fix(ci): pass the upload file to curl, not its interpolation

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>;

CHANGELOG.md

@@ -9,6 +9,31 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+-
+
+## [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 `$symbol(SB)` values, laid down as an absolute
+  relocation at the data field (GOOBJ on all four architectures and ELF
+  on all four as of this release), and U+2215 is accepted inside symbol
+  package paths.
 - **Macro expansion and include splicing.**  `gasm asm`, `gasm diff` and
   `gasm audit-instructions` now preprocess assembly the way the
   toolchain does: object and parameterised `#define` macros expand at
@@ -19,7 +44,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (`$(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.
-- **The GOROOT instruction wave, part 1.**  The encoder now covers the
+- **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,
@@ -35,14 +61,90 @@ 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
 

README.md

@@ -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
@@ -110,9 +113,9 @@ 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
@@ -124,8 +127,8 @@ 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
+`gasm audit-instructions --corpus` reports 291 of 353 attemptable files
+(82.4 %) 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.
 
@@ -157,6 +160,39 @@ 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:
@@ -282,6 +318,8 @@ 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

@@ -8,6 +8,10 @@
 // names so gasm-devkit 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
@@ -26,6 +30,9 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+
+	"sourcedock.dev/petrbalvin/gasm-devkit/arch"
+	"sourcedock.dev/petrbalvin/gasm-devkit/asm"
 )
 
 // archDirs maps a gasm-devkit architecture name to its obj sub-directory.
@@ -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)
 	}
 }
 
@@ -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-devkit'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/arm64_gen.go

@@ -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/loong64_gen.go

@@ -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

@@ -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/arm64_assemble.go

@@ -637,6 +637,20 @@ func encodeARM64Branch(mnem string, ops []*ast.Operand, pc int, offsets map[stri
 		return a64wordLE(a64UncondBranch(opc, uint32(rn), 0)), nil
 	}
 
+	// The bare spelling BL R9 is the same indirect branch: the parser reads
+	// a bare identifier as a symbol, and one named for a register is an
+	// indirect branch through it, which the toolchain accepts alongside the
+	// parenthesised form (BL (R3) and BL R3 both encode BLR R3).
+	if op.Addr.Sym != nil && op.Addr.Sym.Pseudo == "" && op.Addr.Base == "" && op.Addr.Index == "" {
+		if rn := arm64RegNum(op.Addr.Sym.Name); rn >= 0 {
+			opc := uint32(0) // BR
+			if link {
+				opc = 1 // BLR
+			}
+			return a64wordLE(a64UncondBranch(opc, uint32(rn), 0)), nil
+		}
+	}
+
 	// Symbol reference: BL sym(SB), or B sym(SB) for a tail call, against a
 	// relocation (R_CALLARM64 either way).
 	if op.Addr.Sym != nil && op.Addr.Sym.Pseudo == "SB" {
@@ -1454,6 +1468,15 @@ func encodeARM64Mov(instr *ast.Instr, mnem string, wb string, fi arm64FrameInfo,
 			}
 			return encodeARM64SBAddr(src.Imm.Sym, rd, relocs), nil
 		}
+		// Immediate → memory: only storing zero is encodable (the ZR
+		// register); the toolchain rejects any other immediate-to-memory
+		// combination ("illegal combination").
+		if isMemOperand(dst) {
+			if arm64Imm64(src) != 0 {
+				return nil, fmt.Errorf("%s: illegal combination: an immediate store must be zero", mnem)
+			}
+			return encodeARM64MemOp(mnem, dst, 31, false, fi, "")
+		}
 		rd := arm64RegNum(operandRegName(dst))
 		if rd < 0 {
 			return nil, fmt.Errorf("%s $imm: invalid destination register", mnem)

asm/assemble.go

@@ -5,6 +5,7 @@ package asm
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
 	"sourcedock.dev/petrbalvin/gasm-devkit/ast"
@@ -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
@@ -66,9 +82,9 @@ 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, err
+		return nil, nil, nil, nil, nil, nil, err
 	}
 	fi := computeFrame(t)
 	chain := jumpChain(t)
@@ -85,29 +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 {
@@ -229,12 +334,18 @@ 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 {
@@ -272,7 +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
@@ -419,6 +530,83 @@ 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.  It reports false when the count runs past the end of the function.
+func pcJumpTarget(t *ast.Text, j, n int, pcs []int) (int, bool) {
+	if n == 0 {
+		return pcs[j], true
+	}
+	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 {
@@ -593,7 +781,7 @@ 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
 	}
@@ -628,9 +816,21 @@ 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
@@ -638,6 +838,7 @@ 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) {
@@ -646,7 +847,7 @@ 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
@@ -656,23 +857,23 @@ 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.
@@ -681,49 +882,183 @@ 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)))
 
@@ -756,7 +1091,7 @@ 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
 	}
@@ -797,6 +1132,11 @@ 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
 	}
@@ -813,7 +1153,7 @@ 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
 		}
@@ -830,8 +1170,11 @@ 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 {
@@ -841,11 +1184,45 @@ 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" {
@@ -877,12 +1254,44 @@ 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)
@@ -893,6 +1302,21 @@ 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 {
@@ -903,3 +1327,37 @@ 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

@@ -568,3 +568,28 @@ TEXT ·framed(SB), $16-8
 		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/encodable.go

@@ -20,9 +20,9 @@ func Encodable(mnemonic string) bool {
 	switch upper {
 	case "RET", "NOP", "CALL", "JMP",
 		"POPFQ", "PUSHFQ", "INT", "LDMXCSR", "STMXCSR", "CMPSD", "SHA256RNDS2",
-		// The literal-data pseudo-ops, the accepted-and-ignored END and the
-		// SP adjust.
-		"BYTE", "WORD", "LONG", "QUAD", "END", "ADJSP":
+		// 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 {
@@ -102,6 +138,11 @@ func (e *enc) encode(mnem string, ops []Operand) error {
 		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
@@ -141,11 +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
@@ -222,7 +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)
@@ -285,6 +338,33 @@ func (e *enc) encodeData(mnem string, ops []Operand) error {
 	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
@@ -319,6 +399,120 @@ func (e *enc) encodeAdjsp(ops []Operand) error {
 	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 == "" {
@@ -385,6 +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
@@ -427,6 +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
@@ -481,12 +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
@@ -499,6 +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-devkit/ast"
+	"sourcedock.dev/petrbalvin/gasm-devkit/parser"
 )
 
 // decode encodes an instruction and decodes it back, returning the decoded
@@ -1064,3 +1067,157 @@ func TestAdjsp(t *testing.T) {
 		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

@@ -737,6 +737,91 @@ var evexTable = map[string]evexSpec{
 	"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
 // depends on the source kind, a GPR source uses opReg, a memory source uses
 // opMem with a disp8×N of n.
@@ -812,8 +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
@@ -995,6 +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)

asm/evex_test.go

@@ -810,3 +810,127 @@ func TestAvx512CorpusFamilies(t *testing.T) {
 		}
 	}
 }
+
+// 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/guard_test.go

@@ -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

@@ -192,6 +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)
@@ -232,11 +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
@@ -627,7 +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")
@@ -647,29 +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/kernels_differential_test.go

@@ -63,7 +63,10 @@ func toolAsmObject(t *testing.T, path, goarch string) []byte {
 }
 
 // oracleFuncCode extracts the non-package TEXT functions' code bytes from a
-// toolchain object, keyed by the name the object records (pkg.name).
+// 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)
@@ -76,18 +79,13 @@ func oracleFuncCode(t *testing.T, obj []byte) map[string][]byte {
 	for _, bi := range []int{blkSymdef, blkHashed64def, blkHasheddef} {
 		preceding += len(v.blk(bi)) / symSize
 	}
-	total := preceding + len(nps)
 	out := make(map[string][]byte, len(nps))
 	for i, s := range nps {
 		if s.typ != kindSTEXT {
 			continue
 		}
 		start := le.Uint32(didx[4*(preceding+i):])
-		end := uint32(len(data))
-		if preceding+i+1 < total {
-			end = le.Uint32(didx[4*(preceding+i+1):])
-		}
-		out[s.name] = data[start:end]
+		out[s.name] = data[start : start+s.size]
 	}
 	return out
 }
@@ -129,6 +127,10 @@ func TestDifferentialKernels(t *testing.T) {
 		{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},
 	} {

asm/link.go

@@ -5,6 +5,7 @@ package asm
 
 import (
 	"fmt"
+	"math"
 	"sort"
 	"strconv"
 
@@ -149,6 +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
@@ -156,7 +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
@@ -165,7 +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{}
@@ -179,7 +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)
 		}
@@ -299,6 +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 {
@@ -306,10 +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,
@@ -561,11 +621,6 @@ func collectData(f *ast.File) ([]dataSym, error) {
 			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)) {
@@ -587,9 +642,54 @@ func collectData(f *ast.File) ([]dataSym, error) {
 			})
 			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

@@ -5,6 +5,7 @@ package asm
 
 import (
 	"encoding/binary"
+	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -418,3 +419,75 @@ func main() {
 		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/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_assemble.go

@@ -6,6 +6,7 @@ package asm
 import (
 	"errors"
 	"fmt"
+	"math/bits"
 	"slices"
 	"strings"
 
@@ -14,13 +15,14 @@ import (
 
 // assembleRISCV assembles a RISC-V TEXT function body into machine code.
 // It handles the full RV64IMAFDC instruction set including RVC compression.
-func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, []SpadjStep, error) {
+func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, []SpadjStep, []RiscvLiteral, error) {
 	fi := riscvComputeFrame(t)
 	prologue := riscvPrologue(fi)
 	guardLen, err := riscvGuardLen(fi)
 	if err != nil {
-		return nil, nil, nil, nil, nil, err
+		return nil, nil, nil, nil, nil, nil, err
 	}
+	lits := &riscvLiterals{}
 
 	var relocs []Reloc
 	var spadj []SpadjStep
@@ -74,9 +76,9 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 	pc := len(prologue)
 	for i := range recs {
 		branchLike := isBranchLike(recs[i].instr.Mnemonic.Text) || riscvIsCondBranch(recs[i].instr.Mnemonic.Text)
-		code, err := encodeRISCVInstr(recs[i].instr, pc, offsets, fi, nil, nil) // no relocs in Pass 2
+		code, err := encodeRISCVInstr(recs[i].instr, pc, offsets, fi, nil, nil, lits) // no relocs in Pass 2
 		if err != nil && !(branchLike && riscvIsRangeError(err)) {
-			return nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", recs[i].instr.Mnemonic.Text, err)
+			return nil, nil, nil, nil, nil, nil, fmt.Errorf("%s: %w", recs[i].instr.Mnemonic.Text, err)
 		}
 		if err != nil {
 			code = make([]byte, 4)
@@ -178,13 +180,20 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 			}
 		}
 		if !changed {
-			// Capture the final pcs for the N(PC) branch forms: their target
-			// is the instruction N source slots away, resolved by index.
+			// Capture the final pcs for the N(PC) branch and jump forms: the
+			// target is the instruction N source slots away (N=0 the branch
+			// itself, N negative backwards), resolved by index against the
+			// final layout.
 			pcRelPcs = map[*ast.Instr]int{}
 			for i := range recs {
-				if _, ok := riscvPCRelOffset(recs[i].instr); ok {
-					pcRelPcs[recs[i].instr] = pcs[i]
+				n, ok := riscvPCRelOffset(recs[i].instr)
+				if !ok {
+					continue
 				}
+				if i+n < 0 || i+n >= len(recs) {
+					continue
+				}
+				pcRelPcs[recs[i].instr] = pcs[i+n]
 			}
 			break
 		}
@@ -198,7 +207,7 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 	var out []byte
 	guardBytes, guardReloc, err := riscvGuard(fi)
 	if err != nil {
-		return nil, nil, nil, nil, nil, err
+		return nil, nil, nil, nil, nil, nil, err
 	}
 	if fi.needSplit {
 		out = append(out, guardBytes...)
@@ -220,11 +229,11 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 			// The JMP a relaxation inserted: JAL X0 to the original target.
 			targetOff, ok := offsets[r.jmpTo]
 			if !ok {
-				return nil, nil, nil, nil, nil, fmt.Errorf("undefined label %q", r.jmpTo)
+				return nil, nil, nil, nil, nil, nil, fmt.Errorf("undefined label %q", r.jmpTo)
 			}
 			offset := int32(targetOff - pc)
 			if err := riscvCheckJumpOffset(r.jmpTo, offset); err != nil {
-				return nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, err
 			}
 			word := riscvJType(0, offset)
 			code = []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}
@@ -233,7 +242,7 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 			// JMP, always the very next instruction (offset 4).
 			enc, rs1, rs2, ok := riscvInvertedBranchEnc(strings.ToUpper(r.instr.Mnemonic.Text), r.instr.Operands)
 			if !ok {
-				return nil, nil, nil, nil, nil, fmt.Errorf("%s: cannot relax branch", r.instr.Mnemonic.Text)
+				return nil, nil, nil, nil, nil, nil, fmt.Errorf("%s: cannot relax branch", r.instr.Mnemonic.Text)
 			}
 			word := riscvBType(enc, rs1, rs2, 4)
 			code = []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}
@@ -241,9 +250,9 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 			code = r.code
 		default:
 			var err error
-			code, err = encodeRISCVInstr(r.instr, pc, offsets, fi, &relocs, pcRelPcs)
+			code, err = encodeRISCVInstr(r.instr, pc, offsets, fi, &relocs, pcRelPcs, lits)
 			if err != nil {
-				return nil, nil, nil, nil, nil, err
+				return nil, nil, nil, nil, nil, nil, err
 			}
 			if c16, ok := tryCompressRVC(r.instr, fi); ok {
 				code = []byte{byte(c16), byte(c16 >> 8)}
@@ -270,7 +279,7 @@ func assembleRISCV(t *ast.Text) ([]byte, map[string]int, []Reloc, []LineEntry, [
 	if fi.needSplit {
 		relocs = append(relocs, guardReloc)
 	}
-	return out, offsets, relocs, lines, spadj, nil
+	return out, offsets, relocs, lines, spadj, lits.list(), nil
 }
 
 // riscvImmAlias maps the R-type ALU mnemonics onto their I-type immediate
@@ -348,6 +357,11 @@ func riscvPadBytes(pad int) []byte {
 func riscvInstrSize(instr *ast.Instr, fi riscvFrameInfo) int {
 	mnem := instr.Mnemonic.Text
 	ops := instr.Operands
+	mnem = riscvNormalisePseudo(mnem)
+	if mnem == "FUNCDATA" || mnem == "PCDATA" {
+		// The bookkeeping statements contribute no bytes.
+		return 0
+	}
 	var immNeg bool
 	mnem, immNeg = riscvNormaliseImmAlias(mnem, ops)
 	if mnem == "RET" {
@@ -368,7 +382,25 @@ func riscvInstrSize(instr *ast.Instr, fi riscvFrameInfo) int {
 		}
 		// MOV $imm, rd → size depends on the immediate and RVC compression.
 		if isImmOperand(ops[0]) && ops[0].Imm.Sym == nil {
-			return riscvMovImmSize(regFromOperand(ops[1]), immFromOperand(ops[0]))
+			imm := riscvOperandImm64(ops[0])
+			if int64(int32(imm)) != imm {
+				return riscvMovImm64Size(regFromOperand(ops[1]), imm)
+			}
+			return riscvMovImmSize(regFromOperand(ops[1]), int32(imm))
+		}
+		// MOV $sym+off(FP|SP), rd → the frame-adjusted offset as an ADDI,
+		// compressed like riscvSPAddiBytes encodes it.
+		if isImmOperand(ops[0]) && ops[0].Imm.Sym != nil &&
+			(ops[0].Imm.Sym.Pseudo == "FP" || ops[0].Imm.Sym.Pseudo == "SP") {
+			rd := regFromOperand(ops[1])
+			_, off := riscvResolvePseudo(ops[0].Imm.Sym, fi)
+			if rd > 0 && off == 0 {
+				return 2 // C.MV rd, SP
+			}
+			if isRVCIntReg(rd) && off > 0 && off < 1024 && off%4 == 0 {
+				return 2 // C.ADDI4SPN
+			}
+			return riscvItypeImmediateSize("ADDI", off)
 		}
 		// Frame-relative loads and stores: a frame offset beyond the signed
 		// 12-bit range materialises the address in X31 first.
@@ -664,9 +696,10 @@ func riscvCheckJumpOffset(target string, off int32) error {
 }
 
 // encodeRISCVInstr encodes a single RISC-V instruction.
-func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscvFrameInfo, relocs *[]Reloc, pcRelPcs map[*ast.Instr]int) ([]byte, error) {
+func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscvFrameInfo, relocs *[]Reloc, pcRelPcs map[*ast.Instr]int, lits *riscvLiterals) ([]byte, error) {
 	mnem := instr.Mnemonic.Text
 	ops := instr.Operands
+	mnem = riscvNormalisePseudo(mnem)
 	var immNeg bool
 	mnem, immNeg = riscvNormaliseImmAlias(mnem, ops)
 	var word uint32
@@ -677,6 +710,22 @@ func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscv
 		// RET = epilogue (restore LR and close the frame when present) +
 		// uncompressed JALR X0, 0(X1) (the toolchain never compresses RET).
 		return riscvReturn(fi), nil
+	case "FUNCDATA":
+		// The assembler's bookkeeping statement, the expanded form of the
+		// GO_ARGS and NO_LOCAL_POINTERS macros: FUNCDATA $n, sym(SB)
+		// contributes no bytes, exactly as the toolchain's listing shows
+		// (the FUNCDATA entries and the instruction after them share a PC).
+		if len(ops) != 2 || !isImmOperand(ops[0]) {
+			return nil, fmt.Errorf("FUNCDATA expects $n, sym(SB)")
+		}
+		return nil, nil
+	case "PCDATA":
+		// The other bookkeeping statement, the expanded form of
+		// GO_RESULTS_INITIALIZED: PCDATA $n, $m contributes no bytes too.
+		if len(ops) != 2 || !isImmOperand(ops[0]) || !isImmOperand(ops[1]) {
+			return nil, fmt.Errorf("PCDATA expects $n, $m")
+		}
+		return nil, nil
 	case "WORD":
 		// WORD $w lays down a raw 32-bit little-endian word.
 		if len(ops) != 1 {
@@ -739,6 +788,22 @@ func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscv
 				return []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}, nil
 			}
 			target = labelFromOperand(ops[0])
+			// JMP N(PC): the PC-relative slot form, resolved like the
+			// branches (the toolchain counts source instructions at a
+			// uniform 4 bytes, so JMP 0(PC) is a self-loop and JMP -3(PC)
+			// reaches twelve bytes back).  It must be recognised before the
+			// indirect-register form, whose operand it resembles.
+			if off, isPCRel, err := riscvPCRelTargetOff(instr, pc, pcRelPcs); isPCRel {
+				if err != nil {
+					return nil, err
+				}
+				offset := int32(off - pc)
+				if err := riscvCheckJumpOffset("", offset); err != nil {
+					return nil, err
+				}
+				word = riscvJType(0, offset)
+				return []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}, nil
+			}
 			// JMP (X5): an indirect branch, the toolchain's JALR X0, 0(X5).
 			if ops[0].Addr.Sym == nil && ops[0].Addr.Base != "" {
 				if ops[0].Addr.Offset != 0 || ops[0].Addr.Index != "" {
@@ -751,17 +816,6 @@ func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscv
 				word = riscvIType(riscvEnc{0x67, 0x0, 0x00}, 0, rs1, 0)
 				return []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}, nil
 			}
-			if off, isPCRel, err := riscvPCRelTargetOff(instr, pc, pcRelPcs); isPCRel {
-				if err != nil {
-					return nil, err
-				}
-				offset := int32(off - pc)
-				if err := riscvCheckJumpOffset("", offset); err != nil {
-					return nil, err
-				}
-				word = riscvJType(0, offset)
-				return []byte{byte(word), byte(word >> 8), byte(word >> 16), byte(word >> 24)}, nil
-			}
 		}
 		targetOff, ok := offsets[target]
 		if !ok {
@@ -810,7 +864,7 @@ func encodeRISCVInstr(instr *ast.Instr, pc int, offsets map[string]int, fi riscv
 	// (MOVB/MOVH/MOVW and unsigned forms) select the access width, and
 	// MOVD/MOVF address the FP registers.
 	case "MOV", "MOVB", "MOVBU", "MOVH", "MOVHU", "MOVW", "MOVWU", "MOVF", "MOVD":
-		return encodeRISCVMov(instr, fi, relocs)
+		return encodeRISCVMov(instr, fi, relocs, lits)
 
 	// JALR: indirect jump/call.  Plan 9: JALR rs1, rd or JALR offset(rs1).
 	case "JALR":
@@ -1316,7 +1370,7 @@ func isImmOperand(op *ast.Operand) bool {
 //   - MOV Rs, (Rd)          register-relative store
 //   - MOV Rs, Rd            register-to-register move (ADDI $0)
 //   - MOV $imm, Rd          load immediate (ADDI or LUI+ADDIW)
-func encodeRISCVMov(instr *ast.Instr, fi riscvFrameInfo, relocs *[]Reloc) ([]byte, error) {
+func encodeRISCVMov(instr *ast.Instr, fi riscvFrameInfo, relocs *[]Reloc, lits *riscvLiterals) ([]byte, error) {
 	ops := instr.Operands
 	if len(ops) != 2 {
 		return nil, fmt.Errorf("MOV expects 2 operands, got %d", len(ops))
@@ -1335,8 +1389,21 @@ func encodeRISCVMov(instr *ast.Instr, fi riscvFrameInfo, relocs *[]Reloc) ([]byt
 			}
 			return encodeRISCVSBAddr(src.Imm.Sym, rd, relocs), nil
 		}
+		// MOV $sym+off(FP|SP), rd: the address of a frame slot as an
+		// immediate is the frame-adjusted offset against the hardware SP,
+		// the toolchain's ADDI $adj, SP, rd (argframe+0(FP) in the runtime's
+		// reflect trampolines is the spelling).
+		if src.Imm.Sym != nil && (src.Imm.Sym.Pseudo == "FP" || src.Imm.Sym.Pseudo == "SP") {
+			rd := regFromOperand(dst)
+			if rd < 0 {
+				return nil, fmt.Errorf("MOV $%s(%s): invalid destination register", src.Imm.Sym.Name, src.Imm.Sym.Pseudo)
+			}
+			_, off := riscvResolvePseudo(src.Imm.Sym, fi)
+			return riscvSPAddiBytes(rd, off), nil
+		}
 		// MOV $sym(FP/SP), rd, not supported: immediate symbol references
-		// other than SB cannot be encoded as a simple immediate.
+		// other than the frame pseudos cannot be encoded as a simple
+		// immediate.
 		if src.Imm.Sym != nil && src.Imm.Sym.Pseudo != "" {
 			return nil, fmt.Errorf("MOV $%s(%s): unsupported immediate symbol reference (only SB is supported)", src.Imm.Sym.Name, src.Imm.Sym.Pseudo)
 		}
@@ -1344,11 +1411,14 @@ func encodeRISCVMov(instr *ast.Instr, fi riscvFrameInfo, relocs *[]Reloc) ([]byt
 		if rd < 0 {
 			return nil, fmt.Errorf("MOV $imm: invalid destination register")
 		}
-		imm, err := riscvImm32FromOperand(src, false)
-		if err != nil {
-			return nil, err
+		imm := riscvOperandImm64(src)
+		if int64(int32(imm)) != imm {
+			// Beyond the signed 32-bit span the toolchain either builds the
+			// value from a shifted 32-bit part or loads it from the pooled
+			// $i64 constant it synthesises for the purpose.
+			return riscvLoadImm64(rd, imm, lits, relocs), nil
 		}
-		return encodeRISCVLoadImm(rd, imm), nil
+		return encodeRISCVLoadImm(rd, int32(imm)), nil
 	}
 
 	// Memory → register (load).
@@ -1557,6 +1627,186 @@ func splitRISCV32Imm(imm int32) (low, high int32) {
 	return low, high
 }
 
+// riscvNormalisePseudo rewrites the toolchain's UNDEF spelling onto EBREAK:
+// the assembler accepts UNDEF where the hardware wants the trap instruction
+// and emits ebreak (compressed to C.EBREAK under RVC), so every pass sees the
+// canonical name.
+func riscvNormalisePseudo(mnem string) string {
+	if strings.EqualFold(mnem, "UNDEF") {
+		return "EBREAK"
+	}
+	return mnem
+}
+
+// riscvOperandImm64 reads an immediate operand as a full signed 64-bit value,
+// where immFromOperand would truncate to int32; the MOV immediate path uses
+// it to classify the wide constants.
+func riscvOperandImm64(op *ast.Operand) int64 {
+	if !op.Imm.HasVal {
+		return 0
+	}
+	v := op.Imm.Val
+	if op.Imm.Neg {
+		v = -v
+	}
+	return v
+}
+
+// riscvSplitShiftConst mirrors cmd/internal/obj/riscv's splitShiftConst: it
+// looks for the signed 32-bit integer a constant can be rebuilt from with a
+// left shift, a left-and-right shift pair (a run of ones), or a zero-extended
+// 32-bit pattern.  A constant that fits none of the shapes is materialised
+// from the pooled $i64 data symbol instead.
+func riscvSplitShiftConst(v int64) (imm int64, lsh int, rsh int, ok bool) {
+	// Rebuild from a signed 32-bit integer shifted left.
+	lsh = bits.TrailingZeros64(uint64(v))
+	c := v >> lsh
+	if int64(int32(c)) == c {
+		return c, lsh, 0, true
+	}
+
+	// Rebuild from a small negative constant: shift left into place, then
+	// shift the sign-extended ones run right.
+	rsh = bits.LeadingZeros64(uint64(v))
+	ones := bits.OnesCount64((uint64(v) >> lsh) >> 11)
+	if rsh+ones+lsh+11 == 64 {
+		c = (1<<11 | ((v >> lsh) & 0x7ff)) << 52 >> 52 // sign extend 12 bits
+		if lsh > 0 || c != -1 {
+			lsh += rsh
+		}
+		return c, lsh, rsh, true
+	}
+
+	// Rebuild from a zero-extended signed 32-bit integer.
+	if int64(uint32(c)) == c {
+		c = int64(int32(c))
+		lsh, rsh = 32, 32-lsh
+		return c, lsh, rsh, true
+	}
+
+	return 0, 0, 0, false
+}
+
+// riscvSPAddiBytes encodes ADDI rd, SP, imm for the frame-address immediates
+// (the MOV $sym+off(FP|SP) form), using the compressed forms the toolchain
+// picks under RVC: C.ADDI4SPN for a positive 4-byte multiple that fits, C.MV
+// for the zero offset, the plain ADDI otherwise.
+func riscvSPAddiBytes(rd int, imm int32) []byte {
+	if rd != 0 && imm == 0 {
+		return word16(rvcCR(0x8, uint32(rd), 2)) // C.MV rd, SP
+	}
+	if isRVCIntReg(rd) && imm > 0 && imm < 1024 && imm%4 == 0 {
+		return word16(rvcCIW(0x0, rvcReg3(rd), uint32(imm)))
+	}
+	return wordLE(riscvIType(riscvInstrTable["ADDI"], rd, 2, imm))
+}
+
+// riscvMovImm64Size returns the encoded byte length of MOV $imm, rd when the
+// immediate sits outside the signed 32-bit span: the shifted-part sequences
+// of riscvLoadImm64, or the 8-byte AUIPC+LD pool load.
+func riscvMovImm64Size(rd int, imm int64) int {
+	c, lsh, rsh, ok := riscvSplitShiftConst(imm)
+	if !ok {
+		return 8 // AUIPC + LD against the $i64 pool symbol
+	}
+	size := riscvMovImmSize(rd, int32(c))
+	if lsh > 0 {
+		size += riscvShiftImmSize(rd, true)
+	}
+	if rsh > 0 {
+		size += riscvShiftImmSize(rd, false)
+	}
+	return size
+}
+
+// riscvShiftImmSize returns the encoded size of one SLLI/SRLI expansion
+// part: two bytes under RVC when the destination can carry a compressed
+// shift (C.SLLI admits every register but X0, C.SRLI only X8 to X15), four
+// otherwise.
+func riscvShiftImmSize(rd int, left bool) int {
+	if rd != 0 && (left || isRVCIntReg(rd)) {
+		return 2
+	}
+	return 4
+}
+
+// riscvLoadImm64 encodes MOV $imm, rd for an immediate beyond the signed
+// 32-bit span, mirroring the toolchain's instructionsForMOVConst: when a
+// shifted 32-bit part rebuilds the value it emits that part (compressed like
+// any written MOV) followed by the SLLI and SRLI shifts; otherwise it loads
+// the constant from the pooled read-only $i64.<hex> symbol via AUIPC + LD
+// and registers the literal so the data section carries its bytes.
+func riscvLoadImm64(rd int, imm int64, lits *riscvLiterals, relocs *[]Reloc) []byte {
+	c, lsh, rsh, ok := riscvSplitShiftConst(imm)
+	if !ok {
+		name := fmt.Sprintf("$i64.%016x", uint64(imm))
+		if lits != nil {
+			lits.add(name, riscvLiteralBytes(imm))
+		}
+		return encodeRISCVSBLoad(&ast.Symbol{Name: name}, rd, relocs)
+	}
+	out := encodeRISCVLoadImm(rd, int32(c))
+	if lsh > 0 {
+		out = append(out, riscvShiftImmBytes(rd, lsh, true)...)
+	}
+	if rsh > 0 {
+		out = append(out, riscvShiftImmBytes(rd, rsh, false)...)
+	}
+	return out
+}
+
+// riscvShiftImmBytes encodes one SLLI (left) or SRLI expansion part, using
+// the compressed form the toolchain picks under RVC: C.SLLI admits every
+// register but X0, C.SRLI only X8 to X15.
+func riscvShiftImmBytes(rd, shamt int, left bool) []byte {
+	if rd != 0 && shamt >= 1 && shamt <= 63 && (left || isRVCIntReg(rd)) {
+		if left {
+			return word16(rvcSLLI(uint32(rd), uint32(shamt)&0x3F))
+		}
+		return word16(rvcCBShift(0x0, rvcReg3(rd), uint32(shamt)&0x3F))
+	}
+	enc := riscvEnc{0x13, 0x1, 0x00} // SLLI
+	imm := int32(shamt)
+	if !left {
+		enc = riscvEnc{0x13, 0x5, 0x00} // SRLI: funct6 000000, funct3 101
+	}
+	return wordLE(riscvIType(enc, rd, rd, imm))
+}
+
+// riscvLiteralBytes renders a 64-bit constant as the little-endian bytes the
+// $i64 pool symbol holds.
+func riscvLiteralBytes(v int64) []byte {
+	return []byte{byte(v), byte(v >> 8), byte(v >> 16), byte(v >> 24),
+		byte(v >> 32), byte(v >> 40), byte(v >> 48), byte(v >> 56)}
+}
+
+// RiscvLiteral is one pooled 64-bit constant: a MOV whose immediate sits
+// beyond both the 32-bit span and the shift sequences loads its bits from a
+// read-only data symbol named like the toolchain's $i64 pool.
+type RiscvLiteral struct {
+	Name string
+	Data []byte
+}
+
+// riscvLiterals collects the pooled constants the MOV expansions refer to,
+// deduplicated by name, in first-use order.
+type riscvLiterals struct {
+	order []RiscvLiteral
+	seen  map[string]bool
+}
+
+func (l *riscvLiterals) add(name string, data []byte) {
+	if l.seen == nil {
+		l.seen = map[string]bool{}
+	}
+	if !l.seen[name] {
+		l.seen[name] = true
+		l.order = append(l.order, RiscvLiteral{Name: name, Data: data})
+	}
+}
+
+func (l *riscvLiterals) list() []RiscvLiteral { return l.order }
+
 // encodeRISCVItypeImmediate encodes an I-type arithmetic instruction, expanding
 // large immediates for ADDI/ANDI/ORI/XORI into LUI+ADDIW+op (or two ADDIs for
 // ADDI), matching the Go assembler.
@@ -1734,6 +1984,7 @@ func encodeRISCVJALR(instr *ast.Instr, fi riscvFrameInfo) ([]byte, error) {
 // RVC form.  It returns the compressed instruction word and true on success.
 func tryCompressRVC(instr *ast.Instr, fi riscvFrameInfo) (uint16, bool) {
 	mnem := riscvCompressMnem(instr)
+	mnem = riscvNormalisePseudo(mnem)
 	ops := instr.Operands
 	// The immediate aliases fold onto their I-type mnemonics before
 	// compression: the toolchain compresses ADD $imm, rd as c.addi, exactly

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

asm/riscv_encode_test.go

@@ -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, nil)
+	return encodeRISCVInstr(instr, pc, offsets, riscvFrameInfo{}, nil, nil, nil)
 }
 
 // TestRISCVBranchJumpRange checks that displacements beyond the B-type span
@@ -917,7 +1041,7 @@ func TestRISCVBranchFarBody(t *testing.T) {
 	}
 	sb.WriteString("done:\n\tRET\n")
 	fn := firstTextRISCV(t, sb.String())
-	out, _, _, _, _, err := assembleRISCV(fn)
+	out, _, _, _, _, _, err := assembleRISCV(fn)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -943,7 +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"
@@ -951,25 +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)
 		}
 	}
@@ -982,9 +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

ast/ast.go

@@ -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
 }

cmd/gasm/asmhdr.go

@@ -27,7 +27,10 @@ import (
 // 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.
+// 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
@@ -67,11 +70,15 @@ func goAsmHeaderResolved(asmDir string, dirs []string) bool {
 	return false
 }
 
-// generateGoAsmHeader type-checks the Go package in pkgDir for goarch,
-// writes its go_asm.h equivalent into dir, and returns dir.  The caller
-// owns the directory and its removal.
-func generateGoAsmHeader(pkgDir, goarch, dir string) (string, error) {
-	imp := newSourceImporter(goarch)
+// 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)
 	}
@@ -89,7 +96,7 @@ func generateGoAsmHeader(pkgDir, goarch, dir string) (string, error) {
 	}
 
 	var b strings.Builder
-	fmt.Fprintf(&b, "// generated by gasm from package %s (GOARCH %s)\n\n", bp.Name, goarch)
+	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
@@ -203,13 +210,14 @@ type sourceImporter struct {
 	pkgs  map[string]*types.Package
 }
 
-// newSourceImporter returns the importer for one target architecture.
+// 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(goarch string) *sourceImporter {
+func newSourceImporter(goos, goarch string) *sourceImporter {
 	ctxt := new(build.Context)
 	*ctxt = build.Default
+	ctxt.GOOS = goos
 	ctxt.GOARCH = goarch
 	ctxt.CgoEnabled = false
 	return &sourceImporter{
@@ -291,7 +299,7 @@ func (im *sourceImporter) checkPackage(bp *build.Package, files []*ast.File) (*t
 // type-check must not be re-checked once per file.
 type asmhdrCache struct {
 	root string
-	dirs map[string]string // "pkgDir\x00goarch" -> directory holding go_asm.h
+	dirs map[string]string // "pkgDir\x00goos\x00goarch" -> directory holding go_asm.h
 	errs map[string]error
 }
 
