Re-enable optimization for hot functions that have optimization disabled due to many deopts.

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 3493 matching lines @@
 ACCESSORS(SharedFunctionInfo, construct_stub, Code, kConstructStubOffset)
 ACCESSORS(SharedFunctionInfo, initial_map, Object, kInitialMapOffset)
 ACCESSORS(SharedFunctionInfo, instance_class_name, Object,
           kInstanceClassNameOffset)
 ACCESSORS(SharedFunctionInfo, function_data, Object, kFunctionDataOffset)
 ACCESSORS(SharedFunctionInfo, script, Object, kScriptOffset)
 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)
 
 
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, hidden_prototype,
                kHiddenPrototypeBit)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, undetectable, kUndetectableBit)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, needs_access_check,
                kNeedsAccessCheckBit)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, read_only_prototype,
                kReadOnlyPrototypeBit)
 BOOL_ACCESSORS(SharedFunctionInfo, start_position_and_type, is_expression,
@@ skipping 30 matching lines @@
 SMI_ACCESSORS(SharedFunctionInfo, end_position, kEndPositionOffset)
 SMI_ACCESSORS(SharedFunctionInfo, function_token_position,
               kFunctionTokenPositionOffset)
 SMI_ACCESSORS(SharedFunctionInfo, compiler_hints,
               kCompilerHintsOffset)
 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, ic_age, kICAgeOffset)
+SMI_ACCESSORS(SharedFunctionInfo, opt_reenable_tries, kOptReenableTriesOffset)
 #else
 
 #define PSEUDO_SMI_ACCESSORS_LO(holder, name, offset)             \
   STATIC_ASSERT(holder::offset % kPointerSize == 0);              \
   int holder::name() {                                            \
     int value = READ_INT_FIELD(this, offset);                     \
     ASSERT(kHeapObjectTag == 1);                                  \
     ASSERT((value & kHeapObjectTag) == 0);                        \
     return value >> 1;                                            \
   }                                                               \
@@ skipping 33 matching lines @@
                         compiler_hints,
                         kCompilerHintsOffset)
 
 PSEUDO_SMI_ACCESSORS_LO(SharedFunctionInfo,
                         this_property_assignments_count,
                         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, ic_age, kICAgeOffset)
+PSEUDO_SMI_ACCESSORS_HI(SharedFunctionInfo,
+                        opt_reenable_tries,
+                        kOptReenableTriesOffset)
 #endif
 
 
 int SharedFunctionInfo::construction_count() {
   return READ_BYTE_FIELD(this, kConstructionCountOffset);
 }
 
 
 void SharedFunctionInfo::set_construction_count(int value) {
   ASSERT(0 <= value && value < 256);
@@ skipping 19 matching lines @@
 
 
 void SharedFunctionInfo::set_optimization_disabled(bool disable) {
   set_compiler_hints(BooleanBit::set(compiler_hints(),
                                      kOptimizationDisabled,
                                      disable));
   // If disabling optimizations we reflect that in the code object so
   // it will not be counted as optimizable code.
   if ((code()->kind() == Code::FUNCTION) && disable) {
     code()->set_optimizable(false);
+    code()->set_profiler_ticks(0);
   }
 }
 
 
 LanguageMode SharedFunctionInfo::language_mode() {
   int hints = compiler_hints();
   if (BooleanBit::get(hints, kExtendedModeFunction)) {
     ASSERT(BooleanBit::get(hints, kStrictModeFunction));
     return EXTENDED_MODE;
   }
@@ skipping 15 matching lines @@
   hints = BooleanBit::set(
       hints, kExtendedModeFunction, language_mode == EXTENDED_MODE);
   set_compiler_hints(hints);
 }
 
 
 bool SharedFunctionInfo::is_classic_mode() {
   return !BooleanBit::get(compiler_hints(), kStrictModeFunction);
 }
 
+
+void SharedFunctionInfo::TryReenableOptimization() {
+  int tries = opt_reenable_tries();
+  if (tries == Smi::kMaxValue) {
+    tries = 0;
+  }
+  set_opt_reenable_tries(tries + 1);
+  // We reenable optimization whenever the number of tries is a large
+  // enough power of 2.
+  if (tries > 4 && (((tries - 1) & tries) == 0)) {

[Jakob Kummerow, 2012/04/24 10:38:22]

nit: did you mean ">= 4"?

[ulan, 2012/04/24 12:36:08]

Yes, that's what I meant. :)
Performance on our benchmarks is similar, but in mandreel test the ">=" version
runs slightly faster.

+    set_optimization_disabled(false);
+    set_opt_count(0);
+    code()->set_optimizable(true);
+  }
+}
+
+
 BOOL_GETTER(SharedFunctionInfo, compiler_hints, is_extended_mode,
             kExtendedModeFunction)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, native, kNative)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints,
                name_should_print_as_anonymous,
                kNameShouldPrintAsAnonymous)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, bound, kBoundFunction)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, is_anonymous, kIsAnonymous)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, is_function, kIsFunction)
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, dont_optimize,
@@ skipping 1240 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_