[turbofan] Use StringCompareStub for string comparisons.

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 1326 matching lines @@
   const ElementAccess& access = ElementAccessOf(node->op());
   Type* type = NodeProperties::GetType(node->InputAt(2));
   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)));
 }
 
 
-Node* SimplifiedLowering::StringComparison(Node* node, bool requires_ordering) {
-  Runtime::FunctionId f =
-      requires_ordering ? Runtime::kStringCompare : 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),
-                          NodeProperties::GetValueInput(node, 0),
-                          NodeProperties::GetValueInput(node, 1),
-                          jsgraph()->ExternalConstant(ref),
-                          jsgraph()->Int32Constant(2),
-                          jsgraph()->NoContextConstant());
+Node* SimplifiedLowering::StringComparison(Node* node) {
+  Operator::Properties properties = node->op()->properties();
+  Callable callable = CodeFactory::StringCompare(isolate());
+  CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
+  CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+      isolate(), zone(), callable.descriptor(), 0, flags, properties);
+  return graph()->NewNode(
+      common()->Call(desc), jsgraph()->HeapConstant(callable.code()),
+      NodeProperties::GetValueInput(node, 0),
+      NodeProperties::GetValueInput(node, 1), jsgraph()->NoContextConstant());
 }
 
 
 Node* SimplifiedLowering::Int32Div(Node* const node) {
   Int32BinopMatcher m(node);
   Node* const zero = jsgraph()->Int32Constant(0);
   Node* const minus_one = jsgraph()->Int32Constant(-1);
   Node* const lhs = m.left().node();
   Node* const rhs = m.right().node();
 
@@ skipping 245 matching lines @@
   Type* const rhs_type = NodeProperties::GetType(rhs);
   if (!rhs_type->Is(zero_thirtyone_range_)) {
     node->ReplaceInput(1, graph()->NewNode(machine()->Word32And(), rhs,
                                            jsgraph()->Int32Constant(0x1f)));
   }
 }
 
 
 void SimplifiedLowering::DoStringEqual(Node* node) {
   node->set_op(machine()->WordEqual());
-  node->ReplaceInput(0, StringComparison(node, false));
+  node->ReplaceInput(0, StringComparison(node));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 
 void SimplifiedLowering::DoStringLessThan(Node* node) {
   node->set_op(machine()->IntLessThan());
-  node->ReplaceInput(0, StringComparison(node, true));
+  node->ReplaceInput(0, StringComparison(node));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 
 void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
   node->set_op(machine()->IntLessThanOrEqual());
-  node->ReplaceInput(0, StringComparison(node, true));
+  node->ReplaceInput(0, StringComparison(node));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8