// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause

package parser

import (
	"math"
	"os"
	"slices"
	"strings"
	"testing"

	"sourcedock.dev/petrbalvin/gasm-sdk/ast"
)

func mustParse(t *testing.T, path string) *ast.File {
	t.Helper()
	src, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read %s: %v", path, err)
	}
	file, errs := Parse(path, string(src))
	if len(errs) > 0 {
		t.Fatalf("parse %s: %v", path, errs)
	}
	return file
}

func texts(f *ast.File) []*ast.Text {
	var out []*ast.Text
	for _, d := range f.Decls {
		if t, ok := d.(*ast.Text); ok {
			out = append(out, t)
		}
	}
	return out
}

// TestNegativeDisplacement is a regression test for a leading negative
// displacement with a base and index: the sign pushed the parenthesis one
// token further out than the lookahead expected, and the whole address used
// to parse empty.
func TestNegativeDisplacement(t *testing.T) {
	f, errs := Parse("neg_amd64.s", `
#include "textflag.h"
TEXT ·f(SB), NOSPLIT, $0
	LEAQ -4(DX)(R9*4), R9
	MOVQ +8(AX), BX
	RET
`)
	if len(errs) > 0 {
		t.Fatalf("parse: %v", errs)
	}
	fn := texts(f)[0]
	var leaq, movq *ast.Instr
	for _, s := range fn.Body {
		if in, ok := s.(*ast.Instr); ok {
			switch in.Mnemonic.Text {
			case "LEAQ":
				leaq = in
			case "MOVQ":
				movq = in
			}
		}
	}
	if leaq == nil || movq == nil {
		t.Fatalf("instructions not parsed: leaq=%v movq=%v", leaq, movq)
	}
	a := leaq.Operands[0].Addr
	if a.Base != "DX" || a.Index != "R9" || a.Scale != 4 || a.Offset != -4 || !a.HasOff {
		t.Errorf("LEAQ addr = %+v, want -4(DX)(R9*4)", a)
	}
	b := movq.Operands[0].Addr
	if b.Base != "AX" || b.Offset != 8 || !b.HasOff {
		t.Errorf("MOVQ addr = %+v, want +8(AX)", b)
	}
}

func TestParseSample(t *testing.T) {
	f := mustParse(t, "../testdata/sample_amd64.s")

	// Includes, GLOBL/DATA and two TEXT functions.
	var includes, globls, datas int
	for _, d := range f.Decls {
		switch d.(type) {
		case *ast.Include:
			includes++
		case *ast.Globl:
			globls++
		case *ast.Data:
			datas++
		}
	}
	if includes != 1 {
		t.Errorf("includes = %d, want 1", includes)
	}
	if globls != 2 {
		t.Errorf("globls = %d, want 2", globls)
	}
	if datas != 4 {
		t.Errorf("datas = %d, want 4", datas)
	}

	txts := texts(f)
	if len(txts) != 2 {
		t.Fatalf("text functions = %d, want 2", len(txts))
	}

	fn := txts[0]
	if fn.Name.Name != "analyzeO1RangeAVX2" {
		t.Errorf("name = %q, want analyzeO1RangeAVX2", fn.Name.Name)
	}
	if fn.Name.Pseudo != "SB" {
		t.Errorf("pseudo = %q, want SB", fn.Name.Pseudo)
	}
	if len(fn.Flags) != 1 || fn.Flags[0] != "NOSPLIT" {
		t.Errorf("flags = %v, want [NOSPLIT]", fn.Flags)
	}
	if fn.Frame == nil || !fn.Frame.Imm.HasVal || fn.Frame.Imm.Val != 0 {
		t.Errorf("frame = %+v, want $0", fn.Frame)
	}
	if fn.Args == nil || fn.Args.Imm.Val != 65 {
		t.Errorf("args = %+v, want 65", fn.Args)
	}
	if fn.Doc == "" {
		t.Error("expected a doc comment on the first TEXT")
	}

	// The body must contain the two labels vec1 and vec1done.
	labels := map[string]bool{}
	for _, s := range fn.Body {
		if l, ok := s.(*ast.Label); ok {
			labels[l.Name.Text] = true
		}
	}
	for _, want := range []string{"vec1", "vec1done"} {
		if !labels[want] {
			t.Errorf("missing label %q", want)
		}
	}
}

func TestOperandStructure(t *testing.T) {
	f := mustParse(t, "../testdata/sample_amd64.s")
	fn := texts(f)[0]

	// Index instructions by mnemonic for targeted checks.
	byMnem := map[string]*ast.Instr{}
	for _, s := range fn.Body {
		if in, ok := s.(*ast.Instr); ok {
			byMnem[in.Mnemonic.Text] = in
		}
	}

