Lower simplified StringLessThan[OrEqual] to runtime call.

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 "src/base/bits.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/node-properties-inl.h"
@@ skipping 508 matching lines @@
         if (lower()) node->set_op(lowering->machine()->WordEqual());
         break;
       }
       case IrOpcode::kStringEqual: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
         if (lower()) lowering->DoStringEqual(node);
         break;
       }
       case IrOpcode::kStringLessThan: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
-        // TODO(titzer): lower StringLessThan to stub/runtime call.
+        if (lower()) lowering->DoStringLessThan(node);
         break;
       }
       case IrOpcode::kStringLessThanOrEqual: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
-        // TODO(titzer): lower StringLessThanOrEqual to stub/runtime call.
+        if (lower()) lowering->DoStringLessThanOrEqual(node);
         break;
       }
       case IrOpcode::kStringAdd: {
         VisitBinop(node, kMachAnyTagged, kMachAnyTagged);
         if (lower()) lowering->DoStringAdd(node);
         break;
       }
       case IrOpcode::kLoadField: {
         FieldAccess access = FieldAccessOf(node->op());
         ProcessInput(node, 0, changer_->TypeForBasePointer(access));
@@ skipping 303 matching lines @@
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   CallDescriptor* desc = Linkage::GetStubCallDescriptor(d, 0, flags, zone());
   node->set_op(common()->Call(desc));
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(stub.GetCode()));
   node->AppendInput(zone(), jsgraph()->UndefinedConstant());
   node->AppendInput(zone(), graph()->start());
   node->AppendInput(zone(), graph()->start());
 }
 
 
+Node* SimplifiedLowering::StringComparison(Node* node, bool requires_ordering) {
+  CEntryStub stub(zone()->isolate(), 1);
+  Runtime::FunctionId f =
+      requires_ordering ? Runtime::kStringCompare : Runtime::kStringEquals;
+  ExternalReference ref(f, zone()->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(f, 2, props, zone());
+  return graph()->NewNode(common()->Call(desc),
+                          jsgraph()->HeapConstant(stub.GetCode()),
+                          NodeProperties::GetValueInput(node, 0),
+                          NodeProperties::GetValueInput(node, 1),
+                          jsgraph()->ExternalConstant(ref),
+                          jsgraph()->Int32Constant(2),
+                          jsgraph()->UndefinedConstant());
+}
+
+
 void SimplifiedLowering::DoStringEqual(Node* node) {
-  CEntryStub stub(zone()->isolate(), 1);
-  ExternalReference ref(Runtime::kStringEquals, zone()->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(
-      Runtime::kStringEquals, 2, props, zone());
-  Node* call = graph()->NewNode(common()->Call(desc),
-                                jsgraph()->HeapConstant(stub.GetCode()),
-                                NodeProperties::GetValueInput(node, 0),
-                                NodeProperties::GetValueInput(node, 1),
-                                jsgraph()->ExternalConstant(ref),
-                                jsgraph()->Int32Constant(2),
-                                jsgraph()->UndefinedConstant());
   node->set_op(machine()->WordEqual());
-  node->ReplaceInput(0, call);
+  node->ReplaceInput(0, StringComparison(node, false));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
+
+void SimplifiedLowering::DoStringLessThan(Node* node) {
+  node->set_op(machine()->IntLessThan());
+  node->ReplaceInput(0, StringComparison(node, true));
+  node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
+}
+
+
+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