[dev.ssa] cmd/compile/internal/ssa/gen: implement OXOR.

From compiling go there were 260 functions where XOR was needed.

Much of the required changes for implementing XOR were already
done in 12813.

Change-Id: I5a68aa028f5ed597bc1d62cedbef3620753dfe82
Reviewed-on: https://go-review.googlesource.com/12901Reviewed-by: Keith Randall <khr@golang.org>

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

@@ -763,6 +763,15 @@ var opToSSA = map[opAndType]ssa.Op{
 	opAndType{OOR, TINT64}:  ssa.OpOr64,
 	opAndType{OOR, TUINT64}: ssa.OpOr64,
 
+	opAndType{OXOR, TINT8}:   ssa.OpXor8,
+	opAndType{OXOR, TUINT8}:  ssa.OpXor8,
+	opAndType{OXOR, TINT16}:  ssa.OpXor16,
+	opAndType{OXOR, TUINT16}: ssa.OpXor16,
+	opAndType{OXOR, TINT32}:  ssa.OpXor32,
+	opAndType{OXOR, TUINT32}: ssa.OpXor32,
+	opAndType{OXOR, TINT64}:  ssa.OpXor64,
+	opAndType{OXOR, TUINT64}: ssa.OpXor64,
+
 	opAndType{OEQ, TBOOL}:      ssa.OpEq8,
 	opAndType{OEQ, TINT8}:      ssa.OpEq8,
 	opAndType{OEQ, TUINT8}:     ssa.OpEq8,
@@ -1123,7 +1132,7 @@ func (s *state) expr(n *Node) *ssa.Value {
 		a := s.expr(n.Left)
 		b := s.expr(n.Right)
 		return s.newValue2(s.ssaOp(n.Op, n.Left.Type), ssa.TypeBool, a, b)
-	case OADD, OSUB, OMUL, OAND, OOR:
+	case OADD, OAND, OMUL, OOR, OSUB, OXOR:
 		a := s.expr(n.Left)
 		b := s.expr(n.Right)
 		return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)

src/cmd/compile/internal/gc/testdata/arith_ssa.go

@@ -57,9 +57,15 @@ func testBitwiseLogic() {
 	a, b := uint32(57623283), uint32(1314713839)
 	if want, got := uint32(38551779), testBitwiseAnd_ssa(a, b); want != got {
 		println("testBitwiseAnd failed, wanted", want, "got", got)
+		failed = true
 	}
 	if want, got := uint32(1333785343), testBitwiseOr_ssa(a, b); want != got {
-		println("testBitwiseAnd failed, wanted", want, "got", got)
+		println("testBitwiseOr failed, wanted", want, "got", got)
+		failed = true
+	}
+	if want, got := uint32(1295233564), testBitwiseXor_ssa(a, b); want != got {
+		println("testBitwiseXor failed, wanted", want, "got", got)
+		failed = true
 	}
 }
 
@@ -75,6 +81,12 @@ func testBitwiseOr_ssa(a, b uint32) uint32 {
 	return a | b
 }
 
+func testBitwiseXor_ssa(a, b uint32) uint32 {
+	switch { // prevent inlining
+	}
+	return a ^ b
+}
+
 // testSubqToNegq ensures that the SUBQ -> NEGQ translation works correctly.
 func testSubqToNegq(a, b, c, d, e, f, g, h, i, j, k int64) {
 	want := a + 8207351403619448057 - b - 1779494519303207690 + c*8810076340510052032*d - 4465874067674546219 - e*4361839741470334295 - f + 8688847565426072650*g*8065564729145417479
@@ -83,6 +95,7 @@ func testSubqToNegq(a, b, c, d, e, f, g, h, i, j, k int64) {
 		failed = true
 	}
 }
+
 func testSubqToNegq_ssa(a, b, c, d, e, f, g, h, i, j, k int64) int64 {
 	switch { // prevent inlining
 	}
@@ -97,6 +110,8 @@ func main() {
 	test64BitConstAdd(1, 2)
 	testRegallocCVSpill(1, 2, 3, 4)
 	testSubqToNegq(1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2)
+	testBitwiseLogic()
+
 	if failed {
 		panic("failed")
 	}