	// MOVQ swin_base+0(FP), SI; the first MOVQ in the body.
	var mov *ast.Instr
	for _, s := range fn.Body {
		if in, ok := s.(*ast.Instr); ok && in.Mnemonic.Text == "MOVQ" {
			mov = in
			break
		}
	}
	if mov == nil {
		t.Fatal("MOVQ not found")
	}
	src := mov.Operands[0]
	if src.Kind != ast.OpAddr || src.Addr.Sym == nil {
		t.Fatalf("src operand = %+v, want symbol address", src)
	}
	if src.Addr.Sym.Name != "swin_base" || src.Addr.Sym.Pseudo != "FP" || src.Addr.Sym.Offset != 0 {
		t.Errorf("src symbol = %+v, want swin_base+0(FP)", src.Addr.Sym)
	}
	if mov.Operands[1].Addr.Sym.Name != "SI" {
		t.Errorf("dst = %+v, want SI", mov.Operands[1].Addr)
	}

	// LEAQ (SI)(BX*4), R9
	leaq := byMnem["LEAQ"]
	if leaq == nil {
		t.Fatal("LEAQ not found")
	}
	mem := leaq.Operands[0].Addr
	if mem.Base != "SI" || mem.Index != "BX" || mem.Scale != 4 {
		t.Errorf("LEAQ addr = %+v, want base SI index BX scale 4", mem)
	}

	// ANDQ $-8, R10
	andq := byMnem["ANDQ"]
	if andq == nil {
		t.Fatal("ANDQ not found")
	}
	imm := andq.Operands[0]
	if imm.Kind != ast.OpImmediate || !imm.Imm.Neg || imm.Imm.Val != 8 {
		t.Errorf("ANDQ imm = %+v, want -8", imm.Imm)
	}
}

func TestAVX512Operands(t *testing.T) {
	f := mustParse(t, "../testdata/sample_amd64.s")
	fn := texts(f)[1]
	byMnem := map[string]*ast.Instr{}
	for _, s := range fn.Body {
		if in, ok := s.(*ast.Instr); ok {
			byMnem[in.Mnemonic.Text] = in
		}
	}

	// VALIGND $15, Z9, Z0, Z1; four operands.
	val := byMnem["VALIGND"]
	if val == nil {
		t.Fatal("VALIGND not found")
	}
	if len(val.Operands) != 4 {
		t.Errorf("VALIGND operands = %d, want 4", len(val.Operands))
	}
	if val.Operands[0].Kind != ast.OpImmediate || val.Operands[0].Imm.Val != 15 {
		t.Errorf("VALIGND first operand = %+v, want $15", val.Operands[0])
	}

	// VMOVDQU32 Z0, 4(SI)(AX*1)
	vmov := byMnem["VMOVDQU32"]
	if vmov == nil {
		t.Fatal("VMOVDQU32 not found")
	}
	dst := vmov.Operands[len(vmov.Operands)-1].Addr
	if dst.Offset != 4 || dst.Base != "SI" || dst.Index != "AX" || dst.Scale != 1 {
		t.Errorf("VMOVDQU32 dst = %+v, want 4(SI)(AX*1)", dst)
	}

	// KTESTW K1, K1; mask registers parse as bare names.
	kt := byMnem["KTESTW"]
	if kt == nil || len(kt.Operands) != 2 {
		t.Fatalf("KTESTW = %+v, want two operands", kt)
	}
}

func TestDataWidthAndStatic(t *testing.T) {
	f := mustParse(t, "../testdata/sample_amd64.s")
	var datas []*ast.Data
	for _, d := range f.Decls {
		if dd, ok := d.(*ast.Data); ok {
			datas = append(datas, dd)
		}
	}
	if datas[0].Width != 4 {
		t.Errorf("first DATA width = %d, want 4", datas[0].Width)
	}
	if datas[0].Name.Pseudo != "SB" || datas[0].Name.Offset != 0 {
		t.Errorf("first DATA name = %+v, want +0(SB)", datas[0].Name)
	}
	if datas[0].Value.Kind != ast.OpImmediate || datas[0].Value.Imm.Val != 1 {
		t.Errorf("first DATA value = %+v, want $1", datas[0].Value)
	}
	// The mask24<> entries are static.
	if !datas[2].Name.Static {
		t.Errorf("mask24 DATA should be static, got %+v", datas[2].Name)
	}
}

// TestTruncatedFrameDollar is a regression test for a TEXT directive whose
// frame size is missing after the $: the parser used to slice past the end
// of the token slice and panic.  It must report a diagnostic instead.
func TestTruncatedFrameDollar(t *testing.T) {
	for _, src := range []string{
		"TEXT $\n",
		"TEXT \u00b7foo(SB), $\n",
		"TEXT \u00b7foo(SB), NOSPLIT, $\n",
	} {
		var file *ast.File
		func() {
			defer func() {
				if r := recover(); r != nil {
					t.Fatalf("Parse(%q) panicked: %v", src, r)
				}
			}()
			file, _ = Parse("t.s", src)
		}()
		if file == nil {
			t.Fatalf("Parse(%q) returned no file", src)
		}
		if len(file.Decls) != 1 {
			t.Fatalf("Parse(%q) decls = %d, want 1", src, len(file.Decls))
		}
		txt := file.Decls[0].(*ast.Text)
		if txt.Frame != nil {
			t.Errorf("Parse(%q) frame = %v, want nil", src, txt.Frame)
		}
	}
}

