string) bool {
+		switch tag {
+		case goarch, goos, "gc":
+			return true
+		case "unix":
+			return unixOS[goos]
+		}
+		return false
+	}
+}
+
+func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 	files, err := asmFiles(root)
 	if err != nil {
 		return nil, err
@@ -471,50 +644,172 @@ func runCorpusAudit(root string) (*corpusStats, error) {
 		tallies[i] = &corpusTally{reasons: map[string]int{}, example: map[string]string{}}
 	}
 	// full is the north-star number: a file counts when every architecture
-	// its name allows assembles it.
-	full, generic, otherPort := 0, 0, 0
+	// its build admits assembles it.
+	full, generic, otherPort, narrowedCount, excluded := 0, 0, 0, 0, 0
+
+	// Header generation is created on first use, so a corpus with no
+	// go_asm.h includes never pays for a temp directory.
+	var hdr *asmhdrCache
+	defer func() {
+		if hdr != nil {
+			hdr.close()
+		}
+	}()
 
 	for _, path := range files {
 		src, err := readSource(path)
 		if err != nil {
 			return nil, err
 		}
-		f, errs := parser.Parse(path, src)
 
+		// The GOOS the header generation type-checks under follows the
+		// file's name when the name carries one; the ambient GOOS is the
+		// honest guess otherwise (a build tag naming another GOOS is
+		// invisible to a file-name rule).
+		goos := goosFromFilename(path)
+
+		// The GOOS the header generation type-checks under follows the
+		// file's name when the name carries one; the ambient GOOS is the
+		// honest guess otherwise.
+		namedArch := arch.FromFilename(path)
 		var wanted []int // indexes into targets
-		if a := arch.FromFilename(path); a != arch.Unknown {
+		other := false
+		switch {
+		case namedArch != arch.Unknown:
 			for i, tg := range targets {
-				if tg.a == a {
+				if tg.a == namedArch {
 					wanted = append(wanted, i)
 				}
 			}
-		} else if otherPortFile(path) {
+		case otherPortFile(path):
 			// A file named for a Go port gasm does not support (arm,
-			// 386, s390x, ...) is compiled by no supported-arch build,
-			// so it is neither generic nor a per-arch attempt: counting
-			// it as generic would make the headline unreachably low
-			// for reasons no supported target can fix.
+			// 386, s390x, ...) or for another GOOS is compiled by no
+			// supported-arch build, so it is neither generic nor a
+			// per-arch attempt: counting it as generic would make the
+			// headline unreachably low for reasons no supported target
+			// can fix.
+			other = true
 			otherPort++
-		} else {
-			generic++
+		default:
 			for i := range targets {
 				wanted = append(wanted, i)
 			}
 		}
 
+		// A //go:build constraint narrows the set of targets the file is
+		// assembled for, the way the go command compiles the file only for
+		// the targets the expression admits: cpu_x86.s belongs to the x86
+		// build alone, and a file whose constraint admits none of the four
+		// targets (the goexperiment.runtimesecret and msan trees) is
+		// compiled by no supported build.  The tags mirror what a plain
+		// `go build` sets: the GOOS and GOARCH, gc, and unix on the
+		// unix-like GOOSes; no experiment, sanitiser or cgo tag is ever
+		// true.  The GOOS is the file's own when the name carries one,
+		// else the ambient one.
+		goosForEval := goos
+		if goosForEval == "" {
+			goosForEval = runtime.GOOS
+		}
+		narrowed := false
+		if len(wanted) > 0 {
+			if ce := buildConstraint(src); ce != nil {
+				kept := make([]int, 0, len(wanted))
+				for _, i := range wanted {
+					tg := targets[i]
+					if ce.Eval(constraintTags(goarchName(tg.a), goosForEval)) {
+						kept = append(kept, i)
+					}
+				}
+				if len(kept) < len(wanted) {
+					narrowed = true
+				}
+				wanted = kept
+			}
+		}
+
+		switch {
+		case other:
+			// already tallied above
+		case len(wanted) == 0:
+			excluded++
+		case namedArch != arch.Unknown:
+			// a per-arch attempt over the constraint's subset
+		case narrowed:
+			narrowedCount++
+		default:
+			generic++
+		}
+
+		// A file that includes go_asm.h parses against a per-target header:
+		// the defines differ per architecture (internal/cpu's layout, for
+		// one) and per GOOS (sys_darwin_arm64.s's trampoline constants,
+		// for another), so the parse cannot be shared the way a
+		// header-free file's can.  A generation failure is a failure for
+		// every target, named for the package rather than a bare "include
+		// not found".  A header already resolvable in the package
+		// directory or the -I list is left alone.
+		if len(wanted) > 0 && needsGoAsmHeader(src) && !goAsmHeaderResolved(filepath.Dir(path), dirs) {
+			if hdr == nil {
+				if hdr, err = newAsmhdrCache(); err != nil {
+					return nil, err
+				}
+			}
+			pkgDir := filepath.Dir(path)
+			ok := true
+			for _, i := range wanted {
+				tg, t := targets[i], tallies[i]
+				t.attempted++
+				hdrDir, err := hdr.dirFor(pkgDir, goos, goarchName(tg.a))
+				if err != nil {
+					ok = false
+					t.fail(path, err)
+					continue
+				}
+				f, errs := parser.ParseWithOptions(path, src, parser.Options{
+					Expand:      true,
+					IncludeDirs: append(slices.Clone(dirs), hdrDir),
+					Predefines:  platformPredefinesFor(goarchName(tg.a), goos),
+				})
+				if len(errs) > 0 {
+					ok = false
+					t.fail(path, errs[0])
+					continue
+				}
+				if _, err := assembleFile(tg.a, f, goos); err != nil {
+					ok = false
+					t.fail(path, err)
+					continue
+				}
+				t.assembled++
+			}
+			if ok && len(wanted) > 0 {
+				full++
+			}
+			continue
+		}
+
 		ok := true
 		for _, i := range wanted {
 			tg, t := targets[i], tallies[i]
 			t.attempted++
+			// The parse carries the target's platform predefines, so it
+			// cannot be shared across targets the way a header-free file's
+			// could: a #ifdef GOARCH_arm block must be live on arm64 and
+			// dead everywhere else.
+			f, errs := parser.ParseWithOptions(path, src, parser.Options{
+				Expand:      true,
+				IncludeDirs: dirs,
+				Predefines:  platformPredefinesFor(goarchName(tg.a), goos),
+			})
 			var err error
 			if len(errs) > 0 {
 				err = errs[0] // a parse failure is a failure for every target
 			} else {
-				_, err = assembleFile(tg.a, f)
+				_, err = assembleFile(tg.a, f, goos)
 			}
 			if err != nil {
 				ok = false
-				t.fail(path, corpusReason(err))
+				t.fail(path, err)
 				continue
 			}
 			t.assembled++
@@ -528,6 +823,8 @@ func runCorpusAudit(root string) (*corpusStats, error) {
 		root:      root,
 		files:     len(files),
 		generic:   generic,
+		narrowed:  narrowedCount,
+		excluded:  excluded,
 		otherPort: otherPort,
 		full:      full,
 		targets:   targets,
@@ -536,14 +833,16 @@ func runCorpusAudit(root string) (*corpusStats, error) {
 }
 
 // printCorpusStats renders the corpus audit report.
-func printCorpusStats(s *corpusStats) {
-	fmt.Printf("corpus %s: %d files (%d generic, attempted for all architectures; %d named for other Go ports, never attempted)\n", s.root, s.files, s.generic, s.otherPort)
+func printCorpusStats(s *corpusStats, list bool) {
+	fmt.Printf("corpus %s: %d files (%d generic, attempted for all architectures; %d narrowed by //go:build; %d excluded by //go:build; %d named for other Go ports, never attempted)\n",
+		s.root, s.files, s.generic, s.narrowed, s.excluded, s.otherPort)
 	// The rate is over the files a supported build would attempt: the
-	// other ports' files sit in the count for completeness but can never
-	// assemble, so counting them in the denominator would report the gap
-	// of architectures gasm deliberately does not target.
-	attemptable := max(s.files-s.otherPort, 1)
-	fmt.Printf("  assemble for every target architecture: %d of %d attemptable (%.1f%%)\n", s.full, attemptable, 100*float64(s.full)/float64(attemptable))
+	// other ports' files and the ones no supported target compiles sit in
+	// the count for completeness but can never assemble, so counting them
+	// in the denominator would report the gap of platforms gasm
+	// deliberately does not target.
+	attemptable := max(s.files-s.otherPort-s.excluded, 1)
+	fmt.Printf("  assemble for every applicable target: %d of %d attemptable (%.1f%%)\n", s.full, attemptable, 100*float64(s.full)/float64(attemptable))
 	for i, tg := range s.targets {
 		t := s.tallies[i]
 		fmt.Printf("  %s: %d/%d attempted\n", tg.name, t.assembled, t.attempted)
@@ -551,6 +850,13 @@ func printCorpusStats(s *corpusStats) {
 			fmt.Printf("    %4d  %s\n", t.reasons[r], r)
 			fmt.Printf("         e.g. %s\n", t.example[r])
 		}
+		if !list {
+			continue
+		}
+		for _, f := range t.fails {
+			fmt.Printf("    FAIL %s\n", f.path)
+			fmt.Printf("         %s: %s\n", f.reason, f.detail)
+		}
 	}
 }
 
@@ -558,6 +864,8 @@ func printCorpusStats(s *corpusStats) {
 func corpusReason(err error) string {
 	msg := err.Error()
 	switch {
+	case strings.Contains(msg, "go_asm.h for GOARCH"):
+		return "go_asm.h generation failed"
 	case strings.Contains(msg, "unsupported"), strings.Contains(msg, "cannot encode"):
 		return "instruction not encodable"
 	case strings.Contains(msg, "undefined label"):

cmd/gasm/audit_test.go

@@ -4,9 +4,10 @@
 package main
 
 import (
+	"runtime"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
 )
 
 func TestDerivedFamily(t *testing.T) {
@@ -64,3 +65,62 @@ func TestGasmEncodable(t *testing.T) {
 		}
 	}
 }
+
+// TestBuildConstraint pins the //go:build reader: the constraint governs the
+// leading comment block, the first non-comment line ends it (a tag below a
+// #include governs nothing, exactly as go/build drops it), and a file
+// without one admits every target.
+func TestBuildConstraint(t *testing.T) {
+	admits := func(src, goarch, goos string) bool {
+		t.Helper()
+		e := buildConstraint(src)
+		if e == nil {
+			return true
+		}
+		return e.Eval(constraintTags(goarch, goos))
+	}
+	const ret = "TEXT \xc2\xb7f(SB), NOSPLIT, $0\n\tRET\n"
+	cases := []struct {
+		name         string
+		src          string
+		amd64, arm64 bool
+	}{
+		{"no constraint", ret, true, true},
+		{"x86 only", "//go:build 386 || amd64\n\n" + ret, true, false},
+		{"arm64 and linux", "//go:build arm64 && linux\n\n" + ret, false, true},
+		{"msan never", "//go:build msan\n\n" + ret, false, false},
+		{"experiment never", "//go:build goexperiment.runtimesecret\n\n" + ret, false, false},
+		{"below an include governs nothing", "#include \"textflag.h\"\n//go:build amd64\n" + ret, true, true},
+		{"unparsable narrows nothing", "//go:build (amd64\n" + ret, true, true},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			if got := admits(c.src, "amd64", runtime.GOOS); got != c.amd64 {
+				t.Errorf("amd64 admission = %v, want %v", got, c.amd64)
+			}
+			if got := admits(c.src, "arm64", runtime.GOOS); got != c.arm64 {
+				t.Errorf("arm64 admission = %v, want %v", got, c.arm64)
+			}
+		})
+	}
+}
+
+// TestConstraintTags pins the tag set a plain `go build` sets: the GOOS and
+// GOARCH, gc, unix on the unix-like GOOSes; nothing else is ever true.
+func TestConstraintTags(t *testing.T) {
+	ok := constraintTags("amd64", "linux")
+	for _, tag := range []string{"amd64", "linux", "gc", "unix"} {
+		if !ok(tag) {
+			t.Errorf("tag %q = false, want true", tag)
+		}
+	}
+	for _, tag := range []string{"arm64", "freebsd", "darwin", "cgo", "race", "msan", "goexperiment.runtimesecret"} {
+		if ok(tag) {
+			t.Errorf("tag %q = true, want false", tag)
+		}
+	}
+	fb := constraintTags("arm64", "freebsd")
+	if !fb("unix") {
+		t.Error("unix on freebsd = false, want true")
+	}
+}

cmd/gasm/debug_other.go

@@ -1,7 +1,7 @@
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build !linux
+//go:build !(linux || (freebsd && (amd64 || arm64 || riscv64)))
 
 package main
 
@@ -11,6 +11,6 @@ import (
 )
 
 func cmdDebug(args []string) int {
-	fmt.Fprintln(os.Stderr, "gasm debug: the interactive debugger requires Linux (ptrace)")
+	fmt.Fprintln(os.Stderr, "gasm debug: the interactive debugger requires Linux or FreeBSD (ptrace)")
 	return 1
 }

cmd/gasm/debug_ptrace.go

@@ -1,7 +1,7 @@
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build linux
+//go:build linux || (freebsd && (amd64 || arm64 || riscv64))
 
 package main
 
@@ -13,8 +13,8 @@ import (
 	"strings"
 	"time"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/debug"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/debug"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 func cmdDebug(args []string) int {

cmd/gasm/dis.go

@@ -9,9 +9,9 @@ import (
 	"sort"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/disasm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // cmdDis disassembles machine code: either a raw binary (standard input with
@@ -84,7 +84,7 @@ func disSource(path string, target arch.Arch) int {
 	if len(errs) > 0 {
 		return 1
 	}
-	img, err := assembleFile(target, f)
+	img, err := assembleFile(target, f, "")
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "gasm dis: %v\n", err)
 		return 1

cmd/gasm/main.go

@@ -27,15 +27,15 @@ import (
 	"sync"
 	"syscall"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	"sourcedock.dev/petrbalvin/gasm-devkit/format"
-	"sourcedock.dev/petrbalvin/gasm-devkit/lexer"
-	"sourcedock.dev/petrbalvin/gasm-devkit/lint"
-	"sourcedock.dev/petrbalvin/gasm-devkit/lsp"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	"sourcedock.dev/petrbalvin/gasm-sdk/format"
+	"sourcedock.dev/petrbalvin/gasm-sdk/lexer"
+	"sourcedock.dev/petrbalvin/gasm-sdk/lint"
+	"sourcedock.dev/petrbalvin/gasm-sdk/lsp"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // version reports the release the toolchain recorded for this build: the
@@ -240,6 +240,16 @@ func readSource(path string) (string, error) {
 	return string(b), err
 }
 
