[turbofan] Lower StringEqual and friends in EffectControlLinearizer.

src/compiler/effect-control-linearizer.cc

 // Copyright 2015 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/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 704 matching lines @@
       break;
     case IrOpcode::kArrayBufferWasNeutered:
       state = LowerArrayBufferWasNeutered(node, *effect, *control);
       break;
     case IrOpcode::kStringFromCharCode:
       state = LowerStringFromCharCode(node, *effect, *control);
       break;
     case IrOpcode::kStringCharCodeAt:
       state = LowerStringCharCodeAt(node, *effect, *control);
       break;
+    case IrOpcode::kStringEqual:
+      state = LowerStringEqual(node, *effect, *control);
+      break;
+    case IrOpcode::kStringLessThan:
+      state = LowerStringLessThan(node, *effect, *control);
+      break;
+    case IrOpcode::kStringLessThanOrEqual:
+      state = LowerStringLessThanOrEqual(node, *effect, *control);
+      break;
     case IrOpcode::kCheckFloat64Hole:
       state = LowerCheckFloat64Hole(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckTaggedHole:
       state = LowerCheckTaggedHole(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kConvertTaggedHoleToUndefined:
       state = LowerConvertTaggedHoleToUndefined(node, *effect, *control);
       break;
     case IrOpcode::kPlainPrimitiveToNumber:
@@ skipping 1863 matching lines @@
 
   control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue0, efalse0, control);
   value = graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                            vtrue0, vfalse0, control);
 
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringComparison(Callable const& callable,
+                                               Node* node, Node* effect,
+                                               Node* control) {
+  Operator::Properties properties =
+      Operator::kCommutative | Operator::kEliminatable;

[Jarin, 2016/09/26 12:21:23]

Nit: less-than is not commutative (actually, I do not even know what
commutativity means for calls).

[Benedikt Meurer, 2016/09/26 12:22:16]

Done.

+  CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
+  CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+      isolate(), graph()->zone(), callable.descriptor(), 0, flags, properties);
+  node->InsertInput(graph()->zone(), 0,
+                    jsgraph()->HeapConstant(callable.code()));
+  node->AppendInput(graph()->zone(), jsgraph()->NoContextConstant());
+  node->AppendInput(graph()->zone(), effect);
+  NodeProperties::ChangeOp(node, common()->Call(desc));
+  return ValueEffectControl(node, node, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringEqual(Node* node, Node* effect,
+                                          Node* control) {
+  return LowerStringComparison(CodeFactory::StringEqual(isolate()), node,
+                               effect, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringLessThan(Node* node, Node* effect,
+                                             Node* control) {
+  return LowerStringComparison(CodeFactory::StringLessThan(isolate()), node,
+                               effect, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringLessThanOrEqual(Node* node, Node* effect,
+                                                    Node* control) {
+  return LowerStringComparison(CodeFactory::StringLessThanOrEqual(isolate()),
+                               node, effect, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckFloat64Hole(Node* node, Node* frame_state,
                                                Node* effect, Node* control) {
   // If we reach this point w/o eliminating the {node} that's marked
   // with allow-return-hole, we cannot do anything, so just deoptimize
   // in case of the hole NaN (similar to Crankshaft).
   Node* value = node->InputAt(0);
   Node* check = graph()->NewNode(
       machine()->Word32Equal(),
       graph()->NewNode(machine()->Float64ExtractHighWord32(), value),
       jsgraph()->Int32Constant(kHoleNanUpper32));
@@ skipping 891 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kEliminatable);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8