feat(asm): resolve every CSR name the toolchain knows

The riscv64 assembler carried fourteen hand-picked CSR names where the toolchain resolves three hundred and twenty-nine: a CSRR/CSRW family instruction naming any privileged register beyond the few base ones came out as unknown CSR. The table now carries the RISC-V privileged specification's register set exactly as go tool asm spells it, and a differential test assembles every name through both assemblers and requires the words to agree byte for byte. Assisted-by: GLM 5.3 Flash
2026-10-07 00:47:27 +02:00
1 parent 103864e8b2
commit bffe408afa
@@ -528,24 +528,339 @@ func riscvIsCondBranch(mnem string) bool {
 	return false
 }

-// riscvCSRNames maps the standard CSR mnemonics the assembler accepts onto
-// their addresses.
+// riscvCSRNames maps every CSR mnemonic the assembler accepts onto its
+// address: the RISC-V privileged specification's register set as the Go
+// toolchain spells it, so a name `go tool asm` reads resolves here too.
 var riscvCSRNames = map[string]int32{
-	"FFLAGS":   0x001,
-	"FRM":      0x002,
-	"FCSR":     0x003,
-	"VSTART":   0x008,
-	"VXSAT":    0x009,
-	"VXRM":     0x00A,
-	"VCSR":     0x00F,
-	"CYCLE":    0xC00,
-	"TIME":     0xC01,
-	"INSTRET":  0xC02,
-	"CYCLEH":   0xC80,
-	"TIMEH":    0xC81,
-	"INSTRETH": 0xC82,
-	"VL":       0xC20,
-	"VLENB":    0xC22,
+	"FFLAGS":        0x001,
+	"FRM":           0x002,
+	"FCSR":          0x003,
+	"UTVT":          0x007,
+	"VSTART":        0x008,
+	"VXSAT":         0x009,
+	"VXRM":          0x00A,
+	"VCSR":          0x00F,
+	"SSP":           0x011,
+	"SEED":          0x015,
+	"JVT":           0x017,
+	"UNXTI":         0x045,
+	"UINTSTATUS":    0x046,
+	"USCRATCHCSW":   0x048,
+	"USCRATCHCSWL":  0x049,
+	"SSTATUS":       0x100,
+	"SIE":           0x104,
+	"STVEC":         0x105,
+	"SCOUNTEREN":    0x106,
+	"STVT":          0x107,
+	"SENVCFG":       0x10A,
+	"SSTATEEN0":     0x10C,
+	"SSTATEEN1":     0x10D,
+	"SSTATEEN2":     0x10E,
+	"SSTATEEN3":     0x10F,
+	"SCOUNTINHIBIT": 0x120,
+	"SSCRATCH":      0x140,
+	"SEPC":          0x141,
+	"SCAUSE":        0x142,
+	"STVAL":         0x143,
+	"SIP":           0x144,
+	"SNXTI":         0x145,
+	"SINTSTATUS":    0x146,
+	"SSCRATCHCSW":   0x148,
+	"SSCRATCHCSWL":  0x149,
+	"STIMECMP":      0x14D,
+	"SCTRCTL":       0x14E,
+	"SCTRSTATUS":    0x14F,
+	"SISELECT":      0x150,
+	"SIREG":         0x151,
+	"SIREG2":        0x152,
+	"SIREG3":        0x153,
+	"SIREG4":        0x155,
+	"SIREG5":        0x156,
+	"SIREG6":        0x157,
+	"STOPEI":        0x15C,
+	"SCTRDEPTH":     0x15F,
+	"SATP":          0x180,
+	"SRMCFG":        0x181,
+	"SPMPEN":        0x183,
