[dev.ssa] cmd/compile: implement ONOT

Co-hacking with josharian at Gophercon.

Change-Id: Ia59dfab676c6ed598c2c25483439cd1395a4ea87
Reviewed-on: https://go-review.googlesource.com/12029
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -496,6 +496,11 @@ func (s *state) expr(n *Node) *ssa.Value {
 		b := s.expr(n.Right)
 		return s.newValue2(binOpToSSA[n.Op], a.Type, a, b)
 
+	// unary ops
+	case ONOT:
+		a := s.expr(n.Left)
+		return s.newValue1(ssa.OpNot, a.Type, a)
+
 	case OADDR:
 		return s.addr(n.Left)
 
@@ -1185,6 +1190,12 @@ func genValue(v *ssa.Value) {
 		p := Prog(obj.ACALL)
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = regnum(v.Args[0])
+	case ssa.OpAMD64XORQconst:
+		p := Prog(x86.AXORQ)
+		p.From.Type = obj.TYPE_CONST
+		p.From.Offset = v.AuxInt
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = regnum(v.Args[0])
 	case ssa.OpSP, ssa.OpSB:
 		// nothing to do
 	default:

src/cmd/compile/internal/ssa/gen/AMD64.rules

@@ -62,6 +62,7 @@
 (Store ptr val mem) && is32BitInt(val.Type) -> (MOVLstore ptr val mem)
 (Store ptr val mem) && is16BitInt(val.Type) -> (MOVWstore ptr val mem)
 (Store ptr val mem) && is8BitInt(val.Type) -> (MOVBstore ptr val mem)
+(Store ptr val mem) && val.Type.IsBoolean() -> (MOVBstore ptr val mem)
 
 // checks
 (IsNonNil p) -> (SETNE (TESTQ <TypeFlags> p p))
@@ -69,6 +70,8 @@
 
 (Move [size] dst src mem) -> (REPMOVSB dst src (Const <TypeUInt64> [size]) mem)
 
+(Not x) -> (XORQconst [1] x)
+
 (OffPtr [off] ptr) -> (ADDQconst [off] ptr)
 
 (Const <t> [val]) && t.IsInteger() -> (MOVQconst [val])

src/cmd/compile/internal/ssa/gen/AMD64Ops.go

@@ -111,7 +111,8 @@ func init() {
 		{name: "SARQ", reg: gp21shift, asm: "SARQ"},  // signed arg0 >> arg1, shift amount is mod 64
 		{name: "SARQconst", reg: gp11, asm: "SARQ"},  // signed arg0 >> auxint, shift amount 0-63
 
-		{name: "NEGQ", reg: gp11}, // -arg0
+		{name: "NEGQ", reg: gp11},                   // -arg0
+		{name: "XORQconst", reg: gp11, asm: "XORQ"}, // arg0^auxint
 
 		{name: "CMPQ", reg: gp2flags, asm: "CMPQ"},      // arg0 compare to arg1
 		{name: "CMPQconst", reg: gp1flags, asm: "CMPQ"}, // arg0 compare to auxint

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

@@ -22,6 +22,9 @@ var genericOps = []opData{
 	{name: "Greater"}, // arg0 > arg1
 	{name: "Geq"},     // arg0 <= arg1
 
+	// 1-input ops
+	{name: "Not"}, // !arg0
+
 	// Data movement
 	{name: "Phi"},  // select an argument based on which predecessor block we came from
 	{name: "Copy"}, // output = arg0

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

@@ -66,6 +66,7 @@ const (
 	OpAMD64SARQ
 	OpAMD64SARQconst
 	OpAMD64NEGQ
+	OpAMD64XORQconst
 	OpAMD64CMPQ
 	OpAMD64CMPQconst
 	OpAMD64TESTQ
@@ -123,6 +124,7 @@ const (
 	OpLeq
 	OpGreater
 	OpGeq
+	OpNot
 	OpPhi
 	OpCopy
 	OpConst
@@ -358,6 +360,19 @@ var opcodeTable = [...]opInfo{
 			},
 		},
 	},
+	{
+		name: "XORQconst",
+		asm:  x86.AXORQ,
+		reg: regInfo{
+			inputs: []regMask{
+				65535, // .AX .CX .DX .BX .SP .BP .SI .DI .R8 .R9 .R10 .R11 .R12 .R13 .R14 .R15
+			},
+			clobbers: 0,
+			outputs: []regMask{
+				65519, // .AX .CX .DX .BX .BP .SI .DI .R8 .R9 .R10 .R11 .R12 .R13 .R14 .R15
+			},
+		},
+	},
 	{
 		name: "CMPQ",
 		asm:  x86.ACMPQ,
@@ -1019,6 +1034,15 @@ var opcodeTable = [...]opInfo{
 		},
 		generic: true,
 	},
+	{
+		name: "Not",
+		reg: regInfo{
+			inputs:   []regMask{},
+			clobbers: 0,
+			outputs:  []regMask{},
+		},
+		generic: true,
+	},
 	{
 		name: "Phi",
 		reg: regInfo{

src/cmd/compile/internal/ssa/rewriteAMD64.go

@@ -1237,6 +1237,23 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto enddccbd4e7581ae8d9916b933d3501987b
 	enddccbd4e7581ae8d9916b933d3501987b:
 		;
+	case OpNot:
+		// match: (Not x)
+		// cond:
+		// result: (XORQconst [1] x)
+		{
+			x := v.Args[0]
+			v.Op = OpAMD64XORQconst
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AuxInt = 1
+			v.AddArg(x)
+			return true
+		}
+		goto endaabd7f5e27417cf3182cd5e4f4360410
+	endaabd7f5e27417cf3182cd5e4f4360410:
+		;
 	case OpOffPtr:
 		// match: (OffPtr [off] ptr)
 		// cond:
@@ -1626,6 +1643,28 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
 		goto ende2dee0bc82f631e3c6b0031bf8d224c1
 	ende2dee0bc82f631e3c6b0031bf8d224c1:
 		;
+		// match: (Store ptr val mem)
+		// cond: val.Type.IsBoolean()
+		// result: (MOVBstore ptr val mem)
+		{
+			ptr := v.Args[0]
+			val := v.Args[1]
+			mem := v.Args[2]
+			if !(val.Type.IsBoolean()) {
+				goto end6f343b676bf49740054e459f972b24f5
+			}
+			v.Op = OpAMD64MOVBstore
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.AddArg(ptr)
+			v.AddArg(val)
+			v.AddArg(mem)
+			return true
+		}
+		goto end6f343b676bf49740054e459f972b24f5
+	end6f343b676bf49740054e459f972b24f5:
+		;
 	case OpSub:
 		// match: (Sub <t> x y)
 		// cond: is64BitInt(t)