@@ -304,17 +312,22 @@ func newAsmhdrCache() (*asmhdrCache, error) {
 }
 
 // dirFor returns the directory holding the generated go_asm.h for pkgDir
-// and goarch, generating it on first use.
-func (c *asmhdrCache) dirFor(pkgDir, goarch string) (string, error) {
-	key := pkgDir + "\x00" + goarch
+// 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", len(c.dirs), goarch))
-	if _, err := generateGoAsmHeader(pkgDir, goarch, dir); err != nil {
+	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
 	}
@@ -327,10 +340,10 @@ 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 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, cache *asmhdrCache) (string, func(), error) {
+// 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)")
 	}
@@ -338,14 +351,14 @@ func ensureGoAsmHeader(path string, target arch.Arch, cache *asmhdrCache) (strin
 		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), goarchName(target))
+		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), goarchName(target), root)
+	dir, err := generateGoAsmHeader(filepath.Dir(path), goos, goarchName(target), root)
 	if err != nil {
 		os.RemoveAll(root)
 		return "", nil, err

cmd/gasm/asmhdr_test.go

@@ -5,6 +5,7 @@ package main
 
 import (
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -22,12 +23,13 @@ func writePkg(t *testing.T, files map[string]string) string {
 	return dir
 }
 
-// generateFor generates the header for dir and returns its text.
-func generateFor(t *testing.T, dir, goarch string) string {
+// 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, goarch, t.TempDir())
+	hdrDir, err := generateGoAsmHeader(dir, goos, goarch, t.TempDir())
 	if err != nil {
-		t.Fatalf("generateGoAsmHeader(%q, %s): %v", dir, goarch, err)
+		t.Fatalf("generateGoAsmHeader(%q, %s, %s): %v", dir, goos, goarch, err)
 	}
 	b, err := os.ReadFile(filepath.Join(hdrDir, "go_asm.h"))
 	if err != nil {
@@ -72,7 +74,7 @@ type aliased struct {
 
 type alias = aliased
 `})
-	hdr := generateFor(t, dir, "amd64")
+	hdr := generateFor(t, dir, "", "amd64")
 	want := []string{
 		"#define const_bufSize 1024",
 		// iota resolves through go/types, one define per name.
@@ -133,8 +135,8 @@ package perarch
 const flavour = 2
 `,
 	})
-	amd64 := generateFor(t, dir, "amd64")
-	arm64 := generateFor(t, dir, "arm64")
+	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)
 	}
@@ -149,19 +151,90 @@ const flavour = 2
 	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")
+	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())
+		_, err := generateGoAsmHeader(dir, "", "amd64", t.TempDir())
 		if err == nil {
 			t.Fatal("generation must fail for a package that does not type-check")
 		}
@@ -174,7 +247,7 @@ const x = undefinedIdent
 	})
 	t.Run("no go files", func(t *testing.T) {
 		dir := t.TempDir()
-		_, err := generateGoAsmHeader(dir, "amd64", t.TempDir())
+		_, err := generateGoAsmHeader(dir, "", "amd64", t.TempDir())
 		if err == nil {
 			t.Fatal("generation must fail without Go files")
 		}
@@ -281,14 +354,60 @@ type header struct {
 	}
 }
 
+// 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)
+	}
+}
+
 // TestGenerateGoAsmHeaderRuntime pins the generator against the real thing:
-// the runtime package, whose header the toolchain's own -asmhdr output was
-// sampled from.  Skipped in short mode: it type-checks the whole package.
+// 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")
 	}
-	dir, err := generateGoAsmHeader("/usr/local/go/src/runtime", "amd64", t.TempDir())
+	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)
 	}

cmd/gasm/audit.go

@@ -5,6 +5,7 @@ package main
 
 import (
 	"fmt"
+	"maps"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -37,7 +38,7 @@ 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]] [-I 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
@@ -54,16 +55,19 @@ 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(), dirs)
+		return cmdAuditCorpus(fs.Args(), dirs, *list)
 	}
 	archName := "amd64"
 	switch n := len(fs.Args()); {
@@ -288,6 +292,11 @@ 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{
@@ -307,6 +316,9 @@ 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:
@@ -323,6 +335,12 @@ 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",
 			"",
 		}
 	}
@@ -388,20 +406,30 @@ 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.  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) error {
+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")}
 	}
@@ -439,7 +467,7 @@ func cmdAuditCorpus(args []string, dirs includeDirs) error {
 	if err != nil {
 		return err
 	}
-	printCorpusStats(stats)
+	printCorpusStats(stats, list)
 	return nil
 }
 
@@ -460,8 +488,8 @@ 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 belongs to a build no supported
@@ -487,10 +515,47 @@ func otherPortFile(path string) bool {
 
 // goOSNames are the GOOS values go/build recognises in file names.
 var goOSNames = map[string]bool{
-	"aix": true, "darwin": true, "dragonfly": true, "freebsd": true,
-	"ios": true, "js": true, "linux": true, "netbsd": true,
+	"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,
+	"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
@@ -543,6 +608,12 @@ func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 			return nil, err
 		}
 
+		// 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)
+
 		var wanted []int // indexes into targets
 		if a := arch.FromFilename(path); a != arch.Unknown {
 			for i, tg := range targets {
@@ -567,11 +638,12 @@ func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 
 		// A file that includes go_asm.h parses against a per-target header:
 		// the defines differ per architecture (internal/cpu's layout, for
-		// one), 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.
+		// 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 {
@@ -583,24 +655,25 @@ func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 			for _, i := range wanted {
 				tg, t := targets[i], tallies[i]
 				t.attempted++
-				hdrDir, err := hdr.dirFor(pkgDir, goarchName(tg.a))
+				hdrDir, err := hdr.dirFor(pkgDir, goos, goarchName(tg.a))
 				if err != nil {
 					ok = false
-					t.fail(path, corpusReason(err))
+					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, corpusReason(errs[0]))
+					t.fail(path, errs[0])
 					continue
 				}
-				if _, err := assembleFile(tg.a, f); err != nil {
+				if _, err := assembleFile(tg.a, f, goos); err != nil {
 					ok = false
-					t.fail(path, corpusReason(err))
+					t.fail(path, err)
 					continue
 				}
 				t.assembled++
@@ -611,21 +684,28 @@ func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 			continue
 		}
 
-		f, errs := parser.ParseWithOptions(path, src, parser.Options{Expand: true, IncludeDirs: dirs})
-
 		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++
@@ -647,7 +727,7 @@ func runCorpusAudit(root string, dirs includeDirs) (*corpusStats, error) {
 }
 
 // printCorpusStats renders the corpus audit report.
-func printCorpusStats(s *corpusStats) {
+func printCorpusStats(s *corpusStats, list bool) {
 	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)
 	// The rate is over the files a supported build would attempt: the
 	// other ports' files sit in the count for completeness but can never
@@ -662,6 +742,13 @@ 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)
+		}
 	}
 }
 

cmd/gasm/dis.go

@@ -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

@@ -486,7 +486,7 @@ hover, document symbols, diagnostics and semantic-token highlighting.
 }
 
 func cmdAsm(args []string) int {
-	fs := newCommand("asm", "gasm asm [--format raw|elf|goobj] [-I dir] [-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,
@@ -507,18 +507,22 @@ 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.  A package that has no Go files for the
-target or does not type-check is a hard error naming the package.
+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] [-I dir] [-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
@@ -539,6 +543,15 @@ target or does not type-check is a hard error naming the package.
 		}
 		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)
@@ -553,7 +566,7 @@ target or does not type-check is a hard error naming the package.
 	// 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, nil)
+		hdrDir, cleanup, err := ensureGoAsmHeader(path, targetArch, goos, nil)
 		if err != nil {
 			fmt.Fprintln(os.Stderr, "gasm asm:", err)
 			return 1
@@ -561,7 +574,7 @@ target or does not type-check is a hard error naming the package.
 		defer cleanup()
 		dirs = append(dirs, hdrDir)
 	}
-	f, errs := parser.ParseWithOptions(path, src, parser.Options{Expand: true, IncludeDirs: dirs})
+	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)
 	}
@@ -569,7 +582,7 @@ target or does not type-check is a hard error naming the package.
 		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
@@ -776,11 +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:
@@ -800,18 +836,18 @@ func assemblePath(path string, forced arch.Arch, dirs includeDirs) (*asm.Image,
 	if err != nil {
 		return nil, err
 	}
-	f, errs := parser.ParseWithOptions(path, src, parser.Options{Expand: true, IncludeDirs: dirs})
+	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.
@@ -907,7 +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

docs/ARCHITECTURE.md

@@ -119,6 +119,20 @@ identifier is a register or a label is an *architecture* question, so it is
 left to `arch` and resolved in the lint/lsp layers.  This keeps the parser
 arch-agnostic and its output deterministic.
 
+### Optional preprocessing
+
+With `Options{Expand: true}` the parser runs a pre-parse pass
+(`preproc.go`) that splices `#include` files (the source directory, then the
+`-I` directories), expands object and parameterised `#define` macros,
+applies `#undef` and the `#ifdef`/`#ifndef`/`#else`/`#endif` family, and
+folds constant expressions left in operands.  The go command's platform
+macros (`GOARCH_<arch>`, `GOOS_<goos>`) arrive through `Options.Predefines`.
+The assembly path (`asm`, `diff`, `audit`) expands; `lint`, `fmt` and the
+language server read the raw file.  The command layer adds the go_asm.h
+generator (`asmhdr.go`): a file that includes go_asm.h gets the package's
+defines type-checked out of its Go files for the target architecture and
+GOOS, with no compiler in the loop.
+
 ### `arch`
 
 Register files are generated programmatically (the regular `R8`-`R15`,

docs/CLI.md

@@ -141,7 +141,7 @@ gasm lint kernel_amd64.s
 ## asm
 
 ```text
-Usage: gasm asm [--format raw|elf|goobj] [-I dir] [-p pkg] [-GOARCH arch] [-o out] <file>
+Usage: gasm asm [--format raw|elf|goobj] [-I dir] [-p pkg] [-GOARCH arch] [-GOOS os] [-o out] <file>
 ```
 
 | Flag | Default | Effect |
@@ -150,6 +150,7 @@ Usage: gasm asm [--format raw|elf|goobj] [-I dir] [-p pkg] [-GOARCH arch] [-o ou
 | `-I` | empty | directory to search for `#include` files; may be repeated, searched in order after the source directory |
 | `-p` | empty | package path for `--format goobj`, qualifying the exported symbols |
 | `-GOARCH` | empty | target architecture: `amd64`, `arm64`, `riscv64` or `loong64`; overrides the file-name suffix |
+| `-GOOS` | empty | operating system for the generated `go_asm.h`: any GOOS `go/build` recognises in file names; default is the host's |
 | `-o` | empty | write the output to this file instead of a hex dump on stdout |
 
 Supported architectures: amd64 (VEX/AVX2 and EVEX/AVX-512 included), arm64,
@@ -163,6 +164,13 @@ system toolchain; `goobj` emits the Go toolchain's own object format, which
 installed: the object preamble is captured from `go tool asm` and the format
 version from `go version`. `raw` and `elf` need no toolchain at all.
 
+A file that includes `go_asm.h` gets that header generated from the Go
+files beside it, type-checked for the target. `-GOOS` selects the
+type-checking GOOS for that header, because a GOOS-specific file needs its
+platform's defines: `sys_darwin_arm64.s` fails against the ambient GOOS
+(`machTimebaseInfo_numer` is missing from a linux type-check) and assembles
+with `-GOOS darwin`.
+
 Assembly preprocessing matches the toolchain's: `#define` macros (object and
 parameterised) expand at the point of use, `#undef`, `#ifdef`, `#ifndef`,
 `#else` and `#endif` behave as in `go tool asm`, `;` separates statements,
@@ -357,7 +365,7 @@ add: 16 bytes, args=24, frame=0 NOSPLIT
 ## audit-instructions
 
 ```text
-Usage: gasm audit-instructions [--corpus [dir]] [-I dir] [amd64|arm64|riscv64|loong64]
+Usage: gasm audit-instructions [--corpus [dir]] [--list] [-I dir] [amd64|arm64|riscv64|loong64]
 ```
 