+	"VSSTATUS":      0x200,
+	"VSIE":          0x204,
+	"VSTVEC":        0x205,
+	"VSSCRATCH":     0x240,
+	"VSEPC":         0x241,
+	"VSCAUSE":       0x242,
+	"VSTVAL":        0x243,
+	"VSIP":          0x244,
+	"VSTIMECMP":     0x24D,
+	"VSCTRCTL":      0x24E,
+	"VSISELECT":     0x250,
+	"VSIREG":        0x251,
+	"VSIREG2":       0x252,
+	"VSIREG3":       0x253,
+	"VSIREG4":       0x255,
+	"VSIREG5":       0x256,
+	"VSIREG6":       0x257,
+	"VSTOPEI":       0x25C,
+	"VSATP":         0x280,
+	"MSTATUS":       0x300,
+	"MISA":          0x301,
+	"MEDELEG":       0x302,
+	"MIDELEG":       0x303,
+	"MIE":           0x304,
+	"MTVEC":         0x305,
+	"MCOUNTEREN":    0x306,
+	"MTVT":          0x307,
+	"MVIEN":         0x308,
+	"MVIP":          0x309,
+	"MENVCFG":       0x30A,
+	"MSTATEEN0":     0x30C,
+	"MSTATEEN1":     0x30D,
+	"MSTATEEN2":     0x30E,
+	"MSTATEEN3":     0x30F,
+	"MPMPDELEG":     0x316,
+	"MCOUNTINHIBIT": 0x320,
+	"MCYCLECFG":     0x321,
+	"MINSTRETCFG":   0x322,
+	"MHPMEVENT3":    0x323,
+	"MHPMEVENT4":    0x324,
+	"MHPMEVENT5":    0x325,
+	"MHPMEVENT6":    0x326,
+	"MHPMEVENT7":    0x327,
+	"MHPMEVENT8":    0x328,
+	"MHPMEVENT9":    0x329,
+	"MHPMEVENT10":   0x32A,
+	"MHPMEVENT11":   0x32B,
+	"MHPMEVENT12":   0x32C,
+	"MHPMEVENT13":   0x32D,
+	"MHPMEVENT14":   0x32E,
+	"MHPMEVENT15":   0x32F,
+	"MHPMEVENT16":   0x330,
+	"MHPMEVENT17":   0x331,
+	"MHPMEVENT18":   0x332,
+	"MHPMEVENT19":   0x333,
+	"MHPMEVENT20":   0x334,
+	"MHPMEVENT21":   0x335,
+	"MHPMEVENT22":   0x336,
+	"MHPMEVENT23":   0x337,
+	"MHPMEVENT24":   0x338,
+	"MHPMEVENT25":   0x339,
+	"MHPMEVENT26":   0x33A,
+	"MHPMEVENT27":   0x33B,
+	"MHPMEVENT28":   0x33C,
+	"MHPMEVENT29":   0x33D,
+	"MHPMEVENT30":   0x33E,
+	"MHPMEVENT31":   0x33F,
+	"MSCRATCH":      0x340,
+	"MEPC":          0x341,
+	"MCAUSE":        0x342,
+	"MTVAL":         0x343,
+	"MIP":           0x344,
+	"MNXTI":         0x345,
+	"MINTSTATUS":    0x346,
+	"MSCRATCHCSW":   0x348,
+	"MSCRATCHCSWL":  0x349,
+	"MTINST":        0x34A,
+	"MTVAL2":        0x34B,
+	"MCTRCTL":       0x34E,
+	"MISELECT":      0x350,
+	"MIREG":         0x351,
+	"MIREG2":        0x352,
+	"MIREG3":        0x353,
+	"MIREG4":        0x355,
+	"MIREG5":        0x356,
+	"MIREG6":        0x357,
+	"MTOPEI":        0x35C,
+	"PMPCFG0":       0x3A0,
+	"PMPCFG1":       0x3A1,
+	"PMPCFG2":       0x3A2,
+	"PMPCFG3":       0x3A3,
+	"PMPCFG4":       0x3A4,
+	"PMPCFG5":       0x3A5,
+	"PMPCFG6":       0x3A6,
+	"PMPCFG7":       0x3A7,
+	"PMPCFG8":       0x3A8,
+	"PMPCFG9":       0x3A9,
+	"PMPCFG10":      0x3AA,
+	"PMPCFG11":      0x3AB,
+	"PMPCFG12":      0x3AC,
+	"PMPCFG13":      0x3AD,
+	"PMPCFG14":      0x3AE,
