cmd/internal/obj: convert Aconv to a stringer

Now that assembler opcodes have their own type, they can have a true
stringer, rather than explicit calls to Aconv, which makes for nicer
format strings.

Change-Id: Ic77f5f8ac38b4e519dcaa08c93e7b732226f7bfe
Reviewed-on: https://go-review.googlesource.com/25045
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

15 files changed, 68 insertions, 68 deletions

diff --git a/src/cmd/asm/internal/asm/asm.go b/src/cmd/asm/internal/asm/asm.go
index c9c64203ae..3b41bb9bb1 100644
--- a/src/cmd/asm/internal/asm/asm.go
+++ b/src/cmd/asm/internal/asm/asm.go
@@ -403,7 +403,7 @@ func (p *Parser) asmJump(op obj.As, cond string, a []obj.Addr) {
 
 		fallthrough
 	default:
-		p.errorf("wrong number of arguments to %s instruction", obj.Aconv(op))
+		p.errorf("wrong number of arguments to %s instruction", op)
 		return
 	}
 	switch {
@@ -476,7 +476,7 @@ func (p *Parser) branch(jmp, target *obj.Prog) {
 // asmInstruction assembles an instruction.
 // MOVW R9, (R10)
 func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
-	// fmt.Printf("%s %+v\n", obj.Aconv(op), a)
+	// fmt.Printf("%s %+v\n", op, a)
 	prog := &obj.Prog{
 		Ctxt:   p.ctxt,
 		Lineno: p.histLineNum,
@@ -525,7 +525,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 					prog.To = a[1]
 					break
 				}
-				p.errorf("unrecognized addressing for %s", obj.Aconv(op))
+				p.errorf("unrecognized addressing for %s", op)
 				return
 			}
 			if arch.IsARMFloatCmp(op) {
@@ -572,7 +572,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			// Catch missing operand here, because we store immediate as part of From3, and can't distinguish
 			// missing operand from legal value 0 in obj/x86/asm6.
 			if arch.IsAMD4OP(op) {
-				p.errorf("4 operands required, but only 3 are provided for %s instruction", obj.Aconv(op))
+				p.errorf("4 operands required, but only 3 are provided for %s instruction", op)
 			}
 			prog.From = a[0]
 			prog.From3 = newAddr(a[1])
@@ -583,7 +583,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 				prog.From = a[0]
 				prog.To = a[1]
 				if a[2].Type != obj.TYPE_REG {
-					p.errorf("invalid addressing modes for third operand to %s instruction, must be register", obj.Aconv(op))
+					p.errorf("invalid addressing modes for third operand to %s instruction, must be register", op)
 					return
 				}
 				prog.RegTo2 = a[2].Reg
@@ -619,7 +619,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 				prog.From3 = newAddr(a[1])
 				prog.To = a[2]
 			default:
-				p.errorf("invalid addressing modes for %s instruction", obj.Aconv(op))
+				p.errorf("invalid addressing modes for %s instruction", op)
 				return
 			}
 		case sys.S390X:
@@ -656,10 +656,10 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			prog.From = a[1]
 			prog.From3 = newAddr(a[2])
 			if a[0].Type != obj.TYPE_CONST {
-				p.errorf("first operand must be an immediate in %s instruction", obj.Aconv(op))
+				p.errorf("first operand must be an immediate in %s instruction", op)
 			}
 			if prog.From3.Type != obj.TYPE_REG {
-				p.errorf("third operand must be a register in %s instruction", obj.Aconv(op))
+				p.errorf("third operand must be a register in %s instruction", op)
 			}
 			prog.From3.Offset = int64(p.getImmediate(prog, op, &a[0]))
 			prog.To = a[3]
@@ -690,7 +690,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			prog.To = a[3]
 			break
 		}
-		p.errorf("can't handle %s instruction with 4 operands", obj.Aconv(op))
+		p.errorf("can't handle %s instruction with 4 operands", op)
 		return
 	case 5:
 		if p.arch.Family == sys.PPC64 && arch.IsPPC64RLD(op) {
@@ -712,7 +712,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			prog.To = a[4]
 			break
 		}
-		p.errorf("can't handle %s instruction with 5 operands", obj.Aconv(op))
+		p.errorf("can't handle %s instruction with 5 operands", op)
 		return
 	case 6:
 		if p.arch.Family == sys.ARM && arch.IsARMMRC(op) {
@@ -736,7 +736,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 		}
 		fallthrough
 	default:
-		p.errorf("can't handle %s instruction with %d operands", obj.Aconv(op), len(a))
+		p.errorf("can't handle %s instruction with %d operands", op, len(a))
 		return
 	}
 