 Compare the gasm encoder for the given architecture (default amd64) against the
@@ -390,10 +398,14 @@ With `--corpus` the audit changes shape: it assembles every `.s` file under
 DIR (default `GOROOT/src`) with the gasm encoder only, no 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 headline number (files
+`GOARCH` build would compile it, and a name that names a GOOS
+(`sys_darwin_arm64.s`) type-checks its generated `go_asm.h` for that GOOS.
+The report gives the headline number (files
 that assemble for every target architecture), the per-architecture pass rates
 and the most common failure reasons with one representative file each, which
-drive the encodability backlog by frequency rather than by table order. A run
+drive the encodability backlog by frequency rather than by table order. With
+`--list` the report additionally prints every failing file with its failure
+reason, per architecture. A run
 over GOROOT takes under a second.
 
 ```sh

docs/GOOBJ.md

@@ -0,0 +1,657 @@
+# The GOOBJ object file format
+
+This document is a complete specification of GOOBJ, the object file format
+that the Go toolchain's assembler, compiler and linker exchange, written for
+implementers of independent producers and consumers. It documents the format
+as shipped by Go 1.27.1, identified by the magic string `"\x00go120ld"`.
+
+No comparable document exists upstream. The format is defined only by the
+source of the `cmd/internal/goobj` package inside the toolchain tree, it is an
+internal interface with no stability promise, and it can change in any
+release. This specification was therefore produced by reverse engineering
+that source and by parsing real objects produced by `go tool asm` and
+`go tool compile`, byte for byte, against the layout described here. Within
+gasm-devkit it is kept honest by the differential tests in `asm/goobj_test.go`
+and `asm/link_test.go`, which compare `gasm asm --format goobj` output against
+the toolchain's own products and feed gasm objects to `go build`.
+
+Every numeric value in this document, every block index, structure size, flag
+bit, type code and relocation number, was read from the Go 1.27.1 source at
+`/usr/local/go/src/cmd/internal/goobj`, `cmd/internal/obj` and
+`cmd/internal/objabi`, and exercised against assembled objects.
+
+## Containers
+
+The unit this document specifies is the **object**: one package's worth of
+symbols, relocations and data. An object is never consumed naked. Two
+wrappers exist in practice, and the linker dispatches on the first bytes of
+the file.
+
+**The bare object**, written by `go tool asm`:
+
+```text
+"go object linux amd64 go1.27.1 GOAMD64=v1 X:regabiwrappers,...\n"
+"!\n"
+<GOOBJ blob>
+```
+
+The first line is the toolchain configuration string, produced by
+`objabi.HeaderString`: `go object`, the GOOS, the GOARCH, the toolchain
+version, an optional architecture qualifier such as `GOAMD64=v1`, and
+`X:` followed by the enabled experiments, comma separated. The linker requires
+this line to match its own configuration exactly and rejects the file
+otherwise; the `-f` linker flag waives the check. Header lines may be
+followed by export data delimited by `$$` markers; the header region always
+ends at the first line consisting of exactly `!`, and the GOOBJ blob starts
+immediately after that line.
+
+**The package archive**, written by the compiler output pipeline and consumed
+by `go build`: the classic `ar` format, magic `!<arch>\n`, with the export
+data in a `__.PKGDEF` member and one or more objects as further members, each
+carrying the bare-object structure above. `go tool pack` creates and
+inspects such archives.
+
+| Consumer | Role |
+|---|---|
+| `cmd/asm` | writes objects from `.s` files |
+| `cmd/compile` | writes objects from Go source |
+| `cmd/link` | reads objects and archives, produces executables |
+| `cmd/nm`, `cmd/objdump` | read objects through `cmd/internal/objfile` |
+
+## Conventions
+
+- All integers are **little endian**.
+- There is **no alignment or padding** anywhere in the file; structures follow
+  one another byte by byte.
+- Every offset stored in the file is **relative to the first byte of the GOOBJ
+  blob**, not to the start of the container.
+- The blob opens with a 96 byte header that carries the byte offset of every
+  block. A block's length is the difference between its own offset and the
+  next block's, so the offset array is the only index the format needs.
+
+### Layout overview
+
+```mermaid
+flowchart TB
+    A[Container header line and ! terminator] --> B[File header, 96 bytes]
+    B --> C[String table, implicit region]
+    C --> D[Autolib]
+    D --> E[PkgIndex]
+    E --> F[Files]
+    F --> G[Symbol definition arrays: Symdef, Hashed64def, Hasheddef, Nonpkgdef, Nonpkgref]
+    G --> H[RefFlags]
+    H --> I[Hash64 and Hash]
+    I --> J[RelocIndex, AuxIndex, DataIndex]
+    J --> K[Relocs]
+    K --> L[Aux]
+    L --> M[Data]
+    M --> N[RefNames]
+    N --> O[BlkEnd marks the end of the blob]
+```
+
+## The file header
+
+Exactly 96 bytes: 8 magic, 8 fingerprint, 4 flags, and 19 four byte block
+offsets.
+
+| Offset | Size | Field | Meaning |
+|---|---|---|---|
+| 0 | 8 | Magic | `"\x00go120ld"`. A reader rejects anything else. The digits are the format version and have moved before; a new toolchain release may move them again. |
+| 8 | 8 | Fingerprint | Identifies the package build. The compiler writes a hash of the export data; the assembler leaves all zero. The linker compares this against the fingerprint recorded by importers. |
+| 16 | 4 | Flags | Bit field, see below. |
+| 20 | 76 | Offsets | 19 `uint32` entries, one per block index 0 to 18. |
+
+Header flags:
+
+| Bit | Value | Name | Meaning |
+|---|---|---|---|
+| 0 | 1 | ObjFlagShared | built with `-shared` |
+| 1 | 2 | reserved | was `ObjFlagNeedNameExpansion`, now unused |
+| 2 | 4 | ObjFlagFromAssembly | produced from assembly source; `go tool asm` and gasm set this |
+| 3 | 8 | ObjFlagUnlinkable | package path is invalid, the linker refuses to link |
+| 4 | 16 | ObjFlagStd | standard library package |
+
+### Block indices
+
+The offset array is indexed by these constants, in file order:
+
+| Index | Constant | Contents |
+|---|---|---|
+| 0 | BlkAutolib | imported packages |
+| 1 | BlkPkgIndex | referenced packages, indexed |
+| 2 | BlkFile | source file names |
+| 3 | BlkSymdef | symbol definitions, package scope |
+| 4 | BlkHashed64def | short hashed definitions |
+| 5 | BlkHasheddef | hashed definitions |
+| 6 | BlkNonpkgdef | non-package definitions |
+| 7 | BlkNonpkgref | non-package references |
+| 8 | BlkRefFlags | flags of referenced symbols |
+| 9 | BlkHash64 | 8 byte hashes for short hashed definitions |
+| 10 | BlkHash | 16 byte hashes for hashed definitions |
+| 11 | BlkRelocIndex | per symbol relocation start index |
+| 12 | BlkAuxIndex | per symbol aux start index |
+| 13 | BlkDataIndex | per symbol data offset |
+| 14 | BlkReloc | relocations |
+| 15 | BlkAux | aux symbol entries |
+| 16 | BlkData | symbol payloads |
+| 17 | BlkRefName | names of referenced symbols, for tools |
+| 18 | BlkEnd | no contents; its offset is the end of the blob |
+
+## The string table
+
+There is no block index for strings. The table occupies the implicit region
+between the end of the header (offset 96) and `Offsets[BlkAutolib]`, and every
+string offset in the file points into that region. The writer de-duplicates:
+each distinct string is stored once, in first-use order, and the empty string
+is always the first entry, so its reference is length 0 and offset 96.
+
+A **string reference** is 8 bytes: `uint32` length, then `uint32` absolute
+offset of the bytes. The bytes are stored raw, with no terminator.
+
+## Symbol references and the package index
+
+A **symbol reference** (SymRef) is 8 bytes: two `uint32`, `PkgIdx` and
+`SymIdx`. The pair `{0, 0}` means nil. `PkgIdx` says which array the symbol
+lives in:
+
+| Value | Constant | SymIdx indexes |
+|---|---|---|
+| 0 | PkgIdxInvalid | never valid in a written file |
+| 1 and up, ascending | (imported packages) | the SymbolDefs array of the package named at PkgIndex entry `PkgIdx` |
+| 0x7ffffffb | PkgIdxSelf | this object's Symdef array |
+| 0x7ffffffc | PkgIdxBuiltin | the compiler's builtin table, see Builtins |
+| 0x7ffffffd | PkgIdxHashed | this object's Hasheddef array |
+| 0x7ffffffe | PkgIdxHashed64 | this object's Hashed64def array |
+| 0x7fffffff | PkgIdxNone | NonPkgDefs, overflowing into NonPkgRefs |
+
+Assignment rules, as the toolchain performs them:
+
+- Every definition a package exports to the linker by index lands in Symdefs
+  with PkgIdxSelf. The compiler puts its functions and data here; the
+  assembler puts only its file-local static symbols here, everything else by
+  name, see below.
+- External package references take indices 1, 2, 3, in order of first
+  reference during assembly; the package names go into PkgIndex at those
+  indices, entry 0 is the empty package and is never referenced.
+- References to the compiler's builtin functions become PkgIdxBuiltin with
+  SymIdx set to the builtin's index.
+- A symbol referenced **by name** rather than by index becomes PkgIdxNone and
+  its index counts through NonPkgDefs first, then continues into NonPkgRefs.
+  A producer must emit the definitions it made in NonPkgDefs and the pure
+  references in NonPkgRefs.
+- The assembler's rule, from `cmd/internal/obj/sym.go`: every assembly symbol
+  is referenced by name, PkgIdxNone, **except** file-local static symbols,
+  whose names carry `<>` and which are referenced by index. The compiler also
+  forces references by name for symbols marked `//go:linkname` and for any
+  symbol with the DUPOK attribute, which the linker de-duplicates by name.
+
+## Symbol definition entries
+
+The five definition and reference arrays (block indices 3 to 7) share one
+element layout, 21 bytes:
+
+| Offset | Size | Field | Meaning |
+|---|---|---|---|
+| 0 | 8 | Name | string reference |
+| 8 | 2 | ABI | see table below |
+| 10 | 1 | Type | symbol kind, see the kind table |
+| 11 | 1 | Flag | bit field, see below |
+| 12 | 1 | Flag2 | second bit field, see below |
+| 13 | 4 | Siz | payload size in bytes, `uint32` |
+| 17 | 4 | Align | alignment the linker must honour, `uint32` |
+
+The Name is a real string reference for hand-written symbols. The auxiliary
+symbols the toolchain generates per function, the FuncInfo payload, the DWARF
+entries, have empty names: length 0, and their identity is only via the Aux
+entries that point at them by index.
+
+### The ABI field
+
+| Value | Meaning |
+|---|---|
+| 0 | ABI0, the stack based ABI, the ABI of every hand-written assembly function |
+| 1 | ABIInternal, the register ABI of compiler-generated functions |
+| 0xffff | static, a file-local symbol (`name<>(SB)`), `SymABIstatic` |
+
+### The Flag byte
+
+| Bit | Value | Name | Meaning |
+|---|---|---|---|
+| 0 | 1 | SymFlagDupok | duplicates allowed, the linker merges them |
+| 1 | 2 | SymFlagLocal | file-local |
+| 2 | 4 | SymFlagTypelink | belongs in the typelink table |
+| 3 | 8 | SymFlagLeaf | leaf function |
+| 4 | 16 | SymFlagNoSplit | no stack-split preamble |
+| 5 | 32 | SymFlagReflectMethod | `//go:reflectmethod` reachability |
+| 6 | 64 | SymFlagGoType | a Go type descriptor, `type:` name and SRODATA |
+
+Note that NoSplit is not reserved for explicit `NOSPLIT` declarations. On
+amd64 the assembler itself marks any function whose frame is below
+`abi.StackSmall` and whose body calls nothing that needs stack as NoSplit and
+omits the split check, so a `TEXT` without `NOSPLIT` can still carry the bit.
+
+### The Flag2 byte
+
+| Bit | Value | Name | Meaning |
+|---|---|---|---|
+| 0 | 1 | SymFlagUsedInIface | type or itab reachable through an interface |
+| 1 | 2 | SymFlagItab | an itab, `go:itab.` name and SRODATA |
+| 2 | 4 | SymFlagDict | a generic dictionary symbol |
+| 3 | 8 | SymFlagPkgInit | package initialisation function |
+| 4 | 16 | SymFlagLinkname | reachable through `//go:linkname`; the assembler also sets it on `main.main` |
+| 5 | 32 | SymFlagLinknameStd | linkname into the standard library |
+| 6 | 64 | SymFlagABIWrapper | ABI transition wrapper |
+| 7 | 128 | SymFlagWasmExport | `//go:wasmexport` target |
+
+### The Type byte: symbol kinds
+
+Values of `objabi.SymKind`, in numeric order:
+
+| Value | Name | Meaning |
+|---|---|---|
+| 0 | Sxxx | invalid zero value |
+| 1 | STEXT | executable code |
+| 2 | STEXTFIPS | executable code, FIPS section |
+| 3 | SRODATA | read only data |
+| 4 | SRODATAFIPS | read only data, FIPS section |
+| 5 | SNOPTRDATA | data without pointers |
+| 6 | SNOPTRDATAFIPS | data without pointers, FIPS section |
+| 7 | SDATA | data, may contain pointers |
+| 8 | SDATAFIPS | data, FIPS section |
+| 9 | SBSS | zero initialised data |
+| 10 | SNOPTRBSS | zero initialised data without pointers |
+| 11 | STLSBSS | thread local zero initialised data |
+| 12 | SDWARFCUINFO | DWARF compile unit information |
+| 13 | SDWARFCONST | DWARF constants |
+| 14 | SDWARFFCN | DWARF function entry |
+| 15 | SDWARFABSFCN | DWARF absolute function entry |
+| 16 | SDWARFTYPE | DWARF type information |
+| 17 | SDWARFVAR | DWARF variable information |
+| 18 | SDWARFRANGE | DWARF range lists |
+| 19 | SDWARFLOC | DWARF location lists |
+| 20 | SDWARFLINES | DWARF line programs |
+| 21 | SDWARFADDR | DWARF address table |
+| 22 | SLIBFUZZER_8BIT_COUNTER | libFuzzer coverage counter |
+| 23 | SCOVERAGE_COUNTER | coverage counter |
+| 24 | SCOVERAGE_AUXVAR | coverage auxiliary variable |
+| 25 | SSEHUNWINDINFO | Windows SEH unwind information |
+
+## Referenced symbol flags (RefFlags)
+
+Element size 10 bytes, one per referenced external indexed symbol that
+carries a non-zero Flag2:
+
+| Offset | Size | Field |
+|---|---|---|
+| 0 | 8 | Sym, a SymRef into another package |
+| 8 | 1 | Flag, always 0 in current writers |
+| 9 | 1 | Flag2, only SymFlagUsedInIface is ever written |
+
+The linker uses these to preserve reachability of interface conversions
+across package boundaries. Entries with no flags are omitted entirely.
+
+## Hashes
+
+**Hash64**, block 9: one `uint64` per Hashed64def entry, in array order. Not
+a hash at all: the writer copies the **first 8 bytes of the symbol's
+payload**. Only symbols whose content-hash section byte is 0 may use the
+short form.
+
+**Hash**, block 10: 16 bytes per Hasheddef entry: the first 16 bytes of a
+SHA-256 computation over a seed byte `0x01` followed by the hash input. The
+input, from `cmd/internal/obj/objfile.go`:
+
+1. the payload size, little endian `uint64`;
+2. the section byte, one of `t` for STEXT, `f` for STEXTFIPS, `P` for pcdata,
+   `F` for the `go:func.*` and `go:funcrel.*` families, `T` for `type:`
+   symbols, otherwise 0;
+3. for text symbols, the symbol name, which keeps distinct functions from
+   merging;
+4. the payload with trailing zero bytes trimmed;
+5. for each relocation: a 14 byte record, offset `uint32`, size `uint8`,
+   low type byte `uint8`, addend `int64`, followed by an encoding of the
+   target: tag byte 0 then the target's short hash, tag 1 then its full
+   hash, tag 2 then its expanded name, tag 3 then its builtin index, or,
+   for PkgIdxSelf and imported packages, no tag, then the package path
+   and the symbol index.
+
+Two symbols with equal hashes are interchangeable at link time, which is what
+makes content addressing work. A producer that computes these hashes wrongly
+produces objects that link but de-duplicate wrongly; gasm verifies them by
+byte comparison against `go tool asm`.
+
+## The index arrays
+
+Three arrays of `uint32`, one element per **defined** symbol plus one final
+element, in the order Symdefs, Hashed64defs, Hasheddefs, NonPkgDefs. With N
+defined symbols, each array holds N + 1 entries, and the entry at N is the
+total.
+
+- RelocIndex: entry i is where symbol i's relocations start in BlkReloc;
+  entry i + 1 minus entry i is its count.
+- AuxIndex: the same construction over BlkAux.
+- DataIndex: entry i is the byte offset of symbol i's payload within BlkData;
+  the count is the difference of neighbours.
+
+The toolchain writes relocations grouped per symbol in definition order, and
+sorts each symbol's relocations by their Off field first. A producer that
+skips the sort produces objects the linker still accepts, but that no longer
+compare byte-for-byte with the toolchain's output.
+
+## Relocations
+
+Element size 23 bytes:
+
+| Offset | Size | Field | Meaning |
+|---|---|---|---|
+| 0 | 4 | Off | patch position, bytes from the start of the symbol's payload, `int32` |
+| 4 | 1 | Siz | patch width in bytes |
+| 5 | 2 | Type | relocation type, `uint16`, see the table |
+| 7 | 8 | Add | addend, `int64` |
+| 15 | 8 | Sym | target SymRef |
+
+The computed value `payload[Off:Off+Siz] += address(Sym) + Add` in the
+flavour the type prescribes is the linker's job; the object only records the
+request. A size 0 relocation patches nothing and exists purely as a marker
+for the linker's reachability analysis.
+
+### Relocation types
+
+Values of `objabi.RelocType`. The assembler and compiler emit the generic
+ones plus their own architecture's family; the rest exist for other ports and
+for the linker itself.
+
+| Value | Name | Meaning |
+|---|---|---|
+| 1 | R_ADDR | absolute address |
+| 2 | R_ADDRPOWER | ppc64: high adjusted plus low 16 bits across two D-form instructions |
+| 3 | R_ADDRARM64 | arm64: adrp plus add pair |
+| 4 | R_ADDRMIPS | mips: low 16 bits of an external address |
+| 5 | R_ADDROFF | 32-bit offset from the section start to the symbol |
+| 6 | R_SIZE | size of the referenced symbol |
+| 7 | R_CALL | direct call, PC relative |
+| 8 | R_CALLARM | arm: call with a shifted 24-bit field |
+| 9 | R_CALLARM64 | arm64: BL |
+| 10 | R_CALLIND | indirect call marker |
+| 11 | R_CALLPOWER | ppc64: call |
+| 12 | R_CALLMIPS | mips: non-PC-relative call target |
+| 13 | R_CONST | constant value of the symbol |
+| 14 | R_PCREL | PC relative displacement |
+| 15 | R_TLS_LE | thread local, local exec offset |
+| 16 | R_TLS_IE | thread local, initial exec GOT offset |
+| 17 | R_GOTOFF | offset from the GOT base |
+| 18 | R_PLT0 | PLT sequence, first instruction |
+| 19 | R_PLT1 | PLT sequence, second instruction |
+| 20 | R_PLT2 | PLT sequence, third instruction |
+| 21 | R_USEFIELD | field reachability marker |
+| 22 | R_USETYPE | type reachability marker, no bytes patched |
+| 23 | R_USEIFACE | interface conversion marker, size 0 |
+| 24 | R_USEIFACEMETHOD | interface method marker, size 0, addend is the method offset |
+| 25 | R_USENAMEDMETHOD | keeps named methods alive |
+| 26 | R_METHODOFF | like R_ADDROFF, the linker may zero it when the method is dead |
+| 27 | R_KEEP | keeps the target alive if the source survives |
+| 28 | R_POWER_TOC | ppc64: TOC relative |
+| 29 | R_GOTPCREL | 32-bit PC relative GOT slot |
+| 30 | R_JMPMIPS | mips: non-PC-relative jump target |
+| 31 | R_DWARFSECREF | offset of the symbol from its section, DWARF use |
+| 32 | R_ARM64_TLS_LE | arm64: MOV[NZ] immediate, TLS local exec |
+| 33 | R_ARM64_TLS_IE | arm64: adrp plus ldr, TLS initial exec |
+| 34 | R_ARM64_GOTPCREL | arm64: adrp plus ldr GOT slot |
+| 35 | R_ARM64_GOT | arm64: GOT relative sequence |
+| 36 | R_ARM64_PCREL | arm64: adrp plus add PC relative |
+| 37 | R_ARM64_PCREL_LDST8 | arm64: adrp plus 8-bit load or store |
+| 38 | R_ARM64_PCREL_LDST16 | arm64: adrp plus 16-bit load or store |
+| 39 | R_ARM64_PCREL_LDST32 | arm64: adrp plus 32-bit load or store |
+| 40 | R_ARM64_PCREL_LDST64 | arm64: adrp plus 64-bit load or store |
+| 41 | R_ARM64_LDST8 | arm64: 12-bit load or store immediate, byte |
+| 42 | R_ARM64_LDST16 | arm64: bits 11 to 1 of the address |
+| 43 | R_ARM64_LDST32 | arm64: bits 11 to 2 |
+| 44 | R_ARM64_LDST64 | arm64: bits 11 to 3 |
+| 45 | R_ARM64_LDST128 | arm64: bits 11 to 4 |
+| 46 | R_POWER_TLS_LE | ppc64: TLS local exec across two instructions |
+| 47 | R_POWER_TLS_IE | ppc64: TLS initial exec via GOT |
+| 48 | R_POWER_TLS | ppc64: marks the X-form instruction completing a TLS sequence |
+| 49 | R_POWER_TLS_IE_PCREL34 | ppc64: prefixed TLS initial exec load |
+| 50 | R_POWER_TLS_LE_TPREL34 | ppc64: prefixed TLS local exec |
+| 51 | R_ADDRPOWER_DS | ppc64: DS-form second instruction, bits 15 to 2 |
+| 52 | R_ADDRPOWER_GOT | ppc64: GOT entry relative to TOC |
+| 53 | R_ADDRPOWER_GOT_PCREL34 | ppc64: PC relative GOT, prefixed |
+| 54 | R_ADDRPOWER_PCREL | ppc64: PC relative across two D-form instructions |
+| 55 | R_ADDRPOWER_TOCREL | ppc64: TOC relative across two D-form instructions |
+| 56 | R_ADDRPOWER_TOCREL_DS | ppc64: TOC relative, DS form |
+| 57 | R_ADDRPOWER_D34 | ppc64: prefixed absolute, 34 bits |
+| 58 | R_ADDRPOWER_PCREL34 | ppc64: prefixed PC relative, 34 bits |
+| 59 | R_RISCV_JAL | riscv64: 20-bit J-type offset |
+| 60 | R_RISCV_JAL_TRAMP | riscv64: as R_RISCV_JAL, linker-generated trampolines only |
+| 61 | R_RISCV_CALL | riscv64: AUIPC plus JALR pair |
+| 62 | R_RISCV_PCREL_ITYPE | riscv64: AUIPC plus I-type pair |
+| 63 | R_RISCV_PCREL_STYPE | riscv64: AUIPC plus S-type pair |
+| 64 | R_RISCV_TLS_IE | riscv64: TLS initial exec, AUIPC plus I-type |
+| 65 | R_RISCV_TLS_LE | riscv64: TLS local exec, LUI plus I-type |
+| 66 | R_RISCV_GOT_HI20 | riscv64: high 20 bits of a GOT address |
+| 67 | R_RISCV_GOT_PCREL_ITYPE | riscv64: GOT entry, AUIPC plus I-type |
+| 68 | R_RISCV_PCREL_HI20 | riscv64: high 20 bits of a PC relative address |
+| 69 | R_RISCV_PCREL_LO12_I | riscv64: low 12 bits, I-type |
+| 70 | R_RISCV_PCREL_LO12_S | riscv64: low 12 bits, S-type |
+| 71 | R_RISCV_BRANCH | riscv64: 12-bit branch offset |
+| 72 | R_RISCV_ADD32 | riscv64: in-place addition, V + S + A |
+| 73 | R_RISCV_SUB32 | riscv64: in-place subtraction, V - S - A |
+| 74 | R_RISCV_RVC_BRANCH | riscv64: 8-bit compressed branch offset |
+| 75 | R_RISCV_RVC_JUMP | riscv64: 11-bit compressed jump offset |
+| 76 | R_PCRELDBL | s390x: PC relative, 2-byte aligned |
+| 77 | R_LOONG64_ADDR_HI | loong64: bits 31 to 12 of an address |
+| 78 | R_LOONG64_ADDR_LO | loong64: low 12 bits |
+| 79 | R_LOONG64_ADDR64_HI | loong64: bits 63 to 52 |
+| 80 | R_LOONG64_ADDR64_LO | loong64: bits 51 to 32 |
+| 81 | R_LOONG64_ADDR_PCREL20_S2 | loong64: 22-bit aligned PC relative, PCADDI |
+| 82 | R_LOONG64_TLS_LE_HI | loong64: TLS local exec, high bits |
+| 83 | R_LOONG64_TLS_LE_LO | loong64: TLS local exec, low bits |
+| 84 | R_CALLLOONG64 | loong64: 28-bit aligned BL |
+| 85 | R_LOONG64_CALL36 | loong64: 38-bit aligned PCADDU18I plus JIRL |
+| 86 | R_LOONG64_TLS_IE_HI | loong64: TLS initial exec via GOT, high |
+| 87 | R_LOONG64_TLS_IE_LO | loong64: TLS initial exec via GOT, low |
+| 88 | R_LOONG64_GOT_HI | loong64: GOT entry, high bits |
+| 89 | R_LOONG64_GOT_LO | loong64: GOT entry, low bits |
+| 90 | R_LOONG64_GOT64_HI | loong64: 64-bit GOT entry, high |
+| 91 | R_LOONG64_GOT64_LO | loong64: 64-bit GOT entry, low |
+| 92 | R_LOONG64_ADD64 | loong64: 64-bit in-place addition |
+| 93 | R_LOONG64_SUB64 | loong64: 64-bit in-place subtraction |
+| 94 | R_JMP16LOONG64 | loong64: 18-bit aligned conditional jump |
+| 95 | R_JMP21LOONG64 | loong64: 23-bit aligned BEQZ or BNEZ |
+| 96 | R_ADDRMIPSU | mips: sign-adjusted upper 16 bits |
+| 97 | R_ADDRMIPSTLS | mips: TLS low 16 bits |
+| 98 | R_ADDRCUOFF | pointer-sized offset from the DWARF compile unit start |
+| 99 | R_WASMIMPORT | wasm: import module and name indices |
+| 100 | R_XCOFFREF | aix: keeps the target alive, patches nothing |
+| 101 | R_PEIMAGEOFF | windows: offset from the image base |
+| 102 | R_INITORDER | orders inittask records, patches nothing |
+| 103 | R_DWTXTADDR_U1 | writes a 1-byte ULEB .debug_addr index for the target function |
+| 104 | R_DWTXTADDR_U2 | as above, 2 bytes |
+| 105 | R_DWTXTADDR_U3 | as above, 3 bytes |
+| 106 | R_DWTXTADDR_U4 | as above, 4 bytes; the assembler always picks this one |
+| -32768 | R_WEAK | mask: the target need not be reachable, see below |
+| -32767 | R_WEAKADDR | R_WEAK or R_ADDR |
+| -32763 | R_WEAKADDROFF | R_WEAK or R_ADDROFF |
+
+R_WEAK is bit 15 set on a negative `int16`: a weak relocation is the base
+type's value with bit 15 set. The linker strips the bit before dispatch.
+
+## Aux symbol entries
+
+Element size 9 bytes: a `uint8` type then a SymRef. Aux entries attach
+auxiliary symbols to a definition; the arrays run per symbol in the order
+given by AuxIndex.
+
+| Value | Name | Attaches |
+|---|---|---|
+| 0 | AuxGotype | the Go type of a data symbol |
+| 1 | AuxFuncInfo | the FuncInfo payload of a text symbol |
+| 2 | AuxFuncdata | one funcdata symbol; one entry per slot, nil slots carry the {0,0} reference |
+| 3 | AuxDwarfInfo | DWARF debug info for the function |
+| 4 | AuxDwarfLoc | DWARF location lists |
+| 5 | AuxDwarfRanges | DWARF range lists |
+| 6 | AuxDwarfLines | DWARF line program |
+| 7 | AuxPcsp | pc-value table: SP adjustments |
+| 8 | AuxPcfile | pc-value table: source file indices |
+| 9 | AuxPcline | pc-value table: line numbers |
+| 10 | AuxPcinline | pc-value table: inlining tree positions |
+| 11 | AuxPcdata | one pc-value table per live variable slot |
+| 12 | AuxWasmImport | wasm import description |
+| 13 | AuxWasmType | wasm export type description |
+| 14 | AuxSehUnwindInfo | Windows SEH unwind info |
+
+The writer emits them in the order Gotype, FuncInfo, Funcdata entries,
+DwarfInfo, DwarfLoc, DwarfRanges, DwarfLines, Pcsp, Pcfile, Pcline, Pcinline,
+SehUnwindInfo, Pcdata entries, WasmImport, WasmType, and skips any whose
+payload would be empty. A function assembled from `.s` source by Go 1.27.1
+carries exactly: FuncInfo, the Funcdata slots including nils, DwarfInfo,
+DwarfLines, Pcsp, Pcfile, Pcline and Pcinline; gasm's writer produces the
+same set.
+
+The aux targets are either PkgIdxSelf definitions, PkgIdxHashed pcdata
+symbols, or, for the funcdata of assembly functions, PkgIdxNone references
+carrying names such as `pkg.Fn.args_stackmap` and `pkg.Fn.arginfo0`, which
+resolve to definitions in the package's compiled Go code when there is any.
+
+## Symbol payloads (BlkData)
+
+The payloads of all defined symbols, in definition order, concatenated with
+no padding; DataIndex gives each symbol's slice. A text symbol's payload is
+its machine code, with the stack-split preamble and any morestack block
+already included. A data symbol's payload is the bytes laid down by its DATA
+directives, zero filled to its declared size. If a symbol was created from an
+embedded file, the file's bytes follow the payload and count towards its
+DataIndex extent; assembly producers never write this extension.
+
+### The FuncInfo payload
+
+An SDATA symbol with no name, referenced by AuxFuncInfo. 28 bytes minimum,
+little endian:
+
+| Offset | Size | Field | Meaning |
+|---|---|---|---|
+| 0 | 4 | Args | argument area in bytes; 0x80000000 when the producer declared none |
+| 4 | 4 | Locals | frame size in bytes |
+| 8 | 1 | FuncID | runtime function classification, 0 means normal |
+| 9 | 1 | FuncFlag | TopFrame = 1, SPWrite = 2, Asm = 4 |
+| 10 | 2 | padding | zero, reserved to a 4 byte boundary |
+| 12 | 4 | StartLine | source line of the TEXT declaration |
+| 16 | 4 | NumFile | count of file indices that follow |
+| 20 | 4 × NumFile | Files | indices into the Files block, ascending |
+| then | 4 | NumInlTree | count of inlining tree nodes that follow |
+| then | 24 × NumInlTree | InlTree | nodes, see below |
+
+One InlTree node, 24 bytes: `int32` parent index, `uint32` file index,
+`int32` line, `uint32` PkgIdx and `uint32` SymIdx of the inlined function, and
+`int32` parent PC.
+
+The assembler derives FuncID from the symbol name through
+`objabi.GetFuncID`, so a runtime function with a name the runtime treats
+specially gets that classification even when defined in assembly; an ordinary
+name yields 0. FuncFlag carries the Asm bit, 4, for every assembly function.
+
+### The pc-value tables
+
+The AuxPcsp, AuxPcfile, AuxPcline, AuxPcinline and AuxPcdata payloads are
+pc-value tables, each a sequence of value deltas and PC deltas:
+
+- a signed value delta, zig-zag encoded, `binary.PutVarint` form;
+- an unsigned PC delta in ULEB128 form, counted in instruction units, the
+  raw delta divided by the architecture's minimum instruction length;
+- the table ends with a final PC delta to the end of the function followed by
+  a zero byte.
+
+The first value applies from function entry. The encoding is the one
+`cmd/internal/obj/pcln.go` calls funcpctab, and it is the same encoding the
+final runtime pclntable carries.
+
+### The DWARF payloads
+
+AuxDwarfInfo, AuxDwarfLoc, AuxDwarfRanges and AuxDwarfLines reference SDWARF
+symbols whose payloads are DWARF byte streams. The object format treats them
+as opaque: the linker concatenates them into the final `.debug_*` sections
+and resolves the relocations recorded inside them. The compiler produces
+DWARF content per its own generation; gasm produces DWARF5 streams in
+`asm/goobj_dwarf.go`.
+
+## Builtins
+
+Frequently referenced runtime functions are referenced by index rather than
+by name: PkgIdxBuiltin with SymIdx set to the position in the generated table
+`cmd/internal/goobj/builtinlist.go`, 299 entries in Go 1.27.1, names such as