+// includeDirs collects repeatable -I flags: the directories searched for
+// #include files during macro expansion and include splicing.
+type includeDirs []string
+
+func (d *includeDirs) String() string { return strings.Join(*d, ",") }
+func (d *includeDirs) Set(v string) error {
+	*d = append(*d, v)
+	return nil
+}
+
 func cmdTokens(args []string) int {
 	fs := newCommand("tokens", "gasm tokens <file>", `
 Print the lexical token stream of FILE: position, token kind and text, one
@@ -476,7 +486,7 @@ hover, document symbols, diagnostics and semantic-token highlighting.
 }
 
 func cmdAsm(args []string) int {
-	fs := newCommand("asm", "gasm asm [--format raw|elf|goobj] [-p pkg] [-GOARCH arch] [-o out] <file>", `
+	fs := newCommand("asm", "gasm asm [--format raw|elf|goobj] [-I dir] [-p pkg] [-GOARCH arch] [-GOOS os] [-o out] <file>", `
 	Assemble FILE without the Go toolchain: every TEXT function is encoded to
 	machine code and printed as a hex dump.  Supported architectures: amd64
 	(including VEX/AVX2 and EVEX/AVX-512), arm64 (AArch64 integer, FP,
@@ -493,14 +503,26 @@ system toolchain; goobj emits the Go toolchain's own object format, which
 cmd/link consumes directly (it requires -p, the package path, and the
 installed Go toolchain: the object preamble is captured from go tool asm
 and the format version from go version).
+
+A file that includes go_asm.h gets that header generated automatically from
+the package it lives in (the .go files beside it, type-checked for the
+target architecture, the toolchain's own defines), so GOROOT assembly
+assembles without a compiler.  -GOOS selects the type-checking GOOS for
+that header: a GOOS-specific file (sys_darwin_arm64.s) needs its platform's
+defines, which a header from the ambient GOOS silently omits.  A package
+that has no Go files for the target or does not type-check is a hard error
+naming the package.
 `)
 	out := fs.String("o", "", "write the output to this file")
 	format := fs.String("format", "raw", "output format: raw (concatenated image), elf or goobj (Go object)")
 	pkg := fs.String("p", "", "package path for --format goobj (qualifies the exported symbols)")
 	archName := fs.String("GOARCH", "", "target architecture: amd64, arm64, riscv64 or loong64 (overrides the file-name suffix)")
+	goosName := fs.String("GOOS", "", "operating system for go_asm.h generation: a GOOS go/build recognises (default: the host's)")
+	var dirs includeDirs
+	fs.Var(&dirs, "I", "directory to search for #include files (may be repeated)")
 	fs.Parse(args)
 	if fs.NArg() != 1 {
-		fmt.Fprintln(os.Stderr, "usage: gasm asm [--format raw|elf|goobj] [-p pkg] [-GOARCH arch] [-o out] <file>")
+		fmt.Fprintln(os.Stderr, "usage: gasm asm [--format raw|elf|goobj] [-I dir] [-p pkg] [-GOARCH arch] [-GOOS os] [-o out] <file>")
 		return 2
 	}
 	// The format is validated before anything else, so a bogus value exits 2
@@ -521,12 +543,38 @@ and the format version from go version).
 		}
 		targetArch = a
 	}
+	goos := ""
+	if *goosName != "" {
+		g, err := resolveGOOS(*goosName)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "gasm asm: %v\n", err)
+			return 2
+		}
+		goos = g
+	}
 	src, err := readSource(path)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "gasm:", err)
 		return 1
 	}
-	f, errs := parser.Parse(path, src)
+	// A file that includes go_asm.h cannot assemble without the package's
+	// defines, and without a compiler nothing else has generated them, so
+	// gasm produces the equivalent itself: automatic, because the compiler
+	// behaves the same way and a flag would only ever be forgotten.  A
+	// generation failure is fatal and names the package: assembling against
+	// a missing header would fail later with a bare "undefined" instead.
+	// A go_asm.h that already resolves (placed by hand, or passed with -I)
+	// is left alone.
+	if needsGoAsmHeader(src) && !goAsmHeaderResolved(filepath.Dir(path), dirs) {
+		hdrDir, cleanup, err := ensureGoAsmHeader(path, targetArch, goos, nil)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "gasm asm:", err)
+			return 1
+		}
+		defer cleanup()
+		dirs = append(dirs, hdrDir)
+	}
+	f, errs := parser.ParseWithOptions(path, src, parser.Options{Expand: true, IncludeDirs: dirs, Predefines: platformPredefinesFor(string(targetArch), goos)})
 	for _, e := range errs {
 		fmt.Fprintf(os.Stderr, "%s: %v\n", path, e)
 	}
@@ -534,7 +582,7 @@ and the format version from go version).
 		return 1
 	}
 
-	img, err := assembleFile(targetArch, f)
+	img, err := assembleFile(targetArch, f, goos)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%s: %v\n", path, err)
 		return 1
@@ -634,7 +682,7 @@ and the format version from go version).
 
 // cmdDiff compares the machine code of two assembly files.
 func cmdDiff(args []string) int {
-	set := newCommand("diff", "gasm diff [-GOARCH arch] <file1.s> <file2.s>", `
+	set := newCommand("diff", "gasm diff [-GOARCH arch] [-I dir] <file1.s> <file2.s>", `
 Compare the machine code produced by assembling two files.
 Shows which functions differ and the byte-level differences.
 Useful for verifying that two implementations produce identical code,
@@ -645,9 +693,11 @@ e.g. --map wideCopyAVX2=wideCopyAVX512 pairs the two regardless of suffix.
 `)
 	mapSpec := set.String("map", "", "comma-separated old=new pairs to match functions with different names")
 	archName := set.String("GOARCH", "", "target architecture for both files: amd64, arm64, riscv64 or loong64")
+	var dirs includeDirs
+	set.Var(&dirs, "I", "directory to search for #include files (may be repeated)")
 	set.Parse(args)
 	if set.NArg() != 2 {
-		fmt.Fprintln(os.Stderr, "usage: gasm diff [-GOARCH arch] <file1.s> <file2.s>")
+		fmt.Fprintln(os.Stderr, "usage: gasm diff [-GOARCH arch] [-I dir] <file1.s> <file2.s>")
 		return 2
 	}
 	path1, path2 := set.Arg(0), set.Arg(1)
@@ -675,12 +725,12 @@ e.g. --map wideCopyAVX2=wideCopyAVX512 pairs the two regardless of suffix.
 	}
 
 	// Assemble both files.
-	img1, err := assemblePath(path1, forced)
+	img1, err := assemblePath(path1, forced, dirs)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "gasm diff: %s: %v\n", path1, err)
 		return 1
 	}
-	img2, err := assemblePath(path2, forced)
+	img2, err := assemblePath(path2, forced, dirs)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "gasm diff: %s: %v\n", path2, err)
 		return 1
@@ -739,11 +789,34 @@ e.g. --map wideCopyAVX2=wideCopyAVX512 pairs the two regardless of suffix.
 	return 1
 }
 
+// platformPredefines mirrors the go command's assembler invocation, which
+// defines GOOS_<goos> and GOARCH_<arch> as -D macros: GOROOT headers
+// (go_tls.h, asm_riscv64.h) select their platform blocks with #ifdef on
+// exactly those names, so an assembler without them cannot see the platform
+// definitions at all.
+func platformPredefines(goarch, goos string) map[string]string {
+	return map[string]string{
+		"GOARCH_" + goarch: "1",
+		"GOOS_" + goos:     "1",
+	}
+}
+
+// platformPredefinesFor resolves the ambient GOOS the way a build would: a
+// file whose name carries one (sys_darwin_arm64.s) is compiled for that GOOS
+// and nothing else.
+func platformPredefinesFor(goarch string, fileGoos string) map[string]string {
+	goos := fileGoos
+	if goos == "" {
+		goos = runtime.GOOS
+	}
+	return platformPredefines(goarch, goos)
+}
+
 // assembleFile assembles a parsed file for the given architecture and returns the image.
-func assembleFile(targetArch arch.Arch, f *ast.File) (*asm.Image, error) {
+func assembleFile(targetArch arch.Arch, f *ast.File, goos string) (*asm.Image, error) {
 	switch targetArch {
 	case arch.AMD64:
-		return asm.AssembleFile(f)
+		return asm.AssembleFile(f, asm.WithGOOS(goos))
 	case arch.RISCV:
 		return asm.AssembleFileRISCV(f)
 	case arch.ARM64:
@@ -755,25 +828,26 @@ func assembleFile(targetArch arch.Arch, f *ast.File) (*asm.Image, error) {
 	}
 }
 
-// assemblePath reads, parses and assembles a file (used by cmdDiff).  A
-// non-Unknown forced architecture overrides the file-name suffix.
-func assemblePath(path string, forced arch.Arch) (*asm.Image, error) {
+// assemblePath reads, preprocesses, parses and assembles a file (used by
+// cmdDiff).  A non-Unknown forced architecture overrides the file-name
+// suffix.
+func assemblePath(path string, forced arch.Arch, dirs includeDirs) (*asm.Image, error) {
 	src, err := readSource(path)
 	if err != nil {
 		return nil, err
 	}
-	f, errs := parser.Parse(path, src)
+	target := forced
+	if target == arch.Unknown {
+		target = arch.FromFilename(path)
+	}
+	f, errs := parser.ParseWithOptions(path, src, parser.Options{Expand: true, IncludeDirs: dirs, Predefines: platformPredefinesFor(string(target), "")})
 	for _, e := range errs {
 		fmt.Fprintf(os.Stderr, "%s: %v\n", path, e)
 	}
 	if len(errs) > 0 {
 		return nil, fmt.Errorf("parse errors")
 	}
-	target := forced
-	if target == arch.Unknown {
-		target = arch.FromFilename(path)
-	}
-	return assembleFile(target, f)
+	return assembleFile(target, f, "")
 }
 
 // printByteDiff shows the first few byte differences between two code blocks.
@@ -869,7 +943,7 @@ func cmdVerifyNonJIT(path string, targetArch arch.Arch, groundTruth, profile boo
 	if len(errs) > 0 {
 		return 1
 	}
-	img, err := assembleFile(targetArch, f)
+	img, err := assembleFile(targetArch, f, "")
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "gasm verify: %v\n", err)
 		return 1

cmd/gasm/main_test.go

@@ -14,8 +14,8 @@ import (
 	"syscall"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
 )
 
 const clean = "#include \"textflag.h\"\n" +
@@ -403,7 +403,7 @@ func TestRunCorpusAudit(t *testing.T) {
 	write("generic.s", "#include \"textflag.h\"\nTEXT ·g(SB), NOSPLIT, $0-0\n\tRET\n")
 	write("broken.s", "#include \"textflag.h\"\nTEXT ·b(SB), NOSPLIT, $0-0\n\tJMP nowhere\n\tRET\n")
 
