Add signed/unsigned 8-bit and 16-bit Representations

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 a18ff0d274c75e14eac2701a06f5d93e1cf5e8af..1fcef2312ef3c2b8c0ce20a65fb6cfbb56c15fba 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -950,8 +950,14 @@ void MacroAssembler::Cvtlsi2sd(XMMRegister dst, const Operand& src) {
 
 void MacroAssembler::Load(Register dst, const Operand& src, Representation r) {
   ASSERT(!r.IsDouble());
-  if (r.IsByte()) {
+  if (r.IsInteger8()) {
+    movsxbq(dst, src);
+  } else if (r.IsUInteger8()) {
     movzxbl(dst, src);
+  } else if (r.IsInteger16()) {
+    movsxwq(dst, src);
+  } else if (r.IsUInteger16()) {
+    movzxwl(dst, src);
   } else if (r.IsInteger32()) {
     movl(dst, src);
   } else {
@@ -962,8 +968,10 @@ void MacroAssembler::Load(Register dst, const Operand& src, Representation r) {
 
 void MacroAssembler::Store(const Operand& dst, Register src, Representation r) {
   ASSERT(!r.IsDouble());
-  if (r.IsByte()) {
+  if (r.IsInteger8() || r.IsUInteger8()) {
     movb(dst, src);
+  } else if (r.IsInteger16() || r.IsUInteger16()) {
+    movw(dst, src);
   } else if (r.IsInteger32()) {
     movl(dst, src);
   } else {