cmd/internal/obj: switch to one global Aconv

Aconv is the pretty-printer for instruction opcodes like AMOVQ.
There was one for each architecture.
Make the space of A names have a different region for each architecture,
much as we did for the registers, so a single global Aconv function can
do the work. Each architecture registers its region as a slice of names
at a given offset.

The global names like CALL and JMP are now defined only once.

The A values are used for indexing tables, so make it easy to do the
indexing by making the offset maskable.

Remove a bunch of now-duplicated architecture-specific code.

Change-Id: Ib15647b7145a1c089e21e36543691a19e146b60e
Reviewed-on: https://go-review.googlesource.com/6620Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/5g/peep.go

@@ -544,7 +544,7 @@ gotit:
 	}
 
 	if gc.Debug['P'] != 0 {
-		fmt.Printf(" => %v\n", arm.Aconv(int(p.As)))
+		fmt.Printf(" => %v\n", obj.Aconv(int(p.As)))
 	}
 	return true
 }
@@ -1043,7 +1043,7 @@ func xtramodes(g *gc.Graph, r *gc.Flow, a *obj.Addr) bool {
 func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", arm.Aconv(int(p.As)))
+		fmt.Printf("copyu: can't find %v\n", obj.Aconv(int(p.As)))
 		return 2
 
 	case arm.AMOVM:

src/cmd/9g/peep.go

@@ -615,7 +615,7 @@ func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
 
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", ppc64.Aconv(int(p.As)))
+		fmt.Printf("copyu: can't find %v\n", obj.Aconv(int(p.As)))
 		return 2
 
 	case obj.ANOP, /* read p->from, write p->to */

src/cmd/9g/prog.go

@@ -302,7 +302,7 @@ func as2variant(as int) int {
 			return i
 		}
 	}
-	gc.Fatal("as2variant: instruction %v is not a variant of itself", ppc64.Aconv(as))
+	gc.Fatal("as2variant: instruction %v is not a variant of itself", obj.Aconv(as))
 	return 0
 }
 

src/cmd/asm/internal/arch/arch.go

@@ -34,8 +34,6 @@ type Arch struct {
 	RegisterNumber func(string, int16) (int16, bool)
 	// Instruction is a jump.
 	IsJump func(word string) bool
-	// Aconv pretty-prints an instruction opcode for this architecture.
-	Aconv func(int) string
 }
 
 // nilRegisterNumber is the register number function for architectures
@@ -96,9 +94,14 @@ func arch386() *Arch {
 	// Prefixes not used on this architecture.
 
 	instructions := make(map[string]int)
-	for i, s := range i386.Anames {
+	for i, s := range obj.Anames {
 		instructions[s] = i
 	}
+	for i, s := range i386.Anames {
+		if i >= obj.A_ARCHSPECIFIC {
+			instructions[s] = i + obj.ABase386
+		}
+	}
 	// Annoying aliases.
 	instructions["JA"] = i386.AJHI
 	instructions["JAE"] = i386.AJCC
@@ -140,7 +143,6 @@ func arch386() *Arch {
 		RegisterPrefix: nil,
 		RegisterNumber: nilRegisterNumber,
 		IsJump:         jump386,
-		Aconv:          i386.Aconv,
 	}
 }
 
@@ -158,9 +160,14 @@ func archAmd64() *Arch {
 	// Register prefix not used on this architecture.
 
 	instructions := make(map[string]int)
-	for i, s := range x86.Anames {
+	for i, s := range obj.Anames {
 		instructions[s] = i
 	}
+	for i, s := range x86.Anames {
+		if i >= obj.A_ARCHSPECIFIC {
+			instructions[s] = i + obj.ABaseAMD64
+		}
+	}
 	// Annoying aliases.
 	instructions["JA"] = x86.AJHI
 	instructions["JAE"] = x86.AJCC
@@ -209,7 +216,6 @@ func archAmd64() *Arch {
 		RegisterPrefix: nil,
 		RegisterNumber: nilRegisterNumber,
 		IsJump:         jump386,
-		Aconv:          x86.Aconv,
 	}
 }
 
@@ -240,9 +246,14 @@ func archArm() *Arch {
 	}
 
 	instructions := make(map[string]int)
-	for i, s := range arm.Anames {
+	for i, s := range obj.Anames {
 		instructions[s] = i
 	}
+	for i, s := range arm.Anames {
+		if i >= obj.A_ARCHSPECIFIC {
+			instructions[s] = i + obj.ABaseARM
+		}
+	}
 	// Annoying aliases.
 	instructions["B"] = obj.AJMP
 	instructions["BL"] = obj.ACALL
@@ -254,7 +265,6 @@ func archArm() *Arch {
 		RegisterPrefix: registerPrefix,
 		RegisterNumber: armRegisterNumber,
 		IsJump:         jumpArm,
-		Aconv:          arm.Aconv,
 	}
 }
 
@@ -296,9 +306,14 @@ func archPPC64() *Arch {
 	}
 
 	instructions := make(map[string]int)
-	for i, s := range ppc64.Anames {
+	for i, s := range obj.Anames {
 		instructions[s] = i
 	}
+	for i, s := range ppc64.Anames {
+		if i >= obj.A_ARCHSPECIFIC {
+			instructions[s] = i + obj.ABasePPC64
+		}
+	}
 	// Annoying aliases.
 	instructions["BR"] = ppc64.ABR
 	instructions["BL"] = ppc64.ABL
@@ -311,6 +326,5 @@ func archPPC64() *Arch {
 		RegisterPrefix: registerPrefix,
 		RegisterNumber: ppc64RegisterNumber,
 		IsJump:         jumpPPC64,
-		Aconv:          ppc64.Aconv,
 	}
 }

