Ported ia32 optimization of revision 3487 to x64.

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index 1b6874e9a5f857beb3f50c23388fe980b56a9c8c..8078a94c3a6ae0ab97423589d794d31f1251305f 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -2508,6 +2508,38 @@ void Assembler::divsd(XMMRegister dst, XMMRegister src) {
 }
 
 
+void Assembler::xorpd(XMMRegister dst, XMMRegister src) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  emit(0x66);
+  emit_optional_rex_32(dst, src);
+  emit(0x0f);
+  emit(0x57);
+  emit_sse_operand(dst, src);
+}
+
+
+void Assembler::comisd(XMMRegister dst, XMMRegister src) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  emit(0x66);
+  emit_optional_rex_32(dst, src);
+  emit(0x0f);
+  emit(0x2f);
+  emit_sse_operand(dst, src);
+}
+
+
+void Assembler::ucomisd(XMMRegister dst, XMMRegister src) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  emit(0x66);
+  emit_optional_rex_32(dst, src);
+  emit(0x0f);
+  emit(0x2e);
+  emit_sse_operand(dst, src);
+}
+
 
 void Assembler::emit_sse_operand(XMMRegister reg, const Operand& adr) {
   Register ireg = { reg.code() };