+`runtime.newobject` at index 0; 232 entries carry ABI 1 and the remaining 67
+ABI 0. Builtin names never enter the string table. The mapping only applies
+while the object is not linked against shared libraries, and a linkname'd
+symbol never counts as a builtin even when its name matches.
+
+## Fingerprints
+
+The 8 byte fingerprint identifies one build of a package. The compiler fills
+it with a hash of the package's export data; the assembler leaves it zero.
+The linker checks a package's fingerprint against the fingerprints its
+importers recorded in their Autolib entries and rejects a mismatched build,
+which is how stale objects are caught.
+
+## What a producer must do
+
+The checklist a third-party writer must satisfy for `go build` to accept its
+objects, in one place:
+
+1. Write the container exactly: the `go object` line matching the target
+   toolchain's configuration string, the `!\n` terminator, then the blob.
+2. Emit the 19 block offsets, in order, and make BlkEnd the blob length.
+3. Deduplicate the string table, keep the empty string at offset 96, and
+   reference it everywhere a name appears.
+4. Index relocations, aux entries and data per symbol with the N + 1 arrays,
+   definitions ordered Symdefs, Hashed64defs, Hasheddefs, NonPkgDefs.
+5. Sort relocations by offset within each symbol.
+6. Fill Siz with the true payload length, set Align for every
+   content-addressable symbol, and keep symbols under 2 GB.
+7. Reference symbols by the package-index rules. An assembly producer
+   references everything outside the object by name, PkgIdxNone,
+   except its own file-local statics and the builtins; PkgIdxSelf is
+   reserved for definitions in this object. Assembly TEXT symbols
+   carry ABI 0.
+8. Compute the content hashes exactly as the toolchain does, or emit no
+   hashed definitions at all.
+
+## How gasm-devkit implements and verifies it
+
+The writer lives in `asm/goobj.go`, which carries the shared container and the
+amd64 relocation emission, with per-architecture relocation emitters in
+`asm/goobjarm64.go`, `asm/goobjriscv.go` and `asm/goobjloong64.go`, symbol
+resolution in `asm/goobj_resolve.go` and DWARF generation in
+`asm/goobj_dwarf.go`. `gasm asm --format goobj -p pkg/path` writes objects
+that `go build` consumes in place of the toolchain's own.
+
+Verification is differential and continuous:
+
+- `asm/goobj_test.go` compares gasm's GOOBJ output against `go tool asm`
+  output for the same source, byte for byte;
+- `asm/link_test.go` builds real Go programs whose assembly comes from gasm
+  objects and runs them;
+- `gasm verify` keeps the machine code itself identical to the toolchain's,
+  which is the precondition for the object comparison to be meaningful.
+
+## Versioning and drift
+
+The magic string carries the format generation, `go120ld` in Go 1.27.1. When
+a toolchain release changes the format, it changes that string first, and the
+linker refuses blobs whose magic it does not know. The watch points for a new
+release are, in order: the magic, the block index list, the Aux type list,
+the tail of the relocation table, the FuncInfo layout, and the builtin table
+count. gasm's tests fail against any of these changes, which is the mechanism
+that keeps this document and the writer current.
+
+The authoritative sources, for the release this document covers:
+
+- `cmd/internal/goobj/objfile.go`: the format, every structure in this
+  document;
+- `cmd/internal/goobj/funcinfo.go`: FuncInfo and the inlining tree;
+- `cmd/internal/goobj/builtinlist.go`: the builtin table;
+- `cmd/internal/obj/objfile.go`: the writer, hash inputs and aux order;
+- `cmd/internal/obj/sym.go`: package index assignment and the by-name rule;
+- `cmd/internal/obj/pcln.go`: the pc-value encoding;
+- `cmd/internal/objabi/reloctype.go`: relocation types;
+- `cmd/internal/objabi/symkind.go`: symbol kinds;
+- `cmd/link/internal/ld/lib.go`: container parsing and fingerprint checks.

docs/asm/AMD64.md

@@ -0,0 +1,124 @@
+# AMD64
+
+Layer 1, target page. Verified against `go tool asm` of Go 1.27.1 and against
+gasm's encoder, whose output is compared byte for byte with the toolchain's
+and executed on real hardware (`gasm verify`). The complete mnemonic
+inventory lives in the generated appendix
+[INSTRUCTIONS-AMD64.md](INSTRUCTIONS-AMD64.md); this page is the grammar and
+the conventions.
+
+## Registers
+
+| Group | Names | Notes |
+|---|---|---|
+| General purpose, 64-bit | `AX` `BX` `CX` `DX` `SI` `DI` `BP` `SP` `R8` to `R15` | bare names, no prefix |
+| Sub-registers | `AL` `CL` `DL` `BL` `AH` family; `R8B` `R8W` `R8D` for the byte, word and double word of `R8` | width rides the mnemonic as well |
+| Vector | `X0` to `X15` (128-bit), `Y0` to `Y15` (256-bit), `Z0` to `Z31` (512-bit) | SSE, AVX and AVX-512 |
+| Mask | `K0` to `K7` | AVX-512 opmask |
+| System | `TLS` | the thread pointer, see below |
+
+Roles the calling convention fixes, which assembly must respect and can rely
+on:
+
+- `SP` is the hardware stack pointer; the virtual frame pointer of the
+  common language is the pseudo-register SP of OPERANDS.md, a different
+  spelling with a different meaning.
+- `BP` is callee-save. The assembler inserts the save and restore whenever
+  the function has a non-zero frame, so using BP as a general register
+  interferes with sampling profilers that walk the frame chain.
+- `R14` holds `g`, the goroutine pointer, in the register ABI; `RDX` holds
+  the closure context; `R12` and `R13` are the register ABI's scratch pair
+  and `R15` its GOT temporary; `X15` is the zeroing register the compiler
+  uses. An ABI0 assembly function called from Go sees none of these live
+  across the call, but runtime assembly reads them directly.
+- The legacy spellings for the goroutine pointer are the macros of
+  `runtime/go_tls.h`: `get_tls(r)` expands to `MOVQ TLS, r` and `g(r)` to
+  `0(r)(TLS*1)`, the segment base riding the index field.
+
+## Addressing
+
+The common forms of OPERANDS.md, with the amd64 specifics:
+
+```text
+offset(base)               MOVQ 16(BX), AX
+offset(base)(index*scale)  MOVL foo+32(SP)(R9*8), CX
+scale is 1, 2, 4 or 8
+name±offset(SB)            MOVQ ·table(SB), CX
+```
+
+- Global references assemble as absolute addresses and produce R_ADDR
+  relocations; branch targets produce R_PCREL.
+- Vector indexed memory, the VSIB form with an X, Y or Z register in the
+  index position, exists for the gather and scatter families.
+- There are no segment overrides in source; the one segment-flavoured form
+  is the TLS base in the index field shown above.
+
+## The frame and the split check
+
+The assembler manages the frame, not the programmer:
+
+- It inserts the `BP` save and restore for any non-zero frame.
+- It inserts the stack-split check for any function that is not NoSplit:
+  the check compares SP against the guard, and on exhaustion calls
+  `runtime.morestack_noctxt`. Frames at or below 128 bytes, StackSmall, use
+  the small compare; frames at or below 4096 bytes, StackBig, use the
+  adjusted form; larger frames compare in two steps.
+- On amd64 the assembler marks a function NoSplit itself when the frame is
+  under StackSmall and the body calls nothing that needs stack: such a
+  function carries the NoSplit flag in the object without the source ever
+  writing NOSPLIT.
+
+Results and arguments are stack-only in ABI0: the caller's frame carries
+them at FP offsets, per the Go prototype.
+
+## Instructions
+
+The inventory counts 1654 recognised mnemonics today, of which the encoder
+emits 1113; both numbers are generated in the appendix, and the gap is the
+encoder backlog that `gasm audit-instructions` measures. The families:
+
+- **Integer base.** The ALU and move set with width suffixes, `MOVB`,
+  `MOVW`, `MOVL`, `MOVQ`; the extension moves `MOVBLZX`, `MOVWLSX`,
+  `MOVLQSX` and their siblings, which the compiler's output leans on;
+  `LEA`; `PUSH` and `POP`; the shifts and rotates; the bit operations `BT`
+  through `BTC`, `BSF`, `BSR`, `LZCNT`, `TZCNT`, `POPCNT`, `BSWAP`; the
+  string primitives `MOVS` and `STOS`.
+- **Exchange and atomics.** `XCHG`, `CMPXCHG`, `XADD`; the extended-carry
+  pair `ADCX` and `ADOX`; `CRC32`.
+- **Scalar floating point.** The SSE2 scalar moves and arithmetic
+  (`MOVSD`, `MOVSS`, `ADDSD`, and the `CVT` family). Floating-point
+  immediates are not encodable on this target, so the assembler
+  materialises them: the constant lands in a synthesised read-only pool,
+  and a positive zero collapses to `XORPS` of the register with itself,
+  exactly as the toolchain does.
+- **Legacy SIMD, SSE.** The `MOVO`, `MOVOU`, `MOVAPS` family and the packed
+  integer and floating operations, shuffles, lane extracts and inserts and
+  the imm8-controlled forms.
+- **VEX and EVEX.** The `V`-prefixed forms for 256 and 512-bit work,
+  opmask operations on `K0` to `K7`, gathers and scatters, and the
+  quad-register families 4FMAPS, 4FNMADD, 4VNNIW, VP4DPWSSD and VP4DPWSSDS,
+  whose register list rides the inverted V′VVV field. Mixing VEX and legacy
+  SSE in one loop pays the AVX-SSE transition penalty on every switch: keep
+  a loop in one dialect.
+- **Cryptographic and counting extensions.** AES-NI, SHA-1 and SHA-256,
+  PCLMULQDQ, GFNI.
+- **System.** `CPUID`, `RDTSC`, `SYSCALL`, the fences, `LDMXCSR` and
+  `STMXCSR`, the prefetch family.
+- **Pseudo-operations.** `BYTE`, `WORD`, `LONG`, `QUAD` lay raw bytes or
+  words into the stream for encodings the assembler does not know; `ADJSP`
+  adjusts the stack pointer; `DUFFCOPY` and `DUFFZERO` and `GETCALLERPC`
+  are compiler-side names the table recognises but an encoder need not
+  emit.
+
+A mnemonic the appendix lists with `gasm encodes: no` assembles nowhere:
+gasm reports it as an explicit error, never as wrong bytes, and the
+`unencodable-instruction` lint flags it at edit time.
+
+## Relocations
+
+The relocations an amd64 object carries, all specified in
+[GOOBJ.md](../GOOBJ.md): `R_ADDR` for absolute globals, `R_PCREL` for
+relative addresses, `R_CALL` for direct calls, `R_TLS_LE` and `R_TLS_IE` for
+thread local access and `R_GOTPCREL` for GOT relative sequences, plus
+`R_DWTXTADDR_U4` inside the DWARF records, which the assembler always
+emits in the four-byte flavour.

docs/asm/ARM64.md

@@ -0,0 +1,122 @@
+# ARM64
+
+Layer 1, target page. Verified against `go tool asm` of Go 1.27.1, against the
+toolchain's own arm64 assembler manual (`cmd/internal/obj/arm64/doc.go`) and
+against gasm's encoder, whose output is compared byte for byte with the
+toolchain's. The complete mnemonic inventory lives in the generated appendix
+[INSTRUCTIONS-ARM64.md](INSTRUCTIONS-ARM64.md).
+
+## Registers
+
+- General purpose: `R0` to `R30`, plus `ZR`, the zero register, and `RSP`,
+  the stack pointer. There is no R31: thirty-one names and ZR.
+- Floating-point and SIMD share one file written `Vn`; where an instruction
+  is scalar floating point the operand may be written `Fn` (`F0` to `F31`).
+- SVE register names (`Z0` to `Z31`, `P0` to `P15`) exist in the assembler's
+  tables.
+- Roles the convention fixes: `RSP` is the stack pointer, `R29` the frame
+  pointer, `R30` the link register, `R26` the closure context and `R27` the
+  assembler's scratch register. The goroutine pointer lives in `R28` and is
+  written `g` in source, its fields as `g_m(g)`, `g_sched(g)`; `R18` is the
+  platform-reserved register and the Go toolchain never addresses it.
+
+## Loads, stores and the width suffixes
+
+The MOV series is the load and store interface, with the width in the
+mnemonic rather than the register name:
+
+| Mnemonic | Machine instruction |
+|---|---|
+| `MOVD` | ldr, str, stur, 64-bit |
+| `MOVW` | ldrsw, str, stur, 32-bit sign extending |
+| `MOVWU` | ldr, 32-bit zero extending |
+| `MOVH` | ldrsh, strh, sturh |
+| `MOVHU` | ldrh |
+| `MOVB` | ldrsb, strb, sturb |
+| `MOVBU` | ldrb |
+
+Post-index and pre-index addressing take the `.P` and `.W` suffixes on the
+mnemonic: `MOVD.P -8(R10), R8` is `ldr x8, [x10],#-8`, and `MOVB.W
+16(R16), R10` is `ldrsb x10, [x16,#16]!`.
+
+## Addressing
+
+```text
+imm(Rn|RSP)            28(R17)
+(Rn|RSP)               (R22)
+(Rn)(Rm)               (R27)(R23)
+(Rn)(Rm<<scale)        (R4)(R12<<2)
+(Rn)(Rm.UXTW<<3)       extended and shifted index
+(Rt1, Rt2)             register pair for LDP, STP and the exclusive pair forms
+```
+
+Branch targets are labels, `(R3)` for indirect, `name(SB)` for static.
+
+## Operand order and the special forms
+
+Most instructions appear in left-to-right assignment order: `ADD R11,
+RSP, R25` computes into R25. The exceptions the toolchain's manual lists,
+each with its own order:
+
+- stores and `CBZ`, `CBNZ` keep the GNU order: `MOVD R29, 384(R19)`.
+- The multiply-accumulate family `MADD`, `MSUB`, `SMADDL` and friends are
+  `<Rm>, <Ra>, <Rn>, <Rd>`.
+- The scalar FMA family `FMADDD` and friends are `<Fm>, <Fa>, <Fn>, <Fd>`.
+- The bitfield family `BFI`, `BFXIL`, `SBFIZ`, `SBFX`, `UBFIZ`, `UBFX` is
+  `$<lsb>, <Rn>, $<width>, <Rd>`.
+- The conditional compare and select families carry the condition as the
+  **first** operand: `CSEL GT, R0, R19, R1`, `CCMP MI, R22, $12, $13`,
+  `FCCMPD AL, F8, F26, $0`.
+- The exclusive stores are `<Rf>, (<Rn>), <Rs>` with the status register
+  last: `STLXR ZR, (R15), R16`.
+- `TBZ` and `TBNZ` are `$<imm>, <Rt>, <label>`.
+
+Shifted and extended register operands ride the register: `R19>>30`,
+`R26->24` for arithmetic right shift, `@>` for rotate, and the extend forms
+`R19.UXTB<<4`, `R14.SXTX` with extend operators UXTB, UXTH, UXTW, UXTX,
+SXTB, SXTH, SXTW, SXTX.
+
+## Conditions, branches and names
+
+- Conditions ride the branch mnemonic: `B.EQ`, or the canonical
+  per-condition names such as `BEQ`. Both spellings exist; the canonical
+  names are what the generated inventory lists.
+- `br` is `JMP` and `blr` is `CALL` in this dialect; indirect branches are
+  `JMP (R3)` and `CALL (R17)`.
+- `NOP` is a zero-width pseudo-instruction; the hardware nop is `NOOP`,
+  an alias of `HINT $0`.
+- `umov` is written as `VMOV`.
+
+## Constants
+
+- A 16-bit immediate optionally shifted: `MOVK $(10<<32), R20`, with
+  `MOVZ`, `MOVN` and their W variants; a zero shift is rejected by the
+  assembler.
+- Large integer constants: `MOV` materialises any 64-bit constant, the
+  closest-instruction way.
+- Vector constants: `VMOVS`, `VMOVD` and `VMOVQ`, the last taking two
+  64-bit halves for a 128-bit value:
+  `VMOVQ $0x1122334455667788, $0x99aabbccddeeff00, V2`.
+
+## SIMD
+
+Floating-point and SIMD instructions mostly carry a `V` prefix
+(`VADD`, `VFMLA`), the cryptographic extensions (`AESD`, `SHA256H`) and the
+scalar floating-point instructions being the exceptions. Operands carry an
+arrangement suffix, `V5.H8`, and structure loads and stores use bracket
+lists, `[V21.B16]`, with element selection as `V9.S[1]`.
+
+## Alignment
+
+`PCALIGN $n` pads to a power-of-two boundary between 8 and 2048 and also
+raises the function's alignment to the coarsest boundary any of its PCALIGN
+directives asks for. Functions default to 16-byte alignment on this target.
+
+## Relocations
+
+`R_ADDRARM64` for the adrp-plus-add pair, `R_ARM64_PCREL` and the
+`R_ARM64_PCREL_LDST` family for PC relative addressing, `R_ARM64_LDST` for
+the load and store immediates, `R_ARM64_GOTPCREL` and `R_ARM64_GOT` for the
+GOT, `R_ARM64_TLS_LE` and `R_ARM64_TLS_IE` for thread local storage and
+`R_CALLARM64` for direct calls, all specified in
+[GOOBJ.md](../GOOBJ.md).

docs/asm/DIRECTIVES.md

@@ -0,0 +1,148 @@
+# Directives: TEXT, DATA, GLOBL and the annotations
+
+Layer 1, the common language, with the flag vocabulary both layers share.
+Verified against `go tool asm` of Go 1.27.1, against the shipped headers
+`textflag.h` and `funcdata.h` in `$GOROOT/pkg/include`, and against gasm's
+parser. Where gasm extends a directive, the extension says so and is marked.
+
+Six directives exist. Three define things: TEXT, DATA, GLOBL. Three
+annotate: FUNCDATA, PCDATA, PCALIGN.
+
+## TEXT
+
+```text
+// func Add(a, b int64) int64
+TEXT ·Add(SB), NOSPLIT, $0-24
+	...instructions...
+	RET
+```
+
+```text
+TEXT symbol(SB), [flags,] $framesize[-argsize]
+```
+
+- The symbol is an `·Name(SB)` reference into the current package, or a
+  fully qualified name.
+- The optional flag argument is a constant expression, normally an OR of the
+  names from `textflag.h`, the table below. Without `#include "textflag.h"`
+  the names are not macros and the assembler reports the misleading error
+  `illegal or missing addressing mode for symbol NOSPLIT`: include the
+  header first.
+- `$framesize-argsize` is two constants, not a subtraction: the local frame
+  size in bytes, and the caller's argument area in bytes. The argument size
+  may be omitted entirely, `$16`, which marks the argument size unknown
+  (0x80000000 in the object, the value of `ArgsSizeUnknown` from
+  `funcdata.h`); a frame size may be negative only in the generated ABI
+  wrappers.
+- A function whose last instruction is not a branch cannot fall through into
+  the next TEXT: the toolchain appends a jump to itself, so end functions
+  with `RET` deliberately.
+- One TEXT per symbol; redeclaring is an error. The TEXT line also fixes the
+  function's source line for traceback: it is the line number that pcln
+  reports for the function's start.
+
+The framesize and argsize fields do real work: the framesize drives the
+stack-split preamble (RUNTIME.md carries the contract), and both travel into
+the FuncInfo record of the object (GOOBJ.md carries its layout).
+
+### The flag table
+
+Values from `textflag.h`, in agreement with `cmd/internal/obj/textflag.go`:
+
+| Name | Value | Applies to | Meaning |
+|---|---|---|---|
+| NOPROF | 1 | both | do not profile; deprecated |
+| DUPOK | 2 | both | the linker may keep one of several duplicates |
+| NOSPLIT | 4 | TEXT | no stack-split preamble |
+| RODATA | 8 | data | put the data in a read-only section |
+| NOPTR | 16 | data | the data contains no pointers |
+| WRAPPER | 32 | TEXT | a wrapper; must not disable `recover` |
+| NEEDCTXT | 64 | TEXT | a closure consuming the context register |
+| TLSBSS | 256 | data | a thread local word in BSS |
+| NOFRAME | 512 | TEXT | no frame setup; only valid with a frame size of 0 |
+| REFLECTMETHOD | 1024 | TEXT | the function calls `reflect.Type.Method` or `MethodByName` |
+| TOPFRAME | 2048 | TEXT | the outermost frame; unwinders stop here |
+| ABIWRAPPER | 4096 | TEXT | an ABI transition wrapper |
+
+Rules with teeth:
+
+- `NOSPLIT` removes the split check, so the frame plus everything the
+  function calls must fit in the stack segment that remains. It exists to
+  protect the splitting code itself; reaching for it to save two instructions
+  is how stack overflows corrupt memory. On amd64 the assembler additionally
+  marks small leaf functions NoSplit itself and omits the check, so the
+  absence of the preamble is not proof the flag was written.
+- A TEXT whose symbol is declared `ABIInternal` must carry NOSPLIT: the
+  assembler rejects it otherwise, because it cannot generate
+  the split path for a register-ABI function.
+- `RODATA` implies NOPTR for the garbage collector.
+
+## DATA
+
+```text
+DATA ·table+0(SB)/8, $0x0102030405060708
+DATA ·msg+0(SB)/14, $"hello, world\n"
+GLOBL ·msg(SB), RODATA, $14
+```
+
+```text
+DATA symbol+offset(SB)/width, value
+```
+
+- `width` is exactly 1, 2, 4 or 8: the initialiser is written into the data
+  image at `symbol+offset` in that many bytes.
+- The value is an integer or character constant of the width, or a string
+  literal whose byte length equals the width exactly; escapes count. Long
+  data is written as successive DATA lines at increasing offsets; bytes the
+  directives never name are zero.
+- Every symbol initialised with DATA ends with a GLOBL line declaring its
+  total size, after all of its DATA lines.
+
+A symbol containing pointers cannot be defined in assembly, because the
+collector cannot see into it: define it in Go and refer to it by name. As a
+rule, data that is not read-only belongs in Go.
+
+Extension, gasm only: a DATA initialiser may name a symbol,
+`DATA ·fn+0(SB)/8, $·handler(SB)`, which gasm lays down as an absolute
+relocation on that field. The toolchain offers no ground truth for this
+form; gasm's behaviour is verified by linking and execution.
+
+## GLOBL
+
+```text
+GLOBL symbol(SB), [flags,] $size
+```
+
+Declares the symbol global with its total size in bytes. The useful flags
+are RODATA, NOPTR, DUPOK and TLSBSS from the table above. Uninitialised
+bytes are zero, which makes GLOBL with no DATA the language's BSS.
+
+## FUNCDATA and PCDATA
+
+```text
+FUNCDATA $functypeid, symbol(SB)
+PCDATA $pctypeid, $value
+```
+
+The compiler's annotations for the garbage collector and traceback, named by
+the ids in `funcdata.h`: FUNCDATA 0 to 7 (args pointer maps, locals pointer
+maps, stack objects, inline tree, open-coded defer info, argument info,
+argument liveness, wrap info), PCDATA 0 to 4 (unsafe point, stack map index,
+inline tree index, argument liveness index, panic bounds). Assembly code
+normally reaches them only through the macro forms in `funcdata.h`, which
+RUNTIME.md explains. Outside the macros, hand-written PCDATA is meaningless:
+the values are pc-value tables the compiler builds from its own view of the
+program.
+
+## PCALIGN
+
+```text
+PCALIGN $32
+```
+
+Pads the code so that the next instruction lands on the given boundary,
+which must be a power of two and at least the target's instruction
+alignment. Supported on amd64, arm64, ppc64, loong64 and riscv64. The
+padding instructions are the target's NOP encoding, so the bytes between
+functions differ from what the instruction stream alone would produce, which
+matters to anyone comparing encodings byte for byte.

docs/asm/INSTRUCTIONS-ARM64.md

@@ -0,0 +1,570 @@
+# ARM64: instruction inventory
+
+Generated by gasm-devkit's `_gen` from the Go toolchain's instruction table
+(`cmd/internal/obj/arm64/anames.go`, go1.27.1); DO NOT EDIT. This page lists every mnemonic
+`go tool asm` accepts on this target, which is the upper bound of the
+language on it: a name absent here is not an instruction of the target,
+and a name present here may still be one gasm's encoder cannot emit yet.
+
+The inventory carries no per-mnemonic encoder column: on this target
+encodability is decided per operand shape, and the live measured
+coverage is reported by `gasm audit-instructions`.
+
+| Mnemonic | Notes |
+|---|---|
+| `CALL` |  |
+| `DUFFCOPY` |  |
+| `DUFFZERO` |  |
+| `END` |  |
+| `FUNCDATA` |  |
+| `GETCALLERPC` |  |
+| `JMP` |  |
+| `NOP` | No operation |
+| `PCALIGN` |  |
+| `PCALIGNMAX` |  |
+| `PCDATA` |  |
+| `RET` | Return |
+| `TEXT` |  |
+| `UNDEF` |  |
+| `ADC` | ADC (64-bit) |
+| `ADCS` | ADCS (64-bit) |
+| `ADCSW` | ADCS (32-bit) |
+| `ADCW` | ADC (32-bit) |
+| `ADD` | ADD (64-bit) |
+| `ADDS` | ADDS (64-bit) |
+| `ADDSW` | ADDS (32-bit) |
+| `ADDW` | ADD (32-bit) |
+| `ADR` | Address of label/page |
+| `ADRP` | Address of label/page |
+| `AESD` | AES round |
+| `AESE` | AES round |
+| `AESIMC` | AES round |
+| `AESMC` | AES round |
+| `AND` | AND (64-bit) |
+| `ANDS` | ANDS (64-bit) |
+| `ANDSW` | ANDS (32-bit) |
+| `ANDW` | AND (32-bit) |
+| `ASR` | ASR shift |
+| `ASRW` | ASR shift (32-bit) |
+| `AT` |  |
+| `AUTIA1716` |  |
+| `AUTIASP` |  |
+| `AUTIB1716` |  |
+| `AUTIBSP` |  |
+| `BCC` | Conditional branch |
+| `BCS` | Conditional branch |
+| `BEQ` | Conditional branch |
+| `BFI` |  |
+| `BFIW` |  |
+| `BFM` |  |
+| `BFMW` |  |
+| `BFXIL` | Bitfield extract |
+| `BFXILW` |  |
+| `BGE` | Conditional branch |
+| `BGT` | Conditional branch |
+| `BHI` | Conditional branch |
+| `BHS` | Conditional branch |
+| `BIC` | BIC (64-bit) |
+| `BICS` | BICS (64-bit) |
+| `BICSW` | BICS (32-bit) |
+| `BICW` | BIC (32-bit) |
+| `BLE` | Conditional branch |
+| `BLO` | Conditional branch |
+| `BLS` | Conditional branch |
+| `BLT` | Conditional branch |
+| `BMI` | Conditional branch |
+| `BNE` | Conditional branch |
+| `BPL` | Conditional branch |
+| `BRK` | Breakpoint |
+| `BTI` |  |
+| `BVC` | Conditional branch |
+| `BVS` | Conditional branch |
+| `CASAD` |  |
+| `CASALB` |  |
+| `CASALD` |  |
+| `CASALH` |  |
+| `CASALW` |  |
+| `CASAW` |  |
+| `CASB` |  |
+| `CASD` |  |
+| `CASH` |  |
+| `CASLD` |  |
+| `CASLW` |  |
+| `CASPD` |  |
+| `CASPW` |  |
+| `CASW` |  |
+| `CBNZ` | Compare/test and branch |
+| `CBNZW` | Compare/test and branch (32-bit) |
+| `CBZ` | Compare/test and branch |
+| `CBZW` | Compare/test and branch (32-bit) |
+| `CCMN` | Conditional compare |
+| `CCMNW` | Conditional compare |
+| `CCMP` | Conditional compare |
+| `CCMPW` | Conditional compare |
+| `CINC` | Conditional select |
+| `CINCW` | Conditional select (32-bit) |
+| `CINV` | Conditional select |
+| `CINVW` | Conditional select (32-bit) |
+| `CLREX` |  |
+| `CLS` | Bit manipulation |
+| `CLSW` | Bit manipulation |
+| `CLZ` | Bit manipulation |
+| `CLZW` | Bit manipulation |
+| `CMN` | CMN (64-bit) |
+| `CMNW` | CMN (32-bit) |
+| `CMP` | CMP (64-bit) |
+| `CMPW` | CMP (32-bit) |
+| `CNEG` | Conditional select |
+| `CNEGW` | Conditional select (32-bit) |
+| `CRC32B` |  |
+| `CRC32CB` |  |
+| `CRC32CH` |  |
+| `CRC32CW` |  |
+| `CRC32CX` |  |
+| `CRC32H` |  |
+| `CRC32W` |  |
+| `CRC32X` |  |
+| `CSEL` | Conditional select |
+| `CSELW` | Conditional select (32-bit) |
+| `CSET` | Conditional select |
+| `CSETM` | Conditional select |
+| `CSETMW` | Conditional select (32-bit) |
+| `CSETW` | Conditional select (32-bit) |
+| `CSINC` | Conditional select |
+| `CSINCW` | Conditional select (32-bit) |
+| `CSINV` | Conditional select |
+| `CSINVW` | Conditional select (32-bit) |
+| `CSNEG` | Conditional select |
+| `CSNEGW` | Conditional select (32-bit) |
+| `DC` | Data cache maintenance |
+| `DCPS1` |  |
+| `DCPS2` |  |
+| `DCPS3` |  |
+| `DMB` | Barrier |
+| `DRPS` |  |
+| `DSB` | Barrier |
+| `DWORD` |  |
+| `EON` | EON (64-bit) |
+| `EONW` | EON (32-bit) |
+| `EOR` | EOR (64-bit) |
+| `EORW` | EOR (32-bit) |
+| `ERET` |  |
+| `EXTR` | Bitfield extract |
+| `EXTRW` |  |
+| `FABSD` |  |
+| `FABSS` |  |
+| `FADDD` |  |
+| `FADDS` |  |
+| `FCCMPD` |  |
+| `FCCMPED` |  |
+| `FCCMPES` |  |
+| `FCCMPS` |  |
+| `FCMPD` |  |
+| `FCMPED` |  |
+| `FCMPES` |  |
+| `FCMPS` |  |
+| `FCSELD` |  |
+| `FCSELS` |  |
+| `FCVTDH` |  |
+| `FCVTDS` |  |
+| `FCVTHD` |  |
+| `FCVTHS` |  |
+| `FCVTSD` |  |
+| `FCVTSH` |  |
+| `FCVTZSD` |  |
+| `FCVTZSDW` |  |
+| `FCVTZSS` |  |
+| `FCVTZSSW` |  |
+| `FCVTZUD` |  |
+| `FCVTZUDW` |  |
+| `FCVTZUS` |  |
+| `FCVTZUSW` |  |
+| `FDIVD` |  |
+| `FDIVS` |  |
+| `FLDPD` | Register-pair load or store |
+| `FLDPQ` |  |
+| `FLDPS` |  |
+| `FMADDD` |  |
+| `FMADDS` |  |
+| `FMAXD` |  |
+| `FMAXNMD` |  |
+| `FMAXNMS` |  |
+| `FMAXS` |  |
+| `FMIND` |  |
+| `FMINNMD` |  |
+| `FMINNMS` |  |
+| `FMINS` |  |
+| `FMOVD` | Move / load / store |
+| `FMOVQ` |  |
+| `FMOVS` | Move / load / store |
+| `FMSUBD` |  |
+| `FMSUBS` |  |
+| `FMULD` |  |
+| `FMULS` |  |
+| `FNEGD` |  |
+| `FNEGS` |  |
+| `FNMADDD` |  |
+| `FNMADDS` |  |
+| `FNMSUBD` |  |
+| `FNMSUBS` |  |
+| `FNMULD` |  |
+| `FNMULS` |  |
+| `FRINTAD` |  |
+| `FRINTAS` |  |
+| `FRINTID` |  |
+| `FRINTIS` |  |
+| `FRINTMD` |  |
+| `FRINTMS` |  |
+| `FRINTND` |  |
+| `FRINTNS` |  |
+| `FRINTPD` |  |
+| `FRINTPS` |  |
+| `FRINTXD` |  |
+| `FRINTXS` |  |
+| `FRINTZD` |  |
+| `FRINTZS` |  |
+| `FSQRTD` |  |
+| `FSQRTS` |  |
+| `FSTPD` | Register-pair load or store |
+| `FSTPQ` |  |
+| `FSTPS` |  |
+| `FSUBD` |  |
+| `FSUBS` |  |
+| `HINT` |  |
+| `HLT` |  |
+| `HVC` | Exception generation |
+| `IC` |  |
+| `ISB` | Barrier |
+| `LDADDAB` |  |
+| `LDADDAD` |  |
+| `LDADDAH` |  |
+| `LDADDALB` |  |
+| `LDADDALD` |  |
+| `LDADDALH` |  |
+| `LDADDALW` |  |
+| `LDADDAW` |  |
+| `LDADDB` |  |
+| `LDADDD` |  |
+| `LDADDH` |  |
+| `LDADDLB` |  |
+| `LDADDLD` |  |
+| `LDADDLH` |  |
+| `LDADDLW` |  |
+| `LDADDW` |  |
+| `LDAR` | Atomic memory operation |
+| `LDARB` | Atomic memory operation |
+| `LDARH` | Atomic memory operation |
+| `LDARW` | Atomic memory operation |
+| `LDAXP` |  |
+| `LDAXPW` |  |
+| `LDAXR` | Atomic memory operation |
+| `LDAXRB` | Atomic memory operation |
+| `LDAXRH` | Atomic memory operation |
+| `LDAXRW` | Atomic memory operation |
+| `LDCLRAB` |  |
+| `LDCLRAD` |  |
+| `LDCLRAH` |  |
+| `LDCLRALB` |  |
+| `LDCLRALD` |  |
+| `LDCLRALH` |  |
+| `LDCLRALW` |  |
+| `LDCLRAW` |  |
+| `LDCLRB` |  |
+| `LDCLRD` |  |
+| `LDCLRH` |  |
+| `LDCLRLB` |  |
+| `LDCLRLD` |  |
+| `LDCLRLH` |  |
+| `LDCLRLW` |  |
+| `LDCLRW` |  |
+| `LDEORAB` |  |
+| `LDEORAD` |  |
+| `LDEORAH` |  |
+| `LDEORALB` |  |
+| `LDEORALD` |  |
+| `LDEORALH` |  |
+| `LDEORALW` |  |
+| `LDEORAW` |  |
+| `LDEORB` |  |
+| `LDEORD` |  |
+| `LDEORH` |  |
+| `LDEORLB` |  |
+| `LDEORLD` |  |
+| `LDEORLH` |  |
+| `LDEORLW` |  |
+| `LDEORW` |  |
+| `LDORAB` |  |
+| `LDORAD` |  |
+| `LDORAH` |  |
+| `LDORALB` |  |
+| `LDORALD` |  |
+| `LDORALH` |  |
+| `LDORALW` |  |
+| `LDORAW` |  |
+| `LDORB` |  |
+| `LDORD` |  |
+| `LDORH` |  |
+| `LDORLB` |  |
+| `LDORLD` |  |
+| `LDORLH` |  |
+| `LDORLW` |  |
+| `LDORW` |  |
+| `LDP` | Register-pair load or store |
+| `LDPSW` |  |
+| `LDPW` | Register-pair load or store |
