code review 153750044: cmd/objdump: move armasm, x86asm into internal packages

src/cmd/internal/rsc.io/x86/x86asm/intel.go

Index: src/cmd/internal/rsc.io/x86/x86asm/intel.go
===================================================================
new file mode 100644
--- /dev/null
+++ b/src/cmd/internal/rsc.io/x86/x86asm/intel.go
@@ -0,0 +1,518 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package x86asm
+
+import (
+	"fmt"
+	"strings"
+)
+
+// IntelSyntax returns the Intel assembler syntax for the instruction, as defined by Intel's XED tool.
+func IntelSyntax(inst Inst) string {
+	var iargs []Arg
+	for _, a := range inst.Args {
+		if a == nil {
+			break
+		}
+		iargs = append(iargs, a)
+	}
+
+	switch inst.Op {
+	case INSB, INSD, INSW, OUTSB, OUTSD, OUTSW, LOOPNE, JCXZ, JECXZ, JRCXZ, LOOP, LOOPE, MOV, XLATB:
+		if inst.Op == MOV && (inst.Opcode>>16)&0xFFFC != 0x0F20 {
+			break
+		}
+		for i, p := range inst.Prefix {
+			if p&0xFF == PrefixAddrSize {
+				inst.Prefix[i] &^= PrefixImplicit
+			}
+		}
+	}
+
+	switch inst.Op {
+	case MOV:
+		dst, _ := inst.Args[0].(Reg)
+		src, _ := inst.Args[1].(Reg)
+		if ES <= dst && dst <= GS && EAX <= src && src <= R15L {
+			src -= EAX - AX
+			iargs[1] = src
+		}
+		if ES <= dst && dst <= GS && RAX <= src && src <= R15 {
+			src -= RAX - AX
+			iargs[1] = src
+		}
+
+		if inst.Opcode>>24&^3 == 0xA0 {
+			for i, p := range inst.Prefix {
+				if p&0xFF == PrefixAddrSize {
+					inst.Prefix[i] |= PrefixImplicit
+				}
+			}
+		}
+	}
+
+	switch inst.Op {
+	case AAM, AAD:
+		if imm, ok := iargs[0].(Imm); ok {
+			if inst.DataSize == 32 {
+				iargs[0] = Imm(uint32(int8(imm)))
+			} else if inst.DataSize == 16 {
+				iargs[0] = Imm(uint16(int8(imm)))
+			}
+		}
+
+	case PUSH:
+		if imm, ok := iargs[0].(Imm); ok {
+			iargs[0] = Imm(uint32(imm))
+		}
+	}
+
+	for _, p := range inst.Prefix {
+		if p&PrefixImplicit != 0 {
+			for j, pj := range inst.Prefix {
+				if pj&0xFF == p&0xFF {
+					inst.Prefix[j] |= PrefixImplicit
+				}
+			}
+		}
+	}
+
+	if inst.Op != 0 {
+		for i, p := range inst.Prefix {
+			switch p &^ PrefixIgnored {
+			case PrefixData16, PrefixData32, PrefixCS, PrefixDS, PrefixES, PrefixSS:
+				inst.Prefix[i] |= PrefixImplicit
+			}
+			if p.IsREX() {
+				inst.Prefix[i] |= PrefixImplicit
+			}
+		}
+	}
+
+	if isLoop[inst.Op] || inst.Op == JCXZ || inst.Op == JECXZ || inst.Op == JRCXZ {
+		for i, p := range inst.Prefix {
+			if p == PrefixPT || p == PrefixPN {
+				inst.Prefix[i] |= PrefixImplicit
+			}
+		}
+	}
+
+	switch inst.Op {
+	case AAA, AAS, CBW, CDQE, CLC, CLD, CLI, CLTS, CMC, CPUID, CQO, CWD, DAA, DAS,
+		FDECSTP, FINCSTP, FNCLEX, FNINIT, FNOP, FWAIT, HLT,
+		ICEBP, INSB, INSD, INSW, INT, INTO, INVD, IRET, IRETQ,
+		LAHF, LEAVE, LRET, MONITOR, MWAIT, NOP, OUTSB, OUTSD, OUTSW,
+		PAUSE, POPA, POPF, POPFQ, PUSHA, PUSHF, PUSHFQ,
+		RDMSR, RDPMC, RDTSC, RDTSCP, RET, RSM,
