[stubs] StringToNumberStub --> StringToNumber builtin.

src/mips/builtins-mips.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_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 2747 matching lines @@
   //  -- a0 : requested object size (untagged)
   //  -- ra : return address
   // -----------------------------------
   __ SmiTag(a0);
   __ Move(a1, Smi::FromInt(AllocateTargetSpace::encode(OLD_SPACE)));
   __ Push(a0, a1);
   __ Move(cp, Smi::FromInt(0));
   __ TailCallRuntime(Runtime::kAllocateInTargetSpace);
 }
 
+// static
+void Builtins::Generate_StringToNumber(MacroAssembler* masm) {
+  // The StringToNumber stub takes on argument in a0.
+  __ AssertString(a0);
+
+  // Check if string has a cached array index.
+  Label runtime;
+  __ lw(a2, FieldMemOperand(a0, String::kHashFieldOffset));
+  __ And(at, a2, Operand(String::kContainsCachedArrayIndexMask));
+  __ Branch(&runtime, ne, at, Operand(zero_reg));
+  __ IndexFromHash(a2, v0);
+  __ Ret();
+
+  __ bind(&runtime);
+  __ Push(a0);  // Push argument.
+  __ TailCallRuntime(Runtime::kStringToNumber);
+}
+
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // State setup as expected by MacroAssembler::InvokePrologue.
   // ----------- S t a t e -------------
   //  -- a0: actual arguments count
   //  -- a1: function (passed through to callee)
   //  -- a2: expected arguments count
   //  -- a3: new target (passed through to callee)
   // -----------------------------------
 
   Label invoke, dont_adapt_arguments, stack_overflow;
@@ skipping 118 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS