Fix wraparound of deoptimization count in shared function info.

src/objects-inl.h

 // 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 4870 matching lines @@
 
 
 void SharedFunctionInfo::set_deopt_count(int deopt_count) {
   set_counters(DeoptCountBits::update(counters(), deopt_count));
 }
 
 
 void SharedFunctionInfo::increment_deopt_count() {
   int value = counters();
   int deopt_count = DeoptCountBits::decode(value);
-  deopt_count = (deopt_count + 1) & DeoptCountBits::kMax;
-  set_counters(DeoptCountBits::update(value, deopt_count));
+  if (deopt_count < DeoptCountBits::kMax) {
+    deopt_count = (deopt_count + 1) & DeoptCountBits::kMax;

[Toon Verwaest, 2013/09/05 18:13:57]

I guess this mask isn't necessary anymore.

+    set_counters(DeoptCountBits::update(value, deopt_count));
+    if (deopt_count == DeoptCountBits::kMax) {
+      // We hit the limit; temporarily disable optimization.
+      // The runtime profiler may try to reenable optimization sometime later.
+      DisableOptimization(kDeoptimizedTooManyTimes);
+    }
+  }
 }
 
 
+bool SharedFunctionInfo::too_many_deopts() {
+  return DeoptCountBits::decode(counters()) == DeoptCountBits::kMax;
+}
+
+
 int SharedFunctionInfo::opt_reenable_tries() {
   return OptReenableTriesBits::decode(counters());
 }
 
 
 void SharedFunctionInfo::set_opt_reenable_tries(int tries) {
   set_counters(OptReenableTriesBits::update(counters(), tries));
 }
 
 
@@ skipping 1374 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_