+	"PMPCFG15":      0x3AF,
+	"PMPADDR0":      0x3B0,
+	"PMPADDR1":      0x3B1,
+	"PMPADDR2":      0x3B2,
+	"PMPADDR3":      0x3B3,
+	"PMPADDR4":      0x3B4,
+	"PMPADDR5":      0x3B5,
+	"PMPADDR6":      0x3B6,
+	"PMPADDR7":      0x3B7,
+	"PMPADDR8":      0x3B8,
+	"PMPADDR9":      0x3B9,
+	"PMPADDR10":     0x3BA,
+	"PMPADDR11":     0x3BB,
+	"PMPADDR12":     0x3BC,
+	"PMPADDR13":     0x3BD,
+	"PMPADDR14":     0x3BE,
+	"PMPADDR15":     0x3BF,
+	"PMPADDR16":     0x3C0,
+	"PMPADDR17":     0x3C1,
+	"PMPADDR18":     0x3C2,
+	"PMPADDR19":     0x3C3,
+	"PMPADDR20":     0x3C4,
+	"PMPADDR21":     0x3C5,
+	"PMPADDR22":     0x3C6,
+	"PMPADDR23":     0x3C7,
+	"PMPADDR24":     0x3C8,
+	"PMPADDR25":     0x3C9,
+	"PMPADDR26":     0x3CA,
+	"PMPADDR27":     0x3CB,
+	"PMPADDR28":     0x3CC,
+	"PMPADDR29":     0x3CD,
+	"PMPADDR30":     0x3CE,
+	"PMPADDR31":     0x3CF,
+	"PMPADDR32":     0x3D0,
+	"PMPADDR33":     0x3D1,
+	"PMPADDR34":     0x3D2,
+	"PMPADDR35":     0x3D3,
+	"PMPADDR36":     0x3D4,
+	"PMPADDR37":     0x3D5,
+	"PMPADDR38":     0x3D6,
+	"PMPADDR39":     0x3D7,
+	"PMPADDR40":     0x3D8,
+	"PMPADDR41":     0x3D9,
+	"PMPADDR42":     0x3DA,
+	"PMPADDR43":     0x3DB,
+	"PMPADDR44":     0x3DC,
+	"PMPADDR45":     0x3DD,
+	"PMPADDR46":     0x3DE,
+	"PMPADDR47":     0x3DF,
+	"PMPADDR48":     0x3E0,
+	"PMPADDR49":     0x3E1,
+	"PMPADDR50":     0x3E2,
+	"PMPADDR51":     0x3E3,
+	"PMPADDR52":     0x3E4,
+	"PMPADDR53":     0x3E5,
+	"PMPADDR54":     0x3E6,
+	"PMPADDR55":     0x3E7,
+	"PMPADDR56":     0x3E8,
+	"PMPADDR57":     0x3E9,
+	"PMPADDR58":     0x3EA,
+	"PMPADDR59":     0x3EB,
+	"PMPADDR60":     0x3EC,
+	"PMPADDR61":     0x3ED,
+	"PMPADDR62":     0x3EE,
+	"PMPADDR63":     0x3EF,
+	"SCONTEXT":      0x5A8,
+	"HSTATUS":       0x600,
+	"HEDELEG":       0x602,
+	"HIDELEG":       0x603,
+	"HIE":           0x604,
+	"HTIMEDELTA":    0x605,
+	"HCOUNTEREN":    0x606,
+	"HGEIE":         0x607,
+	"HVIEN":         0x608,
+	"HVICTL":        0x609,
+	"HENVCFG":       0x60A,
+	"HSTATEEN0":     0x60C,
+	"HSTATEEN1":     0x60D,
+	"HSTATEEN2":     0x60E,
+	"HSTATEEN3":     0x60F,
+	"HTVAL":         0x643,
+	"HIP":           0x644,
+	"HVIP":          0x645,
+	"HVIPRIO1":      0x646,
+	"HVIPRIO2":      0x647,
+	"HTINST":        0x64A,
+	"HGATP":         0x680,
+	"HCONTEXT":      0x6A8,
+	"MSECCFG":       0x747,
+	"TSELECT":       0x7A0,
+	"TDATA1":        0x7A1,
+	"TDATA2":        0x7A2,
+	"TDATA3":        0x7A3,
+	"TINFO":         0x7A4,
+	"TCONTROL":      0x7A5,
+	"MCONTEXT":      0x7A8,
+	"MSCONTEXT":     0x7AA,
+	"DCSR":          0x7B0,
+	"DPC":           0x7B1,
+	"DSCRATCH0":     0x7B2,
+	"DSCRATCH1":     0x7B3,
+	"MCYCLE":        0xB00,
