Turn ToNumberStub into a hydrogen code stub.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 652a4db7a6b58d9a4ed08fceb900c6af14bb6611..551a71690e7a45400ec4d078ef7fcf4e89e39f0b 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -39,6 +39,16 @@ namespace v8 {
 namespace internal {
 
 
+void ToNumberStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { rax };
+  descriptor->register_param_count_ = 1;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
 void FastCloneShallowArrayStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -296,27 +306,6 @@ void HydrogenCodeStub::GenerateLightweightMiss(MacroAssembler* masm) {
 }
 
 
-void ToNumberStub::Generate(MacroAssembler* masm) {
-  // The ToNumber stub takes one argument in rax.
-  Label check_heap_number, call_builtin;
-  __ SmiTest(rax);
-  __ j(not_zero, &check_heap_number, Label::kNear);
-  __ Ret();
-
-  __ bind(&check_heap_number);
-  __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
-                 Heap::kHeapNumberMapRootIndex);
-  __ j(not_equal, &call_builtin, Label::kNear);
-  __ Ret();
-
-  __ bind(&call_builtin);
-  __ pop(rcx);  // Pop return address.
-  __ push(rax);
-  __ push(rcx);  // Push return address.
-  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
-}
-
-
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
   // Create a new closure from the given function info in new
   // space. Set the context to the current context in rsi.