+| `LDXP` |  |
+| `LDXPW` |  |
+| `LDXR` |  |
+| `LDXRB` |  |
+| `LDXRH` |  |
+| `LDXRW` |  |
+| `LSL` | LSL shift |
+| `LSLW` | LSL shift (32-bit) |
+| `LSR` | LSR shift |
+| `LSRW` | LSR shift (32-bit) |
+| `MADD` | Multiply / multiply-accumulate |
+| `MADDW` |  |
+| `MNEG` | Multiply / multiply-accumulate |
+| `MNEGW` |  |
+| `MOVB` | Move / load / store |
+| `MOVBU` | Move / load / store |
+| `MOVD` | Move / load / store |
+| `MOVH` | Move / load / store |
+| `MOVHU` | Move / load / store |
+| `MOVK` | Move wide constant |
+| `MOVKW` | Move wide constant |
+| `MOVN` | Move wide constant |
+| `MOVNW` | Move wide constant |
+| `MOVP` |  |
+| `MOVPD` |  |
+| `MOVPQ` |  |
+| `MOVPS` |  |
+| `MOVPSW` |  |
+| `MOVPW` |  |
+| `MOVW` | Move / load / store |
+| `MOVWU` | Move / load / store |
+| `MOVZ` | Move wide constant |
+| `MOVZW` | Move wide constant |
+| `MRS` | System register access |
+| `MSR` | System register access |
+| `MSUB` | Multiply / multiply-accumulate |
+| `MSUBW` |  |
+| `MUL` | Multiply / multiply-accumulate |
+| `MULW` |  |
+| `MVN` | MVN (64-bit) |
+| `MVNW` | MVN (32-bit) |
+| `NEG` | NEG (64-bit) |
+| `NEGS` |  |
+| `NEGSW` |  |
+| `NEGW` | NEG (32-bit) |
+| `NGC` | NGC (64-bit) |
+| `NGCS` |  |
+| `NGCSW` |  |
+| `NGCW` | NGC (32-bit) |
+| `NOOP` |  |
+| `ORN` | ORN (64-bit) |
+| `ORNW` | ORN (32-bit) |
+| `ORR` | ORR (64-bit) |
+| `ORRW` | ORR (32-bit) |
+| `PACIASP` |  |
+| `PACIBSP` |  |
+| `PRFM` | Memory prefetch |
+| `PRFUM` |  |
+| `RBIT` | Bit manipulation |
+| `RBITW` | Bit manipulation |
+| `REM` |  |
+| `REMW` |  |
+| `REV` | Bit manipulation |
+| `REV16` | Bit manipulation |
+| `REV16W` |  |
+| `REV32` | Bit manipulation |
+| `REVW` | Bit manipulation |
+| `ROR` | ROR shift |
+| `RORW` | ROR shift (32-bit) |
+| `SBC` | SBC (64-bit) |
+| `SBCS` | SBCS (64-bit) |
+| `SBCSW` | SBCS (32-bit) |
+| `SBCW` | SBC (32-bit) |
+| `SBFIZ` |  |
+| `SBFIZW` |  |
+| `SBFM` | Bitfield extract |
+| `SBFMW` |  |
+| `SBFX` | Bitfield extract |
+| `SBFXW` |  |
+| `SCVTFD` |  |
+| `SCVTFS` |  |
+| `SCVTFWD` |  |
+| `SCVTFWS` |  |
+| `SDIV` | Divide |
+| `SDIVW` | Divide |
+| `SEV` |  |
+| `SEVL` |  |
+| `SHA1C` | SHA round |
+| `SHA1H` | SHA round |
+| `SHA1M` | SHA round |
+| `SHA1P` | SHA round |
+| `SHA1SU0` | SHA round |
+| `SHA1SU1` | SHA round |
+| `SHA256H` | SHA round |
+| `SHA256H2` | SHA round |
+| `SHA256SU0` | SHA round |
+| `SHA256SU1` | SHA round |
+| `SHA512H` | SHA round |
+| `SHA512H2` | SHA round |
+| `SHA512SU0` | SHA round |
+| `SHA512SU1` | SHA round |
+| `SMADDL` | Multiply / multiply-accumulate |
+| `SMC` | Exception generation |
+| `SMNEGL` |  |
+| `SMSUBL` | Multiply / multiply-accumulate |
+| `SMULH` | Multiply / multiply-accumulate |
+| `SMULL` | Multiply / multiply-accumulate |
+| `STLR` | Atomic memory operation |
+| `STLRB` | Atomic memory operation |
+| `STLRH` | Atomic memory operation |
+| `STLRW` | Atomic memory operation |
+| `STLXP` |  |
+| `STLXPW` |  |
+| `STLXR` |  |
+| `STLXRB` |  |
+| `STLXRH` |  |
+| `STLXRW` |  |
+| `STP` | Register-pair load or store |
+| `STPW` | Register-pair load or store |
+| `STXP` |  |
+| `STXPW` |  |
+| `STXR` | Atomic memory operation |
+| `STXRB` | Atomic memory operation |
+| `STXRH` | Atomic memory operation |
+| `STXRW` | Atomic memory operation |
+| `SUB` | SUB (64-bit) |
+| `SUBS` | SUBS (64-bit) |
+| `SUBSW` | SUBS (32-bit) |
+| `SUBW` | SUB (32-bit) |
+| `SVC` | Exception generation |
+| `SWPAB` |  |
+| `SWPAD` |  |
+| `SWPAH` |  |
+| `SWPALB` |  |
+| `SWPALD` |  |
+| `SWPALH` |  |
+| `SWPALW` |  |
+| `SWPAW` |  |
+| `SWPB` |  |
+| `SWPD` |  |
+| `SWPH` |  |
+| `SWPLB` |  |
+| `SWPLD` |  |
+| `SWPLH` |  |
+| `SWPLW` |  |
+| `SWPW` |  |
+| `SXTB` |  |
+| `SXTBW` |  |
+| `SXTH` |  |
+| `SXTHW` |  |
+| `SXTW` |  |
+| `SYS` |  |
+| `SYSL` |  |
+| `TBNZ` | Compare/test and branch |
+| `TBZ` | Compare/test and branch |
+| `TLBI` |  |
+| `TST` | TST (64-bit) |
+| `TSTW` | TST (32-bit) |
+| `UBFIZ` |  |
+| `UBFIZW` |  |
+| `UBFM` | Bitfield extract |
+| `UBFMW` |  |
+| `UBFX` | Bitfield extract |
+| `UBFXW` |  |
+| `UCVTFD` |  |
+| `UCVTFS` |  |
+| `UCVTFWD` |  |
+| `UCVTFWS` |  |
+| `UDIV` | Divide |
+| `UDIVW` | Divide |
+| `UMADDL` | Multiply / multiply-accumulate |
+| `UMNEGL` |  |
+| `UMSUBL` | Multiply / multiply-accumulate |
+| `UMULH` | Multiply / multiply-accumulate |
+| `UMULL` | Multiply / multiply-accumulate |
+| `UREM` |  |
+| `UREMW` |  |
+| `UXTB` |  |
+| `UXTBW` |  |
+| `UXTH` |  |
+| `UXTHW` |  |
+| `UXTW` |  |
+| `VADD` | NEON SIMD vector operation |
+| `VADDP` |  |
+| `VADDV` | NEON SIMD vector operation |
+| `VAND` | NEON SIMD vector operation |
+| `VBCAX` | Three-way XOR / rotate crypto vector operation |
+| `VBIF` | NEON SIMD vector operation |
+| `VBIT` |  |
+| `VBSL` | NEON SIMD vector operation |
+| `VCMEQ` |  |
+| `VCMTST` |  |
+| `VCNT` | NEON SIMD vector operation |
+| `VDUP` | NEON SIMD vector operation |
+| `VEOR` | NEON SIMD vector operation |
+| `VEOR3` | Three-way XOR / rotate crypto vector operation |
+| `VEXT` | NEON SIMD vector operation |
+| `VFMLA` | NEON SIMD vector operation |
+| `VFMLS` | NEON SIMD vector operation |
+| `VLD1` | NEON SIMD vector operation |
+| `VLD1R` |  |
+| `VLD2` | NEON SIMD vector operation |
+| `VLD2R` |  |
+| `VLD3` | NEON SIMD vector operation |
+| `VLD3R` |  |
+| `VLD4` | NEON SIMD vector operation |
+| `VLD4R` |  |
+| `VMOV` | NEON SIMD vector operation |
+| `VMOVD` |  |
+| `VMOVI` | NEON SIMD vector operation |
+| `VMOVQ` | NEON SIMD vector operation |
+| `VMOVS` |  |
+| `VORR` | NEON SIMD vector operation |
+| `VPMULL` |  |
+| `VPMULL2` |  |
+| `VRAX1` | Three-way XOR / rotate crypto vector operation |
+| `VRBIT` |  |
+| `VREV16` | NEON SIMD vector operation |
+| `VREV32` | NEON SIMD vector operation |
+| `VREV64` | NEON SIMD vector operation |
+| `VSHL` | NEON SIMD vector operation |
+| `VSLI` |  |
+| `VSRI` |  |
+| `VST1` | NEON SIMD vector operation |
+| `VST2` | NEON SIMD vector operation |
+| `VST3` | NEON SIMD vector operation |
+| `VST4` | NEON SIMD vector operation |
+| `VSUB` | NEON SIMD vector operation |
+| `VTBL` | NEON SIMD vector operation |
+| `VTBX` | NEON SIMD vector operation |
+| `VTRN1` | NEON SIMD vector operation |
+| `VTRN2` | NEON SIMD vector operation |
+| `VUADDLV` |  |
+| `VUADDW` |  |
+| `VUADDW2` |  |
+| `VUMAX` |  |
+| `VUMIN` |  |
+| `VUSHLL` |  |
+| `VUSHLL2` |  |
+| `VUSHR` | NEON SIMD vector operation |
+| `VUSRA` |  |
+| `VUXTL` |  |
+| `VUXTL2` |  |
+| `VUZP1` | NEON SIMD vector operation |
+| `VUZP2` | NEON SIMD vector operation |
+| `VXAR` | Three-way XOR / rotate crypto vector operation |
+| `VZIP1` | NEON SIMD vector operation |
+| `VZIP2` | NEON SIMD vector operation |
+| `WFE` |  |
+| `WFI` |  |
+| `WORD` |  |
+| `YIELD` |  |
+| `B` | Unconditional branch |
+| `BL` | Branch with link |
+
+Recognised: 554 mnemonics.

docs/asm/INSTRUCTIONS-LOONG64.md

@@ -0,0 +1,830 @@
+# LoongArch 64: instruction inventory
+
+Generated by gasm-devkit's `_gen` from the Go toolchain's instruction table
+(`cmd/internal/obj/loong64/anames.go`, go1.27.1); DO NOT EDIT. This page lists every mnemonic
+`go tool asm` accepts on this target, which is the upper bound of the
+language on it: a name absent here is not an instruction of the target,
+and a name present here may still be one gasm's encoder cannot emit yet.
+
+The inventory carries no per-mnemonic encoder column: on this target
+encodability is decided per operand shape, and the live measured
+coverage is reported by `gasm audit-instructions`.
+
+| Mnemonic | Notes |
+|---|---|
+| `CALL` |  |
+| `DUFFCOPY` |  |
+| `DUFFZERO` |  |
+| `END` |  |
+| `FUNCDATA` |  |
+| `GETCALLERPC` |  |
+| `JMP` |  |
+| `NOP` | No operation |
+| `PCALIGN` |  |
+| `PCALIGNMAX` |  |
+| `PCDATA` |  |
+| `RET` | Return |
+| `TEXT` |  |
+| `UNDEF` |  |
+| `ABSD` |  |
+| `ABSF` |  |
+| `ADD` | Integer add (word) |
+| `ADDD` | Add doubleword |
+| `ADDF` |  |
+| `ADDV` |  |
+| `ADDV16` |  |
+| `ADDVU` |  |
+| `ADDW` | Add word |
+| `ALSLV` |  |
+| `ALSLW` |  |
+| `ALSLWU` |  |
+| `AMADDDBV` |  |
+| `AMADDDBW` |  |
+| `AMADDV` |  |
+| `AMADDW` |  |
+| `AMANDDBV` |  |
+| `AMANDDBW` |  |
+| `AMANDV` |  |
+| `AMANDW` |  |
+| `AMCASB` |  |
+| `AMCASDBB` |  |
+| `AMCASDBH` |  |
+| `AMCASDBV` |  |
+| `AMCASDBW` |  |
+| `AMCASH` |  |
+| `AMCASV` |  |
+| `AMCASW` |  |
+| `AMMAXDBV` |  |
+| `AMMAXDBVU` |  |
+| `AMMAXDBW` |  |
+| `AMMAXDBWU` |  |
+| `AMMAXV` |  |
+| `AMMAXVU` |  |
+| `AMMAXW` |  |
+| `AMMAXWU` |  |
+| `AMMINDBV` |  |
+| `AMMINDBVU` |  |
+| `AMMINDBW` |  |
+| `AMMINDBWU` |  |
+| `AMMINV` |  |
+| `AMMINVU` |  |
+| `AMMINW` |  |
+| `AMMINWU` |  |
+| `AMORDBV` |  |
+| `AMORDBW` |  |
+| `AMORV` |  |
+| `AMORW` |  |
+| `AMSWAPB` |  |
+| `AMSWAPDBB` |  |
+| `AMSWAPDBH` |  |
+| `AMSWAPDBV` |  |
+| `AMSWAPDBW` |  |
+| `AMSWAPH` |  |
+| `AMSWAPV` |  |
+| `AMSWAPW` |  |
+| `AMXORDBV` |  |
+| `AMXORDBW` |  |
+| `AMXORV` |  |
+| `AMXORW` |  |
+| `AND` | Bitwise AND |
+| `ANDN` |  |
+| `BEQ` | Branch if equal |
+| `BFPF` |  |
+| `BFPT` |  |
+| `BGE` | Branch if greater or equal |
+| `BGEU` | Branch if greater or equal unsigned |
+| `BGEZ` |  |
+| `BGTZ` |  |
+| `BITREV4B` |  |
+| `BITREV8B` |  |
+| `BITREVV` |  |
+| `BITREVW` |  |
+| `BLEZ` |  |
+| `BLT` | Branch if less than |
+| `BLTU` | Branch if less than unsigned |
+| `BLTZ` |  |
+| `BNE` | Branch if not equal |
+| `BREAK` | Breakpoint |
+| `BSTRINSV` |  |
+| `BSTRINSW` |  |
+| `BSTRPICKV` |  |
+| `BSTRPICKW` |  |
+| `CLOV` |  |
+| `CLOW` |  |
+| `CLZV` |  |
+| `CLZW` |  |
+| `CMPEQD` |  |
+| `CMPEQF` |  |
+| `CMPGED` |  |
+| `CMPGEF` |  |
+| `CMPGTD` |  |
+| `CMPGTF` |  |
+| `CPUCFG` |  |
+| `CRCCWBW` |  |
+| `CRCCWHW` |  |
+| `CRCCWVW` |  |
+| `CRCCWWW` |  |
+| `CRCWBW` |  |
+| `CRCWHW` |  |
+| `CRCWVW` |  |
+| `CRCWWW` |  |
+| `CTOV` |  |
+| `CTOW` |  |
+| `CTZV` |  |
+| `CTZW` |  |
+| `DBAR` | Barrier |
+| `DIV` | Divide (word) |
+| `DIVD` | Divide doubleword |
+| `DIVF` |  |
+| `DIVU` |  |
+| `DIVV` |  |
+| `DIVVU` |  |
+| `DIVW` | Divide word |
+| `DIVWU` |  |
+| `EXTWB` |  |
+| `EXTWH` |  |
+| `FCLASSD` |  |
+| `FCLASSF` |  |
+| `FCOPYSGD` |  |
+| `FCOPYSGF` |  |
+| `FFINTDV` |  |
+| `FFINTDW` |  |
+| `FFINTFV` |  |
+| `FFINTFW` |  |
+| `FLOGBD` |  |
+| `FLOGBF` |  |
+| `FMADDD` |  |
+| `FMADDF` |  |
+| `FMAXAD` |  |
+| `FMAXAF` |  |
+| `FMAXD` |  |
+| `FMAXF` |  |
+| `FMINAD` |  |
+| `FMINAF` |  |
+| `FMIND` |  |
+| `FMINF` |  |
+| `FMSUBD` |  |
+| `FMSUBF` |  |
+| `FNMADDD` |  |
+| `FNMADDF` |  |
+| `FNMSUBD` |  |
+| `FNMSUBF` |  |
+| `FSCALEBD` |  |
+| `FSCALEBF` |  |
+| `FSEL` |  |
+| `FTINTRMVD` |  |
+| `FTINTRMVF` |  |
+| `FTINTRMWD` |  |
+| `FTINTRMWF` |  |
+| `FTINTRNEVD` |  |
+| `FTINTRNEVF` |  |
+| `FTINTRNEWD` |  |
+| `FTINTRNEWF` |  |
+| `FTINTRPVD` |  |
+| `FTINTRPVF` |  |
+| `FTINTRPWD` |  |
+| `FTINTRPWF` |  |
+| `FTINTRZVD` |  |
+| `FTINTRZVF` |  |
+| `FTINTRZWD` |  |
+| `FTINTRZWF` |  |
+| `FTINTVD` |  |
+| `FTINTVF` |  |
+| `FTINTWD` |  |
+| `FTINTWF` |  |
+| `JIRL` | Jump indirect with link |
+| `LL` |  |
+| `LLV` |  |
+| `LU12IW` |  |
+| `LU32ID` |  |
+| `LU52ID` |  |
+| `LUI` |  |
+| `MASKEQZ` |  |
+| `MASKNEZ` |  |
+| `MOVB` |  |
+| `MOVBU` |  |
+| `MOVD` |  |
+| `MOVDF` |  |
+| `MOVDV` |  |
+| `MOVDW` |  |
+| `MOVF` |  |
+| `MOVFD` |  |
+| `MOVFV` |  |
+| `MOVFW` |  |
+| `MOVH` |  |
+| `MOVHU` |  |
+| `MOVV` |  |
+| `MOVVD` |  |
+| `MOVVF` |  |
+| `MOVVP` |  |
+| `MOVW` |  |
+| `MOVWD` |  |
+| `MOVWF` |  |
+| `MOVWP` |  |
+| `MOVWU` |  |
+| `MUL` | Multiply (word) |
+| `MULD` | Multiply doubleword |
+| `MULF` |  |
+| `MULH` |  |
+| `MULHU` |  |
+| `MULHV` |  |
+| `MULHVU` |  |
+| `MULV` |  |
+| `MULVU` |  |
+| `MULW` | Multiply word |
+| `MULWVW` |  |
+| `MULWVWU` |  |
+| `NEGD` |  |
+| `NEGF` |  |
+| `NEGV` |  |
+| `NEGW` |  |
+| `NOOP` |  |
+| `NOR` | Bitwise NOR |
+| `OR` | Bitwise OR |
+| `ORN` |  |
+| `PCADDU12I` |  |
+| `PCALAU12I` |  |
+| `PRELD` |  |
+| `PRELDX` |  |
+| `RDTIMED` |  |
+| `RDTIMEHW` |  |
+| `RDTIMELW` |  |
+| `REM` |  |
+| `REMU` |  |
+| `REMV` |  |
+| `REMVU` |  |
+| `REMW` |  |
+| `REMWU` |  |
+| `REVB2H` |  |
+| `REVB2W` |  |
+| `REVB4H` |  |
+| `REVBV` |  |
+| `REVH2W` |  |
+| `REVHV` |  |
+| `RFE` |  |
+| `ROTR` | Rotate right |
+| `ROTRV` |  |
+| `SC` |  |
+| `SCV` |  |
+| `SGT` |  |
+| `SGTU` |  |
+| `SLL` | Shift left logical |
+| `SLLV` |  |
+| `SQRTD` |  |
+| `SQRTF` |  |
+| `SRA` | Shift right arithmetic |
+| `SRAV` |  |
+| `SRL` | Shift right logical |
+| `SRLV` |  |
+| `SUB` | Subtract (word) |
+| `SUBD` | Subtract doubleword |
+| `SUBF` |  |
+| `SUBV` |  |
+| `SUBVU` |  |
+| `SUBW` | Subtract word |
+| `SYSCALL` | System call |
+| `TEQ` |  |
+| `TNE` |  |
+| `TRUNCDV` |  |
+| `TRUNCDW` |  |
+| `TRUNCFV` |  |
+| `TRUNCFW` |  |
+| `VADDB` |  |
+| `VADDBU` |  |
+| `VADDD` |  |
+| `VADDF` |  |
+| `VADDH` |  |
+| `VADDHU` |  |
+| `VADDQ` |  |
+| `VADDV` |  |
+| `VADDVU` |  |
+| `VADDW` |  |
+| `VADDWEVHB` |  |
+| `VADDWEVHBU` |  |
+| `VADDWEVQV` |  |
+| `VADDWEVQVU` |  |
+| `VADDWEVVW` |  |
+| `VADDWEVVWU` |  |
+| `VADDWEVWH` |  |
+| `VADDWEVWHU` |  |
+| `VADDWODHB` |  |
+| `VADDWODHBU` |  |
+| `VADDWODQV` |  |
+| `VADDWODQVU` |  |
+| `VADDWODVW` |  |
+| `VADDWODVWU` |  |
+| `VADDWODWH` |  |
+| `VADDWODWHU` |  |
+| `VADDWU` |  |
+| `VANDB` |  |
+| `VANDNV` |  |
+| `VANDV` |  |
+| `VBITCLRB` |  |
+| `VBITCLRH` |  |
+| `VBITCLRV` |  |
+| `VBITCLRW` |  |
+| `VBITREVB` |  |
+| `VBITREVH` |  |
+| `VBITREVV` |  |
+| `VBITREVW` |  |
+| `VBITSETB` |  |
+| `VBITSETH` |  |
+| `VBITSETV` |  |
+| `VBITSETW` |  |
+| `VDIVB` |  |
+| `VDIVBU` |  |
+| `VDIVD` |  |
+| `VDIVF` |  |
+| `VDIVH` |  |
+| `VDIVHU` |  |
+| `VDIVV` |  |
+| `VDIVVU` |  |
+| `VDIVW` |  |
+| `VDIVWU` |  |
+| `VEXTRINSB` |  |
+| `VEXTRINSH` |  |
+| `VEXTRINSV` |  |
+| `VEXTRINSW` |  |
+| `VFCLASSD` |  |
+| `VFCLASSF` |  |
+| `VFRECIPD` |  |
+| `VFRECIPF` |  |
+| `VFRINTD` |  |
+| `VFRINTF` |  |
+| `VFRINTRMD` |  |
+| `VFRINTRMF` |  |
+| `VFRINTRNED` |  |
+| `VFRINTRNEF` |  |
+| `VFRINTRPD` |  |
+| `VFRINTRPF` |  |
+| `VFRINTRZD` |  |
+| `VFRINTRZF` |  |
+| `VFRSQRTD` |  |
+| `VFRSQRTF` |  |
+| `VFSQRTD` |  |
+| `VFSQRTF` |  |
+| `VILVHB` |  |
+| `VILVHH` |  |
+| `VILVHV` |  |
+| `VILVHW` |  |
+| `VILVLB` |  |
+| `VILVLH` |  |
+| `VILVLV` |  |
+| `VILVLW` |  |
+| `VMADDB` |  |
+| `VMADDH` |  |
+| `VMADDV` |  |
+| `VMADDW` |  |
+| `VMADDWEVHB` |  |
+| `VMADDWEVHBU` |  |
+| `VMADDWEVHBUB` |  |
+| `VMADDWEVQV` |  |
+| `VMADDWEVQVU` |  |
+| `VMADDWEVQVUV` |  |
+| `VMADDWEVVW` |  |
+| `VMADDWEVVWU` |  |
+| `VMADDWEVVWUW` |  |
+| `VMADDWEVWH` |  |
+| `VMADDWEVWHU` |  |
+| `VMADDWEVWHUH` |  |
+| `VMADDWODHB` |  |
+| `VMADDWODHBU` |  |
+| `VMADDWODHBUB` |  |
+| `VMADDWODQV` |  |
+| `VMADDWODQVU` |  |
+| `VMADDWODQVUV` |  |
+| `VMADDWODVW` |  |
+| `VMADDWODVWU` |  |
+| `VMADDWODVWUW` |  |
+| `VMADDWODWH` |  |
+| `VMADDWODWHU` |  |
+| `VMADDWODWHUH` |  |
+| `VMODB` |  |
+| `VMODBU` |  |
+| `VMODH` |  |
+| `VMODHU` |  |
+| `VMODV` |  |
+| `VMODVU` |  |
+| `VMODW` |  |
+| `VMODWU` |  |
+| `VMOVQ` |  |
+| `VMSUBB` |  |
+| `VMSUBH` |  |
+| `VMSUBV` |  |
+| `VMSUBW` |  |
+| `VMUHB` |  |
+| `VMUHBU` |  |
+| `VMUHH` |  |
+| `VMUHHU` |  |
+| `VMUHV` |  |
+| `VMUHVU` |  |
+| `VMUHW` |  |
+| `VMUHWU` |  |
+| `VMULB` |  |
+| `VMULD` |  |
+| `VMULF` |  |
+| `VMULH` |  |
+| `VMULV` |  |
+| `VMULW` |  |
+| `VMULWEVHB` |  |
+| `VMULWEVHBU` |  |
+| `VMULWEVHBUB` |  |
+| `VMULWEVQV` |  |
+| `VMULWEVQVU` |  |
+| `VMULWEVQVUV` |  |
+| `VMULWEVVW` |  |
+| `VMULWEVVWU` |  |
+| `VMULWEVVWUW` |  |
+| `VMULWEVWH` |  |
+| `VMULWEVWHU` |  |
+| `VMULWEVWHUH` |  |
+| `VMULWODHB` |  |
+| `VMULWODHBU` |  |
+| `VMULWODHBUB` |  |
+| `VMULWODQV` |  |
+| `VMULWODQVU` |  |
+| `VMULWODQVUV` |  |
+| `VMULWODVW` |  |
+| `VMULWODVWU` |  |
+| `VMULWODVWUW` |  |
+| `VMULWODWH` |  |
+| `VMULWODWHU` |  |
+| `VMULWODWHUH` |  |
+| `VNEGB` |  |
+| `VNEGH` |  |
+| `VNEGV` |  |
+| `VNEGW` |  |
+| `VNORB` |  |
+| `VNORV` |  |
+| `VORB` |  |
+| `VORNV` |  |
+| `VORV` |  |
+| `VPCNTB` |  |
+| `VPCNTH` |  |
+| `VPCNTV` |  |
+| `VPCNTW` |  |
+| `VPERMIW` |  |
+| `VROTRB` |  |
+| `VROTRH` |  |
+| `VROTRV` |  |
+| `VROTRW` |  |
+| `VSADDB` |  |
+| `VSADDBU` |  |
+| `VSADDH` |  |
+| `VSADDHU` |  |
+| `VSADDV` |  |
+| `VSADDVU` |  |
+| `VSADDW` |  |
+| `VSADDWU` |  |
+| `VSEQB` |  |
+| `VSEQH` |  |
+| `VSEQV` |  |
+| `VSEQW` |  |
+| `VSETALLNEB` |  |
+| `VSETALLNEH` |  |
+| `VSETALLNEV` |  |
+| `VSETALLNEW` |  |
+| `VSETANYEQB` |  |
+| `VSETANYEQH` |  |
+| `VSETANYEQV` |  |
+| `VSETANYEQW` |  |
+| `VSETEQV` |  |
+| `VSETNEV` |  |
+| `VSHUF4IB` |  |
+| `VSHUF4IH` |  |
+| `VSHUF4IV` |  |
+| `VSHUF4IW` |  |
+| `VSHUFB` |  |
+| `VSHUFH` |  |
+| `VSHUFV` |  |
+| `VSHUFW` |  |
+| `VSLLB` |  |
+| `VSLLH` |  |
+| `VSLLV` |  |
+| `VSLLW` |  |
+| `VSLTB` |  |
+| `VSLTBU` |  |
+| `VSLTH` |  |
+| `VSLTHU` |  |
+| `VSLTV` |  |
+| `VSLTVU` |  |
+| `VSLTW` |  |
+| `VSLTWU` |  |
+| `VSRAB` |  |
+| `VSRAH` |  |
+| `VSRAV` |  |
+| `VSRAW` |  |
+| `VSRLB` |  |
+| `VSRLH` |  |
+| `VSRLV` |  |
+| `VSRLW` |  |
+| `VSSUBB` |  |
+| `VSSUBBU` |  |
+| `VSSUBH` |  |
+| `VSSUBHU` |  |
+| `VSSUBV` |  |
+| `VSSUBVU` |  |
+| `VSSUBW` |  |
+| `VSSUBWU` |  |
+| `VSUBB` |  |
+| `VSUBBU` |  |
+| `VSUBD` |  |
+| `VSUBF` |  |
+| `VSUBH` |  |
+| `VSUBHU` |  |
+| `VSUBQ` |  |
+| `VSUBV` |  |
+| `VSUBVU` |  |
+| `VSUBW` |  |
+| `VSUBWEVHB` |  |
+| `VSUBWEVHBU` |  |
+| `VSUBWEVQV` |  |
+| `VSUBWEVQVU` |  |
+| `VSUBWEVVW` |  |
+| `VSUBWEVVWU` |  |
+| `VSUBWEVWH` |  |
+| `VSUBWEVWHU` |  |
+| `VSUBWODHB` |  |
+| `VSUBWODHBU` |  |
+| `VSUBWODQV` |  |
+| `VSUBWODQVU` |  |
+| `VSUBWODVW` |  |
+| `VSUBWODVWU` |  |
+| `VSUBWODWH` |  |
+| `VSUBWODWHU` |  |
+| `VSUBWU` |  |
+| `VXORB` |  |
+| `VXORV` |  |
+| `WORD` |  |
+| `XOR` | Bitwise XOR |
+| `XVADDB` |  |
+| `XVADDBU` |  |
+| `XVADDD` |  |
+| `XVADDF` |  |
+| `XVADDH` |  |
+| `XVADDHU` |  |
+| `XVADDQ` |  |
+| `XVADDV` |  |
+| `XVADDVU` |  |
+| `XVADDW` |  |
+| `XVADDWEVHB` |  |
+| `XVADDWEVHBU` |  |
+| `XVADDWEVQV` |  |
+| `XVADDWEVQVU` |  |
+| `XVADDWEVVW` |  |
+| `XVADDWEVVWU` |  |
+| `XVADDWEVWH` |  |
+| `XVADDWEVWHU` |  |
+| `XVADDWODHB` |  |
+| `XVADDWODHBU` |  |
+| `XVADDWODQV` |  |
+| `XVADDWODQVU` |  |
+| `XVADDWODVW` |  |
+| `XVADDWODVWU` |  |
+| `XVADDWODWH` |  |
+| `XVADDWODWHU` |  |
+| `XVADDWU` |  |
+| `XVANDB` |  |
+| `XVANDNV` |  |
+| `XVANDV` |  |
+| `XVBITCLRB` |  |
+| `XVBITCLRH` |  |
+| `XVBITCLRV` |  |
+| `XVBITCLRW` |  |
+| `XVBITREVB` |  |
+| `XVBITREVH` |  |
+| `XVBITREVV` |  |
+| `XVBITREVW` |  |
+| `XVBITSETB` |  |
+| `XVBITSETH` |  |
+| `XVBITSETV` |  |
+| `XVBITSETW` |  |
+| `XVDIVB` |  |
+| `XVDIVBU` |  |
+| `XVDIVD` |  |
+| `XVDIVF` |  |
+| `XVDIVH` |  |
+| `XVDIVHU` |  |
+| `XVDIVV` |  |
+| `XVDIVVU` |  |
+| `XVDIVW` |  |
+| `XVDIVWU` |  |
+| `XVEXTRINSB` |  |
+| `XVEXTRINSH` |  |
+| `XVEXTRINSV` |  |
+| `XVEXTRINSW` |  |
+| `XVFCLASSD` |  |
+| `XVFCLASSF` |  |
+| `XVFRECIPD` |  |
+| `XVFRECIPF` |  |
+| `XVFRINTD` |  |
+| `XVFRINTF` |  |
+| `XVFRINTRMD` |  |
+| `XVFRINTRMF` |  |
+| `XVFRINTRNED` |  |
+| `XVFRINTRNEF` |  |
+| `XVFRINTRPD` |  |
+| `XVFRINTRPF` |  |
+| `XVFRINTRZD` |  |
+| `XVFRINTRZF` |  |
+| `XVFRSQRTD` |  |
+| `XVFRSQRTF` |  |
+| `XVFSQRTD` |  |
+| `XVFSQRTF` |  |
+| `XVILVHB` |  |
+| `XVILVHH` |  |
+| `XVILVHV` |  |
+| `XVILVHW` |  |
+| `XVILVLB` |  |
+| `XVILVLH` |  |
+| `XVILVLV` |  |
+| `XVILVLW` |  |
+| `XVMADDB` |  |
+| `XVMADDH` |  |
+| `XVMADDV` |  |
+| `XVMADDW` |  |
+| `XVMADDWEVHB` |  |
+| `XVMADDWEVHBU` |  |
+| `XVMADDWEVHBUB` |  |
+| `XVMADDWEVQV` |  |
+| `XVMADDWEVQVU` |  |
+| `XVMADDWEVQVUV` |  |
+| `XVMADDWEVVW` |  |
+| `XVMADDWEVVWU` |  |
+| `XVMADDWEVVWUW` |  |
+| `XVMADDWEVWH` |  |
+| `XVMADDWEVWHU` |  |
+| `XVMADDWEVWHUH` |  |
+| `XVMADDWODHB` |  |
+| `XVMADDWODHBU` |  |
+| `XVMADDWODHBUB` |  |
+| `XVMADDWODQV` |  |
+| `XVMADDWODQVU` |  |
+| `XVMADDWODQVUV` |  |
+| `XVMADDWODVW` |  |
+| `XVMADDWODVWU` |  |
+| `XVMADDWODVWUW` |  |
+| `XVMADDWODWH` |  |
+| `XVMADDWODWHU` |  |
+| `XVMADDWODWHUH` |  |
+| `XVMODB` |  |
+| `XVMODBU` |  |
+| `XVMODH` |  |
+| `XVMODHU` |  |
+| `XVMODV` |  |
+| `XVMODVU` |  |
+| `XVMODW` |  |
+| `XVMODWU` |  |
+| `XVMOVQ` |  |
+| `XVMSUBB` |  |
+| `XVMSUBH` |  |
+| `XVMSUBV` |  |
+| `XVMSUBW` |  |
+| `XVMUHB` |  |
+| `XVMUHBU` |  |
+| `XVMUHH` |  |
+| `XVMUHHU` |  |
+| `XVMUHV` |  |
+| `XVMUHVU` |  |
+| `XVMUHW` |  |
+| `XVMUHWU` |  |
+| `XVMULB` |  |
+| `XVMULD` |  |
+| `XVMULF` |  |
+| `XVMULH` |  |
+| `XVMULV` |  |
+| `XVMULW` |  |
+| `XVMULWEVHB` |  |
+| `XVMULWEVHBU` |  |
+| `XVMULWEVHBUB` |  |
+| `XVMULWEVQV` |  |
+| `XVMULWEVQVU` |  |
+| `XVMULWEVQVUV` |  |
+| `XVMULWEVVW` |  |
+| `XVMULWEVVWU` |  |
+| `XVMULWEVVWUW` |  |
+| `XVMULWEVWH` |  |
+| `XVMULWEVWHU` |  |
+| `XVMULWEVWHUH` |  |
+| `XVMULWODHB` |  |
+| `XVMULWODHBU` |  |
+| `XVMULWODHBUB` |  |
+| `XVMULWODQV` |  |
+| `XVMULWODQVU` |  |
+| `XVMULWODQVUV` |  |
+| `XVMULWODVW` |  |
+| `XVMULWODVWU` |  |
+| `XVMULWODVWUW` |  |
+| `XVMULWODWH` |  |
+| `XVMULWODWHU` |  |
+| `XVMULWODWHUH` |  |
+| `XVNEGB` |  |
+| `XVNEGH` |  |
+| `XVNEGV` |  |
+| `XVNEGW` |  |
+| `XVNORB` |  |
+| `XVNORV` |  |
+| `XVORB` |  |
+| `XVORNV` |  |
+| `XVORV` |  |
+| `XVPCNTB` |  |
+| `XVPCNTH` |  |
+| `XVPCNTV` |  |
+| `XVPCNTW` |  |
+| `XVPERMIQ` |  |
+| `XVPERMIV` |  |
+| `XVPERMIW` |  |
+| `XVROTRB` |  |
+| `XVROTRH` |  |
+| `XVROTRV` |  |
+| `XVROTRW` |  |
+| `XVSADDB` |  |
+| `XVSADDBU` |  |
+| `XVSADDH` |  |
+| `XVSADDHU` |  |
+| `XVSADDV` |  |
+| `XVSADDVU` |  |
+| `XVSADDW` |  |
+| `XVSADDWU` |  |
+| `XVSEQB` |  |
+| `XVSEQH` |  |
+| `XVSEQV` |  |
+| `XVSEQW` |  |
+| `XVSETALLNEB` |  |
+| `XVSETALLNEH` |  |
+| `XVSETALLNEV` |  |
+| `XVSETALLNEW` |  |
+| `XVSETANYEQB` |  |
+| `XVSETANYEQH` |  |
+| `XVSETANYEQV` |  |
+| `XVSETANYEQW` |  |
+| `XVSETEQV` |  |
+| `XVSETNEV` |  |
+| `XVSHUF4IB` |  |
+| `XVSHUF4IH` |  |
+| `XVSHUF4IV` |  |
+| `XVSHUF4IW` |  |
+| `XVSHUFB` |  |
+| `XVSHUFH` |  |
+| `XVSHUFV` |  |
+| `XVSHUFW` |  |
+| `XVSLLB` |  |
+| `XVSLLH` |  |
+| `XVSLLV` |  |
+| `XVSLLW` |  |
+| `XVSLTB` |  |
+| `XVSLTBU` |  |
+| `XVSLTH` |  |
+| `XVSLTHU` |  |
+| `XVSLTV` |  |
+| `XVSLTVU` |  |
+| `XVSLTW` |  |
+| `XVSLTWU` |  |
+| `XVSRAB` |  |
+| `XVSRAH` |  |
+| `XVSRAV` |  |
+| `XVSRAW` |  |
+| `XVSRLB` |  |
+| `XVSRLH` |  |
+| `XVSRLV` |  |
+| `XVSRLW` |  |
+| `XVSSUBB` |  |
+| `XVSSUBBU` |  |
+| `XVSSUBH` |  |
+| `XVSSUBHU` |  |
+| `XVSSUBV` |  |
+| `XVSSUBVU` |  |
+| `XVSSUBW` |  |
+| `XVSSUBWU` |  |
+| `XVSUBB` |  |
+| `XVSUBBU` |  |
+| `XVSUBD` |  |
+| `XVSUBF` |  |
+| `XVSUBH` |  |
+| `XVSUBHU` |  |
+| `XVSUBQ` |  |
+| `XVSUBV` |  |
+| `XVSUBVU` |  |
+| `XVSUBW` |  |
+| `XVSUBWEVHB` |  |
+| `XVSUBWEVHBU` |  |
+| `XVSUBWEVQV` |  |
+| `XVSUBWEVQVU` |  |
+| `XVSUBWEVVW` |  |
+| `XVSUBWEVVWU` |  |
+| `XVSUBWEVWH` |  |
+| `XVSUBWEVWHU` |  |
+| `XVSUBWODHB` |  |
+| `XVSUBWODHBU` |  |
+| `XVSUBWODQV` |  |
+| `XVSUBWODQVU` |  |
+| `XVSUBWODVW` |  |
+| `XVSUBWODVWU` |  |
+| `XVSUBWODWH` |  |
+| `XVSUBWODWHU` |  |
+| `XVSUBWU` |  |
+| `XVXORB` |  |
+| `XVXORV` |  |
+| `JAL` |  |
+
+Recognised: 814 mnemonics.

docs/asm/INSTRUCTIONS-RISCV64.md

@@ -0,0 +1,991 @@
+# RISC-V 64: instruction inventory
+
+Generated by gasm-devkit's `_gen` from the Go toolchain's instruction table
+(`cmd/internal/obj/riscv/anames.go`, go1.27.1); DO NOT EDIT. This page lists every mnemonic
+`go tool asm` accepts on this target, which is the upper bound of the
+language on it: a name absent here is not an instruction of the target,
+and a name present here may still be one gasm's encoder cannot emit yet.
+
+The inventory carries no per-mnemonic encoder column: on this target
+encodability is decided per operand shape, and the live measured
+coverage is reported by `gasm audit-instructions`.
+
+| Mnemonic | Notes |
+|---|---|
+| `CALL` | Call subroutine |
+| `DUFFCOPY` |  |
+| `DUFFZERO` |  |
+| `END` |  |
+| `FUNCDATA` |  |
+| `GETCALLERPC` |  |
+| `JMP` | Unconditional jump |
+| `NOP` |  |
+| `PCALIGN` |  |
+| `PCALIGNMAX` |  |
+| `PCDATA` |  |
+| `RET` | Return |
+| `TEXT` |  |
+| `UNDEF` |  |
+| `ADD` | Integer add |
+| `ADDI` | Add immediate |
+| `ADDIW` | Add immediate (32-bit) |
+| `ADDUW` |  |
+| `ADDW` | Add (32-bit) |
+| `AMOADDD` | Atomic add doubleword |
+| `AMOADDW` | Atomic add word |
+| `AMOANDD` |  |
+| `AMOANDW` |  |
+| `AMOMAXD` |  |
+| `AMOMAXUD` |  |
+| `AMOMAXUW` |  |
+| `AMOMAXW` |  |
+| `AMOMIND` |  |
+| `AMOMINUD` |  |
+| `AMOMINUW` |  |
+| `AMOMINW` |  |
+| `AMOORD` |  |
+| `AMOORW` |  |
+| `AMOSWAPD` | Atomic swap doubleword |
+| `AMOSWAPW` | Atomic swap word |
+| `AMOXORD` |  |
+| `AMOXORW` |  |
+| `AND` | Bitwise AND |
+| `ANDI` | AND immediate |
+| `ANDN` |  |
+| `AUIPC` | Add upper immediate to PC |
+| `BCLR` |  |
+| `BCLRI` |  |
+| `BEQ` | Branch if equal |
+| `BEQZ` |  |
+| `BEXT` |  |
+| `BEXTI` |  |
+| `BGE` | Branch if greater or equal |
+| `BGEU` | Branch if greater or equal unsigned |
+| `BGEZ` |  |
+| `BGT` |  |
+| `BGTU` |  |
+| `BGTZ` |  |
+| `BINV` |  |
+| `BINVI` |  |
+| `BLE` |  |
+| `BLEU` |  |
+| `BLEZ` |  |
+| `BLT` | Branch if less than |
+| `BLTU` | Branch if less than unsigned |
+| `BLTZ` |  |
+| `BNE` | Branch if not equal |
+| `BNEZ` |  |
+| `BSET` |  |
+| `BSETI` |  |
+| `CADD` |  |
+| `CADDI` |  |
+| `CADDI16SP` |  |
+| `CADDI4SPN` |  |
+| `CADDIW` |  |
+| `CADDW` |  |
+| `CAND` |  |
+| `CANDI` |  |
+| `CBEQZ` |  |
+| `CBNEZ` |  |
+| `CEBREAK` |  |
+| `CFLD` |  |
+| `CFLDSP` |  |
+| `CFSD` |  |
+| `CFSDSP` |  |
+| `CJ` |  |
+| `CJALR` |  |
+| `CJR` |  |
+| `CLD` |  |
+| `CLDSP` |  |
+| `CLI` |  |
+| `CLUI` |  |
+| `CLW` |  |
+| `CLWSP` |  |
+| `CLZ` |  |
+| `CLZW` |  |
+| `CMV` |  |
+| `CNOP` |  |
+| `COR` |  |
+| `CPOP` |  |
+| `CPOPW` |  |
+| `CSD` |  |
+| `CSDSP` |  |
+| `CSLLI` |  |
+| `CSRAI` |  |
+| `CSRLI` |  |
+| `CSRRC` |  |
+| `CSRRCI` |  |
+| `CSRRS` |  |
+| `CSRRSI` |  |
+| `CSRRW` |  |
+| `CSRRWI` |  |
+| `CSUB` |  |
+| `CSUBW` |  |
+| `CSW` |  |
+| `CSWSP` |  |
+| `CTZ` |  |
+| `CTZW` |  |
+| `CXOR` |  |
+| `CZEROEQZ` |  |
+| `CZERONEZ` |  |
+| `DIV` | Divide |
+| `DIVU` | Divide unsigned |
+| `DIVUW` |  |
+| `DIVW` | Divide (32-bit) |
+| `DRET` |  |
+| `EBREAK` | Breakpoint |
+| `ECALL` | Environment call |
+| `FABSD` |  |
+| `FABSS` |  |
+| `FADDD` | FP add (double) |
+| `FADDQ` |  |
+| `FADDS` | FP add (single) |
+| `FCLASSD` |  |
+| `FCLASSQ` |  |
+| `FCLASSS` |  |
+| `FCVTDL` |  |
+| `FCVTDLU` |  |
+| `FCVTDQ` |  |
+| `FCVTDS` |  |
+| `FCVTDW` |  |
+| `FCVTDWU` |  |
+| `FCVTLD` |  |
+| `FCVTLQ` |  |
+| `FCVTLS` |  |
+| `FCVTLUD` |  |
+| `FCVTLUQ` |  |
+| `FCVTLUS` |  |
+| `FCVTQD` |  |
+| `FCVTQL` |  |
+| `FCVTQLU` |  |
+| `FCVTQS` |  |
+| `FCVTQW` |  |
+| `FCVTQWU` |  |
+| `FCVTSD` |  |
+| `FCVTSL` |  |
+| `FCVTSLU` |  |
+| `FCVTSQ` |  |
+| `FCVTSW` |  |
+| `FCVTSWU` |  |
+| `FCVTWD` |  |
+| `FCVTWQ` |  |
+| `FCVTWS` |  |
+| `FCVTWUD` |  |
+| `FCVTWUQ` |  |
+| `FCVTWUS` |  |
+| `FDIVD` | FP divide (double) |
+| `FDIVQ` |  |
+| `FDIVS` | FP divide (single) |
+| `FENCE` | Memory barrier |
+| `FEQD` |  |
+| `FEQQ` |  |
+| `FEQS` |  |
+| `FLD` | FP load doubleword |
+| `FLED` |  |
+| `FLEQ` |  |
+| `FLES` |  |
+| `FLQ` |  |
+| `FLTD` |  |
+| `FLTQ` |  |
+| `FLTS` |  |
+| `FLW` | FP load word |
+| `FMADDD` |  |
+| `FMADDQ` |  |
+| `FMADDS` |  |
+| `FMAXD` |  |
+| `FMAXQ` |  |
+| `FMAXS` |  |
+| `FMIND` |  |
+| `FMINQ` |  |
+| `FMINS` |  |
+| `FMSUBD` |  |
+| `FMSUBQ` |  |
+| `FMSUBS` |  |
+| `FMULD` | FP multiply (double) |
+| `FMULQ` |  |
+| `FMULS` | FP multiply (single) |
+| `FMVDX` |  |
+| `FMVSX` |  |
+| `FMVWX` |  |
+| `FMVXD` |  |
+| `FMVXS` |  |
+| `FMVXW` |  |
+| `FNED` |  |
+| `FNEGD` |  |
+| `FNEGS` |  |
+| `FNES` |  |
+| `FNMADDD` |  |
+| `FNMADDQ` |  |
+| `FNMADDS` |  |
+| `FNMSUBD` |  |
+| `FNMSUBQ` |  |
+| `FNMSUBS` |  |
+| `FSD` | FP store doubleword |
+| `FSGNJD` |  |
+| `FSGNJND` |  |
+| `FSGNJNQ` |  |
+| `FSGNJNS` |  |
+| `FSGNJQ` |  |
+| `FSGNJS` |  |
+| `FSGNJXD` |  |
+| `FSGNJXQ` |  |
+| `FSGNJXS` |  |
+| `FSQ` |  |
+| `FSQRTD` |  |
+| `FSQRTQ` |  |
+| `FSQRTS` |  |
+| `FSUBD` | FP subtract (double) |
+| `FSUBQ` |  |
+| `FSUBS` | FP subtract (single) |
+| `FSW` | FP store word |
+| `JAL` | Jump and link |
+| `JALR` | Jump and link register |
+| `LB` | Load byte |
+| `LBU` | Load byte unsigned |
+| `LD` | Load doubleword |
+| `LH` | Load halfword |
+| `LHU` | Load halfword unsigned |
+| `LRD` | Load-reserved doubleword |
+| `LRW` | Load-reserved word |
+| `LUI` | Load upper immediate |
+| `LW` | Load word |
+| `LWU` | Load word unsigned |
+| `MAX` |  |
+| `MAXU` |  |
+| `MIN` |  |
+| `MINU` |  |
+| `MOV` |  |
+| `MOVB` |  |
+| `MOVBU` |  |
+| `MOVD` |  |
+| `MOVF` |  |
+| `MOVH` |  |
+| `MOVHU` |  |
+| `MOVW` |  |
+| `MOVWU` |  |
+| `MRET` |  |
+| `MUL` | Multiply |
+| `MULH` | Multiply high |
+| `MULHSU` | Multiply high signed/unsigned |
+| `MULHU` | Multiply high unsigned |
+| `MULW` | Multiply (32-bit) |
+| `NEG` |  |
+| `NEGW` |  |
+| `NOT` |  |
+| `OR` | Bitwise OR |
+| `ORCB` |  |
+| `ORI` | OR immediate |
+| `ORN` |  |
+| `RDCYCLE` |  |
+| `RDINSTRET` |  |
+| `RDTIME` |  |
+| `REM` | Remainder |
+| `REMU` | Remainder unsigned |
+| `REMUW` |  |
+| `REMW` |  |
+| `REV8` |  |
+| `ROL` |  |
+| `ROLW` |  |
+| `ROR` |  |
+| `RORI` |  |
+| `RORIW` |  |
+| `RORW` |  |
+| `SB` | Store byte |
+| `SBREAK` |  |
+| `SCALL` |  |
+| `SCD` | Store-conditional doubleword |
+| `SCW` | Store-conditional word |
+| `SD` | Store doubleword |
+| `SEQZ` |  |
+| `SEXTB` |  |
+| `SEXTH` |  |
+| `SFENCEVMA` |  |
+| `SH` | Store halfword |
+| `SH1ADD` |  |
