cmd/compile/internal/ssa: add Op.UsesScratch method

Passes toolstash/buildall.

Change-Id: I928a2ef39fb10091957f35bb3f1564498f6f1b83
Reviewed-on: https://go-review.googlesource.com/30312
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

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

@@ -250,14 +250,8 @@ func (s *ssaExport) AllocFrame(f *ssa.Func) {
 				a.Node.(*Node).Used = true
 			}
 
-			// TODO(mdempsky): Encode in opcodeTable
-			// whether an Op requires scratch memory.
-			switch v.Op {
-			case ssa.Op386UCOMISS, ssa.Op386UCOMISD,
-				ssa.Op386ADDSS, ssa.Op386SUBSS, ssa.Op386MULSS, ssa.Op386DIVSS,
-				ssa.Op386CVTSD2SS, ssa.Op386CVTSL2SS, ssa.Op386CVTSL2SD, ssa.Op386CVTTSD2SL, ssa.Op386CVTTSS2SL,
-				ssa.OpPPC64Xf2i64, ssa.OpPPC64Xi2f64:
-				scratchUsed = true
+			if !scratchUsed {
+				scratchUsed = v.Op.UsesScratch()
 			}
 		}
 	}

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

@@ -4420,6 +4420,9 @@ func AddrAuto(a *obj.Addr, v *ssa.Value) {
 }
 
 func (s *SSAGenState) AddrScratch(a *obj.Addr) {
+	if s.ScratchFpMem == nil {
+		panic("no scratch memory available; forgot to declare usesScratch for Op?")
+	}
 	a.Type = obj.TYPE_MEM
 	a.Name = obj.NAME_AUTO
 	a.Node = s.ScratchFpMem

src/cmd/compile/internal/ssa/gen/386Ops.go

@@ -148,13 +148,13 @@ func init() {
 
 	var _386ops = []opData{
 		// fp ops
-		{name: "ADDSS", argLength: 2, reg: fp21, asm: "ADDSS", commutative: true, resultInArg0: true}, // fp32 add
+		{name: "ADDSS", argLength: 2, reg: fp21, asm: "ADDSS", commutative: true, resultInArg0: true, usesScratch: true}, // fp32 add
 		{name: "ADDSD", argLength: 2, reg: fp21, asm: "ADDSD", commutative: true, resultInArg0: true},                    // fp64 add
-		{name: "SUBSS", argLength: 2, reg: fp21, asm: "SUBSS", resultInArg0: true},                    // fp32 sub
+		{name: "SUBSS", argLength: 2, reg: fp21, asm: "SUBSS", resultInArg0: true, usesScratch: true},                    // fp32 sub
 		{name: "SUBSD", argLength: 2, reg: fp21, asm: "SUBSD", resultInArg0: true},                                       // fp64 sub
-		{name: "MULSS", argLength: 2, reg: fp21, asm: "MULSS", commutative: true, resultInArg0: true}, // fp32 mul
+		{name: "MULSS", argLength: 2, reg: fp21, asm: "MULSS", commutative: true, resultInArg0: true, usesScratch: true}, // fp32 mul
 		{name: "MULSD", argLength: 2, reg: fp21, asm: "MULSD", commutative: true, resultInArg0: true},                    // fp64 mul
-		{name: "DIVSS", argLength: 2, reg: fp21, asm: "DIVSS", resultInArg0: true},                    // fp32 div
+		{name: "DIVSS", argLength: 2, reg: fp21, asm: "DIVSS", resultInArg0: true, usesScratch: true},                    // fp32 div
 		{name: "DIVSD", argLength: 2, reg: fp21, asm: "DIVSD", resultInArg0: true},                                       // fp64 div
 
 		{name: "MOVSSload", argLength: 2, reg: fpload, asm: "MOVSS", aux: "SymOff", faultOnNilArg0: true}, // fp32 load
@@ -228,8 +228,8 @@ func init() {
 		{name: "CMPWconst", argLength: 1, reg: gp1flags, asm: "CMPW", typ: "Flags", aux: "Int16"}, // arg0 compare to auxint
 		{name: "CMPBconst", argLength: 1, reg: gp1flags, asm: "CMPB", typ: "Flags", aux: "Int8"},  // arg0 compare to auxint
 
