Introduce extra IC state to record additional feedback from IC-s.

src/objects-inl.h

 // Copyright 2010 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 2378 matching lines @@
   // objects. This is used in the debugger to determine whether or not
   // a call to code object has been replaced with a debug break call.
   ASSERT(is_inline_cache_stub() ||
          result == UNINITIALIZED ||
          result == DEBUG_BREAK ||
          result == DEBUG_PREPARE_STEP_IN);
   return result;
 }
 
 
+Code::ExtraICState Code::extra_ic_state() {
+  ASSERT(is_inline_cache_stub());
+  return ExtractExtraICStateFromFlags(flags());
+}
+
+
 PropertyType Code::type() {
   ASSERT(ic_state() == MONOMORPHIC);
   return ExtractTypeFromFlags(flags());
 }
 
 
 int Code::arguments_count() {
   ASSERT(is_call_stub() || is_keyed_call_stub() || kind() == STUB);
   return ExtractArgumentsCountFromFlags(flags());
 }
@@ skipping 156 matching lines @@
 
 bool Code::is_inline_cache_stub() {
   Kind kind = this->kind();
   return kind >= FIRST_IC_KIND && kind <= LAST_IC_KIND;
 }
 
 
 Code::Flags Code::ComputeFlags(Kind kind,
                                InLoopFlag in_loop,
                                InlineCacheState ic_state,
+                               ExtraICState extra_ic_state,
                                PropertyType type,
                                int argc,
                                InlineCacheHolderFlag holder) {
+  // Extra IC state is only allowed for monomorphic call IC stubs.
+  ASSERT(extra_ic_state == kNoExtraICState ||
+         (kind == CALL_IC && (ic_state == MONOMORPHIC ||
+                              ic_state == MONOMORPHIC_PROTOTYPE_FAILURE)));
   // Compute the bit mask.
   int bits = kind << kFlagsKindShift;
   if (in_loop) bits |= kFlagsICInLoopMask;
   bits |= ic_state << kFlagsICStateShift;
   bits |= type << kFlagsTypeShift;
+  bits |= extra_ic_state << kFlagsExtraICStateShift;
   bits |= argc << kFlagsArgumentsCountShift;
   if (holder == PROTOTYPE_MAP) bits |= kFlagsCacheInPrototypeMapMask;
   // Cast to flags and validate result before returning it.
   Flags result = static_cast<Flags>(bits);
   ASSERT(ExtractKindFromFlags(result) == kind);
   ASSERT(ExtractICStateFromFlags(result) == ic_state);
   ASSERT(ExtractICInLoopFromFlags(result) == in_loop);
   ASSERT(ExtractTypeFromFlags(result) == type);
+  ASSERT(ExtractExtraICStateFromFlags(result) == extra_ic_state);
   ASSERT(ExtractArgumentsCountFromFlags(result) == argc);
   return result;
 }
 
 
 Code::Flags Code::ComputeMonomorphicFlags(Kind kind,
                                           PropertyType type,
+                                          ExtraICState extra_ic_state,
                                           InlineCacheHolderFlag holder,
                                           InLoopFlag in_loop,
                                           int argc) {
-  return ComputeFlags(kind, in_loop, MONOMORPHIC, type, argc, holder);
+  return ComputeFlags(
+      kind, in_loop, MONOMORPHIC, extra_ic_state, type, argc, holder);
 }
 
 
 Code::Kind Code::ExtractKindFromFlags(Flags flags) {
   int bits = (flags & kFlagsKindMask) >> kFlagsKindShift;
   return static_cast<Kind>(bits);
 }
 
 
 InlineCacheState Code::ExtractICStateFromFlags(Flags flags) {
   int bits = (flags & kFlagsICStateMask) >> kFlagsICStateShift;
   return static_cast<InlineCacheState>(bits);
 }
 
 
+Code::ExtraICState Code::ExtractExtraICStateFromFlags(Flags flags) {
+  int bits = (flags & kFlagsExtraICStateMask) >> kFlagsExtraICStateShift;
+  return static_cast<ExtraICState>(bits);
+}
+
+
 InLoopFlag Code::ExtractICInLoopFromFlags(Flags flags) {
   int bits = (flags & kFlagsICInLoopMask);
   return bits != 0 ? IN_LOOP : NOT_IN_LOOP;
 }
 
 
 PropertyType Code::ExtractTypeFromFlags(Flags flags) {
   int bits = (flags & kFlagsTypeMask) >> kFlagsTypeShift;
   return static_cast<PropertyType>(bits);
 }
@@ skipping 1222 matching lines @@
 #undef WRITE_INT_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_