+| `SH1ADDUW` |  |
+| `SH2ADD` |  |
+| `SH2ADDUW` |  |
+| `SH3ADD` |  |
+| `SH3ADDUW` |  |
+| `SLL` | Shift left logical |
+| `SLLI` | Shift left logical immediate |
+| `SLLIUW` |  |
+| `SLLIW` |  |
+| `SLLW` |  |
+| `SLT` | Set if less than |
+| `SLTI` | Set if less than immediate |
+| `SLTIU` | Set if less than unsigned immediate |
+| `SLTU` | Set if less than unsigned |
+| `SNEZ` |  |
+| `SRA` | Shift right arithmetic |
+| `SRAI` | Shift right arithmetic immediate |
+| `SRAIW` |  |
+| `SRAW` |  |
+| `SRET` |  |
+| `SRL` | Shift right logical |
+| `SRLI` | Shift right logical immediate |
+| `SRLIW` |  |
+| `SRLW` |  |
+| `SUB` | Integer subtract |
+| `SUBW` | Subtract (32-bit) |
+| `SW` | Store word |
+| `VAADDUVV` |  |
+| `VAADDUVX` |  |
+| `VAADDVV` |  |
+| `VAADDVX` |  |
+| `VADCVIM` |  |
+| `VADCVVM` |  |
+| `VADCVXM` |  |
+| `VADDVI` |  |
+| `VADDVV` |  |
+| `VADDVX` |  |
+| `VANDVI` |  |
+| `VANDVV` |  |
+| `VANDVX` |  |
+| `VASUBUVV` |  |
+| `VASUBUVX` |  |
+| `VASUBVV` |  |
+| `VASUBVX` |  |
+| `VCOMPRESSVM` |  |
+| `VCPOPM` |  |
+| `VDIVUVV` |  |
+| `VDIVUVX` |  |
+| `VDIVVV` |  |
+| `VDIVVX` |  |
+| `VFABSV` |  |
+| `VFADDVF` |  |
+| `VFADDVV` |  |
+| `VFCLASSV` |  |
+| `VFCVTFXUV` |  |
+| `VFCVTFXV` |  |
+| `VFCVTRTZXFV` |  |
+| `VFCVTRTZXUFV` |  |
+| `VFCVTXFV` |  |
+| `VFCVTXUFV` |  |
+| `VFDIVVF` |  |
+| `VFDIVVV` |  |
+| `VFIRSTM` |  |
+| `VFMACCVF` |  |
+| `VFMACCVV` |  |
+| `VFMADDVF` |  |
+| `VFMADDVV` |  |
+| `VFMAXVF` |  |
+| `VFMAXVV` |  |
+| `VFMERGEVFM` |  |
+| `VFMINVF` |  |
+| `VFMINVV` |  |
+| `VFMSACVF` |  |
+| `VFMSACVV` |  |
+| `VFMSUBVF` |  |
+| `VFMSUBVV` |  |
+| `VFMULVF` |  |
+| `VFMULVV` |  |
+| `VFMVFS` |  |
+| `VFMVSF` |  |
+| `VFMVVF` |  |
+| `VFNCVTFFW` |  |
+| `VFNCVTFXUW` |  |
+| `VFNCVTFXW` |  |
+| `VFNCVTRODFFW` |  |
+| `VFNCVTRTZXFW` |  |
+| `VFNCVTRTZXUFW` |  |
+| `VFNCVTXFW` |  |
+| `VFNCVTXUFW` |  |
+| `VFNEGV` |  |
+| `VFNMACCVF` |  |
+| `VFNMACCVV` |  |
+| `VFNMADDVF` |  |
+| `VFNMADDVV` |  |
+| `VFNMSACVF` |  |
+| `VFNMSACVV` |  |
+| `VFNMSUBVF` |  |
+| `VFNMSUBVV` |  |
+| `VFRDIVVF` |  |
+| `VFREC7V` |  |
+| `VFREDMAXVS` |  |
+| `VFREDMINVS` |  |
+| `VFREDOSUMVS` |  |
+| `VFREDUSUMVS` |  |
+| `VFRSQRT7V` |  |
+| `VFRSUBVF` |  |
+| `VFSGNJNVF` |  |
+| `VFSGNJNVV` |  |
+| `VFSGNJVF` |  |
+| `VFSGNJVV` |  |
+| `VFSGNJXVF` |  |
+| `VFSGNJXVV` |  |
+| `VFSLIDE1DOWNVF` |  |
+| `VFSLIDE1UPVF` |  |
+| `VFSQRTV` |  |
+| `VFSUBVF` |  |
+| `VFSUBVV` |  |
+| `VFWADDVF` |  |
+| `VFWADDVV` |  |
+| `VFWADDWF` |  |
+| `VFWADDWV` |  |
+| `VFWCVTFFV` |  |
+| `VFWCVTFXUV` |  |
+| `VFWCVTFXV` |  |
+| `VFWCVTRTZXFV` |  |
+| `VFWCVTRTZXUFV` |  |
+| `VFWCVTXFV` |  |
+| `VFWCVTXUFV` |  |
+| `VFWMACCVF` |  |
+| `VFWMACCVV` |  |
+| `VFWMSACVF` |  |
+| `VFWMSACVV` |  |
+| `VFWMULVF` |  |
+| `VFWMULVV` |  |
+| `VFWNMACCVF` |  |
+| `VFWNMACCVV` |  |
+| `VFWNMSACVF` |  |
+| `VFWNMSACVV` |  |
+| `VFWREDOSUMVS` |  |
+| `VFWREDUSUMVS` |  |
+| `VFWSUBVF` |  |
+| `VFWSUBVV` |  |
+| `VFWSUBWF` |  |
+| `VFWSUBWV` |  |
+| `VIDV` |  |
+| `VIOTAM` |  |
+| `VL1RE16V` |  |
+| `VL1RE32V` |  |
+| `VL1RE64V` |  |
+| `VL1RE8V` |  |
+| `VL1RV` |  |
+| `VL2RE16V` |  |
+| `VL2RE32V` |  |
+| `VL2RE64V` |  |
+| `VL2RE8V` |  |
+| `VL2RV` |  |
+| `VL4RE16V` |  |
+| `VL4RE32V` |  |
+| `VL4RE64V` |  |
+| `VL4RE8V` |  |
+| `VL4RV` |  |
+| `VL8RE16V` |  |
+| `VL8RE32V` |  |
+| `VL8RE64V` |  |
+| `VL8RE8V` |  |
+| `VL8RV` |  |
+| `VLE16FFV` |  |
+| `VLE16V` |  |
+| `VLE32FFV` |  |
+| `VLE32V` |  |
+| `VLE64FFV` |  |
+| `VLE64V` |  |
+| `VLE8FFV` |  |
+| `VLE8V` |  |
+| `VLMV` |  |
+| `VLOXEI16V` |  |
+| `VLOXEI32V` |  |
+| `VLOXEI64V` |  |
+| `VLOXEI8V` |  |
+| `VLOXSEG2EI16V` |  |
+| `VLOXSEG2EI32V` |  |
+| `VLOXSEG2EI64V` |  |
+| `VLOXSEG2EI8V` |  |
+| `VLOXSEG3EI16V` |  |
+| `VLOXSEG3EI32V` |  |
+| `VLOXSEG3EI64V` |  |
+| `VLOXSEG3EI8V` |  |
+| `VLOXSEG4EI16V` |  |
+| `VLOXSEG4EI32V` |  |
+| `VLOXSEG4EI64V` |  |
+| `VLOXSEG4EI8V` |  |
+| `VLOXSEG5EI16V` |  |
+| `VLOXSEG5EI32V` |  |
+| `VLOXSEG5EI64V` |  |
+| `VLOXSEG5EI8V` |  |
+| `VLOXSEG6EI16V` |  |
+| `VLOXSEG6EI32V` |  |
+| `VLOXSEG6EI64V` |  |
+| `VLOXSEG6EI8V` |  |
+| `VLOXSEG7EI16V` |  |
+| `VLOXSEG7EI32V` |  |
+| `VLOXSEG7EI64V` |  |
+| `VLOXSEG7EI8V` |  |
+| `VLOXSEG8EI16V` |  |
+| `VLOXSEG8EI32V` |  |
+| `VLOXSEG8EI64V` |  |
+| `VLOXSEG8EI8V` |  |
+| `VLSE16V` |  |
+| `VLSE32V` |  |
+| `VLSE64V` |  |
+| `VLSE8V` |  |
+| `VLSEG2E16FFV` |  |
+| `VLSEG2E16V` |  |
+| `VLSEG2E32FFV` |  |
+| `VLSEG2E32V` |  |
+| `VLSEG2E64FFV` |  |
+| `VLSEG2E64V` |  |
+| `VLSEG2E8FFV` |  |
+| `VLSEG2E8V` |  |
+| `VLSEG3E16FFV` |  |
+| `VLSEG3E16V` |  |
+| `VLSEG3E32FFV` |  |
+| `VLSEG3E32V` |  |
+| `VLSEG3E64FFV` |  |
+| `VLSEG3E64V` |  |
+| `VLSEG3E8FFV` |  |
+| `VLSEG3E8V` |  |
+| `VLSEG4E16FFV` |  |
+| `VLSEG4E16V` |  |
+| `VLSEG4E32FFV` |  |
+| `VLSEG4E32V` |  |
+| `VLSEG4E64FFV` |  |
+| `VLSEG4E64V` |  |
+| `VLSEG4E8FFV` |  |
+| `VLSEG4E8V` |  |
+| `VLSEG5E16FFV` |  |
+| `VLSEG5E16V` |  |
+| `VLSEG5E32FFV` |  |
+| `VLSEG5E32V` |  |
+| `VLSEG5E64FFV` |  |
+| `VLSEG5E64V` |  |
+| `VLSEG5E8FFV` |  |
+| `VLSEG5E8V` |  |
+| `VLSEG6E16FFV` |  |
+| `VLSEG6E16V` |  |
+| `VLSEG6E32FFV` |  |
+| `VLSEG6E32V` |  |
+| `VLSEG6E64FFV` |  |
+| `VLSEG6E64V` |  |
+| `VLSEG6E8FFV` |  |
+| `VLSEG6E8V` |  |
+| `VLSEG7E16FFV` |  |
+| `VLSEG7E16V` |  |
+| `VLSEG7E32FFV` |  |
+| `VLSEG7E32V` |  |
+| `VLSEG7E64FFV` |  |
+| `VLSEG7E64V` |  |
+| `VLSEG7E8FFV` |  |
+| `VLSEG7E8V` |  |
+| `VLSEG8E16FFV` |  |
+| `VLSEG8E16V` |  |
+| `VLSEG8E32FFV` |  |
+| `VLSEG8E32V` |  |
+| `VLSEG8E64FFV` |  |
+| `VLSEG8E64V` |  |
+| `VLSEG8E8FFV` |  |
+| `VLSEG8E8V` |  |
+| `VLSSEG2E16V` |  |
+| `VLSSEG2E32V` |  |
+| `VLSSEG2E64V` |  |
+| `VLSSEG2E8V` |  |
+| `VLSSEG3E16V` |  |
+| `VLSSEG3E32V` |  |
+| `VLSSEG3E64V` |  |
+| `VLSSEG3E8V` |  |
+| `VLSSEG4E16V` |  |
+| `VLSSEG4E32V` |  |
+| `VLSSEG4E64V` |  |
+| `VLSSEG4E8V` |  |
+| `VLSSEG5E16V` |  |
+| `VLSSEG5E32V` |  |
+| `VLSSEG5E64V` |  |
+| `VLSSEG5E8V` |  |
+| `VLSSEG6E16V` |  |
+| `VLSSEG6E32V` |  |
+| `VLSSEG6E64V` |  |
+| `VLSSEG6E8V` |  |
+| `VLSSEG7E16V` |  |
+| `VLSSEG7E32V` |  |
+| `VLSSEG7E64V` |  |
+| `VLSSEG7E8V` |  |
+| `VLSSEG8E16V` |  |
+| `VLSSEG8E32V` |  |
+| `VLSSEG8E64V` |  |
+| `VLSSEG8E8V` |  |
+| `VLUXEI16V` |  |
+| `VLUXEI32V` |  |
+| `VLUXEI64V` |  |
+| `VLUXEI8V` |  |
+| `VLUXSEG2EI16V` |  |
+| `VLUXSEG2EI32V` |  |
+| `VLUXSEG2EI64V` |  |
+| `VLUXSEG2EI8V` |  |
+| `VLUXSEG3EI16V` |  |
+| `VLUXSEG3EI32V` |  |
+| `VLUXSEG3EI64V` |  |
+| `VLUXSEG3EI8V` |  |
+| `VLUXSEG4EI16V` |  |
+| `VLUXSEG4EI32V` |  |
+| `VLUXSEG4EI64V` |  |
+| `VLUXSEG4EI8V` |  |
+| `VLUXSEG5EI16V` |  |
+| `VLUXSEG5EI32V` |  |
+| `VLUXSEG5EI64V` |  |
+| `VLUXSEG5EI8V` |  |
+| `VLUXSEG6EI16V` |  |
+| `VLUXSEG6EI32V` |  |
+| `VLUXSEG6EI64V` |  |
+| `VLUXSEG6EI8V` |  |
+| `VLUXSEG7EI16V` |  |
+| `VLUXSEG7EI32V` |  |
+| `VLUXSEG7EI64V` |  |
+| `VLUXSEG7EI8V` |  |
+| `VLUXSEG8EI16V` |  |
+| `VLUXSEG8EI32V` |  |
+| `VLUXSEG8EI64V` |  |
+| `VLUXSEG8EI8V` |  |
+| `VMACCVV` |  |
+| `VMACCVX` |  |
+| `VMADCVI` |  |
+| `VMADCVIM` |  |
+| `VMADCVV` |  |
+| `VMADCVVM` |  |
+| `VMADCVX` |  |
+| `VMADCVXM` |  |
+| `VMADDVV` |  |
+| `VMADDVX` |  |
+| `VMANDMM` |  |
+| `VMANDNMM` |  |
+| `VMAXUVV` |  |
+| `VMAXUVX` |  |
+| `VMAXVV` |  |
+| `VMAXVX` |  |
+| `VMCLRM` |  |
+| `VMERGEVIM` |  |
+| `VMERGEVVM` |  |
+| `VMERGEVXM` |  |
+| `VMFEQVF` |  |
+| `VMFEQVV` |  |
+| `VMFGEVF` |  |
+| `VMFGEVV` |  |
+| `VMFGTVF` |  |
+| `VMFGTVV` |  |
+| `VMFLEVF` |  |
+| `VMFLEVV` |  |
+| `VMFLTVF` |  |
+| `VMFLTVV` |  |
+| `VMFNEVF` |  |
+| `VMFNEVV` |  |
+| `VMINUVV` |  |
+| `VMINUVX` |  |
+| `VMINVV` |  |
+| `VMINVX` |  |
+| `VMMVM` |  |
+| `VMNANDMM` |  |
+| `VMNORMM` |  |
+| `VMNOTM` |  |
+| `VMORMM` |  |
+| `VMORNMM` |  |
+| `VMSBCVV` |  |
+| `VMSBCVVM` |  |
+| `VMSBCVX` |  |
+| `VMSBCVXM` |  |
+| `VMSBFM` |  |
+| `VMSEQVI` |  |
+| `VMSEQVV` |  |
+| `VMSEQVX` |  |
+| `VMSETM` |  |
+| `VMSGEUVI` |  |
+| `VMSGEUVV` |  |
+| `VMSGEVI` |  |
+| `VMSGEVV` |  |
+| `VMSGTUVI` |  |
+| `VMSGTUVV` |  |
+| `VMSGTUVX` |  |
+| `VMSGTVI` |  |
+| `VMSGTVV` |  |
+| `VMSGTVX` |  |
+| `VMSIFM` |  |
+| `VMSLEUVI` |  |
+| `VMSLEUVV` |  |
+| `VMSLEUVX` |  |
+| `VMSLEVI` |  |
+| `VMSLEVV` |  |
+| `VMSLEVX` |  |
+| `VMSLTUVI` |  |
+| `VMSLTUVV` |  |
+| `VMSLTUVX` |  |
+| `VMSLTVI` |  |
+| `VMSLTVV` |  |
+| `VMSLTVX` |  |
+| `VMSNEVI` |  |
+| `VMSNEVV` |  |
+| `VMSNEVX` |  |
+| `VMSOFM` |  |
+| `VMULHSUVV` |  |
+| `VMULHSUVX` |  |
+| `VMULHUVV` |  |
+| `VMULHUVX` |  |
+| `VMULHVV` |  |
+| `VMULHVX` |  |
+| `VMULVV` |  |
+| `VMULVX` |  |
+| `VMV1RV` |  |
+| `VMV2RV` |  |
+| `VMV4RV` |  |
+| `VMV8RV` |  |
+| `VMVSX` |  |
+| `VMVVI` |  |
+| `VMVVV` |  |
+| `VMVVX` |  |
+| `VMVXS` |  |
+| `VMXNORMM` |  |
+| `VMXORMM` |  |
+| `VNCLIPUWI` |  |
+| `VNCLIPUWV` |  |
+| `VNCLIPUWX` |  |
+| `VNCLIPWI` |  |
+| `VNCLIPWV` |  |
+| `VNCLIPWX` |  |
+| `VNCVTXXW` |  |
+| `VNEGV` |  |
+| `VNMSACVV` |  |
+| `VNMSACVX` |  |
+| `VNMSUBVV` |  |
+| `VNMSUBVX` |  |
+| `VNOTV` |  |
+| `VNSRAWI` |  |
+| `VNSRAWV` |  |
+| `VNSRAWX` |  |
+| `VNSRLWI` |  |
+| `VNSRLWV` |  |
+| `VNSRLWX` |  |
+| `VORVI` |  |
+| `VORVV` |  |
+| `VORVX` |  |
+| `VREDANDVS` |  |
+| `VREDMAXUVS` |  |
+| `VREDMAXVS` |  |
+| `VREDMINUVS` |  |
+| `VREDMINVS` |  |
+| `VREDORVS` |  |
+| `VREDSUMVS` |  |
+| `VREDXORVS` |  |
+| `VREMUVV` |  |
+| `VREMUVX` |  |
+| `VREMVV` |  |
+| `VREMVX` |  |
+| `VRGATHEREI16VV` |  |
+| `VRGATHERVI` |  |
+| `VRGATHERVV` |  |
+| `VRGATHERVX` |  |
+| `VRSUBVI` |  |
+| `VRSUBVX` |  |
+| `VS1RV` |  |
+| `VS2RV` |  |
+| `VS4RV` |  |
+| `VS8RV` |  |
+| `VSADDUVI` |  |
+| `VSADDUVV` |  |
+| `VSADDUVX` |  |
+| `VSADDVI` |  |
+| `VSADDVV` |  |
+| `VSADDVX` |  |
+| `VSBCVVM` |  |
+| `VSBCVXM` |  |
+| `VSE16V` |  |
+| `VSE32V` |  |
+| `VSE64V` |  |
+| `VSE8V` |  |
+| `VSETIVLI` |  |
+| `VSETVL` |  |
+| `VSETVLI` |  |
+| `VSEXTVF2` |  |
+| `VSEXTVF4` |  |
+| `VSEXTVF8` |  |
+| `VSLIDE1DOWNVX` |  |
+| `VSLIDE1UPVX` |  |
+| `VSLIDEDOWNVI` |  |
+| `VSLIDEDOWNVX` |  |
+| `VSLIDEUPVI` |  |
+| `VSLIDEUPVX` |  |
+| `VSLLVI` |  |
+| `VSLLVV` |  |
+| `VSLLVX` |  |
+| `VSMULVV` |  |
+| `VSMULVX` |  |
+| `VSMV` |  |
+| `VSOXEI16V` |  |
+| `VSOXEI32V` |  |
+| `VSOXEI64V` |  |
+| `VSOXEI8V` |  |
+| `VSOXSEG2EI16V` |  |
+| `VSOXSEG2EI32V` |  |
+| `VSOXSEG2EI64V` |  |
+| `VSOXSEG2EI8V` |  |
+| `VSOXSEG3EI16V` |  |
+| `VSOXSEG3EI32V` |  |
+| `VSOXSEG3EI64V` |  |
+| `VSOXSEG3EI8V` |  |
+| `VSOXSEG4EI16V` |  |
+| `VSOXSEG4EI32V` |  |
+| `VSOXSEG4EI64V` |  |
+| `VSOXSEG4EI8V` |  |
+| `VSOXSEG5EI16V` |  |
+| `VSOXSEG5EI32V` |  |
+| `VSOXSEG5EI64V` |  |
+| `VSOXSEG5EI8V` |  |
+| `VSOXSEG6EI16V` |  |
+| `VSOXSEG6EI32V` |  |
+| `VSOXSEG6EI64V` |  |
+| `VSOXSEG6EI8V` |  |
+| `VSOXSEG7EI16V` |  |
+| `VSOXSEG7EI32V` |  |
+| `VSOXSEG7EI64V` |  |
+| `VSOXSEG7EI8V` |  |
+| `VSOXSEG8EI16V` |  |
+| `VSOXSEG8EI32V` |  |
+| `VSOXSEG8EI64V` |  |
+| `VSOXSEG8EI8V` |  |
+| `VSRAVI` |  |
+| `VSRAVV` |  |
+| `VSRAVX` |  |
+| `VSRLVI` |  |
+| `VSRLVV` |  |
+| `VSRLVX` |  |
+| `VSSE16V` |  |
+| `VSSE32V` |  |
+| `VSSE64V` |  |
+| `VSSE8V` |  |
+| `VSSEG2E16V` |  |
+| `VSSEG2E32V` |  |
+| `VSSEG2E64V` |  |
+| `VSSEG2E8V` |  |
+| `VSSEG3E16V` |  |
+| `VSSEG3E32V` |  |
+| `VSSEG3E64V` |  |
+| `VSSEG3E8V` |  |
+| `VSSEG4E16V` |  |
+| `VSSEG4E32V` |  |
+| `VSSEG4E64V` |  |
+| `VSSEG4E8V` |  |
+| `VSSEG5E16V` |  |
+| `VSSEG5E32V` |  |
+| `VSSEG5E64V` |  |
+| `VSSEG5E8V` |  |
+| `VSSEG6E16V` |  |
+| `VSSEG6E32V` |  |
+| `VSSEG6E64V` |  |
+| `VSSEG6E8V` |  |
+| `VSSEG7E16V` |  |
+| `VSSEG7E32V` |  |
+| `VSSEG7E64V` |  |
+| `VSSEG7E8V` |  |
+| `VSSEG8E16V` |  |
+| `VSSEG8E32V` |  |
+| `VSSEG8E64V` |  |
+| `VSSEG8E8V` |  |
+| `VSSRAVI` |  |
+| `VSSRAVV` |  |
+| `VSSRAVX` |  |
+| `VSSRLVI` |  |
+| `VSSRLVV` |  |
+| `VSSRLVX` |  |
+| `VSSSEG2E16V` |  |
+| `VSSSEG2E32V` |  |
+| `VSSSEG2E64V` |  |
+| `VSSSEG2E8V` |  |
+| `VSSSEG3E16V` |  |
+| `VSSSEG3E32V` |  |
+| `VSSSEG3E64V` |  |
+| `VSSSEG3E8V` |  |
+| `VSSSEG4E16V` |  |
+| `VSSSEG4E32V` |  |
+| `VSSSEG4E64V` |  |
+| `VSSSEG4E8V` |  |
+| `VSSSEG5E16V` |  |
+| `VSSSEG5E32V` |  |
+| `VSSSEG5E64V` |  |
+| `VSSSEG5E8V` |  |
+| `VSSSEG6E16V` |  |
+| `VSSSEG6E32V` |  |
+| `VSSSEG6E64V` |  |
+| `VSSSEG6E8V` |  |
+| `VSSSEG7E16V` |  |
+| `VSSSEG7E32V` |  |
+| `VSSSEG7E64V` |  |
+| `VSSSEG7E8V` |  |
+| `VSSSEG8E16V` |  |
+| `VSSSEG8E32V` |  |
+| `VSSSEG8E64V` |  |
+| `VSSSEG8E8V` |  |
+| `VSSUBUVV` |  |
+| `VSSUBUVX` |  |
+| `VSSUBVV` |  |
+| `VSSUBVX` |  |
+| `VSUBVV` |  |
+| `VSUBVX` |  |
+| `VSUXEI16V` |  |
+| `VSUXEI32V` |  |
+| `VSUXEI64V` |  |
+| `VSUXEI8V` |  |
+| `VSUXSEG2EI16V` |  |
+| `VSUXSEG2EI32V` |  |
+| `VSUXSEG2EI64V` |  |
+| `VSUXSEG2EI8V` |  |
+| `VSUXSEG3EI16V` |  |
+| `VSUXSEG3EI32V` |  |
+| `VSUXSEG3EI64V` |  |
+| `VSUXSEG3EI8V` |  |
+| `VSUXSEG4EI16V` |  |
+| `VSUXSEG4EI32V` |  |
+| `VSUXSEG4EI64V` |  |
+| `VSUXSEG4EI8V` |  |
+| `VSUXSEG5EI16V` |  |
+| `VSUXSEG5EI32V` |  |
+| `VSUXSEG5EI64V` |  |
+| `VSUXSEG5EI8V` |  |
+| `VSUXSEG6EI16V` |  |
+| `VSUXSEG6EI32V` |  |
+| `VSUXSEG6EI64V` |  |
+| `VSUXSEG6EI8V` |  |
+| `VSUXSEG7EI16V` |  |
+| `VSUXSEG7EI32V` |  |
+| `VSUXSEG7EI64V` |  |
+| `VSUXSEG7EI8V` |  |
+| `VSUXSEG8EI16V` |  |
+| `VSUXSEG8EI32V` |  |
+| `VSUXSEG8EI64V` |  |
+| `VSUXSEG8EI8V` |  |
+| `VWADDUVV` |  |
+| `VWADDUVX` |  |
+| `VWADDUWV` |  |
+| `VWADDUWX` |  |
+| `VWADDVV` |  |
+| `VWADDVX` |  |
+| `VWADDWV` |  |
+| `VWADDWX` |  |
+| `VWCVTUXXV` |  |
+| `VWCVTXXV` |  |
+| `VWMACCSUVV` |  |
+| `VWMACCSUVX` |  |
+| `VWMACCUSVX` |  |
+| `VWMACCUVV` |  |
+| `VWMACCUVX` |  |
+| `VWMACCVV` |  |
+| `VWMACCVX` |  |
+| `VWMULSUVV` |  |
+| `VWMULSUVX` |  |
+| `VWMULUVV` |  |
+| `VWMULUVX` |  |
+| `VWMULVV` |  |
+| `VWMULVX` |  |
+| `VWREDSUMUVS` |  |
+| `VWREDSUMVS` |  |
+| `VWSUBUVV` |  |
+| `VWSUBUVX` |  |
+| `VWSUBUWV` |  |
+| `VWSUBUWX` |  |
+| `VWSUBVV` |  |
+| `VWSUBVX` |  |
+| `VWSUBWV` |  |
+| `VWSUBWX` |  |
+| `VXORVI` |  |
+| `VXORVV` |  |
+| `VXORVX` |  |
+| `VZEXTVF2` |  |
+| `VZEXTVF4` |  |
+| `VZEXTVF8` |  |
+| `WFI` |  |
+| `WORD` |  |
+| `XNOR` |  |
+| `XOR` | Bitwise XOR |
+| `XORI` | XOR immediate |
+| `ZEXTH` |  |
+
+Recognised: 975 mnemonics.

docs/asm/LANGUAGE.md

@@ -0,0 +1,140 @@
+# Language: lexicon, statements and expressions
+
+Layer 1, the common language, the same on every target. Verified against
+`go tool asm` of Go 1.27.1 and against gasm's parser, which is differentially
+tested against the toolchain. The authoritative sources behind this page are
+the assembler's lexer (`cmd/asm/internal/lex`), its parser
+(`cmd/asm/internal/asm/parse.go`) and the toolchain's own test data.
+
+## Source files and targets
+
+An assembly source is a `.s` file. The Go build convention names a
+target-specific file with the architecture suffix, `_amd64.s`, `_arm64.s`,
+`_riscv64.s` or `_loong64.s`; files without a suffix are portable across
+targets. The same assembler program assembles every target: `go tool asm`
+picks the target from the `GOOS` and `GOARCH` environment variables, and gasm
+from the file name suffix or the `--arch` flag.
+
+## Character set and identifiers
+
+Sources are ASCII text. An identifier is a sequence of ASCII letters, digits
+and underscores, digits never first, with exactly two additions:
+
+- U+00B7, the middle dot `·`, stands for the period in a symbol's
+  package-qualified name;
+- U+2215, the division slash `∕`, stands for the slash in a package path.
+
+The two substitutions exist because the parser treats a real period and a
+real slash as punctuation. The syntax is otherwise uppercase throughout:
+instructions, registers and directives are written in upper case. The one
+inherited exception is the `g` register name on 32-bit ARM.
+
+## Comments
+
+Two comment forms, both Go's:
+
+```text
+// a line comment
+/* a block comment */
+```
+
+A comment of the form `//go:build` or the legacy `+build` comment is not a
+plain comment: the lexer reports it to the build system as a build
+constraint.
+
+## Statements
+
+The grammar of one line, from the parser:
+
+```text
+{label:} WORD[.qualifier] [ arg {, arg} ] (';' | '\n')
+```
+
+- A **label** is an identifier followed by a colon. Labels are
+  function-local: two functions in one file may reuse the same name, and a
+  reference resolves within the function that contains it. A branch
+  instruction names its target with a bare label operand, and the assembler
+  resolves it PC-relative. The explicit forms `offset(PC)`, a constant
+  counting instructions from the branch, and `name(SB)`, a cross-function
+  static reference, appear as branch targets as well.
+- **WORD** is the instruction or directive name, upper case. On the ARM
+  family the word may carry a dot qualifier selecting a condition or shift
+  mode, such as the condition suffixes on 32-bit ARM; the amd64, arm64,
+  riscv64 and loong64 assemblies carry no instruction qualifiers apart from
+  their own width suffixes, which are part of the mnemonic.
+- **Arguments** are separated by commas, with no trailing comma.
+- A statement ends at a newline or at a semicolon, so several statements fit
+  on one line separated by `;`. Blank lines are free.
+
+The first word of a line is a directive if it is one of the directive names
+(TEXT, DATA, GLOBL, FUNCDATA, PCDATA, PCALIGN) and an instruction otherwise.
+Unknown instruction names are errors; the instruction set is the set the
+toolchain itself defines per target, plus the common pseudo-instructions.
+
+## Literals
+
+| Form | Examples | Notes |
+|---|---|---|
+| Integer | `0`, `42`, `0x2a`, `0o52`, `0b101010`, `1_000` | decimal, hexadecimal, octal and binary forms with Go's digit separators |
+| Character | `'a'`, `'\n'`, `'\x41'` | single quoted, Go escape rules |
+| String | `"this program can only run\n"` | double quoted, Go escape rules; accepted where an operand takes raw bytes, in practice a DATA initialiser |
+| Float | `1.5`, `1e9` | accepted by the lexer; only meaningful where the target's encoding takes a float operand |
+
+## Expressions
+
+Constant expressions may appear wherever a constant is expected: in
+immediates after `$`, in memory offsets, in frame and data sizes. The
+evaluator works on unsigned 64-bit values with Go's operator precedence, and
+the parser states its grammar in exactly those terms:
+
+```text
+expr   = term   { '+' term | '-' term | '|' term | '^' term }
+term   = factor { '*' factor | '/' factor | '%' factor | '<<' factor | '>>' factor | '&' factor }
+factor = const  | '+' factor | '-' factor | '~' factor | '(' expr ')'
+```
+
+Two consequences are worth naming, because the arithmetic surprises people
+who read it as C:
+
+- Shifts bind at the multiplicative level, next to `*` and `&`, while `|`
+  and `^` bind at the additive level. `$x<<1|3` computes `(x<<1)|3`, which
+  differs from `x*2+3` whenever `x` is odd. Plan 9 arithmetic is Go
+  precedence applied to a byte-oriented language, not the C expression it
+  resembles.
+- The evaluator is unsigned and guarded: division or modulo by zero is an
+  error, and so is dividing a value with the high bit set; shift counts must
+  be non-negative; and a right shift of a value with the high bit set is
+  rejected rather than sign-extended.
+
+An address expression such as `(index*4)(base)` is evaluated at assembly
+time only if every name in it is a constant; a name that resolves to a
+symbol turns the expression into a relocation request, never into a folded
+constant.
+
+Named constants enter expressions through the preprocessor (`#define`,
+`-D`) and, in Go-embedded packages, through the generated `go_asm.h`; see
+PREPROCESSOR.md and RUNTIME.md.
+
+## The common pseudo-instructions
+
+A handful of instructions exist on every target, assembled by the assembler
+itself rather than the encoder: `NOP`, which emits the target's no-operation
+encoding, and the frame-management pseudo-instructions the compiler emits
+(`FUNCDATA`, `PCDATA`) which DIRECTIVES.md specifies. Everything else is the
+target's own instruction set, and the assembler knows only the instructions
+the toolchain's compiler emits; a hand-written kernel wanting more lays the
+encoding down with `BYTE` on amd64 or waits for the extended layer.
+
+## Case study: three lines, decomposed
+
+```text
+B.EQ	1(PC)                  // arm64: condition qualifier on the mnemonic,
+                               // target one instruction past the branch
+JMP	done                   // every target: bare label, function-local,
+                               // resolved PC-relative
+MOVQ	$reader__size>>3, CX   // amd64: expression over a go_asm.h constant
+```
+
+The first shows a qualifier and the explicit relative target form; the second
+the ordinary label reference; the third an expression over a generated
+constant. Labels are reusable between functions without conflict.

docs/asm/LOONG64.md

@@ -0,0 +1,94 @@
+# LoongArch 64
+
+Layer 1, target page. Verified against `go tool asm` of Go 1.27.1, against
+the toolchain's own loong64 assembler manual (`cmd/internal/obj/loong64/doc.go`)
+and against gasm's encoder, whose output is compared byte for byte with the
+toolchain's. The complete mnemonic inventory lives in the generated appendix
+[INSTRUCTIONS-LOONG64.md](INSTRUCTIONS-LOONG64.md).
+
+## Registers
+
+- General purpose `R0` to `R31`, floating point `F0` to `F31`, LSX vectors
+  `V0` to `V31` and LASX vectors `X0` to `X31`.
+- Fixed roles from the toolchain's table: `R0` is the constant zero, `R1`
+  the return address, `R3` the stack pointer, `R22` the goroutine pointer,
+  `R29` the closure context and `R30` the assembler's temporary. `R12`,
+  `R13`, `R14`, `R15` and `R20` serve the PLT and trampoline sequences:
+  usable in assembly, but saved before any call.
+
+## Widths ride the mnemonic
+
+| Suffix | Width |
+|---|---|
+| `B`, `BU` | 8-bit, 8-bit unsigned |
+| `H`, `HU` | 16-bit, 16-bit unsigned |
+| `W`, `WU` | 32-bit, 32-bit unsigned |
+| `V` | 64-bit |
+| `F`, `D` | 32-bit and 64-bit float |
+| `V` prefix (LSX) | 128-bit vector |
+| `XV` prefix (LASX) | 256-bit vector |
+
+The MOV series is the load and store interface: `MOVB (R2), R3` loads a
+byte, `MOVV (R2), R3` a double word, `VMOVQ (R2), V1` a 128-bit vector and
+`XVMOVQ (R2), X1` a 256-bit one.
+
+## Operand order
+
+Most instructions appear in left-to-right assignment order: `ADDV R11, R12,
+R13` is `add.d R13, R12, R11`, and the two-operand form
+`OR R5, R6` assigns into R6. Exceptions:
+
+- Jump and branch instructions keep the GNU order: `BEQ R0, R4, label1`.
+- The bitfield family is `BSTRINSW`, `BSTRINSV`, `BSTRPICKW`, `BSTRPICKV`
+  `$<msb>, <Rj>, $<lsb>, <Rd>`.
+
+## Addressing
+
+- Plain: `offset(Rbase)`.
+- Base plus offset **register**, no scale: `(R4)(R5)`, as in
+  `MOVB (R4)(R5), R6`, the `ldx` family.
+- The pointer loads and stores `MOVWP` and `MOVVP` take a source-level
+  16-bit offset that the encoder halves into the 14-bit field, writing
+  `MOVWP 8(R4), R5` as `ldptr.w r5, r4, $2`.
+
+## Vector element syntax
+
+The `VMOVQ` and `XVMOVQ` transfer family covers register-to-vector moves
+with arrangement and index suffixes: `VMOVQ Rj, Vd.B[index]` inserts a
+general register into one lane, `VMOVQ Vj.B[index], Rd` extracts one,
+`VMOVQ Rj, Vd.B16` broadcasts across all sixteen, and `VMOVQ Vj.B[index],
+Vd.B16` replicates one lane. The broadcast-from-memory form takes the true
+byte offset at source level, which the encoder rescales per arrangement.
+The permute and extract families take their 8-bit control word first:
+`VPERMIW ui8, Vj, Vd`, `VEXTRINSB ui8, Vj, Vd`.
+
+## Alignment
+
+`PCALIGN $n` pads with NOOP to a power-of-two boundary between 8 and 2048,
+and this target additionally auto-aligns loop heads to 16 bytes.
+
+## Atomics, barriers and prefetch
+
+- The `AM` atomic family comes in plain and `_DB` flavours; the `_DB`
+  forms, such as `AMSWAPDBW`, complete the atomic sequence and act as a
+  full data barrier. Within the AM family the destination and base
+  registers may not coincide and the destination may not equal the operand
+  register: one is an exception, the other silently unspecified.
+- `DBAR` carries the graded hint encoding documented for LA664 and later,
+  with hint 0x700 as the read-after-read lightweight barrier; older cores
+  treat every hint as the full barrier.
+- `PRELD offset(Rbase), $hint` prefetches with the documented hints (0
+  load to L1, 2 load to L3, 8 store to L1); `PRELDX` adds the encoded
+  block descriptor.
+- `ALSL`-family shift-and-add writes the desired shift amount in source and
+  encodes one less: `ALSLV $4, R4, R5, R6` shifts by 4.
+- `ADDV16 si16<<16, Rj, Rd` is the high-immediate add paired with the
+  pointer loads for GOT relative access.
+
+## Relocations
+
+`R_CALLLOONG64` for the 28-bit BL, `R_LOONG64_CALL36` for the
+PCADDU18I-plus-JIRL pair, the `R_LOONG64_ADDR`, `ADDR64`, `TLS_LE`, `TLS_IE`,
+`GOT` and `GOT64` high and low pairs, the aligned conditional jump forms
+`R_JMP16LOONG64` and `R_JMP21LOONG64`, and `R_LOONG64_ADD64` and `SUB64`
+for in-place arithmetic, all specified in [GOOBJ.md](../GOOBJ.md).

docs/asm/OPERANDS.md

@@ -0,0 +1,114 @@
+# Operands: grammar, pseudo-registers, addressing and symbols
+
+Layer 1, the common language. Verified against `go tool asm` of Go 1.27.1 and
+against gasm's parser. The operand grammar is the part of the language that
+varies most between targets, so this page fixes the common grammar and the
+pseudo-registers; the per architecture pages carry the register names and the
+addressing quirks each target adds.
+
+## The four operand kinds
+
+Every operand is one of four kinds:
+
+```text
+R1                  register
+$4                  immediate
+label               branch target or symbol
+-8(BX)(DI*4)        memory
+```
+
+**Operands go source first, destination last**: `MOVQ x+0(FP), AX` loads the
+argument into AX. This is the opposite of Intel order and the same order as
+AT&T, with the sigils removed: registers are bare names, immediates take
+`$`, memory is `offset(base)`.
+
+## Registers
+
+A register operand is its bare name, with no prefix: `AX`, `X15`, `R14` on
+amd64; `R0` to `R30`, `ZR`, `V0` to `V31` on arm64; `X0` to `X31`, `F0` to
+`F31`, `V0` on riscv64; `R0` to `R31`, `F0` to `F31`, `V0` on loong64.
+Sub-register and width selection rides the mnemonic, not the operand: the
+amd64 family spells `MOVB`, `MOVW`, `MOVL`, `MOVQ`, and the arm64 family
+suffices `B`, `H`, `S`, `D`, `Q` on the shared forms. Each architecture page
+lists its registers and the reserved ones.
+
+## Immediates
+
+`$` introduces a constant: `$42`, `$-1`, `$0x2a`, `$'A'`, `$bufSize`. The
+`$` applies to the whole constant expression that follows, so
+`$(4*8+reader__size)` is one immediate. Without the `$`, a number in operand
+position is an address, not a value; the classic error `ADDQ 1, AX` asks the
+assembler for the byte at address 1.
+
+The one place a `$` number is not an immediate is the frame and argument
+size field of TEXT, `$16-24`, which is two separate constants and not a
+subtraction; DIRECTIVES.md specifies it.
+
+## Memory
+
+```text
+offset(base)
+offset(base)(index*scale)
+```
+
+Both parts are optional where the target allows them: `(BX)` is the memory
+at BX, `foo+16(SB)` is a global, and on amd64 `foo+32(SP)(R9*8)` adds a
+scaled index. `offset` is a constant expression, optionally carrying a
+symbol name. The extensions beyond `offset(base)` are where the targets
+diverge, and each belongs to its architecture page: amd64 carries the
+`index*scale` form with scale 1, 2, 4 or 8 and its own rules on which
+registers may index; loong64 writes base plus index as `(R4)(R5)`; the ARM
+family attaches shift amounts to the index register in its own spelling.
+
+The address arithmetic is on **byte addresses**: the offset is added to the
+base as it stands, whatever the operand width of the instruction. Loading
+the third 8-byte word of an array at BX is `16(BX)`, not `2(BX)`.
+
+## The four pseudo-registers
+
+Four names denote locations no target register holds, and they mean the same
+on every architecture:
+
+- **FP**, the frame pointer: the arguments and results of the current
+  function, at positive offsets, in the order the Go prototype declares
+  them. Every FP reference must carry a name: `x+0(FP)`, and an unnamed
+  `0(FP)` is rejected. Results follow arguments; an unnamed result is called
+  `ret`.
+- **SP**, the virtual stack pointer: the high end of the function's local
+  frame, so locals live at negative offsets, `x-8(SP)`. A reference without
+  a name and without a plus, `-8(SP)`, addresses the **hardware** stack
+  pointer instead: the two spellings are one character apart and mean
+  different registers. That is the sharpest edge in the language and the
+  source of the deepest bugs.
+- **SB**, the static base: the origin of memory, used for globals and
+  cross-package symbols, always with a name: `foo(SB)`, `foo+4(SB)`.
+- **PC**, the program counter: branch targets, and the explicit relative
+  form `1(PC)`.
+
+## Symbol names
+
+A symbol's full name is the package path, a period, and the base name. In
+source, the period is written U+00B7 (`·`) and a slash in the path U+2215
+(`∕`), because the parser treats the ASCII forms as punctuation. Inside the
+package's own file, `·Name` is enough and is the preferred spelling, since
+it survives a rename of the import path.
+
+| Spelling | Meaning |
+|---|---|
