Add support to load/store byte fields.

src/x64/lithium-x64.cc

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@@ skipping 2039 matching lines @@
     context = UseRegister(instr->context());
     value = UseRegister(instr->value());
     temp = NULL;
   }
   LInstruction* result = new(zone()) LStoreContextSlot(context, value, temp);
   return instr->RequiresHoleCheck() ? AssignEnvironment(result) : result;
 }
 
 
 LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
-  if (instr->access().IsExternalMemory() && instr->access().offset() == 0) {
+  if (instr->access().IsExternalMemory() &&
+      !instr->access().representation().IsSpecialization() &&

[mvstanton, 2013/10/02 11:13:12]

Could you add a comment to summarize this decision?

[Benedikt Meurer, 2013/10/02 11:48:06]

Done.

+      instr->access().offset() == 0) {
     LOperand* obj = UseRegisterOrConstantAtStart(instr->object());
     return DefineFixed(new(zone()) LLoadNamedField(obj), rax);
   }
   LOperand* obj = UseRegisterAtStart(instr->object());
   return DefineAsRegister(new(zone()) LLoadNamedField(obj));
 }
 
 
 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
   LOperand* object = UseFixed(instr->object(), rax);
@@ skipping 464 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64