[x64] simply tweak materialization of float/double constants

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 6e44253ed5218d40cd45395fff2ec337380a89ad..7965e771f7d7d5d5c7cd05f9568774cdc727e364 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -2614,6 +2614,7 @@ void Assembler::movss(const Operand& src, XMMRegister dst) {
 void Assembler::psllq(XMMRegister reg, byte imm8) {
   EnsureSpace ensure_space(this);
   emit(0x66);
+  emit_optional_rex_32(reg);
   emit(0x0F);
   emit(0x73);
   emit_sse_operand(rsi, reg);  // rsi == 6
@@ -2621,6 +2622,39 @@ void Assembler::psllq(XMMRegister reg, byte imm8) {
 }
 
 
+void Assembler::psrlq(XMMRegister reg, byte imm8) {
+  EnsureSpace ensure_space(this);
+  emit(0x66);
+  emit_optional_rex_32(reg);
+  emit(0x0F);
+  emit(0x73);
+  emit_sse_operand(rdx, reg);  // rdx == 2
+  emit(imm8);
+}
+
+
+void Assembler::pslld(XMMRegister reg, byte imm8) {
+  EnsureSpace ensure_space(this);
+  emit(0x66);
+  emit_optional_rex_32(reg);
+  emit(0x0F);
+  emit(0x72);
+  emit_sse_operand(rsi, reg);  // rsi == 6
+  emit(imm8);
+}
+
+
+void Assembler::psrld(XMMRegister reg, byte imm8) {
+  EnsureSpace ensure_space(this);
+  emit(0x66);
+  emit_optional_rex_32(reg);
+  emit(0x0F);
+  emit(0x72);
+  emit_sse_operand(rdx, reg);  // rdx == 2
+  emit(imm8);
+}
+
+
 void Assembler::cvttss2si(Register dst, const Operand& src) {
   EnsureSpace ensure_space(this);
   emit(0xF3);
@@ -2966,6 +3000,16 @@ void Assembler::movmskps(Register dst, XMMRegister src) {
 }
 
 
+void Assembler::pcmpeqd(XMMRegister dst, XMMRegister src) {
+  EnsureSpace ensure_space(this);
+  emit(0x66);
+  emit_optional_rex_32(dst, src);
+  emit(0x0F);
+  emit(0x76);
+  emit_sse_operand(dst, src);
+}
+
+
 void Assembler::emit_sse_operand(XMMRegister reg, const Operand& adr) {
   Register ireg = { reg.code() };
   emit_operand(ireg, adr);