-		{name: "UCOMISS", argLength: 2, reg: fp2flags, asm: "UCOMISS", typ: "Flags"}, // arg0 compare to arg1, f32
-		{name: "UCOMISD", argLength: 2, reg: fp2flags, asm: "UCOMISD", typ: "Flags"}, // arg0 compare to arg1, f64
+		{name: "UCOMISS", argLength: 2, reg: fp2flags, asm: "UCOMISS", typ: "Flags", usesScratch: true}, // arg0 compare to arg1, f32
+		{name: "UCOMISD", argLength: 2, reg: fp2flags, asm: "UCOMISD", typ: "Flags", usesScratch: true}, // arg0 compare to arg1, f64
 
 		{name: "TESTL", argLength: 2, reg: gp2flags, asm: "TESTL", typ: "Flags"},                    // (arg0 & arg1) compare to 0
 		{name: "TESTW", argLength: 2, reg: gp2flags, asm: "TESTW", typ: "Flags"},                    // (arg0 & arg1) compare to 0
@@ -306,11 +306,11 @@ func init() {
 
 		{name: "MOVLconst", reg: gp01, asm: "MOVL", typ: "UInt32", aux: "Int32", rematerializeable: true}, // 32 low bits of auxint
 
-		{name: "CVTTSD2SL", argLength: 1, reg: fpgp, asm: "CVTTSD2SL"}, // convert float64 to int32
-		{name: "CVTTSS2SL", argLength: 1, reg: fpgp, asm: "CVTTSS2SL"}, // convert float32 to int32
-		{name: "CVTSL2SS", argLength: 1, reg: gpfp, asm: "CVTSL2SS"},   // convert int32 to float32
-		{name: "CVTSL2SD", argLength: 1, reg: gpfp, asm: "CVTSL2SD"},   // convert int32 to float64
-		{name: "CVTSD2SS", argLength: 1, reg: fp11, asm: "CVTSD2SS"},   // convert float64 to float32
+		{name: "CVTTSD2SL", argLength: 1, reg: fpgp, asm: "CVTTSD2SL", usesScratch: true}, // convert float64 to int32
+		{name: "CVTTSS2SL", argLength: 1, reg: fpgp, asm: "CVTTSS2SL", usesScratch: true}, // convert float32 to int32
+		{name: "CVTSL2SS", argLength: 1, reg: gpfp, asm: "CVTSL2SS", usesScratch: true},   // convert int32 to float32
+		{name: "CVTSL2SD", argLength: 1, reg: gpfp, asm: "CVTSL2SD", usesScratch: true},   // convert int32 to float64
+		{name: "CVTSD2SS", argLength: 1, reg: fp11, asm: "CVTSD2SS", usesScratch: true},   // convert float64 to float32
 		{name: "CVTSS2SD", argLength: 1, reg: fp11, asm: "CVTSS2SD"},                      // convert float32 to float64
 
 		{name: "PXOR", argLength: 2, reg: fp21, asm: "PXOR", commutative: true, resultInArg0: true}, // exclusive or, applied to X regs for float negation.

src/cmd/compile/internal/ssa/gen/PPC64Ops.go

@@ -209,8 +209,8 @@ func init() {
 		// There are optimizations that should apply -- (Xi2f64 (MOVWload (not-ADD-ptr+offset) ) ) could use
 		// the word-load instructions.  (Xi2f64 (MOVDload ptr )) can be (FMOVDload ptr)
 
-		{name: "Xf2i64", argLength: 1, reg: fpgp, typ: "Int64"},   // move 64 bits of F register into G register
-		{name: "Xi2f64", argLength: 1, reg: gpfp, typ: "Float64"}, // move 64 bits of G register into F register
+		{name: "Xf2i64", argLength: 1, reg: fpgp, typ: "Int64", usesScratch: true},   // move 64 bits of F register into G register
+		{name: "Xi2f64", argLength: 1, reg: gpfp, typ: "Float64", usesScratch: true}, // move 64 bits of G register into F register
 