@@ -771,7 +771,7 @@ 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 obj.As, 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", obj.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected integer constant; found %s", op, obj.Dconv(prog, addr))
 	}
 	return addr.Offset
 }
@@ -779,7 +779,7 @@ func (p *Parser) getConstant(prog *obj.Prog, op obj.As, addr *obj.Addr) int64 {
 // getImmediate checks that addr represents an immediate constant and returns its value.
 func (p *Parser) getImmediate(prog *obj.Prog, op obj.As, 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", obj.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected immediate constant; found %s", op, obj.Dconv(prog, addr))
 	}
 	return addr.Offset
 }
@@ -787,7 +787,7 @@ func (p *Parser) getImmediate(prog *obj.Prog, op obj.As, addr *obj.Addr) int64 {
 // getRegister checks that addr represents a register and returns its value.
 func (p *Parser) getRegister(prog *obj.Prog, op obj.As, 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", obj.Aconv(op), obj.Dconv(prog, addr))
+		p.errorf("%s: expected register; found %s", op, obj.Dconv(prog, addr))
 	}
 	return addr.Reg
 }
diff --git a/src/cmd/compile/internal/arm/peep.go b/src/cmd/compile/internal/arm/peep.go
index e1c8e4d0d9..2c5896c2f7 100644
--- a/src/cmd/compile/internal/arm/peep.go
+++ b/src/cmd/compile/internal/arm/peep.go
@@ -538,7 +538,7 @@ gotit:
 	}
 
 	if gc.Debug['P'] != 0 {
-		fmt.Printf(" => %v\n", obj.Aconv(p.As))
+		fmt.Printf(" => %v\n", p.As)
 	}
 	return true
 }
@@ -1036,7 +1036,7 @@ 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", obj.Aconv(p.As))
+		fmt.Printf("copyu: can't find %v\n", p.As)
 		return 2
 
 	case arm.AMOVM:
diff --git a/src/cmd/compile/internal/arm64/peep.go b/src/cmd/compile/internal/arm64/peep.go
index e32c264215..9f07ae1479 100644
--- a/src/cmd/compile/internal/arm64/peep.go
+++ b/src/cmd/compile/internal/arm64/peep.go
@@ -162,7 +162,7 @@ loop1:
 			continue
 		}
 		if gc.Debug['P'] != 0 {
-			fmt.Printf("encoding $%d directly into %v in:\n%v\n%v\n", p.From.Offset, obj.Aconv(p1.As), p, p1)
+			fmt.Printf("encoding $%d directly into %v in:\n%v\n%v\n", p.From.Offset, p1.As, p, p1)
 		}
 		p1.From.Type = obj.TYPE_CONST
 		p1.From = p.From
@@ -423,7 +423,7 @@ func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
 
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
+		fmt.Printf("copyu: can't find %v\n", p.As)
 		return 2
 
 	case obj.ANOP, /* read p->from, write p->to */
diff --git a/src/cmd/compile/internal/mips64/peep.go b/src/cmd/compile/internal/mips64/peep.go
index 6bb51583e2..f6717e60f9 100644
--- a/src/cmd/compile/internal/mips64/peep.go
+++ b/src/cmd/compile/internal/mips64/peep.go
@@ -402,7 +402,7 @@ func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
 
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
+		fmt.Printf("copyu: can't find %v\n", p.As)
 		return 2
 
 	case obj.ANOP, /* read p->from, write p->to */
diff --git a/src/cmd/compile/internal/ppc64/peep.go b/src/cmd/compile/internal/ppc64/peep.go
index 6efe0b7747..4b2b985d91 100644
--- a/src/cmd/compile/internal/ppc64/peep.go
+++ b/src/cmd/compile/internal/ppc64/peep.go
@@ -601,7 +601,7 @@ func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
 
