[turbofan] Use InternalizedString feedback abstract/strict equality comparisons.

src/compiler/redundancy-elimination.cc

 // Copyright 2016 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/redundancy-elimination.h"
 
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 RedundancyElimination::RedundancyElimination(Editor* editor, Zone* zone)
     : AdvancedReducer(editor), node_checks_(zone), zone_(zone) {}
 
 RedundancyElimination::~RedundancyElimination() {}
 
 Reduction RedundancyElimination::Reduce(Node* node) {
   if (node_checks_.Get(node)) return NoChange();
   switch (node->opcode()) {
     case IrOpcode::kCheckBounds:
     case IrOpcode::kCheckFloat64Hole:
     case IrOpcode::kCheckHeapObject:
     case IrOpcode::kCheckIf:
+    case IrOpcode::kCheckInternalizedString:
     case IrOpcode::kCheckNumber:
     case IrOpcode::kCheckSmi:
     case IrOpcode::kCheckString:
     case IrOpcode::kCheckTaggedHole:
     case IrOpcode::kCheckedFloat64ToInt32:
     case IrOpcode::kCheckedInt32Add:
     case IrOpcode::kCheckedInt32Sub:
     case IrOpcode::kCheckedInt32Div:
     case IrOpcode::kCheckedInt32Mod:
     case IrOpcode::kCheckedInt32Mul:
@@ skipping 78 matching lines @@
 RedundancyElimination::EffectPathChecks::AddCheck(Zone* zone,
                                                   Node* node) const {
   Check* head = new (zone->New(sizeof(Check))) Check(node, head_);
   return new (zone->New(sizeof(EffectPathChecks)))
       EffectPathChecks(head, size_ + 1);
 }
 
 namespace {
 
 bool IsCompatibleCheck(Node const* a, Node const* b) {
-  if (a->op() != b->op()) return false;
+  if (a->op() != b->op()) {
+    if (a->opcode() == IrOpcode::kCheckInternalizedString &&
+        b->opcode() == IrOpcode::kCheckString) {
+      // CheckInternalizedString(node) implies CheckString(node)
+    } else {
+      return false;
+    }
+  }
   for (int i = a->op()->ValueInputCount(); --i >= 0;) {
     if (a->InputAt(i) != b->InputAt(i)) return false;
   }
   return true;
 }
 
 }  // namespace
 
 Node* RedundancyElimination::EffectPathChecks::LookupCheck(Node* node) const {
   for (Check const* check = head_; check != nullptr; check = check->next) {
@@ skipping 144 matching lines @@
       node_checks_.Set(node, checks);
       return Changed(node);
     }
   }
   return NoChange();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8