Fix wraparound of deoptimization count in shared function info.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index fc5ed247ee5a86f38aa6a59794ace121fe538da4..8dce54443a0da786216d8283f4f8cb47747619f9 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4888,8 +4888,20 @@ void SharedFunctionInfo::set_deopt_count(int 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;
 }