[turbofan] Enable typed lowering of string addition.

src/compiler/simplified-lowering.cc

 // Copyright 2014 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/compiler/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 764 matching lines @@
       case IrOpcode::kStringLessThan: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
         if (lower()) lowering->DoStringLessThan(node);
         break;
       }
       case IrOpcode::kStringLessThanOrEqual: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
         if (lower()) lowering->DoStringLessThanOrEqual(node);
         break;
       }
-      case IrOpcode::kStringAdd: {
-        VisitBinop(node, kMachAnyTagged, kMachAnyTagged);
-        if (lower()) lowering->DoStringAdd(node);
-        break;
-      }
       case IrOpcode::kAllocate: {
         ProcessInput(node, 0, kMachAnyTagged);
         ProcessRemainingInputs(node, 1);
         SetOutput(node, kMachAnyTagged);
         if (lower()) lowering->DoAllocate(node);
         break;
       }
       case IrOpcode::kLoadField: {
         FieldAccess access = FieldAccessOf(node->op());
         ProcessInput(node, 0, changer_->TypeForBasePointer(access));
@@ skipping 506 matching lines @@
   const ElementAccess& access = ElementAccessOf(node->op());
   Type* type = NodeProperties::GetBounds(node->InputAt(2)).upper;
   node->set_op(machine()->Store(
       StoreRepresentation(access.machine_type,
                           ComputeWriteBarrierKind(access.base_is_tagged,
                                                   access.machine_type, type))));
   node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1)));
 }
 
 
-void SimplifiedLowering::DoStringAdd(Node* node) {
-  Operator::Properties properties = node->op()->properties();
-  Callable callable = CodeFactory::StringAdd(
-      jsgraph()->isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
-  CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-  CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-      jsgraph()->isolate(), zone(), callable.descriptor(), 0, flags,
-      properties);
-  node->set_op(common()->Call(desc));
-  node->InsertInput(graph()->zone(), 0,
-                    jsgraph()->HeapConstant(callable.code()));
-  node->AppendInput(graph()->zone(), jsgraph()->UndefinedConstant());
-  node->AppendInput(graph()->zone(), graph()->start());
-  node->AppendInput(graph()->zone(), graph()->start());
-}
-
-
 Node* SimplifiedLowering::StringComparison(Node* node, bool requires_ordering) {
   Runtime::FunctionId f =
       requires_ordering ? Runtime::kStringCompareRT : Runtime::kStringEquals;
   ExternalReference ref(f, jsgraph()->isolate());
   Operator::Properties props = node->op()->properties();
   // TODO(mstarzinger): We should call StringCompareStub here instead, once an
   // interface descriptor is available for it.
   CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(zone(), f, 2, props);
   return graph()->NewNode(common()->Call(desc),
                           jsgraph()->CEntryStubConstant(1),
@@ skipping 270 matching lines @@
 
 void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
   node->set_op(machine()->IntLessThanOrEqual());
   node->ReplaceInput(0, StringComparison(node, true));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8