X64 Crankshaft: Implement LValueOf and (dummy) LArgumentsObject.

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 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 911 matching lines @@
 
 
 void LCodeGen::DoPixelArrayLength(LPixelArrayLength* instr) {
   Register result = ToRegister(instr->result());
   Register array = ToRegister(instr->InputAt(0));
   __ movq(result, FieldOperand(array, PixelArray::kLengthOffset));
 }
 
 
 void LCodeGen::DoValueOf(LValueOf* instr) {
-  Abort("Unimplemented: %s", "DoValueOf");
+  Register input = ToRegister(instr->InputAt(0));
+  Register result = ToRegister(instr->result());
+  ASSERT(input.is(result));
+  NearLabel done;
+  // If the object is a smi return the object.
+  __ JumpIfSmi(input, &done);
+
+  // If the object is not a value type, return the object.
+  __ CmpObjectType(input, JS_VALUE_TYPE, kScratchRegister);
+  __ j(not_equal, &done);
+  __ movq(result, FieldOperand(input, JSValue::kValueOffset));
+
+  __ bind(&done);
 }
 
 
 void LCodeGen::DoBitNotI(LBitNotI* instr) {
   LOperand* input = instr->InputAt(0);
   ASSERT(input->Equals(instr->result()));
   __ not_(ToRegister(input));
 }
 
 
@@ skipping 1900 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64