[builtins] Create StringToNumber helper.

src/builtins/builtins-conversion.cc

 // Copyright 2016 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.
 
 #include "src/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/code-factory.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 92 matching lines @@
     CodeStubAssembler* assembler) {
   Generate_NonPrimitiveToPrimitive(assembler, ToPrimitiveHint::kNumber);
 }
 
 void Builtins::Generate_NonPrimitiveToPrimitive_String(
     CodeStubAssembler* assembler) {
   Generate_NonPrimitiveToPrimitive(assembler, ToPrimitiveHint::kString);
 }
 
 void Builtins::Generate_StringToNumber(CodeStubAssembler* assembler) {
-  typedef CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
   typedef TypeConversionDescriptor Descriptor;
-
-  Node* input = assembler->Parameter(Descriptor::kArgument);

[Benedikt Meurer, 2016/09/02 04:23:47]

Nit: Please leave the explicit input/context assignment lines for consistency.

-  Node* context = assembler->Parameter(Descriptor::kContext);
-
-  Label runtime(assembler);
-
-  // Check if string has a cached array index.
-  Node* hash = assembler->LoadNameHashField(input);
-  Node* bit = assembler->Word32And(
-      hash, assembler->Int32Constant(String::kContainsCachedArrayIndexMask));
-  assembler->GotoIf(assembler->Word32NotEqual(bit, assembler->Int32Constant(0)),
-                    &runtime);
-
-  assembler->Return(assembler->SmiTag(
-      assembler->BitFieldDecode<String::ArrayIndexValueBits>(hash)));
-
-  assembler->Bind(&runtime);
-  {
-    // Note: We cannot tail call to the runtime here, as js-to-wasm
-    // trampolines also use this code currently, and they declare all
-    // outgoing parameters as untagged, while we would push a tagged
-    // object here.
-    Node* result =
-        assembler->CallRuntime(Runtime::kStringToNumber, context, input);
-    assembler->Return(result);
-  }
+  assembler->Return(
+      assembler->StringToNumber(assembler->Parameter(Descriptor::kContext),
+                                assembler->Parameter(Descriptor::kArgument)));
 }
 
 // ES6 section 7.1.3 ToNumber ( argument )
 void Builtins::Generate_NonNumberToNumber(CodeStubAssembler* assembler) {
   typedef CodeStubAssembler::Label Label;
   typedef compiler::Node Node;
   typedef CodeStubAssembler::Variable Variable;
   typedef TypeConversionDescriptor Descriptor;
 
   Node* input = assembler->Parameter(Descriptor::kArgument);
@@ skipping 24 matching lines @@
         &if_inputisoddball);
     STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
     assembler->Branch(assembler->Int32GreaterThanOrEqual(
                           input_instance_type,
                           assembler->Int32Constant(FIRST_JS_RECEIVER_TYPE)),
                       &if_inputisreceiver, &if_inputisother);
 
     assembler->Bind(&if_inputisstring);
     {
       // The {input} is a String, use the fast stub to convert it to a Number.
-      // TODO(bmeurer): Consider inlining the StringToNumber logic here.
-      Callable callable = CodeFactory::StringToNumber(assembler->isolate());
-      assembler->TailCallStub(callable, context, input);
+      assembler->Return(assembler->StringToNumber(context, input));
     }
 
     assembler->Bind(&if_inputisoddball);
     {
       // The {input} is an Oddball, we just need to the Number value of it.
       Node* result =
           assembler->LoadObjectField(input, Oddball::kToNumberOffset);
       assembler->Return(result);
     }
 
@@ skipping 149 matching lines @@
 
   assembler->Bind(&return_true);
   assembler->Return(assembler->BooleanConstant(true));
 
   assembler->Bind(&return_false);
   assembler->Return(assembler->BooleanConstant(false));
 }
 
 }  // namespace internal
 }  // namespace v8