[x64] Emit vcvtss2sd & vcvtsd2ss when AVX is enabled.

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 4d9a6bf03c2b40a448cf21609580ba72672a7267..00f6ae1ccb838f4eaa3b7a01506c354c333950d0 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -3131,6 +3131,7 @@ void Assembler::cvtqsi2sd(XMMRegister dst, Register src) {
 
 
 void Assembler::cvtss2sd(XMMRegister dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF3);
   emit_optional_rex_32(dst, src);
@@ -3141,6 +3142,7 @@ void Assembler::cvtss2sd(XMMRegister dst, XMMRegister src) {
 
 
 void Assembler::cvtss2sd(XMMRegister dst, const Operand& src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF3);
   emit_optional_rex_32(dst, src);
@@ -3151,6 +3153,7 @@ void Assembler::cvtss2sd(XMMRegister dst, const Operand& src) {
 
 
 void Assembler::cvtsd2ss(XMMRegister dst, XMMRegister src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF2);
   emit_optional_rex_32(dst, src);
@@ -3161,6 +3164,7 @@ void Assembler::cvtsd2ss(XMMRegister dst, XMMRegister src) {
 
 
 void Assembler::cvtsd2ss(XMMRegister dst, const Operand& src) {
+  DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
   emit(0xF2);
   emit_optional_rex_32(dst, src);