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
+		fmt.Printf("copyu: can't find %v\n", p.As)
 		return 2
 
 	case obj.ANOP, /* read p->from, write p->to */
diff --git a/src/cmd/compile/internal/ppc64/prog.go b/src/cmd/compile/internal/ppc64/prog.go
index 117eb24299..b08ec49f6d 100644
--- a/src/cmd/compile/internal/ppc64/prog.go
+++ b/src/cmd/compile/internal/ppc64/prog.go
@@ -313,7 +313,7 @@ func as2variant(as obj.As) int {
 			return i
 		}
 	}
-	gc.Fatalf("as2variant: instruction %v is not a variant of itself", obj.Aconv(as&obj.AMask))
+	gc.Fatalf("as2variant: instruction %v is not a variant of itself", as&obj.AMask)
 	return 0
 }
 
diff --git a/src/cmd/compile/internal/s390x/peep.go b/src/cmd/compile/internal/s390x/peep.go
index cd6a8c5d8c..aca8218988 100644
--- a/src/cmd/compile/internal/s390x/peep.go
+++ b/src/cmd/compile/internal/s390x/peep.go
@@ -419,7 +419,7 @@ func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) usage {
 
 	switch p.As {
 	default:
-		fmt.Printf("copyu: can't find %v\n", obj.Aconv(p.As))
+		fmt.Printf("copyu: can't find %v\n", p.As)
 		return _ReadWriteSame
 
 	case // read p.From, write p.To
diff --git a/src/cmd/internal/obj/arm/asm5.go b/src/cmd/internal/obj/arm/asm5.go
index 2158cf19fa..1e0ff57c7a 100644
--- a/src/cmd/internal/obj/arm/asm5.go
+++ b/src/cmd/internal/obj/arm/asm5.go
@@ -1191,7 +1191,7 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 	}
 
 	if false { /*debug['O']*/
-		fmt.Printf("oplook %v %v %v %v\n", obj.Aconv(p.As), DRconv(a1), DRconv(a2), DRconv(a3))
+		fmt.Printf("oplook %v %v %v %v\n", p.As, DRconv(a1), DRconv(a2), DRconv(a3))
 		fmt.Printf("\t\t%d %d\n", p.From.Type, p.To.Type)
 	}
 
@@ -1343,7 +1343,7 @@ func buildop(ctxt *obj.Link) {
 
 		switch r {
 		default:
-			ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
+			ctxt.Diag("unknown op in build: %v", r)
 			log.Fatalf("bad code")
 
 		case AADD:
@@ -2636,7 +2636,7 @@ func opbra(ctxt *obj.Link, p *obj.Prog, a obj.As, sc int) uint32 {
 		return 0xe<<28 | 0x5<<25
 	}
 
-	ctxt.Diag("bad bra %v", obj.Aconv(a))
+	ctxt.Diag("bad bra %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -2756,7 +2756,7 @@ func ofsr(ctxt *obj.Link, a obj.As, r int, v int32, b int, sc int, p *obj.Prog)
 
 	switch a {
 	default:
-		ctxt.Diag("bad fst %v", obj.Aconv(a))
+		ctxt.Diag("bad fst %v", a)
 		fallthrough
 
 	case AMOVD:
diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index fbf0378591..33acb826cb 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -1234,7 +1234,7 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 	}
 
 	if false {
-		fmt.Printf("oplook %v %d %d %d\n", obj.Aconv(p.As), a1, a2, a3)
+		fmt.Printf("oplook %v %d %d %d\n", p.As, a1, a2, a3)
 		fmt.Printf("\t\t%d %d\n", p.From.Type, p.To.Type)
 	}
 
@@ -1460,7 +1460,7 @@ func buildop(ctxt *obj.Link) {
 		oprangeset(r, t)
 		switch r {
 		default:
-			ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
+			ctxt.Diag("unknown op in build: %v", r)
 			log.Fatalf("bad code")
 
 		case AADD:
@@ -2379,7 +2379,7 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 		s := movesize(o.as)
 
 		if s < 0 {
-			ctxt.Diag("unexpected long move, op %v tab %v\n%v", obj.Aconv(p.As), obj.Aconv(o.as), p)
+			ctxt.Diag("unexpected long move, op %v tab %v\n%v", p.As, o.as, p)
 		}
 		v := int32(regoff(ctxt, &p.To))
 		if v < 0 {
@@ -2406,7 +2406,7 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 		s := movesize(o.as)
 
 		if s < 0 {
-			ctxt.Diag("unexpected long move, op %v tab %v\n%v", obj.Aconv(p.As), obj.Aconv(o.as), p)
+			ctxt.Diag("unexpected long move, op %v tab %v\n%v", p.As, o.as, p)
 		}
 		v := int32(regoff(ctxt, &p.From))
 		if v < 0 {
@@ -2637,7 +2637,7 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 			o1 = opbfm(ctxt, AUBFMW, 0, 15, rf, rt)
 
 		default:
-			ctxt.Diag("bad sxt %v", obj.Aconv(as))
+			ctxt.Diag("bad sxt %v", as)
 			break
 		}
 
