cmd/compile: give gc.Op a String method, use it

Passes toolstash -cmp.

Change-Id: I915e76374fd64aa2597e6fa47e4fa95ca00ca643
Reviewed-on: https://go-review.googlesource.com/22380
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

src/cmd/compile/internal/gc/bexport.go

@@ -1274,7 +1274,7 @@ func (p *exporter) expr(n *Node) {
 		p.op(ODCLCONST)
 
 	default:
-		Fatalf("exporter: CANNOT EXPORT: %s\nPlease notify gri@\n", opnames[n.Op])
+		Fatalf("exporter: CANNOT EXPORT: %s\nPlease notify gri@\n", n.Op)
 	}
 }
 
@@ -1404,7 +1404,7 @@ func (p *exporter) stmt(n *Node) {
 		p.expr(n.Left)
 
 	default:
-		Fatalf("exporter: CANNOT EXPORT: %s\nPlease notify gri@\n", opnames[n.Op])
+		Fatalf("exporter: CANNOT EXPORT: %s\nPlease notify gri@\n", n.Op)
 	}
 }
 
@@ -1492,7 +1492,7 @@ func (p *exporter) bool(b bool) bool {
 func (p *exporter) op(op Op) {
 	if p.trace {
 		p.tracef("[")
-		defer p.tracef("= %s] ", opnames[op])
+		defer p.tracef("= %s] ", op)
 	}
 
 	p.int(int(op))

src/cmd/compile/internal/gc/bimport.go

@@ -1013,7 +1013,7 @@ func (p *importer) node() *Node {
 		return nil
 
 	default:
-		Fatalf("importer: %s (%d) node not yet supported", opnames[op], op)
+		Fatalf("importer: %s (%d) node not yet supported", op, op)
 		panic("unreachable") // satisfy compiler
 	}
 }

src/cmd/compile/internal/gc/fmt.go

@@ -453,6 +453,10 @@ func (e EType) String() string {
 	return Econv(e)
 }
 
+func (o Op) String() string {
+	return Oconv(o, 0)
+}
+
 // Fmt "%S": syms
 func symfmt(s *Sym, flag FmtFlag) string {
 	if s.Pkg != nil && flag&FmtShort == 0 {

src/cmd/compile/internal/gc/obj.go

@@ -334,7 +334,7 @@ func dsymptrOffLSym(s *obj.LSym, off int, x *obj.LSym, xoff int) int {
 
 func gdata(nam *Node, nr *Node, wid int) {
 	if nam.Op != ONAME {
-		Fatalf("gdata nam op %v", opnames[nam.Op])
+		Fatalf("gdata nam op %v", nam.Op)
 	}
 	if nam.Sym == nil {
 		Fatalf("gdata nil nam sym")
@@ -372,7 +372,7 @@ func gdata(nam *Node, nr *Node, wid int) {
 
 	case OADDR:
 		if nr.Left.Op != ONAME {
-			Fatalf("gdata ADDR left op %s", opnames[nr.Left.Op])
+			Fatalf("gdata ADDR left op %s", nr.Left.Op)
 		}
 		to := nr.Left
 		Linksym(nam.Sym).WriteAddr(Ctxt, nam.Xoffset, wid, Linksym(to.Sym), to.Xoffset)
@@ -384,7 +384,7 @@ func gdata(nam *Node, nr *Node, wid int) {
 		Linksym(nam.Sym).WriteAddr(Ctxt, nam.Xoffset, wid, Linksym(funcsym(nr.Sym)), nr.Xoffset)
 
 	default:
-		Fatalf("gdata unhandled op %v %v\n", nr, opnames[nr.Op])
+		Fatalf("gdata unhandled op %v %v\n", nr, nr.Op)
 	}
 }
 

src/cmd/compile/internal/gc/sinit.go

@@ -1033,7 +1033,7 @@ func anylit(ctxt int, n *Node, var_ *Node, init *Nodes) {
 	t := n.Type
 	switch n.Op {
 	default:
-		Fatalf("anylit: not lit, op=%v node=%v", opnames[n.Op], n)
+		Fatalf("anylit: not lit, op=%v node=%v", n.Op, n)
 
 	case OPTRLIT:
 		if !t.IsPtr() {

src/cmd/compile/internal/gc/ssa.go

@@ -969,7 +969,7 @@ func (s *state) stmt(n *Node) {
 		s.nilCheck(p)
 
 	default:
-		s.Unimplementedf("unhandled stmt %s", opnames[n.Op])
+		s.Unimplementedf("unhandled stmt %s", n.Op)
 	}
 }
 
@@ -1247,7 +1247,7 @@ func (s *state) ssaOp(op Op, t *Type) ssa.Op {
 	etype := s.concreteEtype(t)
 	x, ok := opToSSA[opAndType{op, etype}]
 	if !ok {
-		s.Unimplementedf("unhandled binary op %s %s", opnames[op], Econv(etype))
+		s.Unimplementedf("unhandled binary op %s %s", op, Econv(etype))
 	}
 	return x
 }
@@ -1405,7 +1405,7 @@ func (s *state) ssaShiftOp(op Op, t *Type, u *Type) ssa.Op {
 	etype2 := s.concreteEtype(u)
 	x, ok := shiftOpToSSA[opAndTwoTypes{op, etype1, etype2}]
 	if !ok {
-		s.Unimplementedf("unhandled shift op %s etype=%s/%s", opnames[op], Econv(etype1), Econv(etype2))
+		s.Unimplementedf("unhandled shift op %s etype=%s/%s", op, Econv(etype1), Econv(etype2))
 	}
 	return x
 }
@@ -1414,7 +1414,7 @@ func (s *state) ssaRotateOp(op Op, t *Type) ssa.Op {
 	etype1 := s.concreteEtype(t)
 	x, ok := opToSSA[opAndType{op, etype1}]
 	if !ok {
-		s.Unimplementedf("unhandled rotate op %s etype=%s", opnames[op], Econv(etype1))
+		s.Unimplementedf("unhandled rotate op %s etype=%s", op, Econv(etype1))
 	}
 	return x
 }
@@ -1729,7 +1729,7 @@ func (s *state) expr(n *Node) *ssa.Value {
 			case ONE:
 				return s.newValue1(ssa.OpNot, Types[TBOOL], c)
 			default:
-				s.Fatalf("ordered complex compare %s", opnames[n.Op])
+				s.Fatalf("ordered complex compare %s", n.Op)
 			}
 		}
 		return s.newValue2(s.ssaOp(n.Op, n.Left.Type), Types[TBOOL], a, b)
@@ -2088,7 +2088,7 @@ func (s *state) expr(n *Node) *ssa.Value {
 		return s.append(n, false)
 
 	default:
-		s.Unimplementedf("unhandled expr %s", opnames[n.Op])
+		s.Unimplementedf("unhandled expr %s", n.Op)
 		return nil
 	}
 }
@@ -2632,7 +2632,7 @@ func (s *state) call(n *Node, k callKind) *ssa.Value {
 	case sym != nil:
 		call = s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, sym, s.mem())
 	default:
-		Fatalf("bad call type %s %v", opnames[n.Op], n)
+		Fatalf("bad call type %s %v", n.Op, n)
 	}
 	call.AuxInt = stksize // Call operations carry the argsize of the callee along with them