[x64] Emit vmovss when AVX is enabled.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index eaf0f9fddc0d84b47948b4b6d1932c35900d8b62..ef3d1554da7f151fb91f119b3e923e228e022912 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -2569,6 +2569,26 @@ void MacroAssembler::Movsd(const Operand& dst, XMMRegister src) {
 }
 
 
+void MacroAssembler::Movss(XMMRegister dst, const Operand& src) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vmovss(dst, src);
+  } else {
+    movss(dst, src);
+  }
+}
+
+
+void MacroAssembler::Movss(const Operand& dst, XMMRegister src) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vmovss(dst, src);
+  } else {
+    movss(dst, src);
+  }
+}
+
+
 void MacroAssembler::Movd(XMMRegister dst, Register src) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope scope(this, AVX);