X64 Crankshaft: Implement LValueOf and (dummy) LArgumentsObject.

Review URL: http://codereview.chromium.org/6542011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6850 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -1918,8 +1918,10 @@ LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
 
 
 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
-  // There are no real uses of the arguments object (we bail out in all other
-  // cases).
+  // There are no real uses of the arguments object.
+  // arguments.length and element access are supported directly on
+  // stack arguments, and any real arguments object use causes a bailout.
+  // So this value is never used.
   return NULL;
 }
 

src/ia32/lithium-ia32.cc

@@ -1974,8 +1974,10 @@ LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
 
 
 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
-  // There are no real uses of the arguments object (we bail out in all other
-  // cases).
+  // There are no real uses of the arguments object.
+  // arguments.length and element access are supported directly on
+  // stack arguments, and any real arguments object use causes a bailout.
+  // So this value is never used.
   return NULL;
 }
 

src/x64/lithium-codegen-x64.cc

@@ -929,7 +929,19 @@ void LCodeGen::DoPixelArrayLength(LPixelArrayLength* instr) {
 
 
 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);
 }
 
 

src/x64/lithium-x64.cc

@@ -1465,8 +1465,9 @@ LInstruction* LChunkBuilder::DoPixelArrayLength(HPixelArrayLength* instr) {
 
 
 LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) {
-  Abort("Unimplemented: %s", "DoValueOf");
-  return NULL;
+  LOperand* object = UseRegister(instr->value());
+  LValueOf* result = new LValueOf(object);
+  return AssignEnvironment(DefineSameAsFirst(result));
 }
 
 
@@ -1830,7 +1831,10 @@ LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
 
 
 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
-  Abort("Unimplemented: %s", "DoArgumentsObject");
+  // There are no real uses of the arguments object.
+  // arguments.length and element access are supported directly on
+  // stack arguments, and any real arguments object use causes a bailout.
+  // So this value is never used.
   return NULL;
 }
 

src/x64/lithium-x64.h

@@ -1005,11 +1005,10 @@ class LFixedArrayLength: public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LValueOf: public LTemplateInstruction<1, 1, 1> {
+class LValueOf: public LTemplateInstruction<1, 1, 0> {
  public:
-  LValueOf(LOperand* value, LOperand* temp) {
+  explicit LValueOf(LOperand* value) {
     inputs_[0] = value;
-    temps_[0] = temp;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(ValueOf, "value-of")