A64: Synchronize with r17635.

src/compiler.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 244 matching lines @@
 }
 
 
 static bool AlwaysFullCompiler(Isolate* isolate) {
   return FLAG_always_full_compiler || IsDebuggerActive(isolate);
 }
 
 
 void RecompileJob::RecordOptimizationStats() {
   Handle<JSFunction> function = info()->closure();
-  int opt_count = function->shared()->opt_count();
-  function->shared()->set_opt_count(opt_count + 1);
+  if (!function->IsOptimized()) {
+    // Concurrent recompilation and OSR may race.  Increment only once.
+    int opt_count = function->shared()->opt_count();
+    function->shared()->set_opt_count(opt_count + 1);
+  }
   double ms_creategraph = time_taken_to_create_graph_.InMillisecondsF();
   double ms_optimize = time_taken_to_optimize_.InMillisecondsF();
   double ms_codegen = time_taken_to_codegen_.InMillisecondsF();
   if (FLAG_trace_opt) {
     PrintF("[optimizing ");
     function->ShortPrint();
     PrintF(" - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph, ms_optimize,
            ms_codegen);
   }
   if (FLAG_trace_opt_stats) {
@@ skipping 1082 matching lines @@
   AllowHandleDereference allow_deref;
   bool tracing_on = info()->IsStub()
       ? FLAG_trace_hydrogen_stubs
       : (FLAG_trace_hydrogen &&
          info()->closure()->PassesFilter(FLAG_trace_hydrogen_filter));
   return (tracing_on &&
       OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL);
 }
 
 } }  // namespace v8::internal