-	stats, err := runCorpusAudit(dir)
+	stats, err := runCorpusAudit(dir, nil)
 	if err != nil {
 		t.Fatalf("runCorpusAudit: %v", err)
 	}

cmd/gasm/preproc_test.go

@@ -0,0 +1,109 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// writeTree writes a directory of files and returns its root.
+func writeTree(t *testing.T, files map[string]string) string {
+	t.Helper()
+	dir := t.TempDir()
+	for name, content := range files {
+		path := filepath.Join(dir, name)
+		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+// TestAsmMacroAndIncludeEndToEnd drives `gasm asm` over a source with an
+// in-file parameterised macro and an include resolved through -I, and checks
+// the assembled bytes came from the expansion (the loop body counts six
+// increments, two per expanded iteration).
+func TestAsmMacroAndIncludeEndToEnd(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	dir := writeTree(t, map[string]string{
+		"inc/consts.h": "#define NITER 3\n",
+		"main_amd64.s": "#include \"textflag.h\"\n" +
+			"#include \"consts.h\"\n" +
+			"#define STEP(r) ADDQ $1, r; ADDQ $1, r\n" +
+			"TEXT ·f(SB), NOSPLIT, $0-8\n" +
+			"\tXORQ AX, AX\n" +
+			"\tMOVQ $NITER, CX\n" +
+			"loop:\n" +
+			"\tSTEP(AX)\n" +
+			"\tDECQ CX\n" +
+			"\tJNZ loop\n" +
+			"\tMOVQ AX, ret+0(FP)\n" +
+			"\tRET\n",
+	})
+	stdout, stderr, code := capture(func() int {
+		return cmdAsm([]string{"-I", filepath.Join(dir, "inc"), "-GOARCH", "amd64", filepath.Join(dir, "main_amd64.s")})
+	})
+	if code != 0 {
+		t.Fatalf("gasm asm exited %d: %s%s", code, stdout, stderr)
+	}
+	// The macro expanded to two ADDQ $1 encodings in the static body; the
+	// iteration count lives in the runtime loop.
+	if n := strings.Count(stdout, "83 c0 01"); n != 2 {
+		t.Errorf("found %d ADDQ $1 encodings in the image, want 2:\n%s", n, stdout)
+	}
+}
+
+// TestAsmIncludeResolutionOrder pins the -I search order end to end: the
+// including file's directory wins over the -I directories.
+func TestAsmIncludeResolutionOrder(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	dir := writeTree(t, map[string]string{
+		"src/main_amd64.s": "#include \"textflag.h\"\n" +
+			"#include \"vals.h\"\n" +
+			"TEXT ·f(SB), NOSPLIT, $0\n" +
+			"\tMOVQ $VAL, AX\n" +
+			"\tRET\n",
+		"src/vals.h":   "#define VAL 1\n",
+		"late/vals.h":  "#define VAL 2\n",
+		"early/vals.h": "#define VAL 3\n",
+	})
+	stdout, stderr, code := capture(func() int {
+		return cmdAsm([]string{"-I", filepath.Join(dir, "early"), "-I", filepath.Join(dir, "late"),
+			"-GOARCH", "amd64", filepath.Join(dir, "src", "main_amd64.s")})
+	})
+	if code != 0 {
+		t.Fatalf("gasm asm exited %d: %s%s", code, stdout, stderr)
+	}
+	// VAL came from src/vals.h, not from either -I directory: the image
+	// loads the immediate 1.
+	if !strings.Contains(stdout, "b8 01 00 00 00") {
+		t.Errorf("expected the source-directory VAL (immediate 1) in:\n%s", stdout)
+	}
+}
+
+// TestAsmMissingIncludeIsAnError pins the diagnostic for an include that
+// resolves nowhere on the assembly path.
+func TestAsmMissingIncludeIsAnError(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	path := writeTemp(t, "main_amd64.s", "#include \"textflag.h\"\n#include \"nothere.h\"\nTEXT ·f(SB), NOSPLIT, $0\n\tRET\n")
+	_, stderr, code := capture(func() int { return cmdAsm([]string{"-GOARCH", "amd64", path}) })
+	if code == 0 {
+		t.Fatal("gasm asm accepted a file whose include resolves nowhere")
+	}
+	if !strings.Contains(stderr, `#include "nothere.h"`) {
+		t.Errorf("stderr does not name the failing include: %s", stderr)
+	}
+}

cmd/gasm/scaffold.go

@@ -11,8 +11,8 @@ import (
 	"os"
 	"strings"
 
-	gasmast "sourcedock.dev/petrbalvin/gasm-devkit/ast"
-	gasmparser "sourcedock.dev/petrbalvin/gasm-devkit/parser"
+	gasmast "sourcedock.dev/petrbalvin/gasm-sdk/ast"
+	gasmparser "sourcedock.dev/petrbalvin/gasm-sdk/parser"
 )
 
 // cmdScaffold generates a differential test skeleton for every kernel in a

debug/breakpoint.go

@@ -1,7 +1,7 @@
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build linux
+//go:build linux || (freebsd && (amd64 || arm64 || riscv64))
 
 package debug
 

debug/disasm_freebsd_amd64.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && amd64
+
+package debug
+
+import (
+	"fmt"
+	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
+)
+
+// Disassemble decodes the instruction at the given address in the debuggee's
+// memory and returns its text representation and length in bytes.
+func (s *Session) Disassemble(addr uint64) (string, int, error) {
+	mem, err := s.ReadMemory(addr, 15)
+	if err != nil {
+		return "", 0, err
+	}
+	ins, err := disasm.Decode(arch.AMD64, mem, addr)
+	if err != nil {
+		return "", 0, err
+	}
+	return ins.Text, ins.Len, nil
+}
+
+// DisassembleN decodes up to n instructions starting at addr and returns
+// them as a formatted string with addresses and byte offsets.
+func (s *Session) DisassembleN(addr uint64, n int) string {
+	var result strings.Builder
+	pc := addr
+	for range n {
+		text, length, err := s.Disassemble(pc)
+		if err != nil {
+			result.WriteString(fmt.Sprintf("  %#08x: <error: %v>\n", pc, err))
+			break
+		}
+		result.WriteString(fmt.Sprintf("  %#08x: %s\n", pc, text))
+		if length == 0 {
+			length = 1
+		}
+		pc += uint64(length)
+	}
+	return result.String()
+}
+
+// isCallInsn reports whether disassembled text (x86asm.IntelSyntax) is a
+// call.  The first token must match exactly: a prefix test would also catch
+// unrelated mnemonics.
+func isCallInsn(text string) bool {
+	m, _, _ := strings.Cut(text, " ")
+	return strings.ToLower(m) == "call"
+}

debug/disasm_freebsd_arm64.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && arm64
+
+package debug
+
+import (
+	"fmt"
+	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
+)
+
+// Disassemble decodes the instruction at the given address in the debuggee's
+// memory and returns its text representation and length in bytes.
+func (s *Session) Disassemble(addr uint64) (string, int, error) {
+	mem, err := s.ReadMemory(addr, 4)
+	if err != nil {
+		return "", 0, err
+	}
+	ins, err := disasm.Decode(arch.ARM64, mem, addr)
+	if err != nil {
+		return "", 0, err
+	}
+	return ins.Text, ins.Len, nil
+}
+
+// DisassembleN decodes up to n instructions starting at addr and returns
+// them as a formatted string with addresses and byte offsets.
+func (s *Session) DisassembleN(addr uint64, n int) string {
+	var result strings.Builder
+	pc := addr
+	for range n {
+		text, length, err := s.Disassemble(pc)
+		if err != nil {
+			result.WriteString(fmt.Sprintf("  %#08x: <error: %v>\n", pc, err))
+			break
+		}
+		result.WriteString(fmt.Sprintf("  %#08x: %s\n", pc, text))
+		if length == 0 {
+			length = 1
+		}
+		pc += uint64(length)
+	}
+	return result.String()
+}
+
+// isCallInsn reports whether disassembled text (arm64asm.GoSyntax) is a
+// call.  GoSyntax renders bl as CALL; the native mnemonic is accepted too.
+// The first token must match exactly so branches never match.
+func isCallInsn(text string) bool {
+	m, _, _ := strings.Cut(text, " ")
+	switch strings.ToLower(m) {
+	case "call", "bl":
+		return true
+	}
+	return false
+}

debug/disasm_freebsd_riscv64.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && riscv64
+
+package debug
+
+import (
+	"fmt"
+	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
+)
+
+// Disassemble decodes the instruction at the given address in the debuggee's
+// memory and returns its text representation and length in bytes.
+func (s *Session) Disassemble(addr uint64) (string, int, error) {
+	mem, err := s.ReadMemory(addr, 4)
+	if err != nil {
+		return "", 0, err
+	}
+	ins, err := disasm.Decode(arch.RISCV, mem, addr)
+	if err != nil {
+		return "", 0, err
+	}
+	return ins.Text, ins.Len, nil
+}
+
+// DisassembleN decodes up to n instructions starting at addr and returns
+// them as a formatted string with addresses and byte offsets.
+func (s *Session) DisassembleN(addr uint64, n int) string {
+	var result strings.Builder
+	pc := addr
+	for range n {
+		text, length, err := s.Disassemble(pc)
+		if err != nil {
+			result.WriteString(fmt.Sprintf("  %#08x: <error: %v>\n", pc, err))
+			break
+		}
+		result.WriteString(fmt.Sprintf("  %#08x: %s\n", pc, text))
+		if length == 0 {
+			length = 1
+		}
+		pc += uint64(length)
+	}
+	return result.String()
+}
+
+// isCallInsn reports whether disassembled text (riscv64asm.GoSyntax) is a
+// call.  GoSyntax renders jal and jalr calls as CALL; the native mnemonics
+// are accepted too.  The first token must match exactly: a prefix test on
+// "bl" would catch branches on other architectures, and jalr as ret prints
+// RET, which must not be stepped over.
+func isCallInsn(text string) bool {
+	m, _, _ := strings.Cut(text, " ")
+	switch strings.ToLower(m) {
+	case "call", "jal", "jalr":
+		return true
+	}
+	return false
+}

debug/disasm_linux_amd64.go

@@ -9,8 +9,8 @@ import (
 	"fmt"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/disasm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
 )
 
 // Disassemble decodes the instruction at the given address in the debuggee's

debug/disasm_linux_arm64.go

@@ -9,8 +9,8 @@ import (
 	"fmt"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/disasm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
 )
 
 // Disassemble decodes the instruction at the given address in the debuggee's

debug/disasm_linux_loong64.go

@@ -9,8 +9,8 @@ import (
 	"fmt"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/disasm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
 )
 
 // Disassemble decodes the instruction at the given address in the debuggee's

debug/disasm_linux_riscv64.go

@@ -9,8 +9,8 @@ import (
 	"fmt"
 	"strings"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
-	"sourcedock.dev/petrbalvin/gasm-devkit/disasm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/arch"
+	"sourcedock.dev/petrbalvin/gasm-sdk/disasm"
 )
 
 // Disassemble decodes the instruction at the given address in the debuggee's

debug/display_freebsd_amd64.go

@@ -0,0 +1,136 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && amd64
+
+package debug
+
+import "fmt"
+
+func printRegs(regs *Regs, codeBase, funcOff uint64) {
+	fmt.Printf("  RIP = %#016x  (func+%#x)\n", regs.RIP, regs.RIP-codeBase-funcOff)
+	fmt.Printf("  RSP = %#016x  RBP = %#016x\n", regs.RSP, regs.RBP)
+	fmt.Printf("  RAX = %#016x  RBX = %#016x\n", regs.RAX, regs.RBX)
+	fmt.Printf("  RCX = %#016x  RDX = %#016x\n", regs.RCX, regs.RDX)
+	fmt.Printf("  RSI = %#016x  RDI = %#016x\n", regs.RSI, regs.RDI)
+	fmt.Printf("  R8  = %#016x  R9  = %#016x\n", regs.R8, regs.R9)
+	fmt.Printf("  R10 = %#016x  R11 = %#016x\n", regs.R10, regs.R11)
+	fmt.Printf("  R12 = %#016x  R13 = %#016x\n", regs.R12, regs.R13)
+	fmt.Printf("  R14 = %#016x  R15 = %#016x\n", regs.R14, regs.R15)
+	fmt.Printf("  RFLAGS = %#x  [%s]\n", regs.RFLAGS, decodeRflags(regs.RFLAGS))
+}
+
+func printVectorRegs(v *VectorRegs) {
+	fmt.Println("\n  Vector registers (YMM):")
+	for i := 0; i < 16; i += 2 {
+		fmt.Printf("  YMM%-2d = ", i)
+		printYMM(v.YMM[i][:])
+		fmt.Printf("  YMM%-2d = ", i+1)
+		printYMM(v.YMM[i+1][:])
+		fmt.Println()
+	}
+}
+
+func printYMM(b []byte) {
+	for j := 0; j < 32; j += 4 {
+		v := uint32(b[j]) | uint32(b[j+1])<<8 | uint32(b[j+2])<<16 | uint32(b[j+3])<<24
+		fmt.Printf("%08x ", v)
+	}
+}
+
+func decodeRflags(f uint64) string {
+	var flags string
+	if f&1 != 0 {
+		flags += "CF "
+	}
+	if f&(1<<2) != 0 {
+		flags += "PF "
+	}
+	if f&(1<<4) != 0 {
+		flags += "AF "
+	}
+	if f&(1<<6) != 0 {
+		flags += "ZF "
+	}
+	if f&(1<<7) != 0 {
+		flags += "SF "
+	}
+	if f&(1<<8) != 0 {
+		flags += "TF "
+	}
+	if f&(1<<9) != 0 {
+		flags += "IF "
+	}
+	if f&(1<<10) != 0 {
+		flags += "DF "
+	}
+	if f&(1<<11) != 0 {
+		flags += "OF "
+	}
+	if flags == "" {
+		return "none"
+	}
+	return flags[:len(flags)-1]
+}
+
+// SetReg modifies a register value in the debuggee.
+func (s *Session) SetReg(name string, value uint64) error {
+	regs, err := s.GetRegs()
+	if err != nil {
+		return err
+	}
+	switch name {
+	case "rax", "eax", "ax", "al":
+		regs.RAX = value
+	case "rbx", "ebx", "bx", "bl":
+		regs.RBX = value
+	case "rcx", "ecx", "cx", "cl":
+		regs.RCX = value
+	case "rdx", "edx", "dx", "dl":
+		regs.RDX = value
+	case "rsi", "esi", "si":
+		regs.RSI = value
+	case "rdi", "edi", "di":
+		regs.RDI = value
+	case "rbp", "ebp", "bp":
+		regs.RBP = value
+	case "rsp", "esp", "sp":
+		regs.RSP = value
+	case "r8":
+		regs.R8 = value
+	case "r9":
+		regs.R9 = value
+	case "r10":
+		regs.R10 = value
+	case "r11":
+		regs.R11 = value
+	case "r12":
+		regs.R12 = value
+	case "r13":
+		regs.R13 = value
+	case "r14":
+		regs.R14 = value
+	case "r15":
+		regs.R15 = value
+	case "rip", "eip":
+		regs.RIP = value
+	default:
+		return fmt.Errorf("debug: unknown register %q", name)
+	}
+	return s.SetRegs(&regs)
+}
+
+// archReturnAddr reads the return address of the current frame (amd64
+// ABI0 convention).  A function that contains a CALL (or has a frame) is
+// assembled with the prologue PUSHQ BP; MOVQ SP, BP, so mid-function the
+// word at SP is the saved caller BP, a stack address, and the return
+// address sits further up.  Walk the stack from SP and take the first word
+// that lies in an executable mapping: stack and data words never do, a
+// return address always does.  FreeBSD exposes no mapping list, so the
+// walk degenerates to the raw entry convention, [SP] before any push.
+func archReturnAddr(s *Session, regs *Regs) (uint64, error) {
+	return s.Peek(regs.RSP)
+}
+
+// archSPLabel returns the SP register name for display.
+func archSPLabel() string { return "RSP" }

debug/display_freebsd_arm64.go

@@ -0,0 +1,127 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && arm64
+
+package debug
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+func printRegs(regs *Regs, codeBase, funcOff uint64) {
+	fmt.Printf("  PC  = %#016x  (func+%#x)\n", regs.PC, regs.PC-codeBase-funcOff)
+	fmt.Printf("  SP  = %#016x  FP  = %#016x\n", regs.SP, regs.X29)
+	fmt.Printf("  LR  = %#016x\n", regs.X30)
+	fmt.Printf("  X0  = %#016x  X1  = %#016x\n", regs.X0, regs.X1)
+	fmt.Printf("  X2  = %#016x  X3  = %#016x\n", regs.X2, regs.X3)
+	fmt.Printf("  X4  = %#016x  X5  = %#016x\n", regs.X4, regs.X5)
+	fmt.Printf("  X6  = %#016x  X7  = %#016x\n", regs.X6, regs.X7)
+	fmt.Printf("  X8  = %#016x  X9  = %#016x\n", regs.X8, regs.X9)
+	fmt.Printf("  X10 = %#016x  X11 = %#016x\n", regs.X10, regs.X11)
+	fmt.Printf("  X12 = %#016x  X13 = %#016x\n", regs.X12, regs.X13)
+	fmt.Printf("  X14 = %#016x  X15 = %#016x\n", regs.X14, regs.X15)
+	fmt.Printf("  X16 = %#016x  X17 = %#016x\n", regs.X16, regs.X17)
+	fmt.Printf("  X18 = %#016x  X19 = %#016x\n", regs.X18, regs.X19)
+	fmt.Printf("  X20 = %#016x  X21 = %#016x\n", regs.X20, regs.X21)
+	fmt.Printf("  X22 = %#016x  X23 = %#016x\n", regs.X22, regs.X23)
+	fmt.Printf("  X24 = %#016x  X25 = %#016x\n", regs.X24, regs.X25)
+	fmt.Printf("  X26 = %#016x  X27 = %#016x\n", regs.X26, regs.X27)
+	fmt.Printf("  X28 = %#016x  PSTATE = %#x\n", regs.X28, regs.PSTATE)
+}
+
+func printVectorRegs(v *VectorRegs) {
+	fmt.Println("\n  Vector registers (V0-V31):")
+	for i := 0; i < 32; i += 2 {
+		fmt.Printf("  V%-2d  = %016x%016x\n", i, binary.LittleEndian.Uint64(v.V[i][8:16]), binary.LittleEndian.Uint64(v.V[i][0:8]))
+		fmt.Printf("  V%-2d  = %016x%016x\n", i+1, binary.LittleEndian.Uint64(v.V[i+1][8:16]), binary.LittleEndian.Uint64(v.V[i+1][0:8]))
+	}
+}
+
+// SetReg modifies a register value in the debuggee.
+func (s *Session) SetReg(name string, value uint64) error {
+	regs, err := s.GetRegs()
+	if err != nil {
+		return err
+	}
+	switch name {
+	case "x0":
+		regs.X0 = value
+	case "x1":
+		regs.X1 = value
+	case "x2":
+		regs.X2 = value
+	case "x3":
+		regs.X3 = value
+	case "x4":
+		regs.X4 = value
+	case "x5":
+		regs.X5 = value
+	case "x6":
+		regs.X6 = value
+	case "x7":
+		regs.X7 = value
+	case "x8":
+		regs.X8 = value
+	case "x9":
+		regs.X9 = value
+	case "x10":
+		regs.X10 = value
+	case "x11":
+		regs.X11 = value
+	case "x12":
+		regs.X12 = value
+	case "x13":
+		regs.X13 = value
+	case "x14":
+		regs.X14 = value
+	case "x15":
+		regs.X15 = value
+	case "x16":
+		regs.X16 = value
+	case "x17":
+		regs.X17 = value
+	case "x18":
+		regs.X18 = value
+	case "x19":
+		regs.X19 = value
+	case "x20":
+		regs.X20 = value
+	case "x21":
+		regs.X21 = value
+	case "x22":
+		regs.X22 = value
+	case "x23":
+		regs.X23 = value
+	case "x24":
+		regs.X24 = value
+	case "x25":
+		regs.X25 = value
+	case "x26":
+		regs.X26 = value
+	case "x27":
+		regs.X27 = value
+	case "x28":
+		regs.X28 = value
+	case "x29", "fp":
+		regs.X29 = value
+	case "x30", "lr":
+		regs.X30 = value
+	case "sp":
+		regs.SP = value
+	case "pc":
+		regs.PC = value
+	default:
+		return fmt.Errorf("debug: unknown register %q", name)
+	}
+	return s.SetRegs(&regs)
+}
+
+// archReturnAddr reads the return address from LR (arm64 convention).
+func archReturnAddr(s *Session, regs *Regs) (uint64, error) {
+	return regs.X30, nil
+}
+
+// archSPLabel returns the SP register name for display.
+func archSPLabel() string { return "SP" }

debug/display_freebsd_riscv64.go

@@ -0,0 +1,121 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && riscv64
+
+package debug
+
+import "fmt"
+
+func printRegs(regs *Regs, codeBase, funcOff uint64) {
+	fmt.Printf("  PC  = %#016x  (func+%#x)\n", regs.PC, regs.PC-codeBase-funcOff)
+	fmt.Printf("  SP  = %#016x  FP  = %#016x\n", regs.Sp, regs.S0)
+	fmt.Printf("  RA  = %#016x\n", regs.Ra)
+	fmt.Printf("  A0  = %#016x  A1  = %#016x\n", regs.A0, regs.A1)
+	fmt.Printf("  A2  = %#016x  A3  = %#016x\n", regs.A2, regs.A3)
+	fmt.Printf("  A4  = %#016x  A5  = %#016x\n", regs.A4, regs.A5)
+	fmt.Printf("  A6  = %#016x  A7  = %#016x\n", regs.A6, regs.A7)
+	fmt.Printf("  T0  = %#016x  T1  = %#016x\n", regs.T0, regs.T1)
+	fmt.Printf("  T2  = %#016x  T3  = %#016x\n", regs.T2, regs.T3)
+	fmt.Printf("  T4  = %#016x  T5  = %#016x\n", regs.T4, regs.T5)
+	fmt.Printf("  T6  = %#016x\n", regs.T6)
+	fmt.Printf("  S1  = %#016x  S2  = %#016x\n", regs.S1, regs.S2)
+	fmt.Printf("  S3  = %#016x  S4  = %#016x\n", regs.S3, regs.S4)
+	fmt.Printf("  S5  = %#016x  S6  = %#016x\n", regs.S5, regs.S6)
+	fmt.Printf("  S7  = %#016x  S8  = %#016x\n", regs.S7, regs.S8)
+	fmt.Printf("  S9  = %#016x  S10 = %#016x\n", regs.S9, regs.S10)
+	fmt.Printf("  S11 = %#016x\n", regs.S11)
+}
+
+func printVectorRegs(v *VectorRegs) {
+	fmt.Println("\n  FP registers (F0-F31):")
+	for i := 0; i < 32; i += 2 {
+		fmt.Printf("  F%-2d  = %#018x  F%-2d  = %#018x\n", i, v.F[i], i+1, v.F[i+1])
+	}
+	fmt.Printf("  FCSR = %#x\n", v.FCSR)
+}
+
+// SetReg modifies a register value in the debuggee.
+func (s *Session) SetReg(name string, value uint64) error {
+	regs, err := s.GetRegs()
+	if err != nil {
+		return err
+	}
+	switch name {
+	case "pc":
+		regs.PC = value
+	case "ra", "x1":
+		regs.Ra = value
+	case "sp", "x2":
+		regs.Sp = value
+	case "gp", "x3":
+		regs.Gp = value
+	case "tp", "x4":
+		regs.Tp = value
+	case "t0", "x5":
+		regs.T0 = value
+	case "t1", "x6":
+		regs.T1 = value
+	case "t2", "x7":
+		regs.T2 = value
+	case "s0", "fp", "x8":
+		regs.S0 = value
+	case "s1", "x9":
+		regs.S1 = value
+	case "a0", "x10":
+		regs.A0 = value
+	case "a1", "x11":
+		regs.A1 = value
+	case "a2", "x12":
+		regs.A2 = value
+	case "a3", "x13":
+		regs.A3 = value
+	case "a4", "x14":
+		regs.A4 = value
+	case "a5", "x15":
+		regs.A5 = value
+	case "a6", "x16":
+		regs.A6 = value
+	case "a7", "x17":
+		regs.A7 = value
+	case "s2", "x18":
+		regs.S2 = value
+	case "s3", "x19":
+		regs.S3 = value
+	case "s4", "x20":
+		regs.S4 = value
+	case "s5", "x21":
+		regs.S5 = value
+	case "s6", "x22":
+		regs.S6 = value
+	case "s7", "x23":
+		regs.S7 = value
+	case "s8", "x24":
+		regs.S8 = value
+	case "s9", "x25":
+		regs.S9 = value
+	case "s10", "x26":
+		regs.S10 = value
+	case "s11", "x27":
+		regs.S11 = value
+	case "t3", "x28":
+		regs.T3 = value
+	case "t4", "x29":
+		regs.T4 = value
+	case "t5", "x30":
+		regs.T5 = value
+	case "t6", "x31":
+		regs.T6 = value
+	default:
+		return fmt.Errorf("debug: unknown register %q", name)
+	}
+	return s.SetRegs(&regs)
+}
+
+// archReturnAddr reads the return address from RA (riscv64 convention).
+func archReturnAddr(s *Session, regs *Regs) (uint64, error) {
+	return regs.Ra, nil
+}
+
+// archSPLabel returns the SP register name for display.
+func archSPLabel() string { return "SP" }

debug/ptrace_extra_test.go

@@ -17,8 +17,8 @@ import (
 	"time"
 	"unsafe"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // Integration tests beyond the basic entry breakpoint: hardware watchpoints,