src/cmd/asm/internal/asm/asm.go

@@ -314,7 +314,7 @@ func (p *Parser) asmJump(op int, cond string, a []obj.Addr) {
 			prog.From = a[0]
 			break
 		}
-		p.errorf("wrong number of arguments to %s instruction", p.arch.Aconv(op))
+		p.errorf("wrong number of arguments to %s instruction", obj.Aconv(op))
 		return
 	case 3:
 		if p.arch.Thechar == '9' {
@@ -330,7 +330,7 @@ func (p *Parser) asmJump(op int, cond string, a []obj.Addr) {
 		}
 		fallthrough
 	default:
-		p.errorf("wrong number of arguments to %s instruction", p.arch.Aconv(op))
+		p.errorf("wrong number of arguments to %s instruction", obj.Aconv(op))
 		return
 	}
 	switch {
@@ -402,7 +402,7 @@ func (p *Parser) branch(jmp, target *obj.Prog) {
 // asmInstruction assembles an instruction.
 // MOVW R9, (R10)
 func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
-	// fmt.Printf("%s %+v\n", p.arch.Aconv(op), a)
+	// fmt.Printf("%s %+v\n", obj.Aconv(op), a)
 	prog := &obj.Prog{
 		Ctxt:   p.ctxt,
 		Lineno: p.histLineNum,
@@ -451,7 +451,7 @@ func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
 					prog.To = a[1]
 					break
 				}
-				p.errorf("unrecognized addressing for %s", p.arch.Aconv(op))
+				p.errorf("unrecognized addressing for %s", obj.Aconv(op))
 			}
 		}
 		prog.From = a[0]
@@ -538,7 +538,7 @@ func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
 				prog.From3 = a[1]
 				prog.To = a[2]
 			default:
-				p.errorf("invalid addressing modes for %s instruction", p.arch.Aconv(op))
+				p.errorf("invalid addressing modes for %s instruction", obj.Aconv(op))
 			}
 		default:
 			p.errorf("TODO: implement three-operand instructions for this architecture")
@@ -567,7 +567,7 @@ func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
 			prog.To = a[3]
 			break
 		}
-		p.errorf("can't handle %s instruction with 4 operands", p.arch.Aconv(op))
+		p.errorf("can't handle %s instruction with 4 operands", obj.Aconv(op))
 	case 5:
 		if p.arch.Thechar == '9' && arch.IsPPC64RLD(op) {
 			// Always reg, reg, con, con, reg.  (con, con is a 'mask').
@@ -588,7 +588,7 @@ func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
 			prog.To = a[4]
 			break
 		}
-		p.errorf("can't handle %s instruction with 5 operands", p.arch.Aconv(op))
+		p.errorf("can't handle %s instruction with 5 operands", obj.Aconv(op))
 	case 6:
 		// MCR and MRC on ARM
 		if p.arch.Thechar == '5' && arch.IsARMMRC(op) {
@@ -631,7 +631,7 @@ func (p *Parser) asmInstruction(op int, cond string, a []obj.Addr) {
 		}
 		fallthrough
 	default:
-		p.errorf("can't handle %s instruction with %d operands", p.arch.Aconv(op), len(a))
+		p.errorf("can't handle %s instruction with %d operands", obj.Aconv(op), len(a))
 	}
 
 	p.append(prog, cond, true)
@@ -650,7 +650,7 @@ func (p *Parser) getConstantPseudo(pseudo string, addr *obj.Addr) int64 {
 // getConstant checks that addr represents a plain constant and returns its value.
 func (p *Parser) getConstant(prog *obj.Prog, op int, addr *obj.Addr) int64 {
 	if addr.Type != obj.TYPE_MEM || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
-		p.errorf("%s: expected integer constant; found %s", p.arch.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected integer constant; found %s", obj.Aconv(op), obj.Dconv(prog, addr))
 	}
 	return addr.Offset
 }
@@ -658,7 +658,7 @@ func (p *Parser) getConstant(prog *obj.Prog, op int, addr *obj.Addr) int64 {
 // getImmediate checks that addr represents an immediate constant and returns its value.
 func (p *Parser) getImmediate(prog *obj.Prog, op int, addr *obj.Addr) int64 {
 	if addr.Type != obj.TYPE_CONST || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
-		p.errorf("%s: expected immediate constant; found %s", p.arch.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected immediate constant; found %s", obj.Aconv(op), obj.Dconv(prog, addr))
 	}
 	return addr.Offset
 }
@@ -666,7 +666,7 @@ func (p *Parser) getImmediate(prog *obj.Prog, op int, addr *obj.Addr) int64 {
 // getRegister checks that addr represents a register and returns its value.
 func (p *Parser) getRegister(prog *obj.Prog, op int, addr *obj.Addr) int16 {
 	if addr.Type != obj.TYPE_REG || addr.Offset != 0 || addr.Name != 0 || addr.Index != 0 {
-		p.errorf("%s: expected register; found %s", p.arch.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected register; found %s", obj.Aconv(op), obj.Dconv(prog, addr))
 	}
 	return addr.Reg
 }

src/cmd/internal/obj/arm/5.out.go

@@ -145,7 +145,7 @@ const (
 )
 
 const (
-	AAND = obj.A_ARCHSPECIFIC + iota
+	AAND = obj.ABaseARM + obj.A_ARCHSPECIFIC + iota
 	AEOR
 	ASUB
 	ARSB

src/cmd/internal/obj/arm/anames5.go

 package arm
 
+import "cmd/internal/obj"
+
 var Anames = []string{
-	"XXX",
-	"CALL",
-	"CHECKNIL",
-	"DATA",
-	"DUFFCOPY",
-	"DUFFZERO",
-	"END",
-	"FUNCDATA",
-	"GLOBL",
-	"JMP",
-	"NOP",
-	"PCDATA",
-	"RET",
-	"TEXT",
-	"TYPE",
-	"UNDEF",
-	"USEFIELD",
-	"VARDEF",
-	"VARKILL",
-	"AND",
+	obj.A_ARCHSPECIFIC: "AND",
 	"EOR",
 	"SUB",
 	"RSB",

src/cmd/internal/obj/arm/asm5.go

@@ -39,7 +39,7 @@ import (
 )
 
 type Optab struct {
-	as       uint8
+	as       uint16
 	a1       uint8
 	a2       int8
 	a3       uint8
@@ -268,7 +268,7 @@ var pool struct {
 	extra uint32
 }
 
-var oprange [ALAST]Oprang
+var oprange [ALAST & obj.AMask]Oprang
 
 var xcmp [C_GOK + 1][C_GOK + 1]uint8
 
@@ -580,7 +580,7 @@ func span5(ctxt *obj.Link, cursym *obj.LSym) {
 		return
 	}
 
-	if oprange[AAND].start == nil {
+	if oprange[AAND&obj.AMask].start == nil {
 		buildop(ctxt)
 	}
 