+		SAHF, STC, STD, STI, SYSENTER, SYSEXIT, SYSRET,
+		UD2, WBINVD, WRMSR, XEND, XLATB, XTEST:
+
+		if inst.Op == NOP && inst.Opcode>>24 != 0x90 {
+			break
+		}
+		if inst.Op == RET && inst.Opcode>>24 != 0xC3 {
+			break
+		}
+		if inst.Op == INT && inst.Opcode>>24 != 0xCC {
+			break
+		}
+		if inst.Op == LRET && inst.Opcode>>24 != 0xcb {
+			break
+		}
+		for i, p := range inst.Prefix {
+			if p&0xFF == PrefixDataSize {
+				inst.Prefix[i] &^= PrefixImplicit | PrefixIgnored
+			}
+		}
+
+	case 0:
+		// ok
+	}
+
+	switch inst.Op {
+	case INSB, INSD, INSW, OUTSB, OUTSD, OUTSW, MONITOR, MWAIT, XLATB:
+		iargs = nil
+
+	case STOSB, STOSW, STOSD, STOSQ:
+		iargs = iargs[:1]
+
+	case LODSB, LODSW, LODSD, LODSQ, SCASB, SCASW, SCASD, SCASQ:
+		iargs = iargs[1:]
+	}
+
+	const (
+		haveData16 = 1 << iota
+		haveData32
+		haveAddr16
+		haveAddr32
+		haveXacquire
+		haveXrelease
+		haveLock
+		haveHintTaken
+		haveHintNotTaken
+		haveBnd
+	)
+	var prefixBits uint32
+	prefix := ""
+	for _, p := range inst.Prefix {
+		if p == 0 {
+			break
+		}
+		if p&0xFF == 0xF3 {
+			prefixBits &^= haveBnd
+		}
+		if p&(PrefixImplicit|PrefixIgnored) != 0 {
+			continue
+		}
+		switch p {
+		default:
+			prefix += strings.ToLower(p.String()) + " "
+		case PrefixCS, PrefixDS, PrefixES, PrefixFS, PrefixGS, PrefixSS:
+			if inst.Op == 0 {
+				prefix += strings.ToLower(p.String()) + " "
+			}
+		case PrefixREPN:
+			prefix += "repne "
+		case PrefixLOCK:
+			prefixBits |= haveLock
+		case PrefixData16, PrefixDataSize:
+			prefixBits |= haveData16
+		case PrefixData32:
+			prefixBits |= haveData32
+		case PrefixAddrSize, PrefixAddr16:
+			prefixBits |= haveAddr16
+		case PrefixAddr32:
+			prefixBits |= haveAddr32
+		case PrefixXACQUIRE:
+			prefixBits |= haveXacquire
+		case PrefixXRELEASE:
+			prefixBits |= haveXrelease
+		case PrefixPT:
+			prefixBits |= haveHintTaken
+		case PrefixPN:
+			prefixBits |= haveHintNotTaken
+		case PrefixBND:
+			prefixBits |= haveBnd
+		}
+	}
+	switch inst.Op {
+	case JMP:
+		if inst.Opcode>>24 == 0xEB {
+			prefixBits &^= haveBnd
+		}
+	case RET, LRET:
+		prefixBits &^= haveData16 | haveData32
+	}
+
+	if prefixBits&haveXacquire != 0 {
+		prefix += "xacquire "
+	}
+	if prefixBits&haveXrelease != 0 {
+		prefix += "xrelease "
+	}
+	if prefixBits&haveLock != 0 {
+		prefix += "lock "
+	}
+	if prefixBits&haveBnd != 0 {
+		prefix += "bnd "
+	}
+	if prefixBits&haveHintTaken != 0 {
+		prefix += "hint-taken "
+	}
+	if prefixBits&haveHintNotTaken != 0 {
+		prefix += "hint-not-taken "
+	}
+	if prefixBits&haveAddr16 != 0 {
+		prefix += "addr16 "
+	}
+	if prefixBits&haveAddr32 != 0 {
+		prefix += "addr32 "
+	}
+	if prefixBits&haveData16 != 0 {
+		prefix += "data16 "
+	}
+	if prefixBits&haveData32 != 0 {
+		prefix += "data32 "
+	}
+
+	if inst.Op == 0 {
+		if prefix == "" {
+			return "<no instruction>"
+		}
+		return prefix[:len(prefix)-1]
