[turbofan] escape analysis supports arguments object and rest elements

src/compiler/escape-analysis.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.h"
 
 #include <limits>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 671 matching lines @@
       break;
     case IrOpcode::kLoadField:
     case IrOpcode::kLoadElement: {
       if (Node* rep = object_analysis_->GetReplacement(node)) {
         if (IsAllocation(rep) && CheckUsesForEscape(node, rep)) {
           RevisitInputs(rep);
           RevisitUses(rep);
         }
       } else {
         Node* from = NodeProperties::GetValueInput(node, 0);
+        from = object_analysis_->ResolveReplacement(from);

[Tobias Tebbi, 2017/02/15 14:16:05]

This is a drive-by fix. It was sound before, but imprecise.

         if (SetEscaped(from)) {
           TRACE("Setting #%d (%s) to escaped because of unresolved load #%i\n",
                 from->id(), from->op()->mnemonic(), node->id());
           RevisitInputs(from);
           RevisitUses(from);
         }
       }
 
       RevisitUses(node);
       break;
@@ skipping 1084 matching lines @@
     }
   }
   return false;
 }
 
 Graph* EscapeAnalysis::graph() const { return status_analysis_->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8