+| `·Name(SB)` | this package's Name |
+| `runtime·morestack(SB)` | another package's morestack |
+| `sourcedock.dev∕petrbalvin∕pkg·Name(SB)` | fully qualified |
+| `msg<>(SB)` | file-local, the static of this language; `<>` also makes the ABI field static in the object |
+| `Name<ABIInternal>(SB)` | ABI-qualified reference, the ABI in angle brackets after the name |
+
+The object file these symbols produce, with the index rules that decide what
+is referenced by name and what by index, is specified in
+[GOOBJ.md](../GOOBJ.md).
+
+## What vet adds in Go
+
+Inside a Go package, `go vet`'s asmdecl analyzer checks every FP offset and
+name against the Go prototype, and checks the declared argument area against
+the frame. That layer, the prototype requirement and `go_asm.h`, belongs to
+RUNTIME.md; the grammar above is the whole of what the assembler itself
+requires.

docs/asm/PREPROCESSOR.md

@@ -0,0 +1,79 @@
+# Preprocessing: include, define and selection
+
+Layer 1, the common language. Verified against the preprocessor inside
+`go tool asm` of Go 1.27.1 (`cmd/asm/internal/lex`), whose directives are
+`#define`, `#undef`, `#include`, `#ifdef`, `#ifndef`, `#else`, `#endif` and
+`#line`, and against gasm's implementation, which is differentially tested
+against the toolchain's.
+
+Input runs through a simplified C preprocessor before the parser sees it.
+The set is deliberately small: there is no `#if` with constant expressions
+and no token pasting with `##`. `#line` is honoured, so it changes the
+positions the assembler reports and records.
+
+## #include
+
+```text
+#include "textflag.h"
+#include "go_asm.h"
+#include "defs_linux_amd64.h"
+```
+
+The search path, in order: the directory of the including file, then the
+directories given by repeatable `-I` flags. The assembler seeds no default
+of its own: a bare `go tool asm` invocation finds none of the standard
+headers, and it is the `go` build system that passes `$GOROOT/pkg/include`
+among the `-I` directories when it drives the build. That directory ships
+`textflag.h`, `funcdata.h` and the per architecture register headers.
+Includes nest; a file included twice through different paths is processed
+twice, which is why headers guard their defines.
+
+## #define and #undef
+
+```text
+#define bufSize 1024
+#define MOVD(d, s) MOVQ s, d
+#undef bufSize
+```
+
+- An object macro replaces its name with its token sequence at the point of
+  use.
+- A parameterised macro takes its arguments in parentheses and substitutes
+  them into the body. Macro parameters compose with the rest of the
+  language: an argument used with an element suffix, as in `A.S4` on the
+  vector forms, substitutes correctly.
+- Redefinition is an error; `#undef` first, or pick a new name.
+- The `-D name[=value]` flag predefines an object macro from the command
+  line, repeatable, exactly as `#define` would; a `-D` without a value
+  defines the name as `1`.
+- Expansion happens when the name is used, so a macro may expand to
+  instructions, operands or fragments of either, and a macro body may use
+  macros defined before it.
+
+`textflag.h` and `funcdata.h` are themselves ordinary `#define` files: the
+flag names and the runtime macros are preprocessor definitions, not language
+keywords. That is why a missing include produces a parser error at the first
+use of `NOSPLIT` rather than a complaint about the name.
+
+## #ifdef, #ifndef, #else, #endif
+
+```text
+#ifdef GOOS_windows
+	#define SYSCALL_INT 0x2b
+#endif
+```
+
+Selection is by defined-name only: `#ifdef`, `#ifndef`, `#else`, `#endif`,
+nesting freely. There is no `#if defined(x) && y`, because the preprocessor
+evaluates no expressions; reach that with a build-tag Go file generating a
+header, which is exactly how the runtime's own `go_asm.h` and defs headers
+are produced.
+
+## What preprocessing does not cover
+
+The preprocessor is textual and runs first, so it knows nothing of assembly
+semantics: it does not check that a macro expansion is a legal instruction,
+and it does not participate in the constant expression evaluator, which runs
+later, in the parser. A constant folded with `#define` and a constant folded
+in an operand expression end at the same value through different doors;
+GOOBJ.md records both in the object identically.

docs/asm/README.md

@@ -0,0 +1,56 @@
+# The Plan 9 assembly language
+
+This directory is the reference for the Plan 9 assembly language as the Go
+toolchain and gasm accept it, written to be complete enough to implement
+against. It exists because no such reference exists upstream: Go documents
+the language on a single page, and the rest of the knowledge lives in the
+toolchain's source and in the practice of reading it.
+
+Every page carries the same conformance statement: which layer of the system
+it describes, which toolchain release it was verified against, and how the
+claims were checked. Pages in this directory are verified against Go 1.27.1
+and against gasm's own differential test suite, which compares gasm's
+behaviour with `go tool asm` byte for byte and output for output.
+
+## The three layers
+
+The reference deliberately separates three layers, because their rules have
+different owners and different lifetimes:
+
+1. **The common language** (LANGUAGE, OPERANDS, DIRECTIVES,
+   PREPROCESSOR): the syntax, operands, directives and preprocessing, the
+   same on every target and meaningful without a Go runtime.
+2. **The Go-embedded layer** (RUNTIME): everything that exists only because
+   the code runs inside a Go program: the ABI0 contract, generated wrappers,
+   `go_asm.h`, the garbage collector annotations and `go vet` checks.
+3. **The standalone layer** (STANDALONE, planned with the standalone
+   compilation phase): using the language outside Go, through gasm's ELF
+   output and the extended instruction set, where the toolchain offers no
+   ground truth and execution testing is the only verification.
+
+A rule stated in layer 1 holds on every target. A rule stated in layer 2
+says which part of the Go machinery imposes it. Nothing in layer 3 changes
+layers 1 or 2; it extends them.
+
+## Pages
+
+| Page | Layer | Contents |
+|---|---|---|
+| [LANGUAGE.md](LANGUAGE.md) | 1 | lexicon, statement structure, labels, literals, expressions |
+| [OPERANDS.md](OPERANDS.md) | 1 | operand grammar, pseudo-registers, addressing modes, symbol naming |
+| [DIRECTIVES.md](DIRECTIVES.md) | 1 | TEXT, DATA, GLOBL, FUNCDATA, PCDATA, PCALIGN and the function flags |
+| [PREPROCESSOR.md](PREPROCESSOR.md) | 1 | `#include`, `#define`, `#ifdef` and friends, `-D`, `-I` |
+| [RUNTIME.md](RUNTIME.md) | 2 | ABI0, prototypes, `go_asm.h`, `funcdata.h`, `go vet` |
+| [AMD64.md](AMD64.md) | 1 | registers, addressing, the frame and split check, families, relocations |
+| [ARM64.md](ARM64.md) | 1 | registers, the MOV load and store series, special operand orders, SIMD |
+| [RISCV64.md](RISCV64.md) | 1 | registers and their constrained names, per class operand order, profiles, vector extension |
+| [LOONG64.md](LOONG64.md) | 1 | registers, width suffixes, vector element syntax, atomics and barriers |
+| INSTRUCTIONS-AMD64.md and the other three | 1 | generated per architecture inventory of every accepted mnemonic |
+| STANDALONE.md | 3 | the language outside Go |
+
+## Status
+
+The common-language core, the Go-embedded layer, all four per-architecture
+pages and the generated instruction appendices are written and verified.
+STANDALONE.md lands with the standalone compilation phase. The object format
+these pages feed is specified in [GOOBJ.md](../GOOBJ.md).

docs/asm/RISCV64.md

@@ -0,0 +1,104 @@
+# RISC-V 64
+
+Layer 1, target page. Verified against `go tool asm` of Go 1.27.1, against
+the toolchain's own riscv64 assembler manual (`cmd/internal/obj/riscv/doc.go`)
+and against gasm's encoder, whose output is compared byte for byte with the
+toolchain's. The complete mnemonic inventory lives in the generated appendix
+[INSTRUCTIONS-RISCV64.md](INSTRUCTIONS-RISCV64.md).
+
+## Registers
+
+- Integer: `X0` to `X31`. `X0` is hardwired zero. Three names the toolchain
+  constrains: `X4` must be written through its ABI name `TP`; `X27`, the
+  goroutine pointer, must be written `g` and may not be written `S11`; in
+  shared builds `X3` is off limits and must be written `GP`.
+- The other integer registers may be written `Xn` or by their ABI names
+  (`A0`, `T0`, `S1`, and so on).
+- Floating point: `F0` to `F31`. Vector: `V0` to `V31`.
+- `X26` is the closure pointer and `X31` is the assembler's own scratch
+  register: its value may be clobbered by instruction sequences the
+  assembler inserts, so hand-written code must not rely on it.
+- There is no reserved frame pointer register on this target.
+
+## Operand order
+
+The ordering differs from the ISA manual, and per instruction class:
+
+- **R-type** is reversed: `ADD X10, X11, X12` is `add x12, x11, x10`.
+- **I-type arithmetic** keeps that shape with the immediate first:
+  `ADDI $1, X11, X12`.
+- **Loads and stores** are source first, like every Plan 9 dialect:
+  `MOV 16(X2), X10` loads and `MOV X10, (X2)` stores. The MOV series hides
+  the width; `MOVB` through `MOVD` spell it out.
+- **Branches** keep the ISA order: `BLT X12, X23, loop1`, which jumps when
+  X12 < X23, the reverse of the SLT operand order.
+- **FMA** is rotated one place left so the destination comes last:
+  `FMADDS F1, F2, F3, F4`.
+- **AMO** is likewise rotated: `AMOSWAPW X5, (X6), X7`.
+- **Ternary abbreviation** is supported and encouraged: `ADD X10, X12` means
+  `ADD X10, X12, X12`.
+
+Where an R-type instruction has an I-type sibling, the assembler picks the
+immediate form from the operand: `AND $3, X12, X13` assembles as `ANDI`.
+
+## Names, suffixes and rounding
+
+Dots are removed and suffixes are upper-cased: the ISA's `fmv.w.x` is
+`FMVWX`. Floating-point rounding modes become suffixes, `FCVTLUS.RNE F0,
+X5`, with RTZ assumed when the suffix is omitted; the toolchain never sets
+the FCSR.
+
+## Constants
+
+- `MOV` materialises any 64-bit integer constant, synthesising it from a
+  few arithmetic instructions where possible and otherwise loading it from
+  a literal pool in the binary.
+- A 32-bit constant is accepted by `ADDI`, `ANDI`, `ORI` and `XORI`, and
+  the assembler synthesises values that exceed the 12-bit encoding window.
+- `MOVF` and `MOVD` materialise floating-point constants, encoding them as
+  `FLW` and `FLD` from a pool location unless the constant is exactly 0.0.
+
+## Extensions and profiles
+
+The default target profile is rva20u64, selected or raised with the
+GORISCV64 environment variable. A short list of instructions outside the
+default profile is synthesised by the assembler when the profile does not
+provide them, so they are safe without guards: `ANDN`, `MAX`, `MAXU`, `MIN`,
+`MINU`, `MOVB`, `MOVH`, `MOVHU`, `MOVWU`, `ORN`, `ROL`, `ROLW`, `ROR`,
+`RORI`, `RORIW`, `RORW`, `XNOR`. The header `asm_riscv64.h` defines the
+`hasZba`, `hasZbb`, `hasZbs` and `hasV` macros for guarding everything else.
+
+## Fences and atomics
+
+`FENCE` takes predecessor and successor sets in that order, uppercase
+letters, `FENCE R, RW`; a bare `FENCE` is a full fence, as is
+`FENCE IORW, IORW`. `FENCE.TSO` exists. The ordering bits of `LR`, `SC`
+and the AMO instructions are not specifiable in source: the assembler sets
+acquire and release on the AMO instructions, acquire on `LR` and release on
+`SC`, always.
+
+## Compressed instructions
+
+The assembler converts 32-bit instructions to their compressed encodings
+automatically; the conversion is a property of the emitted machine code, not
+of the source, and register choice influences how much compresses.
+Hand-writing compressed instructions in source is accepted but discouraged.
+The debug flag `compressinstructions=0` turns the automatic conversion off.
+
+## Vector extension
+
+`VSETVLI` writes its vtype components in uppercase with the destination
+last: `VSETVLI X10, E8, M1, TU, MU, X12`. Vector loads and stores are
+source first like the scalar ones, with an optional stride or index register
+second and the mask register, when present, always penultimate:
+`VLE8V (X10), V3`, `VLE8V (X10), V0, V3` for the masked form. Vector
+arithmetic reverses its operands, `VADDVV V1, V2, V3`, with the mask again
+penultimate.
+
+## Relocations
+
+`R_RISCV_JAL`, `R_RISCV_CALL`, the `R_RISCV_PCREL_ITYPE` and `STYPE` pairs,
+`R_RISCV_BRANCH`, the compressed branch and jump forms, the TLS and GOT
+families and `R_RISCV_ADD32` and `SUB32`, all specified in
+[GOOBJ.md](../GOOBJ.md). The assembler always emits the four-byte
+`R_DWTXTADDR_U4` flavour inside its DWARF records.

docs/asm/RUNTIME.md

@@ -0,0 +1,120 @@
+# The Go-embedded layer: ABI0, prototypes and the runtime contract
+
+Layer 2: everything that exists only because the assembly runs inside a Go
+program. Without a Go runtime this page does not apply; the language of
+OPERANDS.md and DIRECTIVES.md still does. Verified against Go 1.27.1, against
+the shipped `funcdata.h` header, and against the object files the toolchain
+produces, which were parsed and checked field by field while writing
+[GOOBJ.md](../GOOBJ.md).
+
+## Hand-written assembly is ABI0
+
+Go functions compiled from source use ABIInternal, the register-based
+calling convention, which the toolchain documents as unstable and free to
+change between releases. A `.s` function is written against ABI0, the stack
+based convention: arguments and results live in the caller's frame at
+positive FP offsets, byte-addressed, in declaration order, with no registers
+assigned at all. The toolchain generates the wrapper that translates between
+the two; a caller in Go calling an assembly function goes through it, and it
+is marked `ABIWRAPPER` in the object. Hand-writing a bridge is never needed
+and never correct.
+
+## Every assembly function carries a Go prototype
+
+```go
+package add
+
+func Add(x, y int64) int64
+```
+
+The body-less declaration is not optional, and not only for the linker: it
+is what tells the garbage collector which arguments and results hold
+pointers, and what `go vet` checks the assembly against. Even a function
+nothing in Go calls gets one. Consequences:
+
+- The FP operand names and offsets are checked by vet's asmdecl analyzer
+  against the prototype: `x+0(FP)` must name an argument that exists, at the
+  offset the prototype says. A file that assembles and links can still fail
+  vet.
+- The declared argument area in `$framesize-argsize` is checked against the
+  prototype's size. An omitted argsize marks the argument size unknown
+  (0x80000000 in the object, the value of `ArgsSizeUnknown` from
+  `funcdata.h`), which is the normal spelling for functions with no Go
+  callers.
+- `//go:noescape` on the declaration tells the compiler that a pointer
+  argument does not escape, for assembly that keeps the pointer beyond the
+  call.
+
+## The frame, the stack and the collector
+
+The runtime owns the stack and the pointer map, and assembly must hold up
+its end of four rules:
+
+1. **Arguments are initialised on entry; results are not.** A function whose
+   results hold live pointers across a call must zero them and then execute
+   `GO_RESULTS_INITIALIZED`. Designing functions that return no pointers
+   avoids the problem.
+2. **A frame with calls and no local pointers says so** with
+   `NO_LOCAL_POINTERS`. A frame with local pointers that the runtime cannot
+   see is not allowed at all: assembly cannot describe a pointer-containing
+   local, so it must not have one. Data symbols containing pointers are the
+   same: define them in Go.
+3. **The stack may move.** Stack growth copies the frame, so no pointer into
+   the frame may be held across a call, and the raw hardware SP register may
+   not be cached across a call either.
+4. **The split check is not optional by default.** Without NOSPLIT, the
+   assembler inserts the stack-growth preamble, including the morestack
+   block for framed functions; NOSPLIT is a contract that the frame and
+   everything below it fit in the remaining stack segment. On amd64 the
+   assembler also marks small leaf functions NoSplit itself and skips the
+   preamble, so silence is not a promise.
+
+The simplest safe shape is a leaf function with no local frame and no calls:
+it needs no annotation beyond the prototype.
+
+## go_asm.h: Go constants and layout in assembly
+
+A package with `.s` files gets a generated header. Include it and use the
+generated names instead of hard-coding layouts, which lie silently when the
+Go side changes:
+
+| Go declaration | Assembly name |
+|---|---|
+| `const bufSize = 1024` | `const_bufSize` |
+| field `r` of `type reader struct` | `reader_r` |
+| size of `type reader struct` | `reader__size` |
+
+The constants arrive as macros, usable as immediates and offsets, computed
+from the Go declarations. An ambiguous name, such as a struct that really
+has a `_size` field, fails the generation with a redefinition error.
+
+## funcdata.h: the runtime macros
+
+`$GOROOT/pkg/include/funcdata.h` defines the PCDATA and FUNCDATA ids and the
+three macros assembly normally uses instead:
+
+| Macro | Expands to | Meaning |
+|---|---|---|
+| `GO_ARGS` | `FUNCDATA $FUNCDATA_ArgsPointerMaps, go_args_stackmap(SB)` | the Go prototype defines the argument pointer map |
+| `GO_RESULTS_INITIALIZED` | `PCDATA $PCDATA_StackMapIndex, $1` | results are initialised; treat them as live from here |
+| `NO_LOCAL_POINTERS` | `FUNCDATA $FUNCDATA_LocalsPointerMaps, no_pointers_stackmap(SB)` | the frame holds no pointers |
+
+`GO_ARGS` is inserted implicitly by the assembler for any function whose
+package-qualified name belongs to the current package, which is why most
+assembly never writes it. `NOSPLIT` leaf functions that call nothing need
+none of the three.
+
+The underlying ids, for reading toolchain output rather than for writing
+source: FUNCDATA 0 to 7 are args pointer maps, locals pointer maps, stack
+objects, inline tree, open-coded defer info, argument info, argument
+liveness and wrap info; PCDATA 0 to 4 are unsafe point, stack map index,
+inline tree index, argument liveness index and panic bounds.
+
+## What the runtime does with all of this
+
+The object file records the annotations as aux symbols and FuncInfo records;
+GOOBJ.md specifies the encoding. The linker assembles them into the runtime's
+pclntable, which traceback and the collector consume. An assembly function
+that misdeclares its frame is not a compile error and usually not a link
+error: it is a wrong collector decision or a wrong traceback at runtime,
+which is why the annotations are a contract and not documentation.

docs/man/gasm-asm.1

@@ -2,7 +2,7 @@
 .SH NAME
 gasm-asm \- assemble Plan 9 assembly without the Go toolchain
 .SH SYNOPSIS
-.B gasm asm [\-\-format raw|elf|goobj] [\-I dir] [\-p pkg] [\-GOARCH arch] [\-o out] <file>
+.B gasm asm [\-\-format raw|elf|goobj] [\-I dir] [\-p pkg] [\-GOARCH arch] [\-GOOS os] [\-o out] <file>
 .SH DESCRIPTION
 Assemble FILE without the Go toolchain: every TEXT function is encoded
 to machine code and printed as a hex dump.  Supported architectures:
@@ -42,6 +42,15 @@ need no toolchain at all.
 Framed functions receive the stack-split guard and the trailing
 morestack block, byte-identical to the toolchain's output, so split
 functions link too.
+.PP
+A file that includes go_asm.h gets that header generated from the Go
+files beside it, type-checked for the target.
+.B \-GOOS
+selects the type-checking GOOS for that header, because a GOOS-specific
+file needs its platform's defines: sys_darwin_arm64.s fails against the
+ambient GOOS (machTimebaseInfo_numer is missing from a linux type-check)
+and assembles with
+.BR "\-GOOS darwin" .
 .SH OPTIONS
 .TP
 .B \-\-format \fIraw|elf|goobj\fR
@@ -59,6 +68,10 @@ Target architecture: amd64, arm64, riscv64 or loong64; overrides the
 file-name suffix, which is how the suffix-less majority of GOROOT's
 files (cpu_x86.s, stub.s, ...) become assemblable.
 .TP
+.B \-GOOS \fIos\fR
+Operating system for the generated go_asm.h: any GOOS go/build
+recognises in file names; the default is the host's.
+.TP
 .B \-o \fIfile\fR
 Write the output to this file instead of a hex dump on stdout.
 .SH EXIT STATUS

docs/man/gasm-audit-instructions.1

@@ -1,8 +1,8 @@
-.TH GASM-AUDIT-INSTRUCTIONS 1 "2026-09-19" "gasm" "User Commands"
+.TH GASM-AUDIT-INSTRUCTIONS 1 "2026-09-21" "gasm" "User Commands"
 .SH NAME
 gasm-audit-instructions \- diff the encoder against the Go toolchain, or measure a corpus
 .SH SYNOPSIS
-.B gasm audit\-instructions [\-\-corpus [\fIdir\fR]] [\-I dir] [amd64|arm64|riscv64|loong64]
+.B gasm audit\-instructions [\-\-corpus [\fIdir\fR]] [\-\-list] [\-I dir] [amd64|arm64|riscv64|loong64]
 .SH DESCRIPTION
 Compare the gasm encoder for the given architecture (default amd64)
 against
@@ -39,6 +39,12 @@ second.
 Assemble a corpus of .s files and report pass rates and failure
 reasons.
 .TP
+.B \-\-list
+With
+.BR \-\-corpus ,
+print every failing file with its failure reason, per architecture,
+instead of one representative file per reason.
+.TP
 .B \-I \fIdir\fR
 Directory to search for #include files; may be repeated, searched in
 order after the source directory.  A corpus run whose files include

format/format.go

@@ -241,6 +241,13 @@ func renderInstr(line []token.Token, width int) string {
 	if line[0].Kind != token.Ident {
 		return "\t" + mnem + " " + ops
 	}
+	// A statement separator belongs to the statement it ends: when the
+	// operands open with a ';', the alignment padding would land between
+	// the mnemonic and its own separator (REP  ; MOVSQ), so such a line
+	// renders with a single space whatever the function's width.
+	if strings.HasPrefix(ops, ";") {
+		return "\t" + mnem + " " + ops
+	}
 	if width < len(mnem) {
 		width = len(mnem)
 	}

format/format_test.go

@@ -364,6 +364,17 @@ func TestSemicolonSeparators(t *testing.T) {
 			in:   "TEXT ·f(SB), $0\nBYTE $1;\nRET\n",
 			want: "TEXT ·f(SB), $0\n\tBYTE $1;\n\tRET\n",
 		},
+		{
+			// The REP shape: a prefix-style zero-operand statement
+			// followed by the instruction it prefixes.  The separator
+			// belongs to the statement it ends, so the function's
+			// alignment width (MOVSQ is the widest mnemonic here) must
+			// not open a gap before it: one space after the mnemonic
+			// whatever the neighbours' lengths.
+			name: "after a prefix-style statement",
+			in:   "TEXT ·f(SB), $0\nMOVQ AX, BX\nREP; MOVSQ\nRET\n",
+			want: "TEXT ·f(SB), $0\n\tMOVQ AX, BX\n\tREP ; MOVSQ\n\tRET\n",
+		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {

parser/parser.go

@@ -304,7 +304,7 @@ func (p *state) parseGlobl(line []token.Token) *ast.Globl {
 		rest = rest[1:]
 	}
 	if len(rest) > 0 && rest[0].Kind == token.Dollar {
-		g.Size = parseOperand(rest)
+		g.Size = parseOperand(rest, false)
 	}
 	return g
 }
@@ -321,7 +321,7 @@ func (p *state) parseData(line []token.Token) *ast.Data {
 	d.Name = sym
 	d.Width = width
 	if len(valuePart) > 0 {
-		d.Value = parseOperand(stripComment(valuePart))
+		d.Value = parseOperand(stripComment(valuePart), false)
 	}
 	return d
 }
@@ -332,8 +332,13 @@ func (p *state) parseInstr(line []token.Token) {
 		return
 	}
 	instr := &ast.Instr{Mnemonic: body[0], Comment: comment}
-	for _, grp := range splitOperands(body[1:]) {
-		if op := parseOperand(grp); op != nil {
+	grps := splitOperands(body[1:])
+	for i, grp := range grps {
+		// Only the final operand slot may carry a bare constant: the
+		// toolchain reads the trailing 1 of CMPSD X1, X0, 1 as $1
+		// (math/floor_amd64.s), while an earlier bare number names an
+		// absolute address, a form this parser keeps out of the tree.
+		if op := parseOperand(grp, i == len(grps)-1); op != nil {
 			instr.Operands = append(instr.Operands, op)
 		}
 	}
@@ -417,8 +422,10 @@ func setName(raw string, sym *ast.Symbol) {
 
 // --- operand parsing --------------------------------------------------------
 
-// parseOperand parses one operand group into an Operand.
-func parseOperand(g []token.Token) *ast.Operand {
+// parseOperand parses one operand group into an Operand.  allowBare marks
+// the final operand slot of an instruction, where the toolchain reads a
+// bare constant expression as an immediate.
+func parseOperand(g []token.Token, allowBare bool) *ast.Operand {
 	g = stripComment(g)
 	if len(g) == 0 {
 		return nil
@@ -431,9 +438,25 @@ func parseOperand(g []token.Token) *ast.Operand {
 	}
 	op.Kind = ast.OpAddr
 	op.Addr = parseAddress(g)
+	// A trailing bare constant leaves every address field empty: the
+	// grammar sees no register, memory reference or symbol, and the closed
+	// constant expression is the whole group.  Read it as the immediate it
+	// names, exactly what the $ spelling would produce.
+	if allowBare && isEmptyAddress(op.Addr) {
+		if v, rest, ok := foldExpr(g); ok && len(rest) == 0 {
+			op.Kind = ast.OpImmediate
+			op.Imm = ast.Immediate{Val: v, HasVal: true}
+		}
+	}
 	return op
 }
 
+// isEmptyAddress reports whether parseAddress populated nothing, its sign
+// that the group is no register, memory reference, symbol or register range.
+func isEmptyAddress(a ast.Address) bool {
+	return a.Sym == nil && a.Base == "" && a.Index == "" && a.Range == nil && a.Shift == ""
+}
+
 // parseImmediate parses the tokens following a '$'.
 func parseImmediate(g []token.Token) ast.Immediate {
 	var imm ast.Immediate
@@ -466,6 +489,17 @@ func parseImmediate(g []token.Token) ast.Immediate {
 	} else if g[i].Kind == token.Plus {
 		i++
 	}
+	// A constant expression after the sign: $-(R - 8), $+(32-shift).  The
+	// toolchain folds the negated value in place (the cgo ABI macros write
+	// ADJSP $-(REGS_HOST_TO_ABI0_STACK - 8)), so the sign applies to the
+	// folded value exactly as it does to a bare literal.
+	if i < len(g) && (g[i].Kind == token.LParen || g[i].Kind == token.Tilde) {
+		if v, rest, ok := foldExpr(g[i:]); ok && len(rest) == 0 {
+			imm.Val = v
+			imm.HasVal = true
+			return imm
+		}
+	}
 	if i < len(g) && g[i].Kind == token.Number {
 		text := g[i].Text
 		if v, ok := tryInt(text); ok {
@@ -497,6 +531,14 @@ func parseAddress(g []token.Token) ast.Address {
 	if len(g) == 0 {
 		return addr
 	}
+	// A bracketed register range, [Z0-Z3]: the amd64 4FMAPS/4VNNIW
+	// multi-source operand.  The bracket runes arrive as Illegal tokens
+	// (the lexer has no bracket kind), so the shape matches on their text.
+	if isBracket(g[0], "[") && len(g) == 5 && g[1].Kind == token.Ident &&
+		g[2].Kind == token.Minus && g[3].Kind == token.Ident && isBracket(g[4], "]") {
+		addr.Range = &ast.RegRange{Lo: g[1].Text, Hi: g[3].Text, Pos: g[0].Pos}
+		return addr
+	}
 	// Symbol-with-pseudo form: name[<>][+off](PSEUDO).
 	// When the prefix is not a valid symbol name (e.g. a bare number like
 	// 0(SP) in RISC-V), sym is nil, and we fall through to regular memory
@@ -521,6 +563,20 @@ func parseAddress(g []token.Token) ast.Address {
 			i = len(g) - len(rest)
 		}
 	}
+	// The same expression under a leading sign: -(24+8)(X6) puts the sign
+	// outside the fold.  The base group must follow for the value to
+	// commit, exactly as in the unsigned branch above.
+	if i < len(g) && (g[i].Kind == token.Minus || g[i].Kind == token.Plus) &&
+		i+1 < len(g) && g[i+1].Kind == token.LParen {
+		if v, rest, ok := foldExpr(g[i+1:]); ok && len(rest) > 0 && rest[0].Kind == token.LParen {
+			if g[i].Kind == token.Minus {
+				v = -v
+			}
+			addr.Offset = v
+			addr.HasOff = true
+			i = len(g) - len(rest)
+		}
+	}
 	// Optional leading displacement before a '(' base group.  A sign pushes
 	// the parenthesis one token further out: -4(DX) has it at i+2.
 	if isSignedNumber(g, i) {
@@ -577,6 +633,16 @@ func parseAddress(g []token.Token) ast.Address {
 			}
 		}
 	}
+	// A lone (index*scale) group is the VSIB index-only form: the
+	// gather/scatter families address memory through a scaled vector index
+	// with no base register, 8(X4*1).  The two-group grammar below reads
+	// (base)(index*scale), so a first group whose member carries a scale
+	// factor can only be an index.
+	if isIndexGroup(g[i:]) {
+		addr.Index = g[i+1].Text
+		addr.Scale = int(parseInt(g[i+3].Text))
+		i += 5
+	}
 	// First parenthesised group: the base register.
 	if i < len(g) && g[i].Kind == token.LParen {
 		i++
@@ -618,6 +684,26 @@ func parseAddress(g []token.Token) ast.Address {
 	if i > 0 && i < len(g) {
 		addr.Shift = joinRaw(g[i:])
 	}
+	// A lone (possibly signed) number is an absolute address: MOVL $0xf1,
+	// 0xf1 stores through the bare displacement with no base at all.  In
+	// operand position a number without $ is an address, never a value.
+	if addr.Sym == nil && addr.Base == "" && addr.Index == "" && !addr.HasOff {
+		neg := false
+		j := 0
+		if j < len(g) && (g[j].Kind == token.Minus || g[j].Kind == token.Plus) {
+			neg = g[j].Kind == token.Minus
+			j++
+		}
+		if j == len(g)-1 && g[j].Kind == token.Number {
+			v := parseInt(g[j].Text)
+			if neg {
+				v = -v
+			}
+			addr.Offset = v
+			addr.HasOff = true
+			return addr
+		}
+	}
 	return addr
 }
 
@@ -633,6 +719,19 @@ func findPseudoParen(g []token.Token) int {
 	return -1
 }
 
+// isBracket reports whether t is a square bracket.  The lexer has no bracket