@@ -3470,7 +3470,7 @@ func oprrr(ctxt *obj.Link, a obj.As) uint32 {
 		return FPOP1S(0, 0, 3, 5)
 	}
 
-	ctxt.Diag("bad rrr %d %v", a, obj.Aconv(a))
+	ctxt.Diag("bad rrr %d %v", a, a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3657,7 +3657,7 @@ func opirr(ctxt *obj.Link, a obj.As) uint32 {
 		return SYSOP(0, 0, 3, 2, 0, 0, 0x1F)
 	}
 
-	ctxt.Diag("bad irr %v", obj.Aconv(a))
+	ctxt.Diag("bad irr %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3733,7 +3733,7 @@ func opxrrr(ctxt *obj.Link, a obj.As) uint32 {
 		return S32 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
 	}
 
-	ctxt.Diag("bad opxrrr %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opxrrr %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
@@ -3767,7 +3767,7 @@ func opimm(ctxt *obj.Link, a obj.As) uint32 {
 		return SYSOP(0, 0, 3, 3, 0, 2, 0x1F)
 	}
 
-	ctxt.Diag("bad imm %v", obj.Aconv(a))
+	ctxt.Diag("bad imm %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3852,7 +3852,7 @@ func opbra(ctxt *obj.Link, a obj.As) uint32 {
 		return 1<<31 | 5<<26
 	}
 
-	ctxt.Diag("bad bra %v", obj.Aconv(a))
+	ctxt.Diag("bad bra %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3869,7 +3869,7 @@ func opbrr(ctxt *obj.Link, a obj.As) uint32 {
 		return OPBLR(2) /* RET */
 	}
 
-	ctxt.Diag("bad brr %v", obj.Aconv(a))
+	ctxt.Diag("bad brr %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3901,7 +3901,7 @@ func op0(ctxt *obj.Link, a obj.As) uint32 {
 		return SYSHINT(5)
 	}
 
-	ctxt.Diag("bad op0 %v", obj.Aconv(a))
+	ctxt.Diag("bad op0 %v", a)
 	prasm(ctxt.Curp)
 	return 0
 }
@@ -3966,7 +3966,7 @@ func opload(ctxt *obj.Link, a obj.As) uint32 {
 		return S32 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22
 	}
 
-	ctxt.Diag("bad opload %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opload %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
@@ -4033,7 +4033,7 @@ func opstore(ctxt *obj.Link, a obj.As) uint32 {
 		return S32 | 0<<30 | 5<<27 | 0<<26 | 0<<23 | 1<<22
 	}
 
-	ctxt.Diag("bad opstore %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opstore %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
@@ -4081,7 +4081,7 @@ func opldr12(ctxt *obj.Link, a obj.As) uint32 {
 		return LDSTR12U(3, 1, 1)
 	}
 
-	ctxt.Diag("bad opldr12 %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opldr12 %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
@@ -4132,7 +4132,7 @@ func opldr9(ctxt *obj.Link, a obj.As) uint32 {
 		return LDSTR9S(3, 1, 1)
 	}
 
-	ctxt.Diag("bad opldr9 %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opldr9 %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
@@ -4164,7 +4164,7 @@ func opldrpp(ctxt *obj.Link, a obj.As) uint32 {
 		return 0<<30 | 7<<27 | 0<<26 | 0<<24 | 1<<22
 	}
 
-	ctxt.Diag("bad opldr %v\n%v", obj.Aconv(a), ctxt.Curp)
+	ctxt.Diag("bad opldr %v\n%v", a, ctxt.Curp)
 	return 0
 }
 
diff --git a/src/cmd/internal/obj/mips/asm0.go b/src/cmd/internal/obj/mips/asm0.go
index 11aa202215..73daa0a102 100644
--- a/src/cmd/internal/obj/mips/asm0.go
+++ b/src/cmd/internal/obj/mips/asm0.go
@@ -659,7 +659,7 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 		}
 	}
 
