[turbofan] Fix double reduce in escape analysis

src/compiler/escape-analysis-reducer.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/escape-analysis-reducer.h"
 
 #include "src/compiler/js-graph.h"
 #include "src/counters.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 EscapeAnalysisReducer::EscapeAnalysisReducer(Editor* editor, JSGraph* jsgraph,
                                              EscapeAnalysis* escape_analysis,
                                              Zone* zone)
     : AdvancedReducer(editor),
       jsgraph_(jsgraph),
       escape_analysis_(escape_analysis),
-      zone_(zone) {}
+      zone_(zone),
+      visited_(static_cast<int>(jsgraph->graph()->NodeCount()), zone) {}
 
 
 Reduction EscapeAnalysisReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kLoadField:
     case IrOpcode::kLoadElement:
       return ReduceLoad(node);
     case IrOpcode::kStoreField:
     case IrOpcode::kStoreElement:
       return ReduceStore(node);
@@ skipping 14 matching lines @@
       }
       break;
   }
   return NoChange();
 }
 
 
 Reduction EscapeAnalysisReducer::ReduceLoad(Node* node) {
   DCHECK(node->opcode() == IrOpcode::kLoadField ||
          node->opcode() == IrOpcode::kLoadElement);
+  if (visited_.Contains(node->id())) return NoChange();
+  visited_.Add(node->id());
   if (Node* rep = escape_analysis()->GetReplacement(node)) {
+    visited_.Add(node->id());

[Michael Starzinger, 2016/01/12 12:25:00]

nit: Why add the node twice?

     counters()->turbo_escape_loads_replaced()->Increment();
     if (FLAG_trace_turbo_escape) {
       PrintF("Replaced #%d (%s) with #%d (%s)\n", node->id(),
              node->op()->mnemonic(), rep->id(), rep->op()->mnemonic());
     }
     ReplaceWithValue(node, rep);
     return Changed(rep);
   }
   return NoChange();
 }
 
 
 Reduction EscapeAnalysisReducer::ReduceStore(Node* node) {
   DCHECK(node->opcode() == IrOpcode::kStoreField ||
          node->opcode() == IrOpcode::kStoreElement);
+  if (visited_.Contains(node->id())) return NoChange();
+  visited_.Add(node->id());
   if (escape_analysis()->IsVirtual(NodeProperties::GetValueInput(node, 0))) {
     if (FLAG_trace_turbo_escape) {
       PrintF("Removed #%d (%s) from effect chain\n", node->id(),
              node->op()->mnemonic());
     }
     RelaxEffectsAndControls(node);
     return Changed(node);
   }
   return NoChange();
 }
 
 
 Reduction EscapeAnalysisReducer::ReduceAllocate(Node* node) {
   DCHECK_EQ(node->opcode(), IrOpcode::kAllocate);
+  if (visited_.Contains(node->id())) return NoChange();
+  visited_.Add(node->id());
   if (escape_analysis()->IsVirtual(node)) {
     RelaxEffectsAndControls(node);
     counters()->turbo_escape_allocs_replaced()->Increment();
     if (FLAG_trace_turbo_escape) {
       PrintF("Removed allocate #%d from effect chain\n", node->id());
     }
     return Changed(node);
   }
   return NoChange();
 }
@@ skipping 57 matching lines @@
     if (FLAG_trace_turbo_escape) {
       PrintF("Replaced ObjectIsSmi #%d with false\n", node->id());
     }
     return Replace(node);
   }
   return NoChange();
 }
 
 
 Reduction EscapeAnalysisReducer::ReduceFrameStateUses(Node* node) {
+  if (visited_.Contains(node->id())) return NoChange();
+  visited_.Add(node->id());
   DCHECK_GE(node->op()->EffectInputCount(), 1);
   bool changed = false;
   for (int i = 0; i < node->InputCount(); ++i) {
     Node* input = node->InputAt(i);
     if (input->opcode() == IrOpcode::kFrameState) {
       if (Node* ret = ReduceFrameState(input, node, false)) {
         node->ReplaceInput(i, ret);
         changed = true;
       }
     }
@@ skipping 115 matching lines @@
 }
 
 
 Counters* EscapeAnalysisReducer::counters() const {
   return jsgraph_->isolate()->counters();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8