+	}
+
+	var args []string
+	for _, a := range iargs {
+		if a == nil {
+			break
+		}
+		args = append(args, intelArg(&inst, a))
+	}
+
+	var op string
+	switch inst.Op {
+	case NOP:
+		if inst.Opcode>>24 == 0x0F {
+			if inst.DataSize == 16 {
+				args = append(args, "ax")
+			} else {
+				args = append(args, "eax")
+			}
+		}
+
+	case BLENDVPD, BLENDVPS, PBLENDVB:
+		args = args[:2]
+
+	case INT:
+		if inst.Opcode>>24 == 0xCC {
+			args = nil
+			op = "int3"
+		}
+
+	case LCALL, LJMP:
+		if len(args) == 2 {
+			args[0], args[1] = args[1], args[0]
+		}
+
+	case FCHS, FABS, FTST, FLDPI, FLDL2E, FLDLG2, F2XM1, FXAM, FLD1, FLDL2T, FSQRT, FRNDINT, FCOS, FSIN:
+		if len(args) == 0 {
+			args = append(args, "st0")
+		}
+
+	case FPTAN, FSINCOS, FUCOMPP, FCOMPP, FYL2X, FPATAN, FXTRACT, FPREM1, FPREM, FYL2XP1, FSCALE:
+		if len(args) == 0 {
+			args = []string{"st0", "st1"}
+		}
+
+	case FST, FSTP, FISTTP, FIST, FISTP, FBSTP:
+		if len(args) == 1 {
+			args = append(args, "st0")
+		}
+
+	case FLD, FXCH, FCOM, FCOMP, FIADD, FIMUL, FICOM, FICOMP, FISUBR, FIDIV, FUCOM, FUCOMP, FILD, FBLD, FADD, FMUL, FSUB, FSUBR, FISUB, FDIV, FDIVR, FIDIVR:
+		if len(args) == 1 {
+			args = []string{"st0", args[0]}
+		}
+
+	case MASKMOVDQU, MASKMOVQ, XLATB, OUTSB, OUTSW, OUTSD:
+	FixSegment:
+		for i := len(inst.Prefix) - 1; i >= 0; i-- {
+			p := inst.Prefix[i] & 0xFF
+			switch p {
+			case PrefixCS, PrefixES, PrefixFS, PrefixGS, PrefixSS:
+				if inst.Mode != 64 || p == PrefixFS || p == PrefixGS {
+					args = append(args, strings.ToLower((inst.Prefix[i] & 0xFF).String()))
+					break FixSegment
+				}
+			case PrefixDS:
+				if inst.Mode != 64 {
+					break FixSegment
+				}
+			}
+		}
+	}
+
+	if op == "" {
+		op = intelOp[inst.Op]
+	}
+	if op == "" {
+		op = strings.ToLower(inst.Op.String())
+	}
+	if args != nil {
+		op += " " + strings.Join(args, ", ")
+	}
+	return prefix + op
+}
+
+func intelArg(inst *Inst, arg Arg) string {
+	switch a := arg.(type) {
+	case Imm:
+		if inst.Mode == 32 {
+			return fmt.Sprintf("%#x", uint32(a))
+		}
+		if Imm(int32(a)) == a {
+			return fmt.Sprintf("%#x", int64(a))
+		}
+		return fmt.Sprintf("%#x", uint64(a))
+	case Mem:
+		if a.Base == EIP {
+			a.Base = RIP
+		}
+		prefix := ""
+		switch inst.MemBytes {
+		case 1:
+			prefix = "byte "
+		case 2:
+			prefix = "word "
+		case 4:
+			prefix = "dword "
+		case 8:
+			prefix = "qword "
+		case 16:
+			prefix = "xmmword "
+		}
+		switch inst.Op {
+		case INVLPG:
+			prefix = "byte "
+		case STOSB, MOVSB, CMPSB, LODSB, SCASB:
+			prefix = "byte "
+		case STOSW, MOVSW, CMPSW, LODSW, SCASW:
+			prefix = "word "
+		case STOSD, MOVSD, CMPSD, LODSD, SCASD:
+			prefix = "dword "
+		case STOSQ, MOVSQ, CMPSQ, LODSQ, SCASQ:
+			prefix = "qword "
+		case LAR:
+			prefix = "word "
+		case BOUND:
+			if inst.Mode == 32 {
+				prefix = "qword "
+			} else {
+				prefix = "dword "