debug/ptrace_freebsd.go

@@ -0,0 +1,288 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && (amd64 || arm64 || riscv64)
+
+package debug
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// Session is a ptrace debugging session controlling one debuggee process.
+// The FreeBSD implementation sits behind the same surface as the Linux one:
+// PT_TRACE_ME from the debuggee, PT_CONTINUE/PT_STEP from the tracer, and
+// tracee memory through PT_IO (FreeBSD has no /proc/pid/mem to fall back
+// on, so PT_IO is the only supported route).
+type Session struct {
+	pid      int
+	cmd      *exec.Cmd
+	stopped  bool
+	exited   bool
+	codeBase uint64   // base address of the JIT code in the debuggee
+	tmpDir   string   // scratch directory of the session, removed on Kill
+	wpSlots  [16]bool // hardware watchpoint slots in use (DR0-DR3, arm64 dbw 0-15)
+	// lastSignal holds the signal of the most recent stop when that stop
+	// was a genuine signal-delivery-stop the caller must see (a fault such
+	// as SIGSEGV, SIGBUS, SIGFPE or SIGILL); 0 for breakpoint traps,
+	// single-steps, SIGSTOP and suppressed runtime signals.
+	lastSignal syscall.Signal
+}
+
+// Launch starts the debuggee subprocess (gasm debug --target ...) and
+// attaches to it via ptrace.
+func Launch(gasmBin, asmPath, funcName string, args []byte) (*Session, error) {
+	sess, _, err := LaunchWithBuffers(gasmBin, asmPath, funcName, args, "")
+	return sess, err
+}
+
+// LaunchWithBuffers is like Launch but also allocates buffers in the debuggee.
+//
+// It pins the calling goroutine to its OS thread and leaves it pinned: the
+// debuggee's PT_TRACE_ME binds the tracer relation to the forking thread,
+// and every ptrace request on the session must come from that same thread.
+// All Session methods must therefore be called from the goroutine that
+// launched the session (the REPL and coverage loops do exactly that).
+func LaunchWithBuffers(gasmBin, asmPath, funcName string, args []byte, bufSpec string) (*Session, []uint64, error) {
+	runtime.LockOSThread() // ptrace requests must stay on the forking thread
+	self, err := os.Executable()
+	if err != nil {
+		return nil, nil, fmt.Errorf("debug: cannot find gasm binary: %w", err)
+	}
+	if gasmBin != "" {
+		self = gasmBin
+	}
+
+	tmpDir, err := os.MkdirTemp("", "gasm-debug-*")
+	if err != nil {
+		return nil, nil, fmt.Errorf("debug: tempdir: %w", err)
+	}
+	argsFile := filepath.Join(tmpDir, "args.bin")
+	if err := os.WriteFile(argsFile, args, 0o644); err != nil {
+		os.RemoveAll(tmpDir)
+		return nil, nil, fmt.Errorf("debug: write args: %w", err)
+	}
+
+	if bufSpec != "" {
+		if err := os.WriteFile(filepath.Join(tmpDir, "bufspec"), []byte(bufSpec), 0o644); err != nil {
+			os.RemoveAll(tmpDir)
+			return nil, nil, fmt.Errorf("debug: write bufspec: %w", err)
+		}
+	}
+
+	cmd := exec.Command(self, "debug", "--func", funcName, "--args", argsFile, asmPath)
+	cmd.Env = append(os.Environ(), "GASM_DEBUG_TARGET=1", "GASM_DEBUG_TMP="+tmpDir)
+	cmd.Stdout = nil
+	cmd.Stderr = os.Stderr
+	cmd.SysProcAttr = &syscall.SysProcAttr{}
+
+	if err := cmd.Start(); err != nil {
+		os.RemoveAll(tmpDir)
+		return nil, nil, fmt.Errorf("debug: start debuggee: %w", err)
+	}
+
+	s := &Session{pid: cmd.Process.Pid, cmd: cmd, tmpDir: tmpDir}
+
+	readyFile := filepath.Join(tmpDir, "ready")
+	for range 500 {
+		if _, err := os.Stat(readyFile); err == nil {
+			break
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+
+	// The debuggee parks itself with SIGSTOP once the JIT code is mapped.
+	// A Go tracee also reports SIGURG preemption as signal-delivery-stops,
+	// so the wait loops until a stop the debugger cares about instead of
+	// assuming the first event is the SIGSTOP.
+	if _, err := s.waitStopped(); err != nil {
+		cmd.Process.Kill()
+		os.RemoveAll(tmpDir)
+		return nil, nil, fmt.Errorf("debug: wait for debuggee: %w", err)
+	}
+	s.stopped = true
+
+	// The debuggee reports its JIT mapping in the codebase file; that is
+	// the supported path on FreeBSD, where no /proc/pid/maps exists to
+	// scan for the RWX region as a fallback.
+	if data, err := os.ReadFile(filepath.Join(tmpDir, "codebase")); err == nil {
+		fmt.Sscanf(string(data), "%d", &s.codeBase)
+	}
+
+	var bufAddrs []uint64
+	if bufSpec != "" {
+		addrFile := filepath.Join(tmpDir, "bufaddrs")
+		if data, err := os.ReadFile(addrFile); err == nil {
+			for line := range strings.SplitSeq(strings.TrimSpace(string(data)), "\n") {
+				var addr uint64
+				if _, err := fmt.Sscanf(line, "%d", &addr); err == nil {
+					bufAddrs = append(bufAddrs, addr)
+				}
+			}
+		}
+	}
+
+	return s, bufAddrs, nil
+}
+
+// waitStopped consumes ptrace-stop events until one the debugger cares
+// about arrives: SIGTRAP (a breakpoint or a completed single-step), the
+// debuggee's own SIGSTOP, or a genuine signal-delivery-stop.  A Go tracee's
+// runtime raises SIGURG for asynchronous preemption, and every signal on a
+// traced thread surfaces as a signal-delivery-stop, so SIGURG is suppressed
+// and the tracee resumed without it.  Every other signal (SIGSEGV, SIGBUS,
+// SIGFPE, SIGILL, ...) is returned to the caller: resuming with signal 0
+// would restart the faulting instruction and fault forever, so a faulting
+// kernel must surface as a stop the caller reports.
+func (s *Session) waitStopped() (syscall.Signal, error) {
+	for {
+		var ws syscall.WaitStatus
+		if _, err := syscall.Wait4(s.pid, &ws, syscall.WUNTRACED, nil); err != nil {
+			return 0, err
+		}
+		if ws.Exited() {
+			s.exited = true
+			return 0, fmt.Errorf("debuggee exited with status %d", ws.ExitStatus())
+		}
+		if ws.Signaled() {
+			s.exited = true
+			return 0, fmt.Errorf("debuggee killed by signal %v", ws.Signal())
+		}
+		switch sig := ws.StopSignal(); sig {
+		case syscall.SIGTRAP, syscall.SIGSTOP:
+			s.stopped = true
+			s.lastSignal = 0
+			return sig, nil
+		case syscall.SIGURG:
+			// Go runtime asynchronous preemption: resume the tracee
+			// without delivering the signal.
+			s.lastSignal = 0
+			if err := unix.PtraceCont(s.pid, 0); err != nil {
+				return 0, fmt.Errorf("debug: PT_CONTINUE: %w", err)
+			}
+		default:
+			// A genuine signal-delivery-stop.  Report it; the caller
+			// decides how to proceed.
+			s.stopped = true
+			s.lastSignal = sig
+			return sig, nil
+		}
+	}
+}
+
+// LastSignal returns the signal of the most recent stop when that stop was
+// a genuine signal-delivery-stop (a fault such as SIGSEGV, SIGFPE, SIGILL
+// or SIGBUS), and 0 for breakpoint traps, single-steps, SIGSTOP and
+// suppressed runtime signals.
+func (s *Session) LastSignal() syscall.Signal { return s.lastSignal }
+
+// Peek reads a word (8 bytes) from the debuggee's memory at addr, through
+// PT_IO with PIOD_READ_D.
+func (s *Session) Peek(addr uint64) (uint64, error) {
+	var buf [8]byte
+	if _, err := unix.PtraceIO(unix.PIOD_READ_D, s.pid, uintptr(addr), buf[:], len(buf)); err != nil {
+		return 0, fmt.Errorf("debug: read mem %#x: %w", addr, err)
+	}
+	return uint64(buf[0]) | uint64(buf[1])<<8 | uint64(buf[2])<<16 | uint64(buf[3])<<24 |
+		uint64(buf[4])<<32 | uint64(buf[5])<<40 | uint64(buf[6])<<48 | uint64(buf[7])<<56, nil
+}
+
+// Poke writes a word (8 bytes) to the debuggee's memory at addr, through
+// PT_IO with PIOD_WRITE_D.
+func (s *Session) Poke(addr, val uint64) error {
+	buf := []byte{byte(val), byte(val >> 8), byte(val >> 16), byte(val >> 24),
+		byte(val >> 32), byte(val >> 40), byte(val >> 48), byte(val >> 56)}
+	if _, err := unix.PtraceIO(unix.PIOD_WRITE_D, s.pid, uintptr(addr), buf, len(buf)); err != nil {
+		return fmt.Errorf("debug: write mem %#x: %w", addr, err)
+	}
+	return nil
+}
+
+// ReadMemory reads len bytes from the debuggee's memory at addr in one
+// PT_IO request, the shape the request is built for.
+func (s *Session) ReadMemory(addr uint64, length int) ([]byte, error) {
+	out := make([]byte, length)
+	n, err := unix.PtraceIO(unix.PIOD_READ_D, s.pid, uintptr(addr), out, length)
+	return out[:n], err
+}
+
+// WriteMemory writes bytes to the debuggee's memory at addr in one PT_IO
+// request.
+func (s *Session) WriteMemory(addr uint64, data []byte) error {
+	_, err := unix.PtraceIO(unix.PIOD_WRITE_D, s.pid, uintptr(addr), data, len(data))
+	return err
+}
+
+// Step executes a single instruction in the debuggee.
+func (s *Session) Step() error {
+	if s.exited {
+		return fmt.Errorf("debug: debuggee has exited")
+	}
+	if err := unix.PtraceSingleStep(s.pid); err != nil {
+		return fmt.Errorf("debug: PT_STEP: %w", err)
+	}
+	_, err := s.waitStopped()
+	return err
+}
+
+// Continue resumes execution until the next breakpoint or exit.
+func (s *Session) Continue() error {
+	if s.exited {
+		return fmt.Errorf("debug: debuggee has exited")
+	}
+	if err := unix.PtraceCont(s.pid, 0); err != nil {
+		return fmt.Errorf("debug: PT_CONTINUE: %w", err)
+	}
+	_, err := s.waitStopped()
+	return err
+}
+
+// Exited returns true if the debuggee has terminated.
+func (s *Session) Exited() bool { return s.exited }
+
+// Pid returns the debuggee's process ID.
+func (s *Session) Pid() int { return s.pid }
+
+// CodeBase returns the base address of the JIT code in the debuggee.
+func (s *Session) CodeBase() uint64 { return s.codeBase }
+
+// Kill terminates the debuggee and removes the session's scratch
+// directory, so a successful session leaves no gasm-debug-* debris behind.
+func (s *Session) Kill() {
+	if !s.exited {
+		syscall.Kill(s.pid, syscall.SIGKILL)
+		syscall.Wait4(s.pid, nil, 0, nil)
+		s.exited = true
+	}
+	if s.cmd != nil && s.cmd.Process != nil {
+		s.cmd.Wait()
+	}
+	if s.tmpDir != "" {
+		os.RemoveAll(s.tmpDir)
+		s.tmpDir = ""
+	}
+}
+
+// execRange is one executable mapping of the debuggee.
+type execRange struct {
+	lo, hi uint64
+}
+
+// execRanges is a stub on FreeBSD: there is no /proc/pid/maps to parse,
+// and procfs(5) is not guaranteed to be mounted.  The callers degrade
+// gracefully: archReturnAddr falls back to the raw stack convention and
+// the mapping scan is skipped.
+func execRanges(pid int) []execRange { return nil }
+
+// findRWXMapping is a stub on FreeBSD for the same reason: the codebase
+// handshake file is the supported way the JIT region is located.
+func findRWXMapping(pid int) uint64 { return 0 }