// TestFrameAndArgs parses a well-formed TEXT header and checks that the
// frame and args operands are picked up.
func TestFrameAndArgs(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7foo(SB), $32-16\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	if txt.Frame == nil || !txt.Frame.Imm.HasVal || txt.Frame.Imm.Val != 32 {
		t.Errorf("frame = %+v, want $32", txt.Frame)
	}
	if txt.Args == nil || !txt.Args.Imm.HasVal || txt.Args.Imm.Val != 16 {
		t.Errorf("args = %+v, want -16", txt.Args)
	}
}

// TestSignedZeroFrame covers the Go runtime's "$-0-24" spelling: a zero
// frame with an explicit sign plus the argument area.
func TestSignedZeroFrame(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7foo<ABIInternal>(SB), NOSPLIT, $-0-24\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	if txt.Frame == nil || !txt.Frame.Imm.HasVal || txt.Frame.Imm.Val != 0 {
		t.Errorf("frame = %+v, want $-0", txt.Frame)
	}
	if txt.Args == nil || !txt.Args.Imm.HasVal || txt.Args.Imm.Val != 24 {
		t.Errorf("args = %+v, want -24", txt.Args)
	}
	// The <ABIInternal> marker belongs to the symbol: the pseudo-register is
	// consumed, the marker is recorded, and neither leaks into the flags.
	if txt.Name.Pseudo != "SB" {
		t.Errorf("pseudo = %q, want SB", txt.Name.Pseudo)
	}
	if txt.Name.ABI != "ABIInternal" {
		t.Errorf("ABI = %q, want ABIInternal", txt.Name.ABI)
	}
	if !strings.Contains(txt.Name.Raw, "<ABIInternal>") {
		t.Errorf("Raw = %q, want it to contain <ABIInternal>", txt.Name.Raw)
	}
	if want := []string{"NOSPLIT"}; !slices.Equal(txt.Flags, want) {
		t.Errorf("flags = %v, want %v", txt.Flags, want)
	}
}

// TestPipedFlags covers TEXT and GLOBL flag lists joined by '|': the bars are
// their own token kind, skipped by the flag loop, and only the identifiers
// are collected as flags.
func TestPipedFlags(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7f(SB), NOSPLIT|NOFRAME|DUPOK, $0\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	if want := []string{"NOSPLIT", "NOFRAME", "DUPOK"}; !slices.Equal(txt.Flags, want) {
		t.Errorf("flags = %v, want %v", txt.Flags, want)
	}

	g, errs := Parse("t.s", "GLOBL \u00b7mask(SB), RODATA|NOPTR, $8\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	gl := g.Decls[0].(*ast.Globl)
	if want := []string{"RODATA", "NOPTR"}; !slices.Equal(gl.Flags, want) {
		t.Errorf("flags = %v, want %v", gl.Flags, want)
	}
}

// TestTextMissingSymbolKeepsDecl covers a TEXT with no symbol at all: the
// decl must stay in the tree with a non-nil placeholder name, because the
// linter and the LSP dereference Name on every parsed TEXT.
func TestTextMissingSymbolKeepsDecl(t *testing.T) {
	file, errs := Parse("t.s", "// func f(a int) int\nTEXT $0\n\tMOVQ AX, BX\n")
	if len(errs) == 0 {
		t.Fatal("expected a diagnostic for the missing symbol")
	}
	if file == nil || len(file.Decls) != 1 {
		t.Fatalf("file = %v, want the TEXT decl kept", file)
	}
	txt := file.Decls[0].(*ast.Text)
	if txt.Name == nil {
		t.Fatal("Name must never be nil: downstream tools dereference it")
	}
	if txt.Name.Name == "" {
		t.Error("placeholder name is empty")
	}
	if txt.Frame == nil || !txt.Frame.Imm.HasVal || txt.Frame.Imm.Val != 0 {
		t.Errorf("frame = %+v, want $0", txt.Frame)
	}
	if len(txt.Body) != 1 {
		t.Errorf("body = %d statements, want 1", len(txt.Body))
	}
}