+			}
+		case PREFETCHW, PREFETCHNTA, PREFETCHT0, PREFETCHT1, PREFETCHT2, CLFLUSH:
+			prefix = "zmmword "
+		}
+		switch inst.Op {
+		case MOVSB, MOVSW, MOVSD, MOVSQ, CMPSB, CMPSW, CMPSD, CMPSQ, STOSB, STOSW, STOSD, STOSQ, SCASB, SCASW, SCASD, SCASQ, LODSB, LODSW, LODSD, LODSQ:
+			switch a.Base {
+			case DI, EDI, RDI:
+				if a.Segment == ES {
+					a.Segment = 0
+				}
+			case SI, ESI, RSI:
+				if a.Segment == DS {
+					a.Segment = 0
+				}
+			}
+		case LEA:
+			a.Segment = 0
+		default:
+			switch a.Base {
+			case SP, ESP, RSP, BP, EBP, RBP:
+				if a.Segment == SS {
+					a.Segment = 0
+				}
+			default:
+				if a.Segment == DS {
+					a.Segment = 0
+				}
+			}
+		}
+
+		if inst.Mode == 64 && a.Segment != FS && a.Segment != GS {
+			a.Segment = 0
+		}
+
+		prefix += "ptr "
+		if a.Segment != 0 {
+			prefix += strings.ToLower(a.Segment.String()) + ":"
+		}
+		prefix += "["
+		if a.Base != 0 {
+			prefix += intelArg(inst, a.Base)
+		}
+		if a.Scale != 0 && a.Index != 0 {
+			if a.Base != 0 {
+				prefix += "+"
+			}
+			prefix += fmt.Sprintf("%s*%d", intelArg(inst, a.Index), a.Scale)
+		}
+		if a.Disp != 0 {
+			if prefix[len(prefix)-1] == '[' && (a.Disp >= 0 || int64(int32(a.Disp)) != a.Disp) {
+				prefix += fmt.Sprintf("%#x", uint64(a.Disp))
+			} else {
+				prefix += fmt.Sprintf("%+#x", a.Disp)
+			}
+		}
+		prefix += "]"
+		return prefix
+	case Rel:
+		return fmt.Sprintf(".%+#x", int64(a))
+	case Reg:
+		if int(a) < len(intelReg) && intelReg[a] != "" {
+			return intelReg[a]
+		}
+	}
+	return strings.ToLower(arg.String())
+}
+
+var intelOp = map[Op]string{
+	JAE:       "jnb",
+	JA:        "jnbe",
+	JGE:       "jnl",
+	JNE:       "jnz",
+	JG:        "jnle",
+	JE:        "jz",
+	SETAE:     "setnb",
+	SETA:      "setnbe",
+	SETGE:     "setnl",
+	SETNE:     "setnz",
+	SETG:      "setnle",
+	SETE:      "setz",
+	CMOVAE:    "cmovnb",
+	CMOVA:     "cmovnbe",
+	CMOVGE:    "cmovnl",
+	CMOVNE:    "cmovnz",
+	CMOVG:     "cmovnle",
+	CMOVE:     "cmovz",
+	LCALL:     "call far",
+	LJMP:      "jmp far",
+	LRET:      "ret far",
+	ICEBP:     "int1",
+	MOVSD_XMM: "movsd",
+	XLATB:     "xlat",
+}
+
+var intelReg = [...]string{
+	F0:  "st0",
+	F1:  "st1",
+	F2:  "st2",
+	F3:  "st3",
+	F4:  "st4",
+	F5:  "st5",
+	F6:  "st6",
+	F7:  "st7",
+	M0:  "mmx0",
+	M1:  "mmx1",
+	M2:  "mmx2",
+	M3:  "mmx3",
+	M4:  "mmx4",
+	M5:  "mmx5",
+	M6:  "mmx6",
+	M7:  "mmx7",
+	X0:  "xmm0",
+	X1:  "xmm1",
+	X2:  "xmm2",
+	X3:  "xmm3",
+	X4:  "xmm4",
+	X5:  "xmm5",
+	X6:  "xmm6",
+	X7:  "xmm7",
+	X8:  "xmm8",
+	X9:  "xmm9",
+	X10: "xmm10",
+	X11: "xmm11",
+	X12: "xmm12",
+	X13: "xmm13",
+	X14: "xmm14",
+	X15: "xmm15",
+
+	// TODO: Maybe the constants are named wrong.
+	SPB: "spl",
+	BPB: "bpl",
+	SIB: "sil",
+	DIB: "dil",
+
+	R8L:  "r8d",
+	R9L:  "r9d",
+	R10L: "r10d",
+	R11L: "r11d",
+	R12L: "r12d",
+	R13L: "r13d",
+	R14L: "r14d",
+	R15L: "r15d",
+}