cmd/asm, cmd/internal/obj/s390x: delete unused instructions

Deletes the following s390x instructions:

 - ADDME
 - ADDZE
 - SUBME
 - SUBZE

They appear to be emulated PPC instructions left over from the
porting process and I don't think they will ever be useful.

Change-Id: I9b1ba78019dbd1218d0c8f8ea2903878802d1990
Reviewed-on: https://go-review.googlesource.com/30538
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/asm/internal/arch/s390x.go

@@ -80,11 +80,7 @@ func IsS390xCMP(op obj.As) bool {
 // one of the NEG-like instructions that require special handling.
 func IsS390xNEG(op obj.As) bool {
 	switch op {
-	case s390x.AADDME,
-		s390x.AADDZE,
-		s390x.ANEG,
-		s390x.ASUBME,
-		s390x.ASUBZE:
+	case s390x.ANEG, s390x.ANEGW:
 		return true
 	}
 	return false

src/cmd/internal/obj/s390x/a.out.go

@@ -209,9 +209,7 @@ const (
 	// integer arithmetic
 	AADD = obj.ABaseS390X + obj.A_ARCHSPECIFIC + iota
 	AADDC
-	AADDME
 	AADDE
-	AADDZE
 	AADDW
 	ADIVW
 	ADIVWU
@@ -227,10 +225,8 @@ const (
 	AMULHDU
 	ASUB
 	ASUBC
-	ASUBME
 	ASUBV
 	ASUBE
-	ASUBZE
 	ASUBW
 	ANEG
 	ANEGW

src/cmd/internal/obj/s390x/anames.go

@@ -8,9 +8,7 @@ import "cmd/internal/obj"
 var Anames = []string{
 	obj.A_ARCHSPECIFIC: "ADD",
 	"ADDC",
-	"ADDME",
 	"ADDE",
-	"ADDZE",
 	"ADDW",
 	"DIVW",
 	"DIVWU",
@@ -26,10 +24,8 @@ var Anames = []string{
 	"MULHDU",
 	"SUB",
 	"SUBC",
-	"SUBME",
 	"SUBV",
 	"SUBE",
-	"SUBZE",
 	"SUBW",
 	"NEG",
 	"NEGW",

src/cmd/internal/obj/s390x/asmz.go

@@ -153,7 +153,6 @@ var optab = []Optab{
 	Optab{ADIVW, C_REG, C_NONE, C_NONE, C_REG, 2, 0},
 	Optab{ASUB, C_REG, C_REG, C_NONE, C_REG, 10, 0},
 	Optab{ASUB, C_REG, C_NONE, C_NONE, C_REG, 10, 0},
-	Optab{AADDME, C_REG, C_NONE, C_NONE, C_REG, 47, 0},
 	Optab{ANEG, C_REG, C_NONE, C_NONE, C_REG, 47, 0},
 	Optab{ANEG, C_NONE, C_NONE, C_NONE, C_REG, 47, 0},
 
@@ -837,10 +836,6 @@ func buildop(ctxt *obj.Link) {
 			opset(ASTMY, r)
 		case ALMG:
 			opset(ALMY, r)
-		case AADDME:
-			opset(AADDZE, r)
-			opset(ASUBME, r)
-			opset(ASUBZE, r)
 		case ABEQ:
 			opset(ABGE, r)
 			opset(ABGT, r)
@@ -3232,49 +3227,15 @@ func asmout(ctxt *obj.Link, asm *[]byte) {
 			*asm = append(*asm, uint8(wd))
 		}
 
-	case 47: // arithmetic op (carry) reg [reg] reg
+	case 47: // negate [reg] reg
 		r := p.From.Reg
+		if r == 0 {
+			r = p.To.Reg
+		}
 		switch p.As {
-		default:
-		case AADDME:
-			if p.To.Reg == p.From.Reg {
-				zRRE(op_LGR, REGTMP, uint32(p.From.Reg), asm)
-				r = REGTMP
-			}
-			zRIL(_a, op_LGFI, uint32(p.To.Reg), 0xffffffff, asm) // p.To.Reg <- -1
-			zRRE(op_ALCGR, uint32(p.To.Reg), uint32(r), asm)
-		case AADDZE:
-			if p.To.Reg == p.From.Reg {
-				zRRE(op_LGR, REGTMP, uint32(p.From.Reg), asm)
-				r = REGTMP
-			}
-			zRI(op_LGHI, uint32(p.To.Reg), 0, asm)
-			zRRE(op_ALCGR, uint32(p.To.Reg), uint32(r), asm)
-		case ASUBME:
-			if p.To.Reg == p.From.Reg {
-				zRRE(op_LGR, REGTMP, uint32(p.From.Reg), asm)
-				r = REGTMP
-			}
-			zRIL(_a, op_LGFI, uint32(p.To.Reg), 0xffffffff, asm) // p.To.Reg <- -1
-			zRRE(op_SLBGR, uint32(p.To.Reg), uint32(r), asm)
-		case ASUBZE:
-			if p.To.Reg == p.From.Reg {
-				zRRE(op_LGR, REGTMP, uint32(p.From.Reg), asm)
-				r = REGTMP
-			}
-			zRI(op_LGHI, uint32(p.To.Reg), 0, asm)
-			zRRE(op_SLBGR, uint32(p.To.Reg), uint32(r), asm)
 		case ANEG:
-			r := p.From.Reg
-			if r == 0 {
-				r = p.To.Reg
-			}
 			zRRE(op_LCGR, uint32(p.To.Reg), uint32(r), asm)
 		case ANEGW:
-			r := p.From.Reg
-			if r == 0 {
-				r = p.To.Reg
-			}
 			zRRE(op_LCGFR, uint32(p.To.Reg), uint32(r), asm)
 		}