-	ctxt.Diag("illegal combination %v %v %v %v", obj.Aconv(p.As), DRconv(a1), DRconv(a2), DRconv(a3))
+	ctxt.Diag("illegal combination %v %v %v %v", p.As, DRconv(a1), DRconv(a2), DRconv(a3))
 	prasm(p)
 	if ops == nil {
 		ops = optab
@@ -809,7 +809,7 @@ func buildop(ctxt *obj.Link) {
 
 		switch r {
 		default:
-			ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
+			ctxt.Diag("unknown op in build: %v", r)
 			log.Fatalf("bad code")
 
 		case AABSF:
@@ -1612,9 +1612,9 @@ func oprrr(ctxt *obj.Link, a obj.As) uint32 {
 	}
 
 	if a < 0 {
-		ctxt.Diag("bad rrr opcode -%v", obj.Aconv(-a))
+		ctxt.Diag("bad rrr opcode -%v", -a)
 	} else {
-		ctxt.Diag("bad rrr opcode %v", obj.Aconv(a))
+		ctxt.Diag("bad rrr opcode %v", a)
 	}
 	return 0
 }
@@ -1764,9 +1764,9 @@ func opirr(ctxt *obj.Link, a obj.As) uint32 {
 	}
 
 	if a < 0 {
-		ctxt.Diag("bad irr opcode -%v", obj.Aconv(-a))
+		ctxt.Diag("bad irr opcode -%v", -a)
 	} else {
-		ctxt.Diag("bad irr opcode %v", obj.Aconv(a))
+		ctxt.Diag("bad irr opcode %v", a)
 	}
 	return 0
 }
diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go
index 52cae12333..968bc95e10 100644
--- a/src/cmd/internal/obj/ppc64/asm9.go
+++ b/src/cmd/internal/obj/ppc64/asm9.go
@@ -776,7 +776,7 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 		}
 	}
 
-	ctxt.Diag("illegal combination %v %v %v %v %v", obj.Aconv(p.As), DRconv(a1), DRconv(a2), DRconv(a3), DRconv(a4))
+	ctxt.Diag("illegal combination %v %v %v %v %v", p.As, DRconv(a1), DRconv(a2), DRconv(a3), DRconv(a4))
 	prasm(p)
 	if ops == nil {
 		ops = optab
@@ -925,8 +925,8 @@ func buildop(ctxt *obj.Link) {
 
 		switch r {
 		default:
-			ctxt.Diag("unknown op in build: %v", obj.Aconv(r))
-			log.Fatalf("instruction missing from switch in asm9.go:buildop: %v", obj.Aconv(r))
+			ctxt.Diag("unknown op in build: %v", r)
+			log.Fatalf("instruction missing from switch in asm9.go:buildop: %v", r)
 
 		case ADCBF: /* unary indexed: op (b+a); op (b) */
 			opset(ADCBI, r0)
@@ -3046,7 +3046,7 @@ func oprrr(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(31, 316, 0, 1)
 	}
 
-	ctxt.Diag("bad r/r opcode %v", obj.Aconv(a))
+	ctxt.Diag("bad r/r opcode %v", a)
 	return 0
 }
 
@@ -3168,7 +3168,7 @@ func opirr(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(27, 0, 0, 0) /* XORIU */
 	}
 
-	ctxt.Diag("bad opcode i/r %v", obj.Aconv(a))
+	ctxt.Diag("bad opcode i/r %v", a)
 	return 0
 }
 
@@ -3215,7 +3215,7 @@ func opload(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(46, 0, 0, 0) /* lmw */
 	}
 
-	ctxt.Diag("bad load opcode %v", obj.Aconv(a))
+	ctxt.Diag("bad load opcode %v", a)
 	return 0
 }
 
@@ -3278,7 +3278,7 @@ func oploadx(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(31, 53, 0, 0) /* ldux */
 	}
 
-	ctxt.Diag("bad loadx opcode %v", obj.Aconv(a))
+	ctxt.Diag("bad loadx opcode %v", a)
 	return 0
 }
 
@@ -3322,7 +3322,7 @@ func opstore(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(62, 0, 0, 1) /* stdu */
 	}
 
-	ctxt.Diag("unknown store opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown store opcode %v", a)
 	return 0
 }
 
@@ -3378,6 +3378,6 @@ func opstorex(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(31, 181, 0, 0) /* stdux */
 	}
 