@@ -1207,14 +1207,14 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 	if p.Reg != 0 {
 		a2 = C_REG
 	}
-	r := int(p.As)
+	r := p.As & obj.AMask
 	o := oprange[r].start
 	if o == nil {
 		o = oprange[r].stop /* just generate an error */
 	}
 
 	if false { /*debug['O']*/
-		fmt.Printf("oplook %v %v %v %v\n", Aconv(int(p.As)), DRconv(a1), DRconv(a2), DRconv(a3))
+		fmt.Printf("oplook %v %v %v %v\n", obj.Aconv(int(p.As)), DRconv(a1), DRconv(a2), DRconv(a3))
 		fmt.Printf("\t\t%d %d\n", p.From.Type, p.To.Type)
 	}
 
@@ -1335,6 +1335,10 @@ func (x ocmp) Less(i, j int) bool {
 	return false
 }
 
+func opset(a, b0 uint16) {
+	oprange[a&obj.AMask] = oprange[b0]
+}
+
 func buildop(ctxt *obj.Link) {
 	var n int
 
@@ -1356,67 +1360,66 @@ func buildop(ctxt *obj.Link) {
 	}
 
 	sort.Sort(ocmp(optab[:n]))
-	var r int
 	for i := 0; i < n; i++ {
-		r = int(optab[i].as)
-		oprange[r].start = optab[i:]
-		for int(optab[i].as) == r {
+		r0 := optab[i].as & obj.AMask
+		oprange[r0].start = optab[i:]
+		for optab[i].as&obj.AMask == r0 {
 			i++
 		}
-		oprange[r].stop = optab[i:]
+		oprange[r0].stop = optab[i:]
 		i--
 
-		switch r {
+		switch r0 {
 		default:
-			ctxt.Diag("unknown op in build: %v", Aconv(r))
+			ctxt.Diag("unknown op in build: %v", obj.Aconv(int(optab[i].as)))
 			log.Fatalf("bad code")
 
 		case AADD:
-			oprange[AAND] = oprange[r]
-			oprange[AEOR] = oprange[r]
-			oprange[ASUB] = oprange[r]
-			oprange[ARSB] = oprange[r]
-			oprange[AADC] = oprange[r]
-			oprange[ASBC] = oprange[r]
-			oprange[ARSC] = oprange[r]
-			oprange[AORR] = oprange[r]
-			oprange[ABIC] = oprange[r]
+			opset(AAND, r0)
+			opset(AEOR, r0)
+			opset(ASUB, r0)
+			opset(ARSB, r0)
+			opset(AADC, r0)
+			opset(ASBC, r0)
+			opset(ARSC, r0)
+			opset(AORR, r0)
+			opset(ABIC, r0)
 
 		case ACMP:
-			oprange[ATEQ] = oprange[r]
-			oprange[ACMN] = oprange[r]
+			opset(ATEQ, r0)
+			opset(ACMN, r0)
 
 		case AMVN:
 			break
 
 		case ABEQ:
-			oprange[ABNE] = oprange[r]
-			oprange[ABCS] = oprange[r]
-			oprange[ABHS] = oprange[r]
-			oprange[ABCC] = oprange[r]
-			oprange[ABLO] = oprange[r]
-			oprange[ABMI] = oprange[r]
-			oprange[ABPL] = oprange[r]
-			oprange[ABVS] = oprange[r]
-			oprange[ABVC] = oprange[r]
-			oprange[ABHI] = oprange[r]
-			oprange[ABLS] = oprange[r]
-			oprange[ABGE] = oprange[r]
-			oprange[ABLT] = oprange[r]
-			oprange[ABGT] = oprange[r]
-			oprange[ABLE] = oprange[r]
+			opset(ABNE, r0)
+			opset(ABCS, r0)
+			opset(ABHS, r0)
+			opset(ABCC, r0)
+			opset(ABLO, r0)
+			opset(ABMI, r0)
+			opset(ABPL, r0)
+			opset(ABVS, r0)
+			opset(ABVC, r0)
+			opset(ABHI, r0)
+			opset(ABLS, r0)
+			opset(ABGE, r0)
+			opset(ABLT, r0)
+			opset(ABGT, r0)
+			opset(ABLE, r0)
 
 		case ASLL:
-			oprange[ASRL] = oprange[r]
-			oprange[ASRA] = oprange[r]
+			opset(ASRL, r0)
+			opset(ASRA, r0)
 
 		case AMUL:
-			oprange[AMULU] = oprange[r]
+			opset(AMULU, r0)
 
 		case ADIV:
-			oprange[AMOD] = oprange[r]
-			oprange[AMODU] = oprange[r]
-			oprange[ADIVU] = oprange[r]
+			opset(AMOD, r0)
+			opset(AMODU, r0)
+			opset(ADIVU, r0)
 
 		case AMOVW,
 			AMOVB,
@@ -1428,7 +1431,7 @@ func buildop(ctxt *obj.Link) {
 			break
 
 		case ASWPW:
-			oprange[ASWPBU] = oprange[r]
+			opset(ASWPBU, r0)
 
 		case AB,
 			ABL,
@@ -1448,42 +1451,42 @@ func buildop(ctxt *obj.Link) {
 			break
 
 		case AADDF:
-			oprange[AADDD] = oprange[r]
-			oprange[ASUBF] = oprange[r]
-			oprange[ASUBD] = oprange[r]
-			oprange[AMULF] = oprange[r]
-			oprange[AMULD] = oprange[r]
-			oprange[ADIVF] = oprange[r]
-			oprange[ADIVD] = oprange[r]
-			oprange[ASQRTF] = oprange[r]
-			oprange[ASQRTD] = oprange[r]
-			oprange[AMOVFD] = oprange[r]
-			oprange[AMOVDF] = oprange[r]
-			oprange[AABSF] = oprange[r]
-			oprange[AABSD] = oprange[r]
+			opset(AADDD, r0)
+			opset(ASUBF, r0)
+			opset(ASUBD, r0)
+			opset(AMULF, r0)
+			opset(AMULD, r0)
+			opset(ADIVF, r0)
+			opset(ADIVD, r0)
+			opset(ASQRTF, r0)
+			opset(ASQRTD, r0)
+			opset(AMOVFD, r0)
+			opset(AMOVDF, r0)
+			opset(AABSF, r0)
+			opset(AABSD, r0)
 