debug/ptrace_freebsd_amd64.go

@@ -0,0 +1,160 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && amd64
+
+package debug
+
+import (
+	"encoding/binary"
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// GetRegs reads the general-purpose registers of the stopped debuggee and
+// converts the FreeBSD struct reg into the portable layout.
+func (s *Session) GetRegs() (Regs, error) {
+	var ur unix.Reg
+	if err := unix.PtraceGetRegs(s.pid, &ur); err != nil {
+		return Regs{}, fmt.Errorf("debug: PT_GETREGS: %w", err)
+	}
+	return Regs{
+		R15:    uint64(ur.R15),
+		R14:    uint64(ur.R14),
+		R13:    uint64(ur.R13),
+		R12:    uint64(ur.R12),
+		R11:    uint64(ur.R11),
+		R10:    uint64(ur.R10),
+		R9:     uint64(ur.R9),
+		R8:     uint64(ur.R8),
+		RDI:    uint64(ur.Rdi),
+		RSI:    uint64(ur.Rsi),
+		RBP:    uint64(ur.Rbp),
+		RBX:    uint64(ur.Rbx),
+		RDX:    uint64(ur.Rdx),
+		RCX:    uint64(ur.Rcx),
+		RAX:    uint64(ur.Rax),
+		RIP:    uint64(ur.Rip),
+		CS:     uint64(ur.Cs),
+		RFLAGS: uint64(ur.Rflags),
+		RSP:    uint64(ur.Rsp),
+		SS:     uint64(ur.Ss),
+		FS:     uint64(ur.Fs),
+		GS:     uint64(ur.Gs),
+		DS:     uint64(ur.Ds),
+		ES:     uint64(ur.Es),
+	}, nil
+}
+
+// SetRegs writes the general-purpose registers of the stopped debuggee.
+func (s *Session) SetRegs(regs *Regs) error {
+	// Read-modify-write keeps the fields FreeBSD owns (trapno, err) intact.
+	var ur unix.Reg
+	if err := unix.PtraceGetRegs(s.pid, &ur); err != nil {
+		return fmt.Errorf("debug: PT_GETREGS: %w", err)
+	}
+	ur.R15 = int64(regs.R15)
+	ur.R14 = int64(regs.R14)
+	ur.R13 = int64(regs.R13)
+	ur.R12 = int64(regs.R12)
+	ur.R11 = int64(regs.R11)
+	ur.R10 = int64(regs.R10)
+	ur.R9 = int64(regs.R9)
+	ur.R8 = int64(regs.R8)
+	ur.Rdi = int64(regs.RDI)
+	ur.Rsi = int64(regs.RSI)
+	ur.Rbp = int64(regs.RBP)
+	ur.Rbx = int64(regs.RBX)
+	ur.Rdx = int64(regs.RDX)
+	ur.Rcx = int64(regs.RCX)
+	ur.Rax = int64(regs.RAX)
+	ur.Rip = int64(regs.RIP)
+	ur.Cs = int64(regs.CS)
+	ur.Rflags = int64(regs.RFLAGS)
+	ur.Rsp = int64(regs.RSP)
+	ur.Ss = int64(regs.SS)
+	return unix.PtraceSetRegs(s.pid, &ur)
+}
+
+// FPRegs holds the x87 FPU and SSE (XMM) register state, the FXSAVE image
+// the FreeBSD struct fpreg mirrors: XMM0-15 at the same offsets.
+type FPRegs struct {
+	XMM [16][16]byte // XMM0-15
+}
+
+// GetFPRegs retrieves the FPU/SSE register state via PT_GETFPREGS.  The
+// FreeBSD struct fpreg mirrors the FXSAVE image: the x87 environment and
+// stack in Env/Acc, XMM0-15 in Xacc.
+func (s *Session) GetFPRegs() (FPRegs, error) {
+	var fp FPRegs
+	var fr unix.FpReg
+	if err := unix.PtraceGetFpRegs(s.pid, &fr); err != nil {
+		return fp, fmt.Errorf("debug: PT_GETFPREGS: %w", err)
+	}
+	for i := range 16 {
+		copy(fp.XMM[i][:], fr.Xacc[i][:])
+	}
+	return fp, nil
+}
+
+// VectorRegs holds the YMM register state.
+type VectorRegs struct {
+	YMM [16][32]byte // YMM0-15 (full 256-bit values)
+}
+
+// The XSAVE area the PT_GETXSTATE request returns follows the architectural
+// layout (Intel SDM vol 1, "XSAVE"): the 512-byte legacy FXSAVE image (x87
+// state in 0-159, XMM0-15 in 160-511), then the 64-byte xsave header whose
+// first 8 bytes are xstate_bv, then one component per set feature bit, each
+// 64-byte aligned.  The YMM high halves are the first extended component,
+// at offset 576; XFEATURE_STATE_BIT_AVX is bit 2 of xstate_bv.
+const (
+	xsaveXMMOffset    = 160
+	xsaveHeaderOffset = 512
+	xsaveBVOffset     = xsaveHeaderOffset
+	ymmOffset         = xsaveHeaderOffset + 64 // 576
+	ymmSize           = 256                    // 16 registers, 16 bytes each
+	xfeatureMaskYMM   = 1 << 2
+	xstateMaxBuffer   = 4096 // PT_GETXSTATE_INFO bounds the size far below this
+)
+
+// GetVectorRegs retrieves the YMM registers via PT_GETXSTATE.  The low
+// (XMM) halves always come from the legacy image; the high halves are
+// copied only when xstate_bv reports the AVX state, and read as zero
+// otherwise.  When the request fails the FP image still provides correct
+// XMM halves, so that is the fallback.
+func (s *Session) GetVectorRegs() (VectorRegs, error) {
+	var v VectorRegs
+	buf := make([]byte, xstateMaxBuffer)
+	n, _, errno := unix.Syscall6(
+		unix.SYS_PTRACE,
+		uintptr(unix.PT_GETXSTATE),
+		uintptr(s.pid),
+		0,
+		uintptr(unsafe.Pointer(&buf[0])),
+		0, 0,
+	)
+	if errno != 0 {
+		fp, err := s.GetFPRegs()
+		if err != nil {
+			return v, err
+		}
+		for i := range 16 {
+			copy(v.YMM[i][:16], fp.XMM[i][:])
+		}
+		return v, nil
+	}
+	for i := range 16 {
+		copy(v.YMM[i][:16], buf[xsaveXMMOffset+16*i:xsaveXMMOffset+16*i+16])
+	}
+	if int(n) >= ymmOffset+ymmSize {
+		if binary.LittleEndian.Uint64(buf[xsaveBVOffset:xsaveBVOffset+8])&xfeatureMaskYMM != 0 {
+			for i := range 16 {
+				copy(v.YMM[i][16:], buf[ymmOffset+16*i:ymmOffset+16*i+16])
+			}
+		}
+	}
+	return v, nil
+}

debug/ptrace_freebsd_arm64.go

@@ -0,0 +1,114 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && arm64
+
+package debug
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
+
+// GetRegs reads the general-purpose registers of the stopped debuggee and
+// converts the FreeBSD struct reg (x[30], lr, sp, elr, spsr) into the
+// portable layout.
+func (s *Session) GetRegs() (Regs, error) {
+	var ur unix.Reg
+	if err := unix.PtraceGetRegs(s.pid, &ur); err != nil {
+		return Regs{}, fmt.Errorf("debug: PT_GETREGS: %w", err)
+	}
+	return Regs{
+		X0:     ur.X[0],
+		X1:     ur.X[1],
+		X2:     ur.X[2],
+		X3:     ur.X[3],
+		X4:     ur.X[4],
+		X5:     ur.X[5],
+		X6:     ur.X[6],
+		X7:     ur.X[7],
+		X8:     ur.X[8],
+		X9:     ur.X[9],
+		X10:    ur.X[10],
+		X11:    ur.X[11],
+		X12:    ur.X[12],
+		X13:    ur.X[13],
+		X14:    ur.X[14],
+		X15:    ur.X[15],
+		X16:    ur.X[16],
+		X17:    ur.X[17],
+		X18:    ur.X[18],
+		X19:    ur.X[19],
+		X20:    ur.X[20],
+		X21:    ur.X[21],
+		X22:    ur.X[22],
+		X23:    ur.X[23],
+		X24:    ur.X[24],
+		X25:    ur.X[25],
+		X26:    ur.X[26],
+		X27:    ur.X[27],
+		X28:    ur.X[28],
+		X29:    ur.X[29],
+		X30:    ur.Lr,
+		SP:     ur.Sp,
+		PC:     ur.Elr,
+		PSTATE: uint64(ur.Spsr),
+	}, nil
+}
+
+// SetRegs writes the general-purpose registers of the stopped debuggee.
+func (s *Session) SetRegs(regs *Regs) error {
+	var ur unix.Reg
+	ur.X = [30]uint64{
+		regs.X0, regs.X1, regs.X2, regs.X3, regs.X4, regs.X5, regs.X6,
+		regs.X7, regs.X8, regs.X9, regs.X10, regs.X11, regs.X12, regs.X13,
+		regs.X14, regs.X15, regs.X16, regs.X17, regs.X18, regs.X19, regs.X20,
+		regs.X21, regs.X22, regs.X23, regs.X24, regs.X25, regs.X26, regs.X27,
+		regs.X28, regs.X29,
+	}
+	ur.Lr = regs.X30
+	ur.Sp = regs.SP
+	ur.Elr = regs.PC
+	ur.Spsr = uint32(regs.PSTATE)
+	return unix.PtraceSetRegs(s.pid, &ur)
+}
+
+// FPRegs holds the arm64 FP/NEON register state: the 32 128-bit V
+// registers, then FPSR and FPCR (the user_fpsimd shape).
+type FPRegs struct {
+	V    [32][16]byte // V0-V31 (128-bit NEON/FP registers)
+	FPSR uint32
+	FPCR uint32
+}
+
+// GetFPRegs retrieves the FP/NEON register state via PT_GETFPREGS.  The
+// FreeBSD struct fpreg holds the 32 128-bit V registers followed by FPSR
+// and FPCR, the user_fpsimd shape.
+func (s *Session) GetFPRegs() (FPRegs, error) {
+	var fp FPRegs
+	var fr unix.FpReg
+	if err := unix.PtraceGetFpRegs(s.pid, &fr); err != nil {
+		return fp, fmt.Errorf("debug: PT_GETFPREGS: %w", err)
+	}
+	for i := range 32 {
+		copy(fp.V[i][:], fr.Q[i][:])
+	}
+	return fp, nil
+}
+
+// VectorRegs holds the full SIMD register state.
+type VectorRegs struct {
+	V [32][16]byte // V0-V31 (128-bit)
+}
+
+// GetVectorRegs retrieves the SIMD registers.
+func (s *Session) GetVectorRegs() (VectorRegs, error) {
+	var v VectorRegs
+	fp, err := s.GetFPRegs()
+	if err != nil {
+		return v, err
+	}
+	copy(v.V[:][:], fp.V[:][:])
+	return v, nil
+}

debug/ptrace_freebsd_riscv64.go

@@ -0,0 +1,115 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && riscv64
+
+package debug
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
+
+// GetRegs reads the general-purpose registers of the stopped debuggee and
+// converts the FreeBSD struct reg into the portable layout.  Sstatus rides
+// the kernel's struct but the portable surface carries the GPRs and PC.
+func (s *Session) GetRegs() (Regs, error) {
+	var ur unix.Reg
+	if err := unix.PtraceGetRegs(s.pid, &ur); err != nil {
+		return Regs{}, fmt.Errorf("debug: PT_GETREGS: %w", err)
+	}
+	return Regs{
+		PC:  ur.Sepc,
+		Ra:  ur.Ra,
+		Sp:  ur.Sp,
+		Gp:  ur.Gp,
+		Tp:  ur.Tp,
+		T0:  ur.T[0],
+		T1:  ur.T[1],
+		T2:  ur.T[2],
+		S0:  ur.S[0],
+		S1:  ur.S[1],
+		A0:  ur.A[0],
+		A1:  ur.A[1],
+		A2:  ur.A[2],
+		A3:  ur.A[3],
+		A4:  ur.A[4],
+		A5:  ur.A[5],
+		A6:  ur.A[6],
+		A7:  ur.A[7],
+		S2:  ur.S[2],
+		S3:  ur.S[3],
+		S4:  ur.S[4],
+		S5:  ur.S[5],
+		S6:  ur.S[6],
+		S7:  ur.S[7],
+		S8:  ur.S[8],
+		S9:  ur.S[9],
+		S10: ur.S[10],
+		S11: ur.S[11],
+		T3:  ur.T[3],
+		T4:  ur.T[4],
+		T5:  ur.T[5],
+		T6:  ur.T[6],
+	}, nil
+}
+
+// SetRegs writes the general-purpose registers of the stopped debuggee.
+// Read-modify-write keeps sstatus, which the kernel owns, intact.
+func (s *Session) SetRegs(regs *Regs) error {
+	var ur unix.Reg
+	if err := unix.PtraceGetRegs(s.pid, &ur); err != nil {
+		return fmt.Errorf("debug: PT_GETREGS: %w", err)
+	}
+	ur.Sepc = regs.PC
+	ur.Ra = regs.Ra
+	ur.Sp = regs.Sp
+	ur.Gp = regs.Gp
+	ur.Tp = regs.Tp
+	ur.T = [7]uint64{regs.T0, regs.T1, regs.T2, regs.T3, regs.T4, regs.T5, regs.T6}
+	ur.S = [12]uint64{regs.S0, regs.S1, regs.S2, regs.S3, regs.S4, regs.S5,
+		regs.S6, regs.S7, regs.S8, regs.S9, regs.S10, regs.S11}
+	ur.A = [8]uint64{regs.A0, regs.A1, regs.A2, regs.A3, regs.A4, regs.A5, regs.A6, regs.A7}
+	return unix.PtraceSetRegs(s.pid, &ur)
+}
+
+// FPRegs holds the RISC-V FP register state (32 64-bit FP registers plus
+// fcsr).
+type FPRegs struct {
+	F    [32]uint64 // F0-F31 (64-bit FP registers)
+	FCSR uint32
+}
+
+// GetFPRegs retrieves the FP register state via PT_GETFPREGS.  The FreeBSD
+// struct fpreg carries each 64-bit FP register in a 128-bit slot (fp_x is
+// the flat [64]-word area the x/sys type renders as [32][2]); the low word
+// holds the register, and FCSR rides the tail.
+func (s *Session) GetFPRegs() (FPRegs, error) {
+	var fp FPRegs
+	var fr unix.FpReg
+	if err := unix.PtraceGetFpRegs(s.pid, &fr); err != nil {
+		return fp, fmt.Errorf("debug: PT_GETFPREGS: %w", err)
+	}
+	for i := range 32 {
+		fp.F[i] = fr.X[i][0]
+	}
+	fp.FCSR = uint32(fr.Fcsr)
+	return fp, nil
+}
+
+// VectorRegs holds the FP register state shown by the regs command
+// (riscv64 has 32 64-bit FP registers and fcsr).
+type VectorRegs struct {
+	F    [32]uint64
+	FCSR uint32
+}
+
+// GetVectorRegs retrieves the FP registers.
+func (s *Session) GetVectorRegs() (VectorRegs, error) {
+	fp, err := s.GetFPRegs()
+	if err != nil {
+		return VectorRegs{}, err
+	}
+	return VectorRegs{F: fp.F, FCSR: fp.FCSR}, nil
+}

