Add initial hydrogenized NewStringAddStub.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4011 matching lines @@
   if (!access.IsInobject()) {
     write_register = ToRegister(instr->temp());
     __ movq(write_register, FieldOperand(object, JSObject::kPropertiesOffset));
   }
 
   if (instr->value()->IsConstantOperand()) {
     LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
     if (operand_value->IsRegister()) {
       Register value = ToRegister(operand_value);
       __ Store(FieldOperand(write_register, offset), value, representation);
+    } else if (representation.IsInteger32()) {
+      int32_t value = ToInteger32(operand_value);
+      ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
+      __ movl(FieldOperand(write_register, offset), Immediate(value));
     } else {
       Handle<Object> handle_value = ToHandle(operand_value);
       ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
       __ Move(FieldOperand(write_register, offset), handle_value);
     }
   } else {
     Register value = ToRegister(instr->value());
     __ Store(FieldOperand(write_register, offset), value, representation);
   }
 
@@ skipping 299 matching lines @@
   Register object = ToRegister(instr->object());
   Register temp = ToRegister(instr->temp());
   Label no_memento_found;
   __ TestJSArrayForAllocationMemento(object, temp, &no_memento_found);
   DeoptimizeIf(equal, instr->environment());
   __ bind(&no_memento_found);
 }
 
 
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
-  EmitPushTaggedOperand(instr->left());
-  EmitPushTaggedOperand(instr->right());
-  StringAddStub stub(instr->hydrogen()->flags());
-  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
+  if (FLAG_new_string_add) {
+    ASSERT(ToRegister(instr->left()).is(rdx));
+    ASSERT(ToRegister(instr->right()).is(rax));
+    NewStringAddStub stub(instr->hydrogen()->flags(),
+                          isolate()->heap()->GetPretenureMode());
+    CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
+  } else {
+    EmitPushTaggedOperand(instr->left());
+    EmitPushTaggedOperand(instr->right());
+    StringAddStub stub(instr->hydrogen()->flags());
+    CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
+  }
 }
 
 
 void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
   class DeferredStringCharCodeAt V8_FINAL : public LDeferredCode {
    public:
     DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() V8_OVERRIDE {
       codegen()->DoDeferredStringCharCodeAt(instr_);
@@ skipping 1181 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64