 		case ACMPF:
-			oprange[ACMPD] = oprange[r]
+			opset(ACMPD, r0)
 
 		case AMOVF:
-			oprange[AMOVD] = oprange[r]
+			opset(AMOVD, r0)
 
 		case AMOVFW:
-			oprange[AMOVDW] = oprange[r]
+			opset(AMOVDW, r0)
 
 		case AMOVWF:
-			oprange[AMOVWD] = oprange[r]
+			opset(AMOVWD, r0)
 
 		case AMULL:
-			oprange[AMULAL] = oprange[r]
-			oprange[AMULLU] = oprange[r]
-			oprange[AMULALU] = oprange[r]
+			opset(AMULAL, r0)
+			opset(AMULLU, r0)
+			opset(AMULALU, r0)
 
 		case AMULWT:
-			oprange[AMULWB] = oprange[r]
+			opset(AMULWB, r0)
 
 		case AMULAWT:
-			oprange[AMULAWB] = oprange[r]
+			opset(AMULAWB, r0)
 
 		case AMULA,
 			ALDREX,
@@ -2660,7 +2663,7 @@ func opbra(ctxt *obj.Link, a int, sc int) uint32 {
 		return 0xe<<28 | 0x5<<25
 	}
 
-	ctxt.Diag("bad bra %v", Aconv(a))
+	ctxt.Diag("bad bra %v", obj.Aconv(a))
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -2780,7 +2783,7 @@ func ofsr(ctxt *obj.Link, a int, r int, v int32, b int, sc int, p *obj.Prog) uin
 
 	switch a {
 	default:
-		ctxt.Diag("bad fst %v", Aconv(a))
+		ctxt.Diag("bad fst %v", obj.Aconv(a))
 		fallthrough
 
 	case AMOVD:

src/cmd/internal/obj/arm/list5.go

@@ -79,57 +79,16 @@ func Pconv(p *obj.Prog) string {
 	var str string
 	if a == obj.ADATA {
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v/%d,%v",
-			p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 	} else if p.As == obj.ATEXT {
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%d,%v",
-			p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 	} else if p.Reg == 0 {
 		str = fmt.Sprintf("%.5d (%v)\t%v%s\t%v,%v",
-			p.Pc, p.Line(), Aconv(a), sc, obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(a), sc, obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 	} else {
 		str = fmt.Sprintf("%.5d (%v)\t%v%s\t%v,%v,%v",
-			p.Pc, p.Line(), Aconv(a), sc, obj.Dconv(p, &p.From), Rconv(int(p.Reg)), obj.Dconv(p, &p.To))
-	}
-
-	var fp string
-	fp += str
-	return fp
-}
-
-func Aconv(a int) string {
-	s := "???"
-	if a >= obj.AXXX && a < ALAST {
-		s = Anames[a]
-	}
-	var fp string
-	fp += s
-	return fp
-}
-
-func RAconv(a *obj.Addr) string {
-	str := fmt.Sprintf("GOK-reglist")
-	switch a.Type {
-	case obj.TYPE_CONST:
-		if a.Reg != 0 {
-			break
-		}
-		if a.Sym != nil {
-			break
-		}
-		v := int(a.Offset)
-		str = ""
-		for i := 0; i < NREG; i++ {
-			if v&(1<<uint(i)) != 0 {
-				if str == "" {
-					str += "[R"
-				} else {
-					str += ",R"
-				}
-				str += fmt.Sprintf("%d", i)
-			}
-		}
-
-		str += "]"
+			p.Pc, p.Line(), obj.Aconv(a), sc, obj.Dconv(p, &p.From), Rconv(int(p.Reg)), obj.Dconv(p, &p.To))
 	}
 
 	var fp string
@@ -139,6 +98,7 @@ func RAconv(a *obj.Addr) string {
 
 func init() {
 	obj.RegisterRegister(obj.RBaseARM, MAXREG, Rconv)
+	obj.RegisterOpcode(obj.ABaseARM, Anames)
 }
 
 func Rconv(r int) string {

src/cmd/internal/obj/i386/8.out.go

@@ -33,7 +33,7 @@ package i386
 import "cmd/internal/obj"
 
 const (
-	AAAA = obj.A_ARCHSPECIFIC + iota
+	AAAA = obj.ABase386 + obj.A_ARCHSPECIFIC + iota
 	AAAD
 	AAAM
 	AAAS

src/cmd/internal/obj/i386/anames8.go

 package i386
 
+import "cmd/internal/obj"
+
 /*
  * this is the ranlib header
  */
 var Anames = []string{
-	"XXX",
-	"CALL",
-	"CHECKNIL",
-	"DATA",
-	"DUFFCOPY",
-	"DUFFZERO",
-	"END",
-	"FUNCDATA",
-	"GLOBL",
-	"JMP",
-	"NOP",
-	"PCDATA",
-	"RET",
-	"TEXT",
-	"TYPE",
-	"UNDEF",
-	"USEFIELD",
-	"VARDEF",
-	"VARKILL",
-	"AAA",
+	obj.A_ARCHSPECIFIC: "AAA",
 	"AAD",
 	"AAM",
 	"AAS",

src/cmd/internal/obj/i386/asm8.go

@@ -58,7 +58,7 @@ type ytab struct {
 	zoffset uint8
 }
 
-var opindex [ALAST + 1]*Optab
+var opindex [(ALAST + 1) & obj.AMask]*Optab
 
 const (
 	Yxxx = 0 + iota
@@ -1331,12 +1331,11 @@ func span8(ctxt *obj.Link, s *obj.LSym) {
 }
 
 func instinit() {
-	var c int
 
 	for i := 1; optab[i].as != 0; i++ {
-		c = int(optab[i].as)
+		c := optab[i].as & obj.AMask
 		if opindex[c] != nil {
-			log.Fatalf("phase error in optab: %d (%v)", i, Aconv(c))
+			log.Fatalf("phase error in optab: %d (%v)", i, obj.Aconv(int(optab[i].as)))
 		}
 		opindex[c] = &optab[i]
 	}
@@ -1969,7 +1968,7 @@ const (
 