+	"MINSTRET":      0xB02,
+	"MHPMCOUNTER3":  0xB03,
+	"MHPMCOUNTER4":  0xB04,
+	"MHPMCOUNTER5":  0xB05,
+	"MHPMCOUNTER6":  0xB06,
+	"MHPMCOUNTER7":  0xB07,
+	"MHPMCOUNTER8":  0xB08,
+	"MHPMCOUNTER9":  0xB09,
+	"MHPMCOUNTER10": 0xB0A,
+	"MHPMCOUNTER11": 0xB0B,
+	"MHPMCOUNTER12": 0xB0C,
+	"MHPMCOUNTER13": 0xB0D,
+	"MHPMCOUNTER14": 0xB0E,
+	"MHPMCOUNTER15": 0xB0F,
+	"MHPMCOUNTER16": 0xB10,
+	"MHPMCOUNTER17": 0xB11,
+	"MHPMCOUNTER18": 0xB12,
+	"MHPMCOUNTER19": 0xB13,
+	"MHPMCOUNTER20": 0xB14,
+	"MHPMCOUNTER21": 0xB15,
+	"MHPMCOUNTER22": 0xB16,
+	"MHPMCOUNTER23": 0xB17,
+	"MHPMCOUNTER24": 0xB18,
+	"MHPMCOUNTER25": 0xB19,
+	"MHPMCOUNTER26": 0xB1A,
+	"MHPMCOUNTER27": 0xB1B,
+	"MHPMCOUNTER28": 0xB1C,
+	"MHPMCOUNTER29": 0xB1D,
+	"MHPMCOUNTER30": 0xB1E,
+	"MHPMCOUNTER31": 0xB1F,
+	"CYCLE":         0xC00,
+	"TIME":          0xC01,
+	"INSTRET":       0xC02,
+	"HPMCOUNTER3":   0xC03,
+	"HPMCOUNTER4":   0xC04,
+	"HPMCOUNTER5":   0xC05,
+	"HPMCOUNTER6":   0xC06,
+	"HPMCOUNTER7":   0xC07,
+	"HPMCOUNTER8":   0xC08,
+	"HPMCOUNTER9":   0xC09,
+	"HPMCOUNTER10":  0xC0A,
+	"HPMCOUNTER11":  0xC0B,
+	"HPMCOUNTER12":  0xC0C,
+	"HPMCOUNTER13":  0xC0D,
+	"HPMCOUNTER14":  0xC0E,
+	"HPMCOUNTER15":  0xC0F,
+	"HPMCOUNTER16":  0xC10,
+	"HPMCOUNTER17":  0xC11,
+	"HPMCOUNTER18":  0xC12,
+	"HPMCOUNTER19":  0xC13,
+	"HPMCOUNTER20":  0xC14,
+	"HPMCOUNTER21":  0xC15,
+	"HPMCOUNTER22":  0xC16,
+	"HPMCOUNTER23":  0xC17,
+	"HPMCOUNTER24":  0xC18,
+	"HPMCOUNTER25":  0xC19,
+	"HPMCOUNTER26":  0xC1A,
+	"HPMCOUNTER27":  0xC1B,
+	"HPMCOUNTER28":  0xC1C,
+	"HPMCOUNTER29":  0xC1D,
+	"HPMCOUNTER30":  0xC1E,
+	"HPMCOUNTER31":  0xC1F,
+	"VL":            0xC20,
+	"VTYPE":         0xC21,
+	"VLENB":         0xC22,
+	"SCOUNTOVF":     0xDA0,
+	"STOPI":         0xDB0,
+	"HGEIP":         0xE12,
+	"VSTOPI":        0xEB0,
+	"MVENDORID":     0xF11,
+	"MARCHID":       0xF12,
+	"MIMPID":        0xF13,
+	"MHARTID":       0xF14,
+	"MCONFIGPTR":    0xF15,
+	"MTOPI":         0xFB0,
 }

 // riscvCSRAddress resolves a CSR operand: an integer immediate or one of the
@@ -0,0 +1,110 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package asm
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/gasm-sdk/parser"
+)
+
+// TestRISCVCSRDifferential proves the whole CSR name table against the
+// toolchain at once: one TEXT whose body reads every register the table
+// carries (CSRRW X0, NAME, X5), assembled by gasm and by go tool asm, must
+// agree byte for byte.  A single wrong address names its register through
+// the first differing word: the CSR address occupies the instruction's top
+// twelve bits, so 329 names spread over distinct words identify themselves.