+// kind, so '[' and ']' arrive as Illegal tokens.
+func isBracket(t token.Token, text string) bool {
+	return t.Kind == token.Illegal && t.Text == text
+}
+
+// isIndexGroup reports whether g begins with a complete (index*scale) group:
+// one identifier followed by a scale factor, all inside a single parenthesis.
+func isIndexGroup(g []token.Token) bool {
+	return len(g) >= 5 && g[0].Kind == token.LParen && g[1].Kind == token.Ident &&
+		g[2].Kind == token.Star && g[3].Kind == token.Number && g[4].Kind == token.RParen
+}
+
 // --- token helpers ----------------------------------------------------------
 
 // splitOperands splits a token slice on top-level commas (commas outside any

parser/parser_test.go

@@ -497,3 +497,164 @@ func TestParseEqualsZeroOptions(t *testing.T) {
 		}
 	}
 }
+
+// TestBracketRegisterRange pins the amd64 multi-source operand of the
+// 4FMAPS/4VNNIW families: the bracket group [Z0-Z3] names four consecutive
+// source registers and must reach the AST as a register range instead of an
+// empty address.
+func TestBracketRegisterRange(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tV4FMADDPS 17(SP), [Z0-Z3], K2, Z0\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse errors: %v", errs)
+	}
+	fn := file.Decls[0].(*ast.Text)
+	in := fn.Body[0].(*ast.Instr)
+	if len(in.Operands) != 4 {
+		t.Fatalf("operands = %d, want 4", len(in.Operands))
+	}
+	rng := in.Operands[1]
+	if rng.Kind != ast.OpAddr {
+		t.Errorf("range operand kind = %v, want OpAddr", rng.Kind)
+	}
+	if rng.Addr.Range == nil {
+		t.Fatalf("range operand = %+v, want a register range", rng.Addr)
+	}
+	if rng.Addr.Range.Lo != "Z0" || rng.Addr.Range.Hi != "Z3" {
+		t.Errorf("range = %s-%s, want Z0-Z3", rng.Addr.Range.Lo, rng.Addr.Range.Hi)
+	}
+	if rng.Addr.Sym != nil || rng.Addr.Base != "" || rng.Addr.Index != "" || rng.Addr.Shift != "" {
+		t.Errorf("range operand carries stray address fields: %+v", rng.Addr)
+	}
+	if rng.Raw != "[ Z0 - Z3 ]" {
+		t.Errorf("range raw = %q, want the verbatim spelling", rng.Raw)
+	}
+}
+
+// TestBracketRegisterRangeNotList pins that arm64-style register lists, whose
+// members carry arrangements, stay out of the simple range shape: they remain
+// plain bracketed groups the arm64 encoder reads from Raw.  A comma inside
+// brackets is a top-level comma, so a multi-member list spans several
+// operands, exactly the shape the arm64 encoder's list scan stitches back.
+func TestBracketRegisterRangeNotList(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tVLD1 (R2), [V21.B16]\n\tVLD1 (R1), [V2.B16, V3.B16]\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse errors: %v", errs)
+	}
+	fn := file.Decls[0].(*ast.Text)
+	for i, want := range []string{"[ V21.B16 ]", "V3.B16 ]"} {
+		in := fn.Body[i].(*ast.Instr)
+		op := in.Operands[len(in.Operands)-1]
+		if op.Addr.Range != nil {
+			t.Errorf("%s: range = %v, want nil", in.Mnemonic.Text, op.Addr.Range)
+		}
+		if op.Raw != want {
+			t.Errorf("operand %d raw = %q, want %q", i, op.Raw, want)
+		}
+	}
+}
+
+// TestVSIBIndexOnly pins the gather/scatter memory operand with a scaled
+// vector index and no base register: 8(X4*1) must carry index and scale and
+// leave the base empty, not strand the scale in the shift suffix.
+func TestVSIBIndexOnly(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tVPGATHERDQ Y0, 8(X4*1), Y6\n\tVPGATHERDQ Y0, (X4*2), Y6\n\tVPGATHERDQ Y0, -8(X4*1), Y6\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse errors: %v", errs)
+	}
+	fn := file.Decls[0].(*ast.Text)
+	want := []ast.Address{
+		{Index: "X4", Scale: 1, Offset: 8, HasOff: true},
+		{Index: "X4", Scale: 2},
+		{Index: "X4", Scale: 1, Offset: -8, HasOff: true},
+	}
+	for i, w := range want {
+		in := fn.Body[i].(*ast.Instr)
+		a := in.Operands[1].Addr
+		if a.Base != "" || a.Index != w.Index || a.Scale != w.Scale || a.Offset != w.Offset || a.HasOff != w.HasOff || a.Shift != "" {
+			t.Errorf("operand %d = %+v, want %+v", i, a, w)
+		}
+	}
+}
+
+// TestVSIBTwoGroupKeepsBase pins that the ordinary (base)(index*scale)
+// grammar is untouched by the index-only recognition.
+func TestVSIBTwoGroupKeepsBase(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tVP4DPWSSD 7(SI)(DI*1), [Z2-Z5], K4, Z17\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse errors: %v", errs)
+	}
+	fn := file.Decls[0].(*ast.Text)
+	in := fn.Body[0].(*ast.Instr)
+	a := in.Operands[0].Addr
+	if a.Base != "SI" || a.Index != "DI" || a.Scale != 1 || a.Offset != 7 || !a.HasOff {
+		t.Errorf("address = %+v, want base SI index DI scale 1 offset 7", a)
+	}
+	if in.Operands[1].Addr.Range == nil || in.Operands[1].Addr.Range.Lo != "Z2" || in.Operands[1].Addr.Range.Hi != "Z5" {
+		t.Errorf("second operand = %+v, want range Z2-Z5", in.Operands[1].Addr)
+	}
+}
+
+// TestBareTrailingImmediate pins the toolchain's bare constant spelling in
+// the final operand slot: CMPSD X1, X0, 1 reads as $1 (math/floor_amd64.s).
+// Earlier slots keep the strict grammar, so a bare number there stays an
+// address rather than becoming an immediate.
+func TestBareTrailingImmediate(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tCMPSD X1, X0, 1\n\tCMPSD X1, X0, -1\n\tADDQ AX, 1+2\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse errors: %v", errs)
+	}
+	fn := file.Decls[0].(*ast.Text)
+	for i, want := range []int64{1, -1, 3} {
+		in := fn.Body[i].(*ast.Instr)
+		last := in.Operands[len(in.Operands)-1]
+		if last.Kind != ast.OpImmediate || !last.Imm.HasVal || last.Imm.Val != want {
+			t.Errorf("operand %d = %+v, want immediate %d", i, last, want)
+		}
+	}
+
+	// A bare number outside the final slot is not an immediate.
+	file2, errs2 := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tADDQ 1, AX\n\tRET\n")
+	if len(errs2) > 0 {
+		t.Fatalf("parse errors: %v", errs2)
+	}
+	fn2 := file2.Decls[0].(*ast.Text)
+	first := fn2.Body[0].(*ast.Instr).Operands[0]
+	if first.Kind != ast.OpAddr {
+		t.Errorf("non-final bare number kind = %v, want OpAddr", first.Kind)
+	}
+	// A bare name in the final slot stays a symbol: labels are names, not
+	// constants, and jump targets depend on the distinction.
+	file3, errs3 := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0\n\tJMP loop\nloop: NOP\n\tRET\n")
+	if len(errs3) > 0 {
+		t.Fatalf("parse errors: %v", errs3)
+	}
+	fn3 := file3.Decls[0].(*ast.Text)
+	jmp := fn3.Body[0].(*ast.Instr)
+	if jmp.Operands[0].Kind != ast.OpAddr || jmp.Operands[0].Addr.Sym == nil || jmp.Operands[0].Addr.Sym.Name != "loop" {
+		t.Errorf("jump target = %+v, want label loop", jmp.Operands[0])
+	}
+}
+
+// TestSignedParenDisplacement pins a sign before a parenthesised
+// displacement expression: -(24+8)(X6) negates the folded value and keeps
+// the base group, the shape GOROOT's riscv64 and loong64 files use.
+func TestSignedParenDisplacement(t *testing.T) {
+	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT, $0-0\n\tMOV X7, -(24+8)(X6)\n\tMOV X7, +(16)(X6)\n\tRET\n")
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	text := file.Decls[0].(*ast.Text)
+	ins := text.Body[0].(*ast.Instr)
+	op := ins.Operands[1] // Plan 9 order: the destination address is last
+	if !op.Addr.HasOff || op.Addr.Offset != -32 {
+		t.Errorf("-(24+8): offset = %v hasOff=%v, want -32 true", op.Addr.Offset, op.Addr.HasOff)
+	}
+	if op.Addr.Base != "X6" {
+		t.Errorf("-(24+8): base = %q, want X6", op.Addr.Base)
+	}
+	ins = text.Body[1].(*ast.Instr)
+	op = ins.Operands[1]
+	if !op.Addr.HasOff || op.Addr.Offset != 16 || op.Addr.Base != "X6" {
+		t.Errorf("+(16): offset = %v hasOff=%v base=%q, want 16 true X6", op.Addr.Offset, op.Addr.HasOff, op.Addr.Base)
+	}
+}

parser/preproc.go

@@ -34,6 +34,12 @@ type Options struct {
 	// Expand enables macro expansion, include splicing and the
 	// statement-separator reading of ';' that the expanded bodies rely on.
 	Expand bool
+	// Predefines names the macros defined before the file is read.  The
+	// go command drives go tool asm with -D GOOS_<goos> -D GOARCH_<arch>,
+	// and GOROOT's own 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.
+	Predefines map[string]string
 }
 
 // ParseWithOptions parses src like Parse, optionally preprocessing it first.
@@ -44,6 +50,9 @@ func ParseWithOptions(path, src string, opts Options) (*ast.File, []error) {
 	var errs []error
 	if opts.Expand {
 		pp := &preproc{opts: opts, macros: map[string]*macroDef{}}
+		for name, value := range opts.Predefines {
+			pp.macros[name] = &macroDef{name: name, body: lexer.Tokenize(value)}
+		}
 		lines = pp.fileLines(path, tokens, token.Position{})
 		errs = pp.errs
 	} else {
@@ -349,7 +358,7 @@ func (pp *preproc) expandTokens(in []token.Token) []token.Token {
 			consecutive = 0
 			continue
 		}
-		def := pp.macros[t.Text]
+		def, suffix := pp.macroFor(t.Text)
 		if def == nil {
 			i++
 			consecutive = 0
@@ -363,7 +372,14 @@ func (pp *preproc) expandTokens(in []token.Token) []token.Token {
 			return nil
 		}
 		if def.args == nil {
-			s = append(s[:i], append(restamp(def.body, t.Pos), s[i+1:]...)...)
+			body := restamp(def.body, t.Pos)
+			if suffix != "" {
+				// The macro was reached only through a compound spelling
+				// (ACC0.B16 over "#define ACC0 V8"), so the selector has
+				// to travel with the expansion.
+				body = appendSelector(body, suffix, t.Pos)
+			}
+			s = append(s[:i], append(body, s[i+1:]...)...)
 			continue
 		}
 		// A parameterised macro invoked without its parentheses stands
@@ -394,6 +410,17 @@ func (pp *preproc) expandTokens(in []token.Token) []token.Token {
 					sub = append(sub, restamp(args[k], t.Pos)...)
 					continue
 				}
+				// A parameter used with an element or lane selector: the
+				// lexer folds A.S4 into one identifier, so the whole-token
+				// match above cannot see the parameter.  The toolchain
+				// lexes the period separately and substitutes the name
+				// alone; splitting at the FIRST period and pasting the
+				// argument back in front of the selector is the equivalent
+				// for this lexer.
+				if k, sel := parameterSelector(bt.Text, def.args); k >= 0 {
+					sub = append(sub, restamp(pasteSelector(args[k], sel), t.Pos)...)
+					continue
+				}
 			}
 			sub = append(sub, bt)
 		}
@@ -402,6 +429,75 @@ func (pp *preproc) expandTokens(in []token.Token) []token.Token {
 	return s
 }
 
+// macroFor finds the macro a use names.  The lexer folds NAME.selector into
+// one identifier token, so a macro written behind a selector suffix
+// (ACC0.B16 over "#define ACC0 V8") never matches a whole-token table
+// lookup; the toolchain splits on the period and reads the two halves, so
+// the prefix before the FIRST period is tried here as well and the caller
+// re-attaches the suffix to whatever the macro expands to.  Only a whole
+// name counts: AB.S4 does not reach a macro named A, and a parameterised
+// macro is not hidden behind a selector, because its invocation would need
+// the parentheses to follow the bare name.
+func (pp *preproc) macroFor(text string) (*macroDef, string) {
+	if def := pp.macros[text]; def != nil {
+		return def, ""
+	}
+	if j := strings.IndexByte(text, '.'); j > 0 {
+		if def := pp.macros[text[:j]]; def != nil && def.args == nil {
+			return def, text[j:]
+		}
+	}
+	return nil, ""
+}
+
+// appendSelector glues a selector suffix onto an object macro's expansion:
+// the selector binds to the identifier the expansion ends with, the way the
+// toolchain's operand parser reads V0 and .B16 back as one register
+// spelling.  An expansion that does not end in an identifier carries the
+// selector as its own token, which the parser then reports where it cannot
+// parse it.
+func appendSelector(body []token.Token, suffix string, pos token.Position) []token.Token {
+	if n := len(body); n > 0 && body[n-1].Kind == token.Ident {
+		body[n-1].Text += suffix
+		return body
+	}
+	return append(body, token.Token{Kind: token.Ident, Text: suffix, Pos: pos, End: pos})
+}
+
+// parameterSelector reports the argument a compound body token names: the
+// parameter whose whole name occupies the text before the token's FIRST
+// period, with the selector that follows.  k is negative when no parameter
+// matches, which leaves tokens like AB.S4 untouched even though a parameter
+// A is bound.
+func parameterSelector(text string, args []string) (int, string) {
+	j := strings.IndexByte(text, '.')
+	if j <= 0 {
+		return -1, ""
+	}
+	if k := slices.Index(args, text[:j]); k >= 0 {
+		return k, text[j:]
+	}
+	return -1, ""
+}
+
+// pasteSelector joins an argument with the selector a compound body token
+// carries, textually: the selector binds to the identifier the argument
+// ends with, so A.S4 over the argument V0.B16 spells V0.B16.S4, exactly the
+// operand the toolchain's split-then-substitute leaves behind.  An argument
+// with no trailing identifier carries the selector as a separate token,
+// which the parser then reports where it cannot parse it.
+func pasteSelector(val []token.Token, suffix string) []token.Token {
+	if len(val) == 0 {
+		return []token.Token{{Kind: token.Ident, Text: suffix}}
+	}
+	out := slices.Clone(val)
+	if n := len(out); out[n-1].Kind == token.Ident {
+		out[n-1].Text += suffix
+		return out
+	}
+	return append(out, token.Token{Kind: token.Ident, Text: suffix})
+}
+
 // collectArgs reads the actual argument tokens of an invocation; the opening
 // parenthesis is at start.  Commas separate arguments except inside nested
 // parentheses.  A nil result means the list was unterminated, which is a

parser/preproc_test.go

@@ -536,6 +536,127 @@ func TestConstantExpressionFoldsWithoutExpand(t *testing.T) {
 	}
 }
 
+func TestParameterWithSelectorSubstitutes(t *testing.T) {
+	// The lexer folds A.S4 into one identifier token, so a parameter used
+	// with an element or lane selector never matched the whole-token
+	// substitution; the toolchain's lexer splits on the period and its
+	// substitution sees the name alone.  Several parameters carry selectors
+	// in one body here, which is the chacha8_arm64.s QR shape in miniature.
+	_, got := expand(t, `
+#define QR(A, B, C, D) VADD A.S4, B.S4, C.S4; VEOR D.B16, A.B16, D.B16
+TEXT ·f(SB), NOSPLIT, $0
+	QR(V0, V1, V2, V3)
+	RET
+`)
+	wantLines(t, got,
+		"VADD V0.S4, V1.S4, V2.S4",
+		"VEOR V3.B16, V0.B16, V3.B16",
+		"RET",
+	)
+}
+
+func TestSelectorWithCompoundArgumentPastesTextually(t *testing.T) {
+	// An argument that is itself one compound identifier pastes verbatim:
+	// A.S4 over V0.B16 spells V0.B16.S4, the operand the toolchain's
+	// split-then-substitute leaves behind.
+	_, got := expand(t, `
+#define M(A) VADD A.S4, A.S4, A.S4
+TEXT ·f(SB), NOSPLIT, $0
+	M(V0.B16)
+	RET
+`)
+	wantLines(t, got, "VADD V0.B16.S4, V0.B16.S4, V0.B16.S4", "RET")
+}
+
+func TestSelectorAlongsideBareParameter(t *testing.T) {
+	// A body may use the parameter bare and suffixed, and the argument may
+	// itself end in a selector; neither disturbs the other.
+	_, got := expand(t, `
+#define M(A) VADD A, A.S4, A
+TEXT ·f(SB), NOSPLIT, $0
+	M(V0)
+	M(V1.B16)
+	RET
+`)
+	wantLines(t, got,
+		"VADD V0, V0.S4, V0",
+		"VADD V1.B16, V1.B16.S4, V1.B16",
+		"RET",
+	)
+}
+
+func TestSelectorKeepsNonParameterPrefixes(t *testing.T) {
+	// The prefix before the period must be the whole parameter name:
+	// AB.S4 never reaches a parameter A.
+	_, got := expand(t, `
+#define M(A) VADD AB.S4, A.S4, AB.S4
+TEXT ·f(SB), NOSPLIT, $0
+	M(V0)
+	RET
+`)
+	wantLines(t, got, "VADD AB.S4, V0.S4, AB.S4", "RET")
+}
+
+func TestSelectorExpandsMacroValuedArgument(t *testing.T) {
+	// gcm_arm64.s invokes mulRound(B1) where B1 is itself an object macro:
+	// the paste stays rescannable, so B1.D1 still expands to V1.D1 the way
+	// the toolchain's rescan of substituted tokens does.
+	_, got := expand(t, `
+#define B1 V1
+#define mulRound(X) VPMULL X.D1, T1.D1, T3.Q1
+TEXT ·f(SB), NOSPLIT, $0
+	mulRound(B1)
+	RET
+`)
+	wantLines(t, got, "VPMULL V1.D1, T1.D1, T3.Q1", "RET")
+}
+
+func TestObjectMacroBehindSelectorExpands(t *testing.T) {
+	// Ordinary code writes ACC0.B16 where ACC0 is an object macro; the
+	// toolchain expands the alias because its lexer reads the selector as
+	// its own token, and the lookup here must reach the macro through the
+	// compound spelling the same way.
+	_, got := expand(t, `
+#define ACC0 V8
+TEXT ·f(SB), NOSPLIT, $0
+	VEOR ACC0.B16, ACC0.B16, ACC0.B16
+	RET
+`)
+	wantLines(t, got, "VEOR V8.B16, V8.B16, V8.B16", "RET")
+}
+
+func TestChacha8QRMacroExpands(t *testing.T) {
+	// The real QR round of chacha8_arm64.s end to end: every parameter
+	// carries a selector somewhere, and the round is sixteen instructions.
+	_, got := expand(t, `
+#define QR(A, B, C, D) \
+	VADD A.S4, B.S4, A.S4; VEOR D.B16, A.B16, D.B16; VREV32 D.H8, D.H8; \
+	VADD C.S4, D.S4, C.S4; VEOR B.B16, C.B16, V30.B16; VSHL $12, V30.S4, B.S4; VSRI $20, V30.S4, B.S4; \
+	VADD A.S4, B.S4, A.S4; VEOR D.B16, A.B16, D.B16; VTBL V31.B16, [D.B16], D.B16; \
+	VADD C.S4, D.S4, C.S4; VEOR B.B16, C.B16, V30.B16; VSHL $7, V30.S4, B.S4; VSRI $25, V30.S4, B.S4
+TEXT ·f(SB), NOSPLIT, $0
+	QR(V0, V1, V2, V3)
+	RET
+`)
+	wantLines(t, got,
+		"VADD V0.S4, V1.S4, V0.S4",
+		"VEOR V3.B16, V0.B16, V3.B16",
+		"VREV32 V3.H8, V3.H8",
+		"VADD V2.S4, V3.S4, V2.S4",
+		"VEOR V1.B16, V2.B16, V30.B16",
+		"VSHL $12, V30.S4, V1.S4",
+		"VSRI $20, V30.S4, V1.S4",
+		"VADD V0.S4, V1.S4, V0.S4",
+		"VEOR V3.B16, V0.B16, V3.B16",
+		"VTBL V31.B16, [V3.B16], V3.B16",
+		"VADD V2.S4, V3.S4, V2.S4",
+		"VEOR V1.B16, V2.B16, V30.B16",
+		"VSHL $7, V30.S4, V1.S4",
+		"VSRI $25, V30.S4, V1.S4",
+		"RET",
+	)
+}
+
 func TestNotAnExpressionFallsBack(t *testing.T) {
 	// Symbol immediates and floats must keep their ordinary parse.
 	f, errs := ParseWithOptions("t_amd64.s", "TEXT ·f(SB), NOSPLIT, $0\n\tMOVQ $1.5, AX\n\tMOVQ $·sym(SB), AX\n\tRET\n", Options{})

testdata/verify/bookkeep_amd64.s

@@ -0,0 +1,32 @@
+// The runtime bookkeeping statements: FUNCDATA and PCDATA contribute no
+// text bytes on any architecture, and amd64 now matches.  They sit between
+// real instructions here, with plain, static and offset symbol references
+// on the FUNCDATA lines, so the byte counts prove the zero contribution.
+
+#include "textflag.h"
+
+// func bookkeep(x int64) int64
+TEXT ·bookkeep(SB), NOSPLIT, $0-16
+	PCDATA   $0, $-1
+	MOVQ     x+0(FP), AX
+	PCDATA   $1, $-2
+	FUNCDATA $0, args_stackmap(SB)
+	ADDQ     $1, AX
+	FUNCDATA $5, arginfo0(SB)
+	PCDATA   $1, $3
+	MOVQ     AX, ret+8(FP)
+	FUNCDATA $1, externalfuncdata(SB)
+	PCDATA   $0, $0
+	RET
+
+// func bookkeepstatic() int64
+TEXT ·bookkeepstatic(SB), NOSPLIT, $0-8
+	// A static symbol and a defined data symbol as the funcdata target.
+	// (A symbol+offset target the toolchain itself refuses.)
+	FUNCDATA $2, fdtable<>(SB)
+	FUNCDATA $3, undefsym(SB)
+	MOVQ     $7, AX
+	MOVQ     AX, ret+0(FP)
+	RET
+
+GLOBL fdtable<>(SB), NOPTR, $16

testdata/verify/bookkeep_riscv64.s

@@ -0,0 +1,40 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Differential kernel for the riscv64 bookkeeping statements and the
+// slot-relative branches: FUNCDATA and PCDATA (the expanded forms of the
+// funcdata.h macros, contributing no bytes), UNDEF (the toolchain's ebreak),
+// and the JMP N(PC) slot jumps including the self-loop and the backward form.
+
+#include "textflag.h"
+
+TEXT ·bookkeep(SB), NOSPLIT, $8-8
+	FUNCDATA $1, marks<>(SB)
+	PCDATA   $1, $-1
+	MOV      ZERO, ret+0(FP)
+	PCDATA   $1, $1
+	UNDEF
+	MOV      $1, X10
+	RET
+
+TEXT ·slots(SB), NOSPLIT, $0-0
+	MOV $1, X10
+	JMP 2(PC)
+	MOV $64, X11
+	MOV $128, X12
+	MOV $2, X11
+	MOV $3, X12
+	BEQ X10, X11, skip
+	JMP -2(PC)
+
+skip:
+	JMP 0(PC)
+
+TEXT ·marksreader(SB), NOSPLIT, $0-8
+	MOV $marks<>(SB), X10
+	MOV (X10), X11
+	MOV X11, ret+0(FP)
+	RET
+
+GLOBL marks<>(SB), RODATA, $8
+DATA marks<>+0(SB)/8, $1234605616436508552

testdata/verify/branch2_loong64.s

@@ -0,0 +1,21 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Differential kernel for the loong64 two-operand BEQ/BNE spellings the
+// msan trampolines use: BEQ Rj, target compares against R0 (the beqz form).
+
+#include "textflag.h"
+
+TEXT ·branch2(SB), NOSPLIT, $0-8
+	MOVV arg+0(FP), R4
+	BEQ  R4, zero
+	ADDV $1, R4, R4
+
+zero:
+	MOVV $16, R5
+	BNE  R4, done
+	ADDV $2, R4, R4
+
+done:
+	MOVV R4, ret+0(FP)
+	RET

testdata/verify/datainit_loong64.s

@@ -0,0 +1,27 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Differential kernel for the loong64 DATA value forms the runtime's exp and
+// asm files use: floating-point initialisers stored as IEEE-754 bits and
+// string initialisers zero-padded within their declared width.
+
+#include "textflag.h"
+
+TEXT ·floatbits(SB), NOSPLIT, $0-8
+	MOVV $floats<>(SB), R12
+	MOVD 8(R12), F0
+	MOVD F0, ret+0(FP)
+	RET
+
+TEXT ·stringhead(SB), NOSPLIT, $0-8
+	MOVV $msg<>(SB), R12
+	MOVV (R12), R13
+	MOVV R13, ret+0(FP)
+	RET
+
+GLOBL floats<>(SB), RODATA, $16
+DATA floats<>+0(SB)/8, $0.0
+DATA floats<>+8(SB)/8, $0.5
+
+GLOBL msg<>(SB), RODATA, $20
+DATA msg<>+0(SB)/20, $"call frame too large"

testdata/verify/floatimm_amd64.s

@@ -0,0 +1,55 @@
+// Floating-point immediates on the SSE scalar paths: the constant is
+// rewritten into a read from a read-only pool symbol ($f64.<hex> or
+// $f32.<hex>, the IEEE-754 bits in the name), RIP-relative with the
+// displacement left to the relocation.  A positive zero on the moves
+// collapses to XORPS dst, dst; a negative zero keeps its sign bit and
+// takes the pool.  The parenthesised $(-1.0) spelling is the one
+// math/floor_amd64.s uses.  Every result is folded back so no
+// instruction is dead.
+
+#include "textflag.h"
+
+// func floatimm(x float64) float64
+TEXT ·floatimm(SB), NOSPLIT, $0-16
+	MOVQ  x+0(FP), AX
+	MOVQ  AX, X0
+	// The floor kernel's sign fold: the parenthesised negative spelling.
+	MOVSD $ (-1.0), X2
+	ANDPD X2, X0
+	// Positive and fractional constants on the scalar moves.
+	MOVSD $1.5, X3
+	MOVSD $0.5, X4
+	MOVSS $2.5, X5
+	MOVSS $-0.5, X6
+	// A positive zero collapses to XORPS; a negative zero does not.
+	MOVSD $0.0, X7
+	MOVSS $0.0, X8
+	MOVSD $-0.0, X9
+	// The scalar arithmetic reads the pool through r/m (hypot's shape).
+	ADDSD $1.0, X3
+	SUBSD $0.5, X4
+	MULSD $-2.5, X4
+	DIVSD $2.0, X3
+	ADDSS $0.25, X5
+	// Fold everything into one double.
+	ADDSD X5, X3
+	ADDSD X6, X3
+	ADDSD X7, X3
+	ADDSD X8, X3
+	ADDSD X9, X3
+	ADDSD X4, X3
+	ADDSD X0, X3
+	MOVSD X3, ret+8(FP)
+	RET
+
+// func floatimmfloat32() float32
+TEXT ·floatimmfloat32(SB), NOSPLIT, $0-4
+	// The single-width pool constants ride the F3 prefix.
+	MOVSS $1.0, X0
+	MOVSS $-1.0, X1
+	MOVSS $0.0, X2
+	ADDSS $0.5, X0
+	ADDSS X1, X0
+	ADDSS X2, X0
+	MOVSS X0, ret+0(FP)
+	RET

testdata/verify/forms_amd64.s

@@ -0,0 +1,52 @@
+// Kernel: the operand forms the GOROOT campaign surfaced — numeric
+// PC-relative jumps, symbol-immediate materialisation (the toolchain rewrites
+// MOVQ $sym(SB) into a RIP-relative LEA) and the negated constant-expression
+// ADJSP the cgo ABI macros write.  Bytes are pinned against go tool asm by
+// TestDifferentialKernels.
+#include "textflag.h"
+
+DATA sd<>(SB)/4, $7
+GLOBL sd<>(SB), RODATA, $4
+
+// func Jumps(flag int64) int64
+TEXT ·Jumps(SB), NOSPLIT, $0-16
+	MOVQ	flag+0(FP), AX
+	TESTQ	AX, AX
+	JEQ	2(PC)
+	MOVQ	$1, AX
+	JMP	3(PC)
+	MOVQ	$2, AX
+	MOVQ	AX, ret+0(FP)
+	RET
+
+// func SymImm() int64
+TEXT ·SymImm(SB), NOSPLIT, $0-16
+	MOVQ	$sd<>(SB), AX
+	MOVQ	$·SymImm(SB), CX
+	MOVQ	AX, ret+0(FP)
+	RET
+
+// func Frame()
+TEXT ·Frame(SB), NOSPLIT, $0
+	PUSHFQ
+	CLD
+	ADJSP	$(64 - 8)
+	ADJSP	$-(64 - 8)
+	POPFQ
+	RET
+
+// func Tls() int64
+TEXT ·Tls(SB), NOSPLIT, $0-8
+	MOVQ	TLS, BX
+	MOVQ	0(BX)(TLS*1), AX
+	MOVQ	AX, ret+0(FP)
+	RET
+
+// func Aligned() int64
+TEXT ·Aligned(SB), NOSPLIT, $0-8
+	MOVQ	$1, AX
+	PCALIGN	$16
+	MOVQ	$2, AX
+	PCALIGN	$32
+	MOVQ	AX, ret+0(FP)
+	RET

testdata/verify/quadreg_amd64.s

@@ -0,0 +1,44 @@
+// The quad-register instructions: the 4FMAPS family (V4FMADDPS,
+// V4FMADDSS, V4FNMADDPS, V4FNMADDSS) and the 4VNNIW pair (VP4DPWSSD,
+// VP4DPWSSDS).  The bracketed list's low register travels the inverted
+// V'VVVV field, the memory source keeps r/m, the opmask rides aaa and the
+// vector length follows the destination (512-bit for the ZMM forms,
+// 128-bit for the scalar ones) while the disp8xN multiplier stays 16 for
+// every member.  Every result is folded back so no instruction is dead.
+
+#include "textflag.h"
+
+// func quadf4(src *[16]uint32, n int) float32
+TEXT ·quadf4(SB), NOSPLIT, $0-20
+	MOVQ        src+0(FP), SI
+	MOVQ        n+8(FP), CX
+	// The packed 4-FMA form over four consecutive ZMM accumulators,
+	// masked with K2, K3 and unmasked alike; the displacements exercise
+	// the disp32 form and the disp8x16 compressed form.
+	V4FMADDPS   17(SI), [Z0-Z3], K2, Z0
+	V4FMADDPS   64(SI), [Z10-Z13], K2, Z1
+	V4FMADDPS   (SI), [Z20-Z23], Z2
+	V4FNMADDPS  96(SI), [Z1-Z4], K3, Z5
+	// The scalar form reads XMM lists and takes the 128-bit length; the
+	// displacement compresses by 16.
+	V4FMADDSS   7(AX), [X0-X3], K5, X22
+	V4FMADDSS   (DI), [X10-X13], K5, X23
+	V4FNMADDSS  16(SI), [X20-X23], K1, X24
+	// The 4-VNNI dot products, indexed source included.
+	VP4DPWSSD   15(DX)(BX*8), [Z2-Z5], K4, Z17
+	VP4DPWSSDS  -7(DI)(R8*1), [Z4-Z7], K1, Z31
+	VP4DPWSSD   (SI), [Z12-Z15], Z6
+	// Zeroing keeps the usual rule: a mask register must ride along.
+	V4FMADDPS.Z 128(SI), [Z24-Z27], K4, Z3
+	// Fold every accumulator into one scalar.
+	VPADDD      Z0, Z1, Z9
+	VPADDD      Z2, Z5, Z10
+	VPADDD      Z9, Z17, Z11
+	VPADDD      Z10, Z31, Z12
+	VPADDD      Z11, Z12, Z13
+	VPADDD      Z13, Z14, Z15
+	VADDSS      X22, X23, X0
+	VADDSS      X24, X0, X1
+	VADDSS      X1, X2, X3
+	VMOVSS      X3, ret+16(FP)
+	RET

testdata/verify/vsib_amd64.s

@@ -0,0 +1,21 @@
+#include "textflag.h"
+
+// The index-only VSIB shapes from amd64enc_extra.s: a scaled vector index
+// addresses memory with no base register.  The comments record the bytes the
+// Go assembler emits.
+TEXT asmtest(SB), DUPOK|NOSPLIT, $0
+	VPGATHERDQ Y0, 8(X4*1), Y6 // c4e2fd90342508000000
+	VPGATHERDQ Y0,-8(X4*1), Y6 // c4e2fd903425f8ffffff
+	VPGATHERDQ Y0, 0(X4*1), Y6 // c4e2fd90342500000000
+	VPGATHERDQ Y0, 664(X4*1), Y6 // c4e2fd90342598020000
+	VPGATHERDQ Y0, 8(X14*1), Y6 // c4a2fd90343508000000
+	VPGATHERDQ Y0, 8(X4*8), Y6 // c4e2fd9034e508000000
+	VGATHERDPD Y0, 8(X4*1), Y6 // c4e2fd92342508000000
+	VPGATHERDD X0, 8(X4*1), X6 // c4e27d90342508000000
+	VPGATHERDD Y0, 8(Y4*1), Y6 // c4e2fd90342508000000
+
+	// The bare trailing immediate of math/floor_amd64.s: the toolchain
+	// reads the final 1 as $1.
+	CMPSD      X1, X0, 1 // f20fc2c101
+	CMPSD      X1, X0, 2 // f20fc2c102
+	RET

testdata/verify/wideimm_riscv64.s

@@ -0,0 +1,40 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Differential kernel for the riscv64 wide MOV immediates: the 64-bit
+// constants the toolchain materialises through shifted 32-bit parts or loads
+// from its pooled $i64 data symbols, and the frame-address immediates
+// ($name+off(FP)) lowered to ADDI against the hardware stack pointer.
+
+#include "textflag.h"
+
+TEXT ·poolload(SB), NOSPLIT, $0-16
+	MOV arg+0(FP), X10
+	MOV $0x0101010101010101, X16
+	MUL X10, X16, X17
+	MOV $0x123456789, X18
+	ADD X18, X17, X17
+	MOV X17, ret+8(FP)
+	RET
+
+TEXT ·shiftload(SB), NOSPLIT, $0-16
+	MOV arg+0(FP), X10
+	MOV $0x8000000000000000, X20
+	MOV $0x100000000, X21
+	ADD X21, X20, X20
+	MOV $0x000fffffffffffda, X22
+	XOR X22, X20, X20
+	ADD X20, X10, X10
+	MOV X10, ret+8(FP)
+	RET
+
+TEXT ·frameaddr(SB), NOSPLIT, $32-16
+	MOV $ret+8(FP), X12
+	MOV $scratch+0(FP), X13
+	ADD X12, X13, X13
+	MOV $slot+16(SP), X14
+	SUB X14, X13, X13
+	MOV X13, ret+8(FP)
+	RET
+
+GLOBL scratch<>(SB), NOPTR, $8

verify/groundtruth_test.go

@@ -123,9 +123,17 @@ func TestGroundTruthAMD64(t *testing.T) {
 		"../testdata/verify/sse_amd64.s",
 		"../testdata/verify/avx_amd64.s",
 		"../testdata/verify/pfx_amd64.s",
+		"../testdata/verify/vsib_amd64.s",
+		"../testdata/verify/floatimm_amd64.s",
+		"../testdata/verify/bookkeep_amd64.s",
+		"../testdata/verify/quadreg_amd64.s",
 		"../testdata/verify/rawdata_amd64.s",
 		"../testdata/verify/avx512_amd64.s",
 		"../testdata/verify/pfx_amd64.s",
+		"../testdata/verify/vsib_amd64.s",
+		"../testdata/verify/floatimm_amd64.s",
+		"../testdata/verify/bookkeep_amd64.s",
+		"../testdata/verify/quadreg_amd64.s",
 		"../testdata/verify/rawdata_amd64.s",
 		"../testdata/verify/avx512_amd64.s",
 		"../testdata/verify/doubleshift_amd64.s",

verify/l64_groundtruth_test.go

@@ -31,6 +31,8 @@ func TestGroundTruthLOONG64(t *testing.T) {
 		"../testdata/verify/vector_loong64.s",
 		"../testdata/verify/pcalign_loong64.s",
 		"../testdata/verify/l64forms_loong64.s",
+		"../testdata/verify/datainit_loong64.s",
+		"../testdata/verify/branch2_loong64.s",
 		"../testdata/verify/vector_arith_add_loong64.s",
 		"../testdata/verify/vector_arith_sub_loong64.s",
 		"../testdata/verify/vector_arith_sat_loong64.s",

verify/riscv_groundtruth_test.go

@@ -35,6 +35,8 @@ func TestGroundTruthRISCV(t *testing.T) {
 		"../testdata/verify/bitmanip_riscv64.s",
 		"../testdata/verify/pcalign_riscv64.s",
 		"../testdata/verify/branch_far_riscv64.s",
+		"../testdata/verify/wideimm_riscv64.s",
+		"../testdata/verify/bookkeep_riscv64.s",
 		"trampoline_riscv64.s",
 	} {
 		t.Run(path, func(t *testing.T) {