[turbofan] Make string comparisons effectful.

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 1345 matching lines @@
 
 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());
+      NodeProperties::GetValueInput(node, 1), jsgraph()->NoContextConstant(),
+      NodeProperties::GetEffectInput(node),
+      NodeProperties::GetControlInput(node));
 }
 
 
 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 243 matching lines @@
   Node* const rhs = NodeProperties::GetValueInput(node, 1);
   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)));
   }
   NodeProperties::ChangeOp(node, op);
 }
 
 
+namespace {
+
+void ReplaceEffectUses(Node* node, Node* replacement) {
+  // Requires distinguishing between value and effect edges.
+  DCHECK(replacement->op()->EffectOutputCount() > 0);
+  for (Edge edge : node->use_edges()) {
+    if (NodeProperties::IsEffectEdge(edge)) {
+      edge.UpdateTo(replacement);
+    } else {
+      DCHECK(NodeProperties::IsValueEdge(edge));
+    }
+  }
+}
+
+}  // namespace
+
+
 void SimplifiedLowering::DoStringEqual(Node* node) {
-  node->ReplaceInput(0, StringComparison(node));
+  Node* comparison = StringComparison(node);
+  ReplaceEffectUses(node, comparison);
+  node->ReplaceInput(0, comparison);
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
+  node->TrimInputCount(2);
   NodeProperties::ChangeOp(node, machine()->WordEqual());
 }
 
 
 void SimplifiedLowering::DoStringLessThan(Node* node) {
-  node->ReplaceInput(0, StringComparison(node));
+  Node* comparison = StringComparison(node);
+  ReplaceEffectUses(node, comparison);
+  node->ReplaceInput(0, comparison);
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
+  node->TrimInputCount(2);
   NodeProperties::ChangeOp(node, machine()->IntLessThan());
 }
 
 
 void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
-  node->ReplaceInput(0, StringComparison(node));
+  Node* comparison = StringComparison(node);
+  ReplaceEffectUses(node, comparison);
+  node->ReplaceInput(0, comparison);
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
+  node->TrimInputCount(2);
   NodeProperties::ChangeOp(node, machine()->IntLessThanOrEqual());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8