+func TestRISCVCSRDifferential(t *testing.T) {
+	names := make([]string, 0, len(riscvCSRNames))
+	for name := range riscvCSRNames {
+		names = append(names, name)
+	}
+	slices.Sort(names)
+
+	var body strings.Builder
+	for _, name := range names {
+		body.WriteString(fmt.Sprintf("\tCSRRW X0, %s, X5\n", name))
+	}
+	src := "#include \"textflag.h\"\n\nTEXT ·csrs(SB), NOSPLIT, $0\n" + body.String() + "\tRET\n"
+
+	dir := t.TempDir()
+	path := filepath.Join(dir, "csrs_riscv64.s")
+	if err := os.WriteFile(path, []byte(src), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	assertRISCVDifferential(t, path, src, "csrs")
+}
+
+// TestRISCVCSRPseudosDifferential pins the CSR pseudo spellings against the
+// oracle: the write-only forms (source first, CSR second), their immediate
+// variants and the CSRR read pseudo, one word each.
+func TestRISCVCSRPseudosDifferential(t *testing.T) {
+	src := `#include "textflag.h"
+
+TEXT ·csrps(SB), NOSPLIT, $0
+	CSRS X5, TIME
+	CSRC X5, CYCLE
+	CSRW X5, INSTRET
+	CSRSI $1, TIME
+	CSRCI $2, CYCLE
+	CSRWI $3, INSTRET
+	CSRR VL, X10
+	CSRRW X0, TIME, X11
+	CSRRS X0, CYCLE, X12
+	CSRRC X0, INSTRET, X13
+	CSRRWI $4, TIME, X14
+	CSRRSI $5, CYCLE, X15
+	CSRRCI $6, INSTRET, X16
+	RET
+`
+	dir := t.TempDir()
+	path := filepath.Join(dir, "csrps_riscv64.s")
+	if err := os.WriteFile(path, []byte(src), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	assertRISCVDifferential(t, path, src, "csrps")
+}
+
+// assertRISCVDifferential assembles the same source with gasm and with the
+// toolchain for riscv64 and requires the named function's code bytes to
+// agree.  The live oracle is a deliberate-run comparison, so -short skips it
+// (the push pipeline's mode); the golden bytes of the individual encoders
+// are pinned separately in every mode.
+func assertRISCVDifferential(t *testing.T, path, src, fn string) {
+	t.Helper()
+	oracle := oracleFuncCode(t, toolAsmObject(t, path, "riscv64"))
+
+	// The oracle keys its functions by the qualified object name
+	// (pkg.name); match on the local part.
+	want := map[string][]byte{}
+	for name, code := range oracle {
+		if _, after, ok := strings.Cut(name, "."); ok {
+			want[after] = code
+		} else {
+			want[name] = code
+		}
+	}
+	if want[fn] == nil {
+		t.Fatalf("the oracle object carries no function %q (has %v)", fn, keysOf(want))
+	}
+
+	f, perrs := parser.Parse(path, src)
+	if len(perrs) > 0 {
+		t.Fatalf("parse: %v", perrs[0])
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	got := trimTrailingZeroWords(img.Code)
+	wantB := trimTrailingZeroWords(want[fn])
+	if !slices.Equal(got, wantB) {
+		t.Errorf("%s: gasm and go tool asm disagree:\n gasm % x\n go   % x", fn, got, wantB)
+	}
+}