Disable speculative LICM when it may lead to unnecessary deopts

src/objects.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 6838 matching lines @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable);
 };
 
 
 class TypeFeedbackInfo: public Struct {
  public:
   inline int ic_total_count();
   inline void set_ic_total_count(int count);
 
   inline int ic_with_type_info_count();
-  inline void set_ic_with_type_info_count(int count);
+  inline void change_ic_with_type_info_count(int count);
+
+  inline void initialize_storage();
+
+  inline void change_own_type_change_checksum();
+  inline int own_type_change_checksum();
+
+  inline void set_inlined_type_change_checksum(int checksum);
+  inline bool matches_inlined_type_change_checksum(int checksum);
 
   DECL_ACCESSORS(type_feedback_cells, TypeFeedbackCells)
 
   static inline TypeFeedbackInfo* cast(Object* obj);
 
 #ifdef OBJECT_PRINT
   inline void TypeFeedbackInfoPrint() {
     TypeFeedbackInfoPrint(stdout);
   }
   void TypeFeedbackInfoPrint(FILE* out);
 #endif
 #ifdef DEBUG
   void TypeFeedbackInfoVerify();
 #endif
 
-  static const int kIcTotalCountOffset = HeapObject::kHeaderSize;
-  static const int kIcWithTypeinfoCountOffset =
-      kIcTotalCountOffset + kPointerSize;
-  static const int kTypeFeedbackCellsOffset =
-      kIcWithTypeinfoCountOffset + kPointerSize;
+  static const int kStorage1Offset = HeapObject::kHeaderSize;
+  static const int kStorage2Offset = kStorage1Offset + kPointerSize;
+  static const int kTypeFeedbackCellsOffset = kStorage2Offset + kPointerSize;
   static const int kSize = kTypeFeedbackCellsOffset + kPointerSize;
 
  private:
+  static const int kTypeChangeChecksumBits = 7;
+
+  class ICTotalCountField: public BitField<int, 0,
+      kSmiValueSize - kTypeChangeChecksumBits> {};  // NOLINT
+  class OwnTypeChangeChecksum: public BitField<int,
+      kSmiValueSize - kTypeChangeChecksumBits,
+      kTypeChangeChecksumBits> {};  // NOLINT
+  class ICsWithTypeInfoCountField: public BitField<int, 0,
+      kSmiValueSize - kTypeChangeChecksumBits> {};  // NOLINT
+  class InlinedTypeChangeChecksum: public BitField<int,
+      kSmiValueSize - kTypeChangeChecksumBits,
+      kTypeChangeChecksumBits> {};  // NOLINT
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo);
 };
 
 
 // Representation of a slow alias as part of a non-strict arguments objects.
 // For fast aliases (if HasNonStrictArgumentsElements()):
 // - the parameter map contains an index into the context
 // - all attributes of the element have default values
 // For slow aliases (if HasDictionaryArgumentsElements()):
 // - the parameter map contains no fast alias mapping (i.e. the hole)
@@ skipping 2022 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_