debug/ptrace_integration_freebsd_test.go

@@ -0,0 +1,91 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && amd64
+
+package debug
+
+import (
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
+)
+
+// TestLaunchAndBreakpoint is the FreeBSD twin of the Linux integration
+// test: it drives the whole launch, breakpoint, trap and register-rewind
+// flow end to end.  It needs a real FreeBSD kernel (ptrace does not work
+// under emulation), so it only runs where it can.
+func TestLaunchAndBreakpoint(t *testing.T) {
+	if runtime.GOARCH != "amd64" {
+		t.Skip("runs only on amd64 hosts")
+	}
+	// The tracer is the OS thread that forked the debuggee (PT_TRACE_ME
+	// binds the relation to that thread); every ptrace request must come
+	// from the same thread, so pin the test goroutine to one thread.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	bin := filepath.Join(t.TempDir(), "gasm")
+	out, err := exec.Command("go", "build", "-o", bin, "sourcedock.dev/petrbalvin/gasm-sdk/cmd/gasm").CombinedOutput()
+	if err != nil {
+		t.Fatalf("build gasm: %v: %s", err, out)
+	}
+
+	const kernelPath = "../testdata/verify/basic_amd64.s"
+	k, err := verify.Load(kernelPath)
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	t.Cleanup(k.Close)
+	fl, err := k.Func("wideCopy")
+	if err != nil {
+		t.Fatalf("Func: %v", err)
+	}
+
+	sess, err := Launch(bin, kernelPath, "wideCopy", make([]byte, fl.Args))
+	if err != nil {
+		t.Fatalf("Launch: %v", err)
+	}
+	t.Cleanup(sess.Kill)
+
+	bm := NewBreakpoints(sess)
+	entry := sess.CodeBase() + uint64(fl.Offset)
+	if _, err := bm.Set(entry, "entry"); err != nil {
+		t.Fatalf("Set: %v", err)
+	}
+
+	// The INT3 must be visible in the debuggee's memory.
+	word, err := sess.Peek(entry)
+	if err != nil {
+		t.Fatalf("Peek: %v", err)
+	}
+	if b := word & 0xFF; b != 0xCC {
+		t.Fatalf("int3 not patched: first byte %#02x at %#x", b, entry)
+	}
+
+	// The debuggee raises a second SIGSTOP after the launch barrier (the
+	// child's RunTarget marks its entry), so like the REPL and the cover
+	// mode the test keeps resuming until the breakpoint trap arrives.
+	for range 10 {
+		if err := sess.Continue(); err != nil {
+			t.Fatalf("Continue: %v", err)
+		}
+		if sess.Exited() {
+			t.Fatal("debuggee exited instead of trapping on the breakpoint")
+		}
+		regs, err := sess.GetRegs()
+		if err != nil {
+			t.Fatalf("GetRegs: %v", err)
+		}
+		if bp := bm.HandleTrap(&regs); bp != nil {
+			if bp.Addr != entry {
+				t.Fatalf("trap at %#x, want %#x", bp.Addr, entry)
+			}
+			return // trap on the entry breakpoint: the whole flow works
+		}
+	}
+	t.Fatal("no breakpoint trap after 10 resumes")
+}

debug/ptrace_integration_test.go

@@ -14,7 +14,7 @@ import (
 	"strings"
 	"testing"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // buildGasm produces the gasm binary the debugger spawns as its debuggee.
@@ -24,7 +24,7 @@ func buildGasm(t *testing.T) string {
 		return p
 	}
 	bin := filepath.Join(t.TempDir(), "gasm")
-	cmd := exec.Command("go", "build", "-o", bin, "sourcedock.dev/petrbalvin/gasm-devkit/cmd/gasm")
+	cmd := exec.Command("go", "build", "-o", bin, "sourcedock.dev/petrbalvin/gasm-sdk/cmd/gasm")
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		t.Fatalf("build gasm: %v: %s", err, out)

debug/regs_freebsd_amd64.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && amd64
+
+package debug
+
+// Regs holds the full general-purpose register set of a traced process
+// (the FreeBSD amd64 struct reg layout, sys/x86/include/reg.h).  FreeBSD
+// reports segment selectors (FS/GS/ES/DS), not the bases the Linux ptrace
+// surface carries, and has no ORIG_RAX slot.
+type Regs struct {
+	R15    uint64
+	R14    uint64
+	R13    uint64
+	R12    uint64
+	RBP    uint64
+	RBX    uint64
+	R11    uint64
+	R10    uint64
+	R9     uint64
+	R8     uint64
+	RAX    uint64
+	RCX    uint64
+	RDX    uint64
+	RSI    uint64
+	RDI    uint64
+	RIP    uint64
+	CS     uint64
+	RFLAGS uint64
+	RSP    uint64
+	SS     uint64
+	FS     uint64
+	GS     uint64
+	DS     uint64
+	ES     uint64
+}
+
+// GetPC returns the program counter.
+func (r *Regs) GetPC() uint64 { return r.RIP }
+
+// SetPC sets the program counter.
+func (r *Regs) SetPC(pc uint64) { r.RIP = pc }
+
+// GetSP returns the stack pointer.
+func (r *Regs) GetSP() uint64 { return r.RSP }
+
+// RegValue returns the value of the named register, or false if unknown.
+func (r *Regs) RegValue(name string) (uint64, bool) {
+	switch name {
+	case "rax", "eax", "ax", "al":
+		return r.RAX, true
+	case "rbx", "ebx", "bx", "bl":
+		return r.RBX, true
+	case "rcx", "ecx", "cx", "cl":
+		return r.RCX, true
+	case "rdx", "edx", "dx", "dl":
+		return r.RDX, true
+	case "rsi", "esi", "si":
+		return r.RSI, true
+	case "rdi", "edi", "di":
+		return r.RDI, true
+	case "rbp", "ebp", "bp":
+		return r.RBP, true
+	case "rsp", "esp", "sp":
+		return r.RSP, true
+	case "r8":
+		return r.R8, true
+	case "r9":
+		return r.R9, true
+	case "r10":
+		return r.R10, true
+	case "r11":
+		return r.R11, true
+	case "r12":
+		return r.R12, true
+	case "r13":
+		return r.R13, true
+	case "r14":
+		return r.R14, true
+	case "r15":
+		return r.R15, true
+	case "rip", "eip":
+		return r.RIP, true
+	default:
+		return 0, false
+	}
+}
+
+// breakpointInsn is the software breakpoint instruction.
+var breakpointInsn = []byte{0xCC} // INT3
+
+// breakpointPCAdjust is how far PC is past the breakpoint instruction after
+// a trap.  INT3 leaves the hardware PC on the following instruction (Intel
+// SDM vol 3, "Debug Exceptions") and the FreeBSD T_BPTFLT path delivers
+// that frame unmodified (sys/amd64/amd64/trap.c), so the trap address is
+// PC-1, the same correction the Linux side applies.
+const breakpointPCAdjust = 1

debug/regs_freebsd_arm64.go

@@ -0,0 +1,139 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && arm64
+
+package debug
+
+// Regs holds the full general-purpose register set of a traced process
+// (the FreeBSD arm64 struct reg layout, sys/arm64/include/reg.h: x[30], lr,
+// sp, elr, spsr).
+type Regs struct {
+	X0     uint64
+	X1     uint64
+	X2     uint64
+	X3     uint64
+	X4     uint64
+	X5     uint64
+	X6     uint64
+	X7     uint64
+	X8     uint64
+	X9     uint64
+	X10    uint64
+	X11    uint64
+	X12    uint64
+	X13    uint64
+	X14    uint64
+	X15    uint64
+	X16    uint64
+	X17    uint64
+	X18    uint64
+	X19    uint64
+	X20    uint64
+	X21    uint64
+	X22    uint64
+	X23    uint64
+	X24    uint64
+	X25    uint64
+	X26    uint64
+	X27    uint64
+	X28    uint64
+	X29    uint64 // FP (frame pointer)
+	X30    uint64 // LR (link register)
+	SP     uint64
+	PC     uint64
+	PSTATE uint64
+}
+
+// GetPC returns the program counter.
+func (r *Regs) GetPC() uint64 { return r.PC }
+
+// SetPC sets the program counter.
+func (r *Regs) SetPC(pc uint64) { r.PC = pc }
+
+// GetSP returns the stack pointer.
+func (r *Regs) GetSP() uint64 { return r.SP }
+
+// RegValue returns the value of the named register, or false if unknown.
+func (r *Regs) RegValue(name string) (uint64, bool) {
+	switch name {
+	case "x0":
+		return r.X0, true
+	case "x1":
+		return r.X1, true
+	case "x2":
+		return r.X2, true
+	case "x3":
+		return r.X3, true
+	case "x4":
+		return r.X4, true
+	case "x5":
+		return r.X5, true
+	case "x6":
+		return r.X6, true
+	case "x7":
+		return r.X7, true
+	case "x8":
+		return r.X8, true
+	case "x9":
+		return r.X9, true
+	case "x10":
+		return r.X10, true
+	case "x11":
+		return r.X11, true
+	case "x12":
+		return r.X12, true
+	case "x13":
+		return r.X13, true
+	case "x14":
+		return r.X14, true
+	case "x15":
+		return r.X15, true
+	case "x16":
+		return r.X16, true
+	case "x17":
+		return r.X17, true
+	case "x18":
+		return r.X18, true
+	case "x19":
+		return r.X19, true
+	case "x20":
+		return r.X20, true
+	case "x21":
+		return r.X21, true
+	case "x22":
+		return r.X22, true
+	case "x23":
+		return r.X23, true
+	case "x24":
+		return r.X24, true
+	case "x25":
+		return r.X25, true
+	case "x26":
+		return r.X26, true
+	case "x27":
+		return r.X27, true
+	case "x28":
+		return r.X28, true
+	case "x29", "fp":
+		return r.X29, true
+	case "x30", "lr":
+		return r.X30, true
+	case "sp":
+		return r.SP, true
+	case "pc":
+		return r.PC, true
+	default:
+		return 0, false
+	}
+}
+
+// breakpointInsn is the software breakpoint instruction (BRK #0).
+var breakpointInsn = []byte{0x00, 0x00, 0x20, 0xD4} // BRK #0
+
+// breakpointPCAdjust is how far PC is past the breakpoint instruction after
+// a trap: 0.  The BRK synchronous exception leaves ELR_EL0 on the BRK
+// itself (ARM DDI 0487), and the FreeBSD EXCP_BRKPT_EL0 handler delivers
+// the frame's elr unmodified (sys/arm64/arm64/trap.c), so the trap address
+// is the PC as reported.
+const breakpointPCAdjust = 0