 var ymovtab = []uint8{
 	/* push */
-	APUSHL,
+	APUSHL & obj.AMask,
 	Ycs,
 	Ynone,
 	0,
@@ -1977,7 +1976,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APUSHL,
+	APUSHL & obj.AMask,
 	Yss,
 	Ynone,
 	0,
@@ -1985,7 +1984,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APUSHL,
+	APUSHL & obj.AMask,
 	Yds,
 	Ynone,
 	0,
@@ -1993,7 +1992,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APUSHL,
+	APUSHL & obj.AMask,
 	Yes,
 	Ynone,
 	0,
@@ -2001,7 +2000,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APUSHL,
+	APUSHL & obj.AMask,
 	Yfs,
 	Ynone,
 	0,
@@ -2009,7 +2008,7 @@ var ymovtab = []uint8{
 	0xa0,
 	E,
 	0,
-	APUSHL,
+	APUSHL & obj.AMask,
 	Ygs,
 	Ynone,
 	0,
@@ -2017,7 +2016,7 @@ var ymovtab = []uint8{
 	0xa8,
 	E,
 	0,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Ycs,
 	Ynone,
 	0,
@@ -2025,7 +2024,7 @@ var ymovtab = []uint8{
 	0x0e,
 	E,
 	0,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Yss,
 	Ynone,
 	0,
@@ -2033,7 +2032,7 @@ var ymovtab = []uint8{
 	0x16,
 	E,
 	0,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Yds,
 	Ynone,
 	0,
@@ -2041,7 +2040,7 @@ var ymovtab = []uint8{
 	0x1e,
 	E,
 	0,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Yes,
 	Ynone,
 	0,
@@ -2049,7 +2048,7 @@ var ymovtab = []uint8{
 	0x06,
 	E,
 	0,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Yfs,
 	Ynone,
 	0,
@@ -2057,7 +2056,7 @@ var ymovtab = []uint8{
 	0x0f,
 	0xa0,
 	E,
-	APUSHW,
+	APUSHW & obj.AMask,
 	Ygs,
 	Ynone,
 	0,
@@ -2067,7 +2066,7 @@ var ymovtab = []uint8{
 	E,
 
 	/* pop */
-	APOPL,
+	APOPL & obj.AMask,
 	Ynone,
 	Yds,
 	0,
@@ -2075,7 +2074,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APOPL,
+	APOPL & obj.AMask,
 	Ynone,
 	Yes,
 	0,
@@ -2083,7 +2082,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APOPL,
+	APOPL & obj.AMask,
 	Ynone,
 	Yss,
 	0,
@@ -2091,7 +2090,7 @@ var ymovtab = []uint8{
 	E,
 	0,
 	0,
-	APOPL,
+	APOPL & obj.AMask,
 	Ynone,
 	Yfs,
 	0,
@@ -2099,7 +2098,7 @@ var ymovtab = []uint8{
 	0xa1,
 	E,
 	0,
-	APOPL,
+	APOPL & obj.AMask,
 	Ynone,
 	Ygs,
 	0,
@@ -2107,7 +2106,7 @@ var ymovtab = []uint8{
 	0xa9,
 	E,
 	0,
-	APOPW,
+	APOPW & obj.AMask,
 	Ynone,
 	Yds,
 	0,
@@ -2115,7 +2114,7 @@ var ymovtab = []uint8{
 	0x1f,
 	E,
 	0,
-	APOPW,
+	APOPW & obj.AMask,
 	Ynone,
 	Yes,
 	0,
@@ -2123,7 +2122,7 @@ var ymovtab = []uint8{
 	0x07,
 	E,
 	0,
-	APOPW,
+	APOPW & obj.AMask,
 	Ynone,
 	Yss,
 	0,
@@ -2131,7 +2130,7 @@ var ymovtab = []uint8{
 	0x17,
 	E,
 	0,
-	APOPW,
+	APOPW & obj.AMask,
 	Ynone,
 	Yfs,
 	0,
@@ -2139,7 +2138,7 @@ var ymovtab = []uint8{
 	0x0f,
 	0xa1,
 	E,
-	APOPW,
+	APOPW & obj.AMask,
 	Ynone,
 	Ygs,
 	0,
@@ -2149,7 +2148,7 @@ var ymovtab = []uint8{
 	E,
 
 	/* mov seg */
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yes,
 	Yml,
 	1,
@@ -2157,7 +2156,7 @@ var ymovtab = []uint8{
 	0,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Ycs,
 	Yml,
 	1,
@@ -2165,7 +2164,7 @@ var ymovtab = []uint8{
 	1,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yss,
 	Yml,
 	1,
@@ -2173,7 +2172,7 @@ var ymovtab = []uint8{
 	2,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yds,
 	Yml,
 	1,
@@ -2181,7 +2180,7 @@ var ymovtab = []uint8{
 	3,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yfs,
 	Yml,
 	1,
@@ -2189,7 +2188,7 @@ var ymovtab = []uint8{
 	4,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Ygs,
 	Yml,
 	1,
@@ -2197,7 +2196,7 @@ var ymovtab = []uint8{
 	5,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Yes,
 	2,
@@ -2205,7 +2204,7 @@ var ymovtab = []uint8{
 	0,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Ycs,
 	2,
@@ -2213,7 +2212,7 @@ var ymovtab = []uint8{
 	1,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Yss,
 	2,
@@ -2221,7 +2220,7 @@ var ymovtab = []uint8{
 	2,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Yds,
 	2,
@@ -2229,7 +2228,7 @@ var ymovtab = []uint8{
 	3,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Yfs,
 	2,
@@ -2237,7 +2236,7 @@ var ymovtab = []uint8{
 	4,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Ygs,
 	2,
@@ -2247,7 +2246,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* mov cr */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ycr0,
 	Yml,
 	3,
@@ -2255,7 +2254,7 @@ var ymovtab = []uint8{
 	0x20,
 	0,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ycr2,
 	Yml,
 	3,
@@ -2263,7 +2262,7 @@ var ymovtab = []uint8{
 	0x20,
 	2,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ycr3,
 	Yml,
 	3,
@@ -2271,7 +2270,7 @@ var ymovtab = []uint8{
 	0x20,
 	3,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ycr4,
 	Yml,
 	3,
@@ -2279,7 +2278,7 @@ var ymovtab = []uint8{
 	0x20,
 	4,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ycr0,
 	4,
@@ -2287,7 +2286,7 @@ var ymovtab = []uint8{
 	0x22,
 	0,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ycr2,
 	4,
@@ -2295,7 +2294,7 @@ var ymovtab = []uint8{
 	0x22,
 	2,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ycr3,
 	4,
@@ -2303,7 +2302,7 @@ var ymovtab = []uint8{
 	0x22,
 	3,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ycr4,
 	4,
@@ -2313,7 +2312,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* mov dr */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ydr0,
 	Yml,
 	3,
@@ -2321,7 +2320,7 @@ var ymovtab = []uint8{
 	0x21,
 	0,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ydr6,
 	Yml,
 	3,
@@ -2329,7 +2328,7 @@ var ymovtab = []uint8{
 	0x21,
 	6,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ydr7,
 	Yml,
 	3,
@@ -2337,7 +2336,7 @@ var ymovtab = []uint8{
 	0x21,
 	7,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ydr0,
 	4,
@@ -2345,7 +2344,7 @@ var ymovtab = []uint8{
 	0x23,
 	0,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ydr6,
 	4,
@@ -2353,7 +2352,7 @@ var ymovtab = []uint8{
 	0x23,
 	6,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ydr7,
 	4,
@@ -2363,7 +2362,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* mov tr */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ytr6,
 	Yml,
 	3,
@@ -2371,7 +2370,7 @@ var ymovtab = []uint8{
 	0x24,
 	6,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ytr7,
 	Yml,
 	3,
@@ -2379,7 +2378,7 @@ var ymovtab = []uint8{
 	0x24,
 	7,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ytr6,
 	4,
@@ -2387,7 +2386,7 @@ var ymovtab = []uint8{
 	0x26,
 	6,
 	E,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ytr7,
 	4,
@@ -2397,7 +2396,7 @@ var ymovtab = []uint8{
 	E,
 
 	/* lgdt, sgdt, lidt, sidt */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ym,
 	Ygdtr,
 	4,
@@ -2405,7 +2404,7 @@ var ymovtab = []uint8{
 	0x01,
 	2,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ygdtr,
 	Ym,
 	3,
@@ -2413,7 +2412,7 @@ var ymovtab = []uint8{
 	0x01,
 	0,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ym,
 	Yidtr,
 	4,
@@ -2421,7 +2420,7 @@ var ymovtab = []uint8{
 	0x01,
 	3,
 	0,
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yidtr,
 	Ym,
 	3,
@@ -2431,7 +2430,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* lldt, sldt */
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Yldtr,
 	4,
@@ -2439,7 +2438,7 @@ var ymovtab = []uint8{
 	0x00,
 	2,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yldtr,
 	Yml,
 	3,
@@ -2449,7 +2448,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* lmsw, smsw */
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Ymsw,
 	4,
@@ -2457,7 +2456,7 @@ var ymovtab = []uint8{
 	0x01,
 	6,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Ymsw,
 	Yml,
 	3,
@@ -2467,7 +2466,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* ltr, str */
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Ytask,
 	4,
@@ -2475,7 +2474,7 @@ var ymovtab = []uint8{
 	0x00,
 	3,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Ytask,
 	Yml,
 	3,
@@ -2485,7 +2484,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* load full pointer */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Yml,
 	Ycol,
 	5,
@@ -2493,7 +2492,7 @@ var ymovtab = []uint8{
 	0,
 	0,
 	0,
-	AMOVW,
+	AMOVW & obj.AMask,
 	Yml,
 	Ycol,
 	5,
@@ -2503,7 +2502,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* double shift */
-	ASHLL,
+	ASHLL & obj.AMask,
 	Ycol,
 	Yml,
 	6,
@@ -2511,7 +2510,7 @@ var ymovtab = []uint8{
 	0xa5,
 	0,
 	0,
-	ASHRL,
+	ASHRL & obj.AMask,
 	Ycol,
 	Yml,
 	6,
@@ -2521,7 +2520,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* extra imul */
-	AIMULW,
+	AIMULW & obj.AMask,
 	Yml,
 	Yrl,
 	7,
@@ -2529,7 +2528,7 @@ var ymovtab = []uint8{
 	0xaf,
 	0,
 	0,
-	AIMULL,
+	AIMULL & obj.AMask,
 	Yml,
 	Yrl,
 	7,
@@ -2539,7 +2538,7 @@ var ymovtab = []uint8{
 	0,
 
 	/* load TLS base pointer */
-	AMOVL,
+	AMOVL & obj.AMask,
 	Ytls,
 	Yrl,
 	8,
@@ -2712,7 +2711,7 @@ func doasm(ctxt *obj.Link, p *obj.Prog) {
 
 	ft := int(p.Ft) * Ymax
 	tt := int(p.Tt) * Ymax
-	o := opindex[p.As]
+	o := opindex[p.As&obj.AMask]
 
 	z := 0
 	var a *obj.Addr
@@ -3163,7 +3162,7 @@ func doasm(ctxt *obj.Link, p *obj.Prog) {
 domov:
 	var pp obj.Prog
 	for t := []byte(ymovtab); t[0] != 0; t = t[8:] {
-		if p.As == int16(t[0]) {
+		if p.As&obj.AMask == int16(t[0]) {
 			if ycover[ft+int(t[1])] != 0 {
 				if ycover[tt+int(t[2])] != 0 {
 					switch t[3] {

src/cmd/internal/obj/i386/list8.go

@@ -47,21 +47,21 @@ func Pconv(p *obj.Prog) string {
 	switch p.As {
 	case obj.ADATA:
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v/%d,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 
 	case obj.ATEXT:
 		if p.From3.Offset != 0 {
 			str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%d,%v",
-				p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 			break
 		}
 
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 
 	default:
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 
 		// TODO(rsc): This special case is for SHRQ $32, AX:DX, which encodes as
 		//	SHRQ $32(DX*0), AX
@@ -76,10 +76,6 @@ func Pconv(p *obj.Prog) string {
 	return fp
 }
 
-func Aconv(i int) string {
-	return Anames[i]
-}
-
 var Register = []string{
 	"AL", /* [REG_AL] */
 	"CL",
@@ -154,6 +150,7 @@ var Register = []string{
 
 func init() {
 	obj.RegisterRegister(obj.RBase386, obj.RBase386+len(Register), Rconv)
+	obj.RegisterOpcode(obj.ABase386, Anames)
 }
 
 func Rconv(r int) string {

src/cmd/internal/obj/link.go

@@ -424,6 +424,10 @@ const (
 // These are the portable opcodes, common to all architectures.
 // Each architecture defines many more arch-specific opcodes,
 // with values starting at A_ARCHSPECIFIC.
+// Each architecture adds an offset to this so each machine has
+// distinct space for its instructions. The offset is a power of
+// two so it can be masked to return to origin zero.
+// See the definitions of ABase386 etc.
 const (
 	AXXX = 0 + iota
 	ACALL
@@ -570,30 +574,4 @@ const (
 	LinkExternal
 )
 
-// asm5.c
-
-// asm6.c
-
-// asm8.c
-
-// asm9.c
-
-// data.c
-
-// go.c
-
-// ld.c
-
-// list[5689].c
-
-// obj.c
-
-// objfile.c
-
-// pass.c
-
-// pcln.c
-
-// sym.c
-
 var linkbasepointer int

src/cmd/internal/obj/ppc64/9.out.go

@@ -218,7 +218,7 @@ const (
 )
 
 const (
-	AADD = obj.A_ARCHSPECIFIC + iota
+	AADD = obj.ABasePPC64 + obj.A_ARCHSPECIFIC + iota
 	AADDCC
 	AADDV
 	AADDVCC

src/cmd/internal/obj/ppc64/anames9.go

 package ppc64
 
-/*
- * this is the ranlib header
- */
+import "cmd/internal/obj"
+
 var Anames = []string{
-	"XXX",
-	"CALL",
-	"CHECKNIL",
-	"DATA",
-	"DUFFCOPY",
-	"DUFFZERO",
-	"END",
-	"FUNCDATA",
-	"GLOBL",
-	"JMP",
-	"NOP",
-	"PCDATA",
-	"RET",
-	"TEXT",
-	"TYPE",
-	"UNDEF",
-	"USEFIELD",
-	"VARDEF",
-	"VARKILL",
-	"ADD",
+	obj.A_ARCHSPECIFIC: "ADD",
 	"ADDCC",
 	"ADDV",
 	"ADDVCC",

src/cmd/internal/obj/ppc64/list9.go

@@ -59,14 +59,14 @@ func Pconv(p *obj.Prog) string {
 	str := ""
 	if a == obj.ADATA {
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v/%d,%v",
-			p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 	} else if a == obj.ATEXT || a == obj.AGLOBL {
 		if p.From3.Offset != 0 {
 			str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%d,%v",
-				p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 		} else {
 			str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-				p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 		}
 	} else {
 		if p.Mark&NOSCHED != 0 {
@@ -74,24 +74,24 @@ func Pconv(p *obj.Prog) string {
 		}
 		if p.Reg == 0 && p.From3.Type == obj.TYPE_NONE {
 			str += fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-				p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 		} else if a != obj.ATEXT && p.From.Type == obj.TYPE_MEM {
 			off := ""
 			if p.From.Offset != 0 {
 				off = fmt.Sprintf("%d", p.From.Offset)
 			}
 			str += fmt.Sprintf("%.5d (%v)\t%v\t%s(%v+%v),%v",
-				p.Pc, p.Line(), Aconv(a), off, Rconv(int(p.From.Reg)), Rconv(int(p.Reg)), obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(a), off, Rconv(int(p.From.Reg)), Rconv(int(p.Reg)), obj.Dconv(p, &p.To))
 		} else if p.To.Type == obj.TYPE_MEM {
 			off := ""
 			if p.From.Offset != 0 {
 				off = fmt.Sprintf("%d", p.From.Offset)
 			}
 			str += fmt.Sprintf("%.5d (%v)\t%v\t%v,%s(%v+%v)",
-				p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From), off, Rconv(int(p.To.Reg)), Rconv(int(p.Reg)))
+				p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From), off, Rconv(int(p.To.Reg)), Rconv(int(p.Reg)))
 		} else {
 			str += fmt.Sprintf("%.5d (%v)\t%v\t%v",
-				p.Pc, p.Line(), Aconv(a), obj.Dconv(p, &p.From))
+				p.Pc, p.Line(), obj.Aconv(a), obj.Dconv(p, &p.From))
 			if p.Reg != 0 {
 				str += fmt.Sprintf(",%v", Rconv(int(p.Reg)))
 			}
@@ -113,18 +113,9 @@ func Pconv(p *obj.Prog) string {
 	return fp
 }
 
-func Aconv(a int) string {
-	s := "???"
-	if a >= obj.AXXX && a < ALAST {
-		s = Anames[a]
-	}
-	var fp string
-	fp += s
-	return fp
-}
-
 func init() {
 	obj.RegisterRegister(obj.RBasePPC64, REG_DCR0+1024, Rconv)
+	obj.RegisterOpcode(obj.ABasePPC64, Anames)
 }
 
 func Rconv(r int) string {

src/cmd/internal/obj/util.go

@@ -491,3 +491,68 @@ func regListConv(list int) string {
 	str += "]"
 	return str
 }
+
+/*
+	Each architecture defines an instruction (A*) space as a unique
+	integer range.
+	Global opcodes like CALL start at 0; the architecture-specific ones
+	start at a distinct, big-maskable offsets.
+	Here is the list of architectures and the base of their opcode spaces.
+*/
+
+const (
+	ABase386 = (1 + iota) << 12
+	ABaseARM
+	ABaseAMD64
+	ABasePPC64
+	AMask = 1<<12 - 1 // AND with this to use the opcode as an array index.
+)
+
+type opSet struct {
+	lo    int
+	names []string
+}
+
+// Not even worth sorting
+var aSpace []opSet
+
+// RegisterOpcode binds a list of instruction names
+// to a given instruction number range.
+func RegisterOpcode(lo int, Anames []string) {
+	aSpace = append(aSpace, opSet{lo, Anames})
+}
+
+func Aconv(a int) string {
+	if a < A_ARCHSPECIFIC {
+		return Anames[a]
+	}
+	for i := range aSpace {
+		as := &aSpace[i]
+		if as.lo <= a && a < as.lo+len(as.names) {
+			return as.names[a-as.lo]
+		}
+	}
+	return fmt.Sprintf("A???%d", a)
+}
+
+var Anames = []string{
+	"XXX",
+	"CALL",
+	"CHECKNIL",
+	"DATA",
+	"DUFFCOPY",
+	"DUFFZERO",
+	"END",
+	"FUNCDATA",
+	"GLOBL",
+	"JMP",
+	"NOP",
+	"PCDATA",
+	"RET",
+	"TEXT",
+	"TYPE",
+	"UNDEF",
+	"USEFIELD",
+	"VARDEF",
+	"VARKILL",
+}

