Parallel recompilation: fewer handle dereferences and tighter checks.

src/code-stubs-hydrogen.cc

 // Copyright 2012 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
@@ skipping 21 matching lines @@
 #include "lithium.h"
 
 namespace v8 {
 namespace internal {
 
 
 static LChunk* OptimizeGraph(HGraph* graph) {
   Isolate* isolate =  graph->isolate();
   AssertNoAllocation no_gc;
   NoHandleAllocation no_handles(isolate);
-  NoHandleDereference no_deref(isolate);
+  HandleDereferenceGuard no_deref(isolate, HandleDereferenceGuard::DISALLOW);
 
   ASSERT(graph != NULL);
   SmartArrayPointer<char> bailout_reason;
   if (!graph->Optimize(&bailout_reason)) {
     FATAL(bailout_reason.is_empty() ? "unknown" : *bailout_reason);
   }
   LChunk* chunk = LChunk::NewChunk(graph);
   if (chunk == NULL) {
     FATAL(graph->info()->bailout_reason());
   }
@@ skipping 322 matching lines @@
 }
 
 
 Handle<Code> ArrayNArgumentsConstructorStub::GenerateCode() {
   CodeStubGraphBuilder<ArrayNArgumentsConstructorStub> builder(this);
   LChunk* chunk = OptimizeGraph(builder.CreateGraph());
   return chunk->Codegen(Code::COMPILED_STUB);
 }
 
 } }  // namespace v8::internal