debug/regs_freebsd_riscv64.go

@@ -0,0 +1,134 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && riscv64
+
+package debug
+
+// Regs holds the full general-purpose register set of a traced process
+// (the FreeBSD riscv64 struct reg layout: ra, sp, gp, tp, t0-t6, s0-s11,
+// a0-a7, sepc, sstatus).
+type Regs struct {
+	PC  uint64 // sepc
+	Ra  uint64 // x1 (return address)
+	Sp  uint64 // x2
+	Gp  uint64 // x3
+	Tp  uint64 // x4
+	T0  uint64 // x5
+	T1  uint64 // x6
+	T2  uint64 // x7
+	S0  uint64 // x8 (frame pointer)
+	S1  uint64 // x9
+	A0  uint64 // x10
+	A1  uint64 // x11
+	A2  uint64 // x12
+	A3  uint64 // x13
+	A4  uint64 // x14
+	A5  uint64 // x15
+	A6  uint64 // x16
+	A7  uint64 // x17
+	S2  uint64 // x18
+	S3  uint64 // x19
+	S4  uint64 // x20
+	S5  uint64 // x21
+	S6  uint64 // x22
+	S7  uint64 // x23
+	S8  uint64 // x24
+	S9  uint64 // x25
+	S10 uint64 // x26
+	S11 uint64 // x27
+	T3  uint64 // x28
+	T4  uint64 // x29
+	T5  uint64 // x30
+	T6  uint64 // x31
+}
+
+// GetPC returns the program counter.
+func (r *Regs) GetPC() uint64 { return r.PC }
+
+// SetPC sets the program counter.
+func (r *Regs) SetPC(pc uint64) { r.PC = pc }
+
+// GetSP returns the stack pointer.
+func (r *Regs) GetSP() uint64 { return r.Sp }
+
+// RegValue returns the value of the named register, or false if unknown.
+func (r *Regs) RegValue(name string) (uint64, bool) {
+	switch name {
+	case "pc":
+		return r.PC, true
+	case "ra", "x1":
+		return r.Ra, true
+	case "sp", "x2":
+		return r.Sp, true
+	case "gp", "x3":
+		return r.Gp, true
+	case "tp", "x4":
+		return r.Tp, true
+	case "t0", "x5":
+		return r.T0, true
+	case "t1", "x6":
+		return r.T1, true
+	case "t2", "x7":
+		return r.T2, true
+	case "s0", "fp", "x8":
+		return r.S0, true
+	case "s1", "x9":
+		return r.S1, true
+	case "a0", "x10":
+		return r.A0, true
+	case "a1", "x11":
+		return r.A1, true
+	case "a2", "x12":
+		return r.A2, true
+	case "a3", "x13":
+		return r.A3, true
+	case "a4", "x14":
+		return r.A4, true
+	case "a5", "x15":
+		return r.A5, true
+	case "a6", "x16":
+		return r.A6, true
+	case "a7", "x17":
+		return r.A7, true
+	case "s2", "x18":
+		return r.S2, true
+	case "s3", "x19":
+		return r.S3, true
+	case "s4", "x20":
+		return r.S4, true
+	case "s5", "x21":
+		return r.S5, true
+	case "s6", "x22":
+		return r.S6, true
+	case "s7", "x23":
+		return r.S7, true
+	case "s8", "x24":
+		return r.S8, true
+	case "s9", "x25":
+		return r.S9, true
+	case "s10", "x26":
+		return r.S10, true
+	case "s11", "x27":
+		return r.S11, true
+	case "t3", "x28":
+		return r.T3, true
+	case "t4", "x29":
+		return r.T4, true
+	case "t5", "x30":
+		return r.T5, true
+	case "t6", "x31":
+		return r.T6, true
+	default:
+		return 0, false
+	}
+}
+
+// breakpointInsn is the software breakpoint instruction (EBREAK).
+var breakpointInsn = []byte{0x73, 0x00, 0x10, 0x00} // ebreak
+
+// breakpointPCAdjust is how far PC is past the breakpoint instruction after
+// a trap: 0.  The EBREAK synchronous exception leaves sepc on the ebreak
+// itself (RISC-V privileged architecture), so the trap address is the PC as
+// reported.
+const breakpointPCAdjust = 0

debug/repl.go

@@ -1,7 +1,7 @@
 // Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build linux
+//go:build linux || (freebsd && (amd64 || arm64 || riscv64))
 
 package debug
 

debug/stopinfo_freebsd.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && (amd64 || arm64 || riscv64)
+
+package debug
+
+import (
+	"encoding/binary"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// FreeBSD TRAP_* si_code values (sys/signal.h).  A breakpoint (INT3, BRK,
+// EBREAK) arrives as TRAP_BRKPT on every supported architecture; TRAP_TRACE
+// is shared by the completed single-step and the hardware watchpoint hit,
+// so the watchpoint layer disambiguates from the debug registers.
+const (
+	trapBRKPT = 1 // TRAP_BRKPT
+	trapTRACE = 2 // TRAP_TRACE
+)
+
+// StopReason describes why the debuggee stopped.
+type StopReason int
+
+const (
+	StopNone       StopReason = iota
+	StopBreakpoint            // software breakpoint hit
+	StopWatchpoint            // hardware watchpoint triggered
+	StopSingleStep            // single-step completed
+	StopSignal                // stopped by a signal
+	StopExited                // process exited
+)
+
+// StopInfo returns the reason the debuggee stopped and the faulting address
+// (for watchpoints, the watched address that was accessed).  FreeBSD has no
+// PTRACE_GETSIGINFO; the stop's signal information comes from PT_LWPINFO,
+// whose pl_siginfo carries the siginfo the kernel delivered.  A ptrace stop
+// with no signal behind it (a completed single-step, the initial attach)
+// fills no siginfo at all.
+func (s *Session) StopInfo() (StopReason, uint64) {
+	if s.exited {
+		return StopExited, 0
+	}
+	var info unix.PtraceLwpInfoStruct
+	if err := unix.PtraceLwpInfo(s.pid, &info); err != nil {
+		return StopNone, 0
+	}
+	// The siginfo layout is the FreeBSD siginfo_t: three leading ints
+	// (signo, errno, code), then the union, 8-byte aligned, whose _fault
+	// member puts the address at byte offset 16.  The read is byte-wise
+	// because the blob's alignment is not guaranteed.
+	si := (*[64]byte)(unsafe.Pointer(&info.Siginfo))
+	signo := int32(binary.LittleEndian.Uint32(si[0:4]))
+	code := int32(binary.LittleEndian.Uint32(si[8:12]))
+	switch {
+	case signo == 0:
+		// A pure ptrace stop: single-step completion, attach, or the
+		// events the kernel resolves internally.
+		return StopSingleStep, 0
+	case signo != int32(syscall.SIGTRAP):
+		return StopSignal, uint64(code)
+	case code == trapBRKPT:
+		return StopBreakpoint, 0
+	case code == trapTRACE:
+		addr := binary.LittleEndian.Uint64(si[16:24])
+		return archStopTrace(s, addr)
+	default:
+		return StopSingleStep, 0
+	}
+}

debug/target_freebsd.go

@@ -0,0 +1,195 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build freebsd && (amd64 || arm64 || riscv64)
+
+package debug
+
+import (
+	"encoding/hex"
+	"fmt"
+	"os"
+	"runtime"
+	"strconv"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
+)
+
+// mapRWX maps code into a read-write-execute region.
+func mapRWX(code []byte) ([]byte, error) {
+	const pageSize = 4096
+	size := (len(code) + pageSize - 1) &^ (pageSize - 1)
+	mem, err := syscall.Mmap(-1, 0, size,
+		syscall.PROT_READ|syscall.PROT_WRITE|syscall.PROT_EXEC,
+		syscall.MAP_PRIVATE|syscall.MAP_ANON)
+	if err != nil {
+		return nil, err
+	}
+	copy(mem, code)
+	return mem, nil
+}
+
+// setupBuffers allocates buffers in the debuggee's memory.
+func setupBuffers(spec string, args []byte, tmpDir string) ([]byte, error) {
+	type bufSpec struct {
+		name    string
+		size    int
+		pattern string
+	}
+	var specs []bufSpec
+	for part := range strings.SplitSeq(spec, ",") {
+		fields := strings.SplitN(part, ":", 3)
+		if len(fields) != 3 {
+			continue
+		}
+		size, err := strconv.Atoi(fields[1])
+		if err != nil || size <= 0 {
+			continue
+		}
+		specs = append(specs, bufSpec{name: fields[0], size: size, pattern: fields[2]})
+	}
+
+	if len(specs) == 0 {
+		return args, nil
+	}
+
+	var bufAddrs []uint64
+	for _, s := range specs {
+		buf, err := syscall.Mmap(-1, 0, s.size,
+			syscall.PROT_READ|syscall.PROT_WRITE,
+			syscall.MAP_PRIVATE|syscall.MAP_ANON)
+		if err != nil {
+			return nil, fmt.Errorf("mmap buffer %s: %w", s.name, err)
+		}
+		fillBuffer(buf, s.pattern)
+		bufAddrs = append(bufAddrs, uint64(uintptr(unsafe.Pointer(&buf[0]))))
+	}
+
+	addrFile, err := os.Create(tmpDir + "/bufaddrs")
+	if err != nil {
+		return nil, err
+	}
+	for _, addr := range bufAddrs {
+		fmt.Fprintf(addrFile, "%d\n", addr)
+	}
+	addrFile.Close()
+
+	return args, nil
+}
+
+// fillBuffer fills a buffer with the specified pattern.
+func fillBuffer(buf []byte, pattern string) {
+	switch pattern {
+	case "zero":
+	case "ones":
+		for i := range buf {
+			buf[i] = 0xFF
+		}
+	case "seq":
+		for i := range buf {
+			buf[i] = byte(i)
+		}
+	default:
+		if data, err := hex.DecodeString(pattern); err == nil && len(data) > 0 {
+			for i := range buf {
+				buf[i] = data[i%len(data)]
+			}
+		}
+	}
+}
+
+// RunTarget is the debuggee entry point (gasm debug --target).
+func RunTarget(asmPath, funcName, argsFile, tmpDir string) error {
+	src, err := os.ReadFile(asmPath)
+	if err != nil {
+		return fmt.Errorf("debug target: %w", err)
+	}
+	file, errs := parser.Parse(asmPath, string(src))
+	if len(errs) > 0 {
+		return fmt.Errorf("debug target: parse: %v", errs[0])
+	}
+	img, err := asm.AssembleFile(file)
+	if err != nil {
+		return fmt.Errorf("debug target: assemble: %w", err)
+	}
+
+	var fl *asm.FuncLayout
+	for i := range img.Funcs {
+		if img.Funcs[i].Name == funcName {
+			fl = &img.Funcs[i]
+			break
+		}
+	}
+	if fl == nil {
+		return fmt.Errorf("debug target: function %q not found", funcName)
+	}
+
+	code := img.Bytes()
+	exec, err := mapRWX(code)
+	if err != nil {
+		return fmt.Errorf("debug target: mmap: %w", err)
+	}
+
+	codeBase := uintptr(unsafe.Pointer(&exec[0]))
+	if err := os.WriteFile(tmpDir+"/codebase", []byte(fmt.Sprintf("%d", codeBase)), 0o644); err != nil {
+		return fmt.Errorf("debug target: write codebase: %w", err)
+	}
+
+	meta := fmt.Sprintf("%d %d %d", fl.Offset, fl.Size, fl.Args)
+	os.WriteFile(tmpDir+"/funcmeta", []byte(meta), 0o644)
+
+	labelsFile, _ := os.Create(tmpDir + "/labels")
+	if labelsFile != nil {
+		for label, off := range fl.Labels {
+			fmt.Fprintf(labelsFile, "%s %d\n", label, off)
+		}
+		labelsFile.Close()
+	}
+
+	args, err := os.ReadFile(argsFile)
+	if err != nil {
+		return fmt.Errorf("debug target: read args: %w", err)
+	}
+	if len(args) < fl.Args {
+		padded := make([]byte, fl.Args)
+		copy(padded, args)
+		args = padded
+	}
+
+	bufSpecFile := tmpDir + "/bufspec"
+	if bufSpec, err := os.ReadFile(bufSpecFile); err == nil && len(bufSpec) > 0 {
+		args, err = setupBuffers(string(bufSpec), args, tmpDir)
+		if err != nil {
+			return fmt.Errorf("debug target: setup buffers: %w", err)
+		}
+	}
+
+	runtime.LockOSThread()
+
+	if _, _, errno := unix.RawSyscall(unix.SYS_PTRACE, uintptr(unix.PT_TRACE_ME), 0, 0); errno != 0 {
+		return fmt.Errorf("debug target: PT_TRACE_ME: %v", errno)
+	}
+	os.WriteFile(tmpDir+"/ready", []byte("ok"), 0o644)
+	syscall.Kill(syscall.Getpid(), syscall.SIGSTOP)
+
+	os.WriteFile(tmpDir+"/entry", []byte("ok"), 0o644)
+	syscall.Kill(syscall.Getpid(), syscall.SIGSTOP)
+
+	fnAddr := codeBase + uintptr(fl.Offset)
+	stackArgs := make([]byte, fl.Args)
+	copy(stackArgs, args)
+
+	if _, callErr := verify.Call(fnAddr, stackArgs); callErr != nil {
+		os.Exit(1)
+	}
+	// Success returns to the caller, which exits with status 0; the JIT
+	// code has already run to its own trampoline by the time Call returns.
+	return nil
+}

debug/target_linux_amd64.go

@@ -12,9 +12,9 @@ import (
 	"syscall"
 	"unsafe"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // RunTarget is the debuggee entry point (gasm debug --target).

debug/target_linux_arm64.go

@@ -12,9 +12,9 @@ import (
 	"syscall"
 	"unsafe"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // RunTarget is the debuggee entry point (gasm debug --target).

debug/target_linux_loong64.go

@@ -12,9 +12,9 @@ import (
 	"syscall"
 	"unsafe"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // RunTarget is the debuggee entry point (gasm debug --target).

debug/target_linux_riscv64.go

@@ -12,9 +12,9 @@ import (
 	"syscall"
 	"unsafe"
 
-	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
-	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
-	"sourcedock.dev/petrbalvin/gasm-devkit/verify"
+	"sourcedock.dev/petrbalvin/gasm-sdk/asm"
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+	"sourcedock.dev/petrbalvin/gasm-sdk/verify"
 )
 
 // RunTarget is the debuggee entry point (gasm debug --target).