[runtime] Add %ToString and %_ToString and remove the TO_STRING builtin.

src/arm/code-stubs-arm.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_ARM
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 3214 matching lines @@
 }
 
 
 void ToNumberStub::Generate(MacroAssembler* masm) {
   // The ToNumber stub takes one argument in r0.
   Label not_smi;
   __ JumpIfNotSmi(r0, &not_smi);
   __ Ret();
   __ bind(&not_smi);
 
-  Label not_heap_number;
-  __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
-  __ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
-  // r0: object
-  // r1: instance type.
-  __ cmp(r1, Operand(HEAP_NUMBER_TYPE));
-  __ b(ne, &not_heap_number);
-  __ Ret();
-  __ bind(&not_heap_number);
+  __ CompareObjectType(r0, r1, r1, HEAP_NUMBER_TYPE);
+  // r0: receiver
+  // r1: receiver instance type
+  __ Ret(eq);
 
   Label not_string, slow_string;
   __ cmp(r1, Operand(FIRST_NONSTRING_TYPE));
   __ b(hs, &not_string);
   // Check if string has a cached array index.
   __ ldr(r2, FieldMemOperand(r0, String::kHashFieldOffset));
   __ tst(r2, Operand(String::kContainsCachedArrayIndexMask));
   __ b(ne, &slow_string);
   __ IndexFromHash(r2, r0);
   __ Ret();
   __ bind(&slow_string);
   __ push(r0);  // Push argument.
   __ TailCallRuntime(Runtime::kStringToNumber, 1, 1);
   __ bind(&not_string);
 
   Label not_oddball;
   __ cmp(r1, Operand(ODDBALL_TYPE));
   __ b(ne, &not_oddball);
   __ ldr(r0, FieldMemOperand(r0, Oddball::kToNumberOffset));
   __ Ret();
   __ bind(&not_oddball);
 
   __ push(r0);  // Push argument.
   __ TailCallRuntime(Runtime::kToNumber, 1, 1);
 }
 
 
+void ToStringStub::Generate(MacroAssembler* masm) {
+  // The ToString stub takes one argument in r0.
+  Label is_number;
+  __ JumpIfSmi(r0, &is_number);
+
+  __ CompareObjectType(r0, r1, r1, FIRST_NONSTRING_TYPE);
+  // r0: receiver
+  // r1: receiver instance type
+  __ Ret(lo);
+
+  Label not_heap_number;
+  __ cmp(r1, Operand(HEAP_NUMBER_TYPE));
+  __ b(ne, &not_heap_number);
+  __ bind(&is_number);
+  NumberToStringStub stub(isolate());
+  __ TailCallStub(&stub);
+  __ bind(&not_heap_number);
+
+  Label not_oddball;
+  __ cmp(r1, Operand(ODDBALL_TYPE));
+  __ b(ne, &not_oddball);
+  __ ldr(r0, FieldMemOperand(r0, Oddball::kToStringOffset));
+  __ Ret();
+  __ bind(&not_oddball);
+
+  __ push(r0);  // Push argument.
+  __ TailCallRuntime(Runtime::kToString, 1, 1);
+}
+
+
 void StringHelper::GenerateFlatOneByteStringEquals(
     MacroAssembler* masm, Register left, Register right, Register scratch1,
     Register scratch2, Register scratch3) {
   Register length = scratch1;
 
   // Compare lengths.
   Label strings_not_equal, check_zero_length;
   __ ldr(length, FieldMemOperand(left, String::kLengthOffset));
   __ ldr(scratch2, FieldMemOperand(right, String::kLengthOffset));
   __ cmp(length, scratch2);
@@ skipping 2149 matching lines @@
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM