[stubs] Split ToNumberStub into reusable subparts.

src/x64/code-stubs-x64.cc

 // Copyright 2013 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-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 2554 matching lines @@
   __ Ret();
   __ bind(&not_smi);
 
   Label not_heap_number;
   __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
                  Heap::kHeapNumberMapRootIndex);
   __ j(not_equal, &not_heap_number, Label::kNear);
   __ Ret();
   __ bind(&not_heap_number);
 
-  Label not_string, slow_string;
+  NonNumberToNumberStub stub(masm->isolate());
+  __ TailCallStub(&stub);
+}
+
+void NonNumberToNumberStub::Generate(MacroAssembler* masm) {
+  // The NonNumberToNumber stub takes one argument in rax.
+  __ AssertNotNumber(rax);
+
+  Label not_string;
   __ CmpObjectType(rax, FIRST_NONSTRING_TYPE, rdi);
   // rax: object
   // rdi: object map
   __ j(above_equal, &not_string, Label::kNear);
-  // Check if string has a cached array index.
-  __ testl(FieldOperand(rax, String::kHashFieldOffset),
-           Immediate(String::kContainsCachedArrayIndexMask));
-  __ j(not_zero, &slow_string, Label::kNear);
-  __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
-  __ IndexFromHash(rax, rax);
-  __ Ret();
-  __ bind(&slow_string);
-  __ PopReturnAddressTo(rcx);     // Pop return address.
-  __ Push(rax);                   // Push argument.
-  __ PushReturnAddressFrom(rcx);  // Push return address.
-  __ TailCallRuntime(Runtime::kStringToNumber);
+  StringToNumberStub stub(masm->isolate());
+  __ TailCallStub(&stub);
   __ bind(&not_string);
 
   Label not_oddball;
   __ CmpInstanceType(rdi, ODDBALL_TYPE);
   __ j(not_equal, &not_oddball, Label::kNear);
   __ movp(rax, FieldOperand(rax, Oddball::kToNumberOffset));
   __ Ret();
   __ bind(&not_oddball);
 
   __ PopReturnAddressTo(rcx);     // Pop return address.
   __ Push(rax);                   // Push argument.
   __ PushReturnAddressFrom(rcx);  // Push return address.
   __ TailCallRuntime(Runtime::kToNumber);
 }
 
+void StringToNumberStub::Generate(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 ToLengthStub::Generate(MacroAssembler* masm) {
   // The ToLength stub takes on argument in rax.
   Label not_smi, positive_smi;
   __ JumpIfNotSmi(rax, &not_smi, Label::kNear);
   STATIC_ASSERT(kSmiTag == 0);
   __ testp(rax, rax);
   __ j(greater_equal, &positive_smi, Label::kNear);
   __ xorl(rax, rax);
   __ bind(&positive_smi);
@@ skipping 2972 matching lines @@
                            NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64