Reland r11425 "Re-enable optimization for hot functions that have optimization disabled due to many…

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 0620e0e876ed6cb7754d35f342bfc8ed5117efc9..3c6e5bace0a4d70d6c0f18526f8918ea44893abe 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3617,7 +3617,7 @@ ACCESSORS(SharedFunctionInfo, debug_info, Object, kDebugInfoOffset)
 ACCESSORS(SharedFunctionInfo, inferred_name, String, kInferredNameOffset)
 ACCESSORS(SharedFunctionInfo, this_property_assignments, Object,
           kThisPropertyAssignmentsOffset)
-SMI_ACCESSORS(SharedFunctionInfo, ic_age, kICAgeOffset)
+SMI_ACCESSORS(SharedFunctionInfo, ast_node_count, kAstNodeCountOffset)
 
 
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, hidden_prototype,
@@ -3666,8 +3666,10 @@ SMI_ACCESSORS(SharedFunctionInfo, compiler_hints,
 SMI_ACCESSORS(SharedFunctionInfo, this_property_assignments_count,
               kThisPropertyAssignmentsCountOffset)
 SMI_ACCESSORS(SharedFunctionInfo, opt_count, kOptCountOffset)
-SMI_ACCESSORS(SharedFunctionInfo, ast_node_count, kAstNodeCountOffset)
-SMI_ACCESSORS(SharedFunctionInfo, deopt_counter, kDeoptCounterOffset)
+SMI_ACCESSORS(SharedFunctionInfo, counters, kCountersOffset)
+SMI_ACCESSORS(SharedFunctionInfo,
+              stress_deopt_counter,
+              kStressDeoptCounterOffset)
 #else
 
 #define PSEUDO_SMI_ACCESSORS_LO(holder, name, offset)             \
@@ -3719,8 +3721,10 @@ PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo,
                         kThisPropertyAssignmentsCountOffset)
 PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, opt_count, kOptCountOffset)
 
-PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, ast_node_count, kAstNodeCountOffset)
-PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo, deopt_counter, kDeoptCounterOffset)
+PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo, counters, kCountersOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo,
+                        stress_deopt_counter,
+                        kStressDeoptCounterOffset)
 #endif
 
 
@@ -3921,12 +3925,72 @@ void SharedFunctionInfo::set_code_age(int code_age) {
 }
 
 
+int SharedFunctionInfo::ic_age() {

[Jakob Kummerow, 2012/06/11 12:13:59]

Y U NO use BitField<type, shift, size>? That'd automate these custom
implementations. Note that you'd still have to manually do the masking before
storing, as the BitField implementation ASSERTs that the provided value fits
into the bit field.

[ulan, 2012/06/11 16:07:31]

Yeah, BitField is cleaner. Done.

+  return (counters() >> kICAgeShift) & kICAgeMask;
+}
+
+
+void SharedFunctionInfo::set_ic_age(int ic_age) {
+  ASSERT(ic_age <= kICAgeMask);
+  int value = counters() & ~(kICAgeMask << kICAgeShift);
+  set_counters(value | ((ic_age & kICAgeMask) << kICAgeShift));
+}
+
+
+int SharedFunctionInfo::deopt_count() {
+  return (counters() >> kDeoptCountShift) & kDeoptCountMask;
+}
+
+
+void SharedFunctionInfo::set_deopt_count(int deopt_count) {
+  ASSERT(deopt_count <= kDeoptCountMask);
+  int value = counters() & ~(kDeoptCountMask << kDeoptCountShift);
+  set_counters(value | ((deopt_count & kDeoptCountMask) << kDeoptCountShift));
+}
+
+
+void SharedFunctionInfo::increment_deopt_count() {
+  int value = counters();
+  int deopt_count = (value >> kDeoptCountShift) & kDeoptCountMask;
+  deopt_count++;
+  value &= ~(kDeoptCountMask << kDeoptCountShift);
+  set_counters(value | ((deopt_count & kDeoptCountMask) << kDeoptCountShift));
+}
+
+
+int SharedFunctionInfo::opt_reenable_tries() {
+  return (counters() >> kOptReenableTriesShift) & kOptReenableTriesMask;
+}
+
+
+void SharedFunctionInfo::set_opt_reenable_tries(int tries) {
+  ASSERT(tries <= kOptReenableTriesMask);
+  int value = counters() & ~(kOptReenableTriesMask << kOptReenableTriesShift);
+  value |= ((tries & kOptReenableTriesMask) << kOptReenableTriesShift);
+  set_counters(value);
+}
+
+
 bool SharedFunctionInfo::has_deoptimization_support() {
   Code* code = this->code();
   return code->kind() == Code::FUNCTION && code->has_deoptimization_support();
 }
 
 
+void SharedFunctionInfo::TryReenableOptimization() {
+  int tries = opt_reenable_tries();
+  set_opt_reenable_tries(tries + 1);
+  // We reenable optimization whenever the number of tries is a large
+  // enough power of 2.
+  if (tries >= 16 && (((tries - 1) & tries) == 0)) {
+    set_optimization_disabled(false);
+    set_opt_count(0);
+    set_deopt_count(0);
+    code()->set_optimizable(true);
+  }
+}
+
+
 bool JSFunction::IsBuiltin() {
   return context()->global()->IsJSBuiltinsObject();
 }