[stubs] Port StringAddStub to TF

src/code-stubs-hydrogen.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.
 
 #include "src/code-stubs.h"
 
 #include <memory>
 
 #include "src/bailout-reason.h"
 #include "src/code-factory.h"
@@ skipping 1102 matching lines @@
   {
     // TODO(bmeurer): Add support for fast ToPrimitive conversion using
     // a dedicated ToPrimitiveStub.
     Add<HPushArguments>(input);
     Push(Add<HCallRuntime>(Runtime::FunctionForId(Runtime::kToPrimitive), 1));
   }
   if_inputisstringwrapper.End();
   return Pop();
 }
 
-
-template <>
-HValue* CodeStubGraphBuilder<StringAddStub>::BuildCodeInitializedStub() {
-  StringAddStub* stub = casted_stub();
-  StringAddFlags flags = stub->flags();
-  PretenureFlag pretenure_flag = stub->pretenure_flag();
-
-  HValue* left = GetParameter(Descriptor::kLeft);
-  HValue* right = GetParameter(Descriptor::kRight);
-
-  // Make sure that both arguments are strings if not known in advance.
-  if ((flags & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT) {
-    left =
-        BuildToString(left, (flags & STRING_ADD_CONVERT) == STRING_ADD_CONVERT);
-  }
-  if ((flags & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT) {
-    right = BuildToString(right,
-                          (flags & STRING_ADD_CONVERT) == STRING_ADD_CONVERT);
-  }
-
-  return BuildStringAdd(left, right, HAllocationMode(pretenure_flag));
-}
-
-
-Handle<Code> StringAddStub::GenerateCode() {
-  return DoGenerateCode(this);
-}
-
 template <>
 HValue* CodeStubGraphBuilder<ToBooleanICStub>::BuildCodeInitializedStub() {
   ToBooleanICStub* stub = casted_stub();
   IfBuilder if_true(this);
   if_true.If<HBranch>(GetParameter(Descriptor::kArgument), stub->types());
   if_true.Then();
   if_true.Return(graph()->GetConstantTrue());
   if_true.Else();
   if_true.End();
   return graph()->GetConstantFalse();
@@ skipping 38 matching lines @@
   return BuildRegExpConstructResult(length, index, input);
 }
 
 
 Handle<Code> RegExpConstructResultStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 }  // namespace internal
 }  // namespace v8