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

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index de0ffa3731b02c06273201cce9c83f52a0c08140..df44674a1ada01f354a8f678db327e5246ecff04 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -2416,6 +2416,12 @@ InlineCacheState Code::ic_state() {
 }
 
 
+Code::ExtraICState Code::extra_ic_state() {
+  ASSERT(is_inline_cache_stub());
+  return ExtractExtraICStateFromFlags(flags());
+}
+
+
 PropertyType Code::type() {
   ASSERT(ic_state() == MONOMORPHIC);
   return ExtractTypeFromFlags(flags());
@@ -2592,14 +2598,20 @@ bool Code::is_inline_cache_stub() {
 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.
@@ -2608,6 +2620,7 @@ Code::Flags Code::ComputeFlags(Kind 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;
 }
@@ -2615,10 +2628,12 @@ Code::Flags Code::ComputeFlags(Kind kind,
 
 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);
 }
 
 
@@ -2634,6 +2649,12 @@ InlineCacheState Code::ExtractICStateFromFlags(Flags flags) {
 }
 
 
+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;