Turn ToNumberStub into a hydrogen code stub.

src/code-stubs-hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 289 matching lines @@
     ASSERT(descriptor->stack_parameter_count_ == NULL);
     return stub->GenerateLightweightMissCode(isolate);
   }
   CodeStubGraphBuilder<Stub> builder(stub);
   LChunk* chunk = OptimizeGraph(builder.CreateGraph());
   return chunk->Codegen();
 }
 
 
 template <>
+HValue* CodeStubGraphBuilder<ToNumberStub>::BuildCodeStub() {
+  HValue* value = GetParameter(0);
+
+  // Check if the parameter is already a SMI or heap number.
+  IfBuilder if_number(this);
+  if_number.If<HIsSmiAndBranch>(value);
+  if_number.OrIf<HCompareMap>(value, isolate()->factory()->heap_number_map());
+  if_number.Then();
+
+  // Return the number.
+  Push(value);
+
+  if_number.Else();
+
+  // Convert the parameter to number using the builtin.
+  HValue* function = AddLoadJSBuiltin(Builtins::TO_NUMBER, context());
+  Add<HPushArgument>(value);
+  Push(Add<HInvokeFunction>(context(), function, 1));
+
+  if_number.End();
+
+  return Pop();
+}
+
+
+Handle<Code> ToNumberStub::GenerateCode() {
+  return DoGenerateCode(this);
+}
+
+
+template <>
 HValue* CodeStubGraphBuilder<FastCloneShallowArrayStub>::BuildCodeStub() {
   Zone* zone = this->zone();
   Factory* factory = isolate()->factory();
   HValue* undefined = graph()->GetConstantUndefined();
   AllocationSiteMode alloc_site_mode = casted_stub()->allocation_site_mode();
   FastCloneShallowArrayStub::Mode mode = casted_stub()->mode();
   int length = casted_stub()->length();
 
   HInstruction* allocation_site =
       AddInstruction(new(zone) HLoadKeyed(GetParameter(0),
@@ skipping 594 matching lines @@
   return value;
 }
 
 
 Handle<Code> ElementsTransitionAndStoreStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 } }  // namespace v8::internal