src/cmd/internal/obj/x86/6.out.go

@@ -36,7 +36,7 @@ import "cmd/internal/obj"
  *	amd64
  */
 const (
-	AAAA = obj.A_ARCHSPECIFIC + iota
+	AAAA = obj.ABaseAMD64 + obj.A_ARCHSPECIFIC + iota
 	AAAD
 	AAAM
 	AAAS

src/cmd/internal/obj/x86/anames6.go

 package x86
 
+import "cmd/internal/obj"
+
 /*
  * this is the ranlib header
  */
 var Anames = []string{
-	"XXX",
-	"CALL",
-	"CHECKNIL",
-	"DATA",
-	"DUFFCOPY",
-	"DUFFZERO",
-	"END",
-	"FUNCDATA",
-	"GLOBL",
-	"JMP",
-	"NOP",
-	"PCDATA",
-	"RET",
-	"TEXT",
-	"TYPE",
-	"UNDEF",
-	"USEFIELD",
-	"VARDEF",
-	"VARKILL",
-	"AAA",
+	obj.A_ARCHSPECIFIC: "AAA",
 	"AAD",
 	"AAM",
 	"AAS",

src/cmd/internal/obj/x86/asm6.go

@@ -1435,7 +1435,7 @@ var optab =
 	Optab{0, nil, 0, [23]uint8{}},
 }
 
-var opindex [ALAST + 1]*Optab
+var opindex [(ALAST + 1) & obj.AMask]*Optab
 
 // isextern reports whether s describes an external symbol that must avoid pc-relative addressing.
 // This happens on systems like Solaris that call .so functions instead of system calls.
@@ -1708,10 +1708,10 @@ func instinit() {
 
 	for i := 1; optab[i].as != 0; i++ {
 		c = int(optab[i].as)
-		if opindex[c] != nil {
-			log.Fatalf("phase error in optab: %d (%v)", i, Aconv(c))
+		if opindex[c&obj.AMask] != nil {
+			log.Fatalf("phase error in optab: %d (%v)", i, obj.Aconv(c))
 		}
-		opindex[c] = &optab[i]
+		opindex[c&obj.AMask] = &optab[i]
 	}
 
 	for i := 0; i < Ymax; i++ {
@@ -2758,7 +2758,7 @@ func mediaop(ctxt *obj.Link, o *Optab, op int, osize int, z int) int {
 func doasm(ctxt *obj.Link, p *obj.Prog) {
 	ctxt.Curp = p // TODO
 
-	o := opindex[p.As]
+	o := opindex[p.As&obj.AMask]
 
 	if o == nil {
 		ctxt.Diag("asmins: missing op %v", p)

src/cmd/internal/obj/x86/list6.go

@@ -59,21 +59,21 @@ func Pconv(p *obj.Prog) string {
 	switch p.As {
 	case obj.ADATA:
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v/%d,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 
 	case obj.ATEXT:
 		if p.From3.Offset != 0 {
 			str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%d,%v",
-				p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
+				p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), p.From3.Offset, obj.Dconv(p, &p.To))
 			break
 		}
 
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 
 	default:
 		str = fmt.Sprintf("%.5d (%v)\t%v\t%v,%v",
-			p.Pc, p.Line(), Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
+			p.Pc, p.Line(), obj.Aconv(int(p.As)), obj.Dconv(p, &p.From), obj.Dconv(p, &p.To))
 
 		// TODO(rsc): This special case is for SHRQ $32, AX:DX, which encodes as
 		//	SHRQ $32(DX*0), AX
@@ -88,10 +88,6 @@ func Pconv(p *obj.Prog) string {
 	return fp
 }
 
-func Aconv(i int) string {
-	return Anames[i]
-}
-
 var Register = []string{
 	"AL", /* [D_AL] */
 	"CL",
@@ -210,6 +206,7 @@ var Register = []string{
 
 func init() {
 	obj.RegisterRegister(REG_AL, REG_AL+len(Register), Rconv)
+	obj.RegisterOpcode(obj.ABaseAMD64, Anames)
 }
 
 func Rconv(r int) string {

src/cmd/internal/obj/x86/obj6.go

@@ -895,7 +895,7 @@ func pushpop(a int) bool {
 	return false
 }
 
-func relinv(a int) int {
+func relinv(a int16) int16 {
 	switch a {
 	case AJEQ:
 		return AJNE
@@ -931,7 +931,7 @@ func relinv(a int) int {
 		return AJOS
 	}
 
-	log.Fatalf("unknown relation: %s", Anames[a])
+	log.Fatalf("unknown relation: %s", obj.Aconv(int(a)))
 	return 0
 }
 
@@ -1001,7 +1001,7 @@ loop:
 					continue
 				}
 
-				q.As = int16(relinv(int(q.As)))
+				q.As = relinv(q.As)
 				p = q.Pcond
 				q.Pcond = q.Link
 				q.Link = p
@@ -1054,7 +1054,7 @@ loop:
 				 * expect conditional jump to be taken.
 				 * rewrite so that's the fall-through case.
 				 */
-				p.As = int16(relinv(a))
+				p.As = relinv(int16(a))
 
 				q = p.Link
 				p.Link = p.Pcond
@@ -1064,7 +1064,7 @@ loop:
 			q = p.Link
 			if q.Mark != 0 {
 				if a != ALOOP {
-					p.As = int16(relinv(a))
+					p.As = relinv(int16(a))
 					p.Link = p.Pcond
 					p.Pcond = q
 				}