Revert "Turn the NumberToStringStub into a hydrogen stub."

src/x64/code-stubs-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 42 matching lines @@
 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 NumberToStringStub::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) {
   static Register registers[] = { rax, rbx, rcx };
   descriptor->register_param_count_ = 3;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(Runtime::kCreateArrayLiteralShallow)->entry;
 }
 
@@ skipping 2829 matching lines @@
   __ jmp(&loop);
 
   __ bind(&done);
   __ ret(3 * kPointerSize);
 
   __ bind(&slowcase);
   __ TailCallRuntime(Runtime::kRegExpConstructResult, 3, 1);
 }
 
 
+void NumberToStringStub::Generate(MacroAssembler* masm) {
+  Label runtime;
+
+  StackArgumentsAccessor args(rsp, 1, ARGUMENTS_DONT_CONTAIN_RECEIVER);
+  __ movq(rbx, args.GetArgumentOperand(0));
+
+  // Generate code to lookup number in the number string cache.
+  __ LookupNumberStringCache(rbx, rax, r8, r9, &runtime);
+  __ ret(1 * kPointerSize);
+
+  __ bind(&runtime);
+  // Handle number to string in the runtime system if not found in the cache.
+  __ TailCallRuntime(Runtime::kNumberToStringSkipCache, 1, 1);
+}
+
+
 static int NegativeComparisonResult(Condition cc) {
   ASSERT(cc != equal);
   ASSERT((cc == less) || (cc == less_equal)
       || (cc == greater) || (cc == greater_equal));
   return (cc == greater || cc == greater_equal) ? LESS : GREATER;
 }
 
 
 static void CheckInputType(MacroAssembler* masm,
                            Register input,
@@ skipping 3608 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64