[stubs] StringToNumberStub --> StringToNumber builtin.

src/x64/builtins-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 2058 matching lines @@
   // -----------------------------------
   __ Integer32ToSmi(rdx, rdx);
   __ PopReturnAddressTo(rcx);
   __ Push(rdx);
   __ Push(Smi::FromInt(AllocateTargetSpace::encode(OLD_SPACE)));
   __ PushReturnAddressFrom(rcx);
   __ Move(rsi, Smi::FromInt(0));
   __ TailCallRuntime(Runtime::kAllocateInTargetSpace);
 }
 
+void Builtins::Generate_StringToNumber(MacroAssembler* masm) {
+  // The StringToNumber stub takes one argument in rax.
+  __ AssertString(rax);
+
+  // Check if string has a cached array index.
+  Label runtime;
+  __ testl(FieldOperand(rax, String::kHashFieldOffset),
+           Immediate(String::kContainsCachedArrayIndexMask));
+  __ j(not_zero, &runtime, Label::kNear);
+  __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
+  __ IndexFromHash(rax, rax);
+  __ Ret();
+
+  __ bind(&runtime);
+  __ PopReturnAddressTo(rcx);     // Pop return address.
+  __ Push(rax);                   // Push argument.
+  __ PushReturnAddressFrom(rcx);  // Push return address.
+  __ TailCallRuntime(Runtime::kStringToNumber);
+}
+
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax : actual number of arguments
   //  -- rbx : expected number of arguments
   //  -- rdx : new target (passed through to callee)
   //  -- rdi : function (passed through to callee)
   // -----------------------------------
 
   Label invoke, dont_adapt_arguments, stack_overflow;
   Counters* counters = masm->isolate()->counters();
@@ skipping 872 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64