 		{name: "AND", argLength: 2, reg: gp21, asm: "AND", commutative: true},               // arg0&arg1
 		{name: "ANDN", argLength: 2, reg: gp21, asm: "ANDN"},                                // arg0&^arg1

src/cmd/compile/internal/ssa/gen/main.go

@@ -50,6 +50,7 @@ type opData struct {
 	nilCheck          bool  // this op is a nil check on arg0
 	faultOnNilArg0    bool  // this op will fault if arg0 is nil (and aux encodes a small offset)
 	faultOnNilArg1    bool  // this op will fault if arg1 is nil (and aux encodes a small offset)
+	usesScratch       bool  // this op requires scratch memory space
 }
 
 type blockData struct {
@@ -203,6 +204,9 @@ func genOp() {
 					log.Fatalf("faultOnNilArg1 with aux %s not allowed", v.aux)
 				}
 			}
+			if v.usesScratch {
+				fmt.Fprintln(w, "usesScratch: true,")
+			}
 			if a.name == "generic" {
 				fmt.Fprintln(w, "generic:true,")
 				fmt.Fprintln(w, "},") // close op
@@ -262,6 +266,8 @@ func genOp() {
 	// generate op string method
 	fmt.Fprintln(w, "func (o Op) String() string {return opcodeTable[o].name }")
 
+	fmt.Fprintln(w, "func (o Op) UsesScratch() bool { return opcodeTable[o].usesScratch }")
+
 	// generate registers
 	for _, a := range archs {
 		if a.generic {

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

@@ -33,6 +33,7 @@ type opInfo struct {
 	nilCheck          bool // this op is a nil check on arg0
 	faultOnNilArg0    bool // this op will fault if arg0 is nil (and aux encodes a small offset)
 	faultOnNilArg1    bool // this op will fault if arg1 is nil (and aux encodes a small offset)
+	usesScratch       bool // this op requires scratch memory space
 }
 
 type inputInfo struct {

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

@@ -1731,6 +1731,7 @@ var opcodeTable = [...]opInfo{
 		argLen:       2,
 		commutative:  true,
 		resultInArg0: true,
+		usesScratch:  true,
 		asm:          x86.AADDSS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -1762,6 +1763,7 @@ var opcodeTable = [...]opInfo{
 		name:         "SUBSS",
 		argLen:       2,
 		resultInArg0: true,
+		usesScratch:  true,
 		asm:          x86.ASUBSS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -1793,6 +1795,7 @@ var opcodeTable = [...]opInfo{
 		argLen:       2,
 		commutative:  true,
 		resultInArg0: true,
+		usesScratch:  true,
 		asm:          x86.AMULSS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -1824,6 +1827,7 @@ var opcodeTable = [...]opInfo{
 		name:         "DIVSS",
 		argLen:       2,
 		resultInArg0: true,
+		usesScratch:  true,
 		asm:          x86.ADIVSS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -2676,6 +2680,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "UCOMISS",
 		argLen:      2,
+		usesScratch: true,
 		asm:         x86.AUCOMISS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -2687,6 +2692,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "UCOMISD",
 		argLen:      2,
+		usesScratch: true,
 		asm:         x86.AUCOMISD,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -3388,6 +3394,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "CVTTSD2SL",
 		argLen:      1,
+		usesScratch: true,
 		asm:         x86.ACVTTSD2SL,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -3401,6 +3408,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "CVTTSS2SL",
 		argLen:      1,
+		usesScratch: true,
 		asm:         x86.ACVTTSS2SL,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -3414,6 +3422,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "CVTSL2SS",
 		argLen:      1,
+		usesScratch: true,
 		asm:         x86.ACVTSL2SS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -3427,6 +3436,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "CVTSL2SD",
 		argLen:      1,
+		usesScratch: true,
 		asm:         x86.ACVTSL2SD,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -3440,6 +3450,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "CVTSD2SS",
 		argLen:      1,
+		usesScratch: true,
 		asm:         x86.ACVTSD2SS,
 		reg: regInfo{
 			inputs: []inputInfo{
@@ -14428,6 +14439,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "Xf2i64",
 		argLen:      1,
+		usesScratch: true,
 		reg: regInfo{
 			inputs: []inputInfo{
 				{0, 576460743713488896}, // F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26
@@ -14440,6 +14452,7 @@ var opcodeTable = [...]opInfo{
 	{
 		name:        "Xi2f64",
 		argLen:      1,
+		usesScratch: true,
 		reg: regInfo{
 			inputs: []inputInfo{
 				{0, 1073733624}, // R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29
@@ -19430,6 +19443,7 @@ var opcodeTable = [...]opInfo{
 
 func (o Op) Asm() obj.As       { return opcodeTable[o].asm }
 func (o Op) String() string    { return opcodeTable[o].name }
+func (o Op) UsesScratch() bool { return opcodeTable[o].usesScratch }
 
 var registers386 = [...]Register{
 	{0, x86.REG_AX, "AX"},