[turbofan] fixed escape analysis crash because of incomplete replacements

R=epertoso@chromium.org,mstarzinger@chromium.org

BUG=671324

Review-Url: https://codereview.chromium.org/2571793002
Cr-Commit-Position: refs/heads/master@{#41679}

src/compiler/escape-analysis-reducer.cc

@@ -31,7 +31,7 @@ EscapeAnalysisReducer::EscapeAnalysisReducer(Editor* editor, JSGraph* jsgraph,
       fully_reduced_(static_cast<int>(jsgraph->graph()->NodeCount() * 2), zone),
       exists_virtual_allocate_(escape_analysis->ExistsVirtualAllocate()) {}
 
-Reduction EscapeAnalysisReducer::Reduce(Node* node) {
+Reduction EscapeAnalysisReducer::ReduceNode(Node* node) {
   if (node->id() < static_cast<NodeId>(fully_reduced_.length()) &&
       fully_reduced_.Contains(node->id())) {
     return NoChange();
@@ -97,6 +97,14 @@ Reduction EscapeAnalysisReducer::Reduce(Node* node) {
   return NoChange();
 }
 
+Reduction EscapeAnalysisReducer::Reduce(Node* node) {
+  Reduction reduction = ReduceNode(node);
+  if (reduction.Changed() && node != reduction.replacement()) {
+    escape_analysis()->SetReplacement(node, reduction.replacement());
+  }
+  return reduction;
+}
+
 namespace {
 
 Node* MaybeGuard(JSGraph* jsgraph, Node* original, Node* replacement) {
@@ -202,7 +210,7 @@ Reduction EscapeAnalysisReducer::ReduceReferenceEqual(Node* node) {
         escape_analysis()->CompareVirtualObjects(left, right)) {
       ReplaceWithValue(node, jsgraph()->TrueConstant());
       TRACE("Replaced ref eq #%d with true\n", node->id());
-      Replace(jsgraph()->TrueConstant());
+      return Replace(jsgraph()->TrueConstant());
     }
     // Right-hand side is not a virtual object, or a different one.
     ReplaceWithValue(node, jsgraph()->FalseConstant());

src/compiler/escape-analysis-reducer.h

@@ -33,6 +33,7 @@ class V8_EXPORT_PRIVATE EscapeAnalysisReducer final
   bool compilation_failed() const { return compilation_failed_; }
 
  private:
+  Reduction ReduceNode(Node* node);
   Reduction ReduceLoad(Node* node);
   Reduction ReduceStore(Node* node);
   Reduction ReduceAllocate(Node* node);

src/compiler/escape-analysis.cc

@@ -1586,7 +1586,7 @@ Node* EscapeAnalysis::GetOrCreateObjectState(Node* effect, Node* node) {
         cache_->fields().clear();
         for (size_t i = 0; i < vobj->field_count(); ++i) {
           if (Node* field = vobj->GetField(i)) {
-            cache_->fields().push_back(field);
+            cache_->fields().push_back(ResolveReplacement(field));
           }
         }
         int input_count = static_cast<int>(cache_->fields().size());

src/compiler/escape-analysis.h

@@ -35,6 +35,7 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
   Node* GetOrCreateObjectState(Node* effect, Node* node);
   bool IsCyclicObjectState(Node* effect, Node* node);
   bool ExistsVirtualAllocate();
+  bool SetReplacement(Node* node, Node* rep);
 
  private:
   void RunObjectAnalysis();
@@ -59,7 +60,6 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
 
   Node* replacement(Node* node);
   Node* ResolveReplacement(Node* node);
-  bool SetReplacement(Node* node, Node* rep);
   bool UpdateReplacement(VirtualState* state, Node* node, Node* rep);
 
   VirtualObject* GetVirtualObject(VirtualState* state, Node* node);

test/mjsunit/compiler/escape-analysis-replacement.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax --turbo-escape
+
+function foo(x){
+  var c = {c: {} === {}};
+  if(x) c.c = true;
+  return c.c;
+}
+
+foo(true);
+foo(false);
+foo(true);
+foo(false);
+%OptimizeFunctionOnNextCall(foo);
+assertTrue(foo(true));
+assertFalse(foo(false));