-	ctxt.Diag("unknown storex opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown storex opcode %v", a)
 	return 0
 }
diff --git a/src/cmd/internal/obj/s390x/asmz.go b/src/cmd/internal/obj/s390x/asmz.go
index 2a99bbe390..847af9c4e0 100644
--- a/src/cmd/internal/obj/s390x/asmz.go
+++ b/src/cmd/internal/obj/s390x/asmz.go
@@ -651,7 +651,7 @@ func oplook(ctxt *obj.Link, p *obj.Prog) *Optab {
 	}
 
 	// cannot find a case; abort
-	ctxt.Diag("illegal combination %v %v %v %v %v\n", obj.Aconv(p.As), DRconv(a1), DRconv(a2), DRconv(a3), DRconv(a4))
+	ctxt.Diag("illegal combination %v %v %v %v %v\n", p.As, DRconv(a1), DRconv(a2), DRconv(a3), DRconv(a4))
 	ctxt.Diag("prog: %v\n", p)
 	return nil
 }
@@ -4039,7 +4039,7 @@ func zopload(ctxt *obj.Link, a obj.As) uint32 {
 		return op_LRVH
 	}
 
-	ctxt.Diag("unknown store opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown store opcode %v", a)
 	return 0
 }
 
@@ -4071,7 +4071,7 @@ func zopstore(ctxt *obj.Link, a obj.As) uint32 {
 		return op_STRVH
 	}
 
-	ctxt.Diag("unknown store opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown store opcode %v", a)
 	return 0
 }
 
@@ -4089,7 +4089,7 @@ func zoprre(ctxt *obj.Link, a obj.As) uint32 {
 	case ACEBR:
 		return op_CEBR
 	}
-	ctxt.Diag("unknown rre opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown rre opcode %v", a)
 	return 0
 }
 
@@ -4101,7 +4101,7 @@ func zoprr(ctxt *obj.Link, a obj.As) uint32 {
 	case ACMPWU:
 		return op_CLR
 	}
-	ctxt.Diag("unknown rr opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown rr opcode %v", a)
 	return 0
 }
 
@@ -4117,7 +4117,7 @@ func zopril(ctxt *obj.Link, a obj.As) uint32 {
 	case ACMPWU:
 		return op_CLFI
 	}
-	ctxt.Diag("unknown ril opcode %v", obj.Aconv(a))
+	ctxt.Diag("unknown ril opcode %v", a)
 	return 0
 }
 
diff --git a/src/cmd/internal/obj/util.go b/src/cmd/internal/obj/util.go
index c8f8760af1..a80af26c07 100644
--- a/src/cmd/internal/obj/util.go
+++ b/src/cmd/internal/obj/util.go
@@ -138,7 +138,7 @@ func (p *Prog) String() string {
 
 	var buf bytes.Buffer
 
-	fmt.Fprintf(&buf, "%.5d (%v)\t%v%s", p.Pc, p.Line(), Aconv(p.As), sc)
+	fmt.Fprintf(&buf, "%.5d (%v)\t%v%s", p.Pc, p.Line(), p.As, sc)
 	sep := "\t"
 	quadOpAmd64 := p.RegTo2 == -1
 	if quadOpAmd64 {
@@ -465,7 +465,7 @@ func RegisterOpcode(lo As, Anames []string) {
 	aSpace = append(aSpace, opSet{lo, Anames})
 }
 
-func Aconv(a As) string {
+func (a As) String() string {
 	if 0 <= a && int(a) < len(Anames) {
 		return Anames[a]
 	}
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 494e422081..d94bd60e8d 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -2013,7 +2013,7 @@ func instinit() {
 	for i := 1; optab[i].as != 0; i++ {
 		c := optab[i].as
 		if opindex[c&obj.AMask] != nil {
-			log.Fatalf("phase error in optab: %d (%v)", i, obj.Aconv(c))
+			log.Fatalf("phase error in optab: %d (%v)", i, c)
 		}
 		opindex[c&obj.AMask] = &optab[i]
 	}
diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go
index c4b0d89cda..93fee97e4b 100644
--- a/src/cmd/internal/obj/x86/obj6.go
+++ b/src/cmd/internal/obj/x86/obj6.go
@@ -1231,7 +1231,7 @@ func relinv(a obj.As) obj.As {
 		return AJOS
 	}
 
-	log.Fatalf("unknown relation: %s", obj.Aconv(a))
+	log.Fatalf("unknown relation: %s", a)
 	return 0
 }