// TestInt64MinimumImmediate covers $-0x8000000000000000: the digits overflow
// int64 when parsed directly, but the negated magnitude is exactly the int64
// minimum and must land in Val rather than the float fallback.
func TestInt64MinimumImmediate(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7f(SB), $0\n\tMOVQ $-0x8000000000000000, AX\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	instr := txt.Body[0].(*ast.Instr)
	imm := instr.Operands[0].Imm
	if !imm.HasVal || imm.Val != math.MinInt64 {
		t.Errorf("imm = %+v, want Val = %d with HasVal set", imm, math.MinInt64)
	}
	if imm.Float != "" {
		t.Errorf("imm.Float = %q, want empty", imm.Float)
	}
}

// TestDivisionSlashPackagePath covers the runtime's package-path spelling:
// U+2215 DIVISION SLASH separates the elements of an import path inside a
// symbol (internal∕runtime∕atomic·Xchg), and the middle dot still separates
// the package from the name.  The whole spelling must reach the symbol, not
// stop at the first slash.
func TestDivisionSlashPackagePath(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7f(SB), $0\n\tCALL internal∕runtime∕atomic·Xchg(SB)\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	instr := txt.Body[0].(*ast.Instr)
	sym := instr.Operands[0].Addr.Sym
	if sym == nil {
		t.Fatal("operand carries no symbol")
	}
	if sym.Pkg != "internal∕runtime∕atomic" {
		t.Errorf("pkg = %q, want internal∕runtime∕atomic", sym.Pkg)
	}
	if sym.Name != "Xchg" {
		t.Errorf("name = %q, want Xchg", sym.Name)
	}
	if sym.Raw != "internal∕runtime∕atomic·Xchg(SB)" {
		t.Errorf("raw = %q", sym.Raw)
	}
}

// TestSemicolonStatements covers the plain parse path: ';' separates
// statements on one line exactly as it does inside macro expansion, and a
// ';' inside a comment is comment text.
func TestSemicolonStatements(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7f(SB), $0\n\tROLQ $3, DI; ROLQ $13, DI\n\tMOVQ AX, BX // note; still comment\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	if len(txt.Body) != 4 {
		t.Fatalf("body = %d statements, want 4", len(txt.Body))
	}
	first := txt.Body[0].(*ast.Instr)
	if first.Mnemonic.Text != "ROLQ" || len(first.Operands) != 2 {
		t.Errorf("first statement = %+v, want ROLQ with two operands", first.Mnemonic)
	}
	second := txt.Body[1].(*ast.Instr)
	if second.Mnemonic.Text != "ROLQ" || len(second.Operands) != 2 {
		t.Errorf("second statement = %s, want ROLQ with two operands", second.Mnemonic.Text)
	}
	// The trailing comment belongs to the second MOVQ, semicolon included.
	third := txt.Body[2].(*ast.Instr)
	if third.Mnemonic.Text != "MOVQ" || third.Comment != "note; still comment" {
		t.Errorf("third = %s, comment %q", third.Mnemonic.Text, third.Comment)
	}
}

// TestSemicolonAfterLabel covers a label sharing its line with two
// statements.
func TestSemicolonAfterLabel(t *testing.T) {
	file, errs := Parse("t.s", "TEXT \u00b7f(SB), $0\nloop: NOP; NOP\n\tRET\n")
	if len(errs) > 0 {
		t.Fatalf("parse errors: %v", errs)
	}
	txt := file.Decls[0].(*ast.Text)
	if len(txt.Body) != 4 {
		t.Fatalf("body = %d statements, want 4 (label, two instructions, RET)", len(txt.Body))
	}
	if _, ok := txt.Body[0].(*ast.Label); !ok {
		t.Errorf("first statement = %T, want *ast.Label", txt.Body[0])
	}
	for i, want := range []string{"NOP", "NOP", "RET"} {
		in, ok := txt.Body[i+1].(*ast.Instr)
		if !ok || in.Mnemonic.Text != want {
			t.Errorf("statement %d = %v, want %s", i+1, txt.Body[i+1], want)
		}
	}
}

// TestParseEqualsZeroOptions pins the contract that ParseWithOptions with
// the zero Options reproduces Parse, here for the semicolon split.
func TestParseEqualsZeroOptions(t *testing.T) {
	src := "TEXT \u00b7f(SB), $0\n\tNOP; NOP\n\tRET\n"
	a, errsA := Parse("t.s", src)
	b, errsB := ParseWithOptions("t.s", src, Options{})
	if len(errsA) > 0 || len(errsB) > 0 {
		t.Fatalf("errors: %v / %v", errsA, errsB)
	}
	ta, tb := texts(a), texts(b)
	if len(ta) != len(tb) {
		t.Fatalf("decl counts differ: %d vs %d", len(ta), len(tb))
	}
	for i := range ta {
		if len(ta[i].Body) != len(tb[i].Body) {
			t.Fatalf("TEXT %d: body lengths differ: %d vs %d", i, len(ta[i].Body), len(tb[i].Body))
		}
	}
}

// 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)
	}
}