Add monomorphic CompareNilICs and Crankshaft support

src/code-stubs.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 29 matching lines @@
 #define CODE_STUB_LIST_ALL_PLATFORMS(V)  \
   V(CallFunction)                        \
   V(CallConstruct)                       \
   V(UnaryOp)                             \
   V(BinaryOp)                            \
   V(StringAdd)                           \
   V(SubString)                           \
   V(StringCompare)                       \
   V(Compare)                             \
   V(CompareIC)                           \
+  V(CompareNilIC)                        \
   V(MathPow)                             \
   V(StringLength)                        \
   V(FunctionPrototype)                   \
   V(StoreArrayLength)                    \
   V(RecordWrite)                         \
   V(StoreBufferOverflow)                 \
   V(RegExpExec)                          \
   V(TranscendentalCache)                 \
   V(Instanceof)                          \
   V(ConvertToDouble)                     \
@@ skipping 879 matching lines @@
   virtual bool UseSpecialCache() { return state_ == CompareIC::KNOWN_OBJECT; }
 
   Token::Value op_;
   CompareIC::State left_;
   CompareIC::State right_;
   CompareIC::State state_;
   Handle<Map> known_map_;
 };
 
 
+class CompareNilICStub : public HydrogenCodeStub  {
+ public:
+  enum Types {
+    kCompareAgainstNull = 1 << 0,
+    kCompareAgainstUndefined = 1 << 1,
+    kCompareAgainstMonomorphicMap = 1 << 2,
+    kCompareAgainstUndetectable = 1 << 3,
+    kFullCompare = kCompareAgainstNull | kCompareAgainstUndefined |
+        kCompareAgainstUndetectable
+  };
+
+  CompareNilICStub(EqualityKind kind, NilValue nil, Types types)
+      : HydrogenCodeStub(CODE_STUB_IS_NOT_MISS), bit_field_(0) {
+    bit_field_ = EqualityKindField::encode(kind) |
+        NilValueField::encode(nil) |
+        TypesField::encode(types);
+  }
+
+  virtual InlineCacheState GetICState() {
+    Types types = GetTypes();
+    if (types == kFullCompare) {
+      return MEGAMORPHIC;
+    } else if ((types & kCompareAgainstMonomorphicMap) != 0) {
+      return MONOMORPHIC;
+    } else {
+      return PREMONOMORPHIC;
+    }
+  }
+
+  virtual Code::Kind GetCodeKind() const { return Code::COMPARE_NIL_IC; }
+
+  Handle<Code> GenerateCode();
+
+  static Handle<Code> GetUninitialized(Isolate* isolate,
+                                       EqualityKind kind,
+                                       NilValue nil) {
+    return CompareNilICStub(kind, nil).GetCode(isolate);
+  }
+
+  virtual void InitializeInterfaceDescriptor(
+      Isolate* isolate,
+      CodeStubInterfaceDescriptor* descriptor);
+
+  static void InitializeForIsolate(Isolate* isolate) {
+    CompareNilICStub compare_stub(kStrictEquality, kNullValue);
+    compare_stub.InitializeInterfaceDescriptor(
+        isolate,
+        isolate->code_stub_interface_descriptor(CodeStub::CompareNilIC));
+  }
+
+  virtual Code::ExtraICState GetExtraICState() {
+    return bit_field_;
+  }
+
+  EqualityKind GetKind() { return EqualityKindField::decode(bit_field_); }
+  NilValue GetNilValue() { return NilValueField::decode(bit_field_); }
+  Types GetTypes() { return TypesField::decode(bit_field_); }
+
+  static Types TypesFromExtraICState(
+      Code::ExtraICState state) {
+    return TypesField::decode(state);
+  }
+  static EqualityKind EqualityKindFromExtraICState(
+      Code::ExtraICState state) {
+    return EqualityKindField::decode(state);
+  }
+  static NilValue NilValueFromExtraICState(Code::ExtraICState state) {
+    return NilValueField::decode(state);
+  }
+
+  static Types GetPatchedICFlags(Code::ExtraICState extra_ic_state,
+                                 Handle<Object> object,
+                                 bool* already_monomorphic);
+
+ private:
+  friend class CompareNilIC;
+
+  class EqualityKindField : public BitField<EqualityKind, 0, 1> {};
+  class NilValueField : public BitField<NilValue, 1, 1> {};
+  class TypesField : public BitField<Types, 3, 4> {};
+
+  CompareNilICStub(EqualityKind kind, NilValue nil)
+      : HydrogenCodeStub(CODE_STUB_IS_MISS), bit_field_(0) {
+    bit_field_ = EqualityKindField::encode(kind) |
+        NilValueField::encode(nil);
+  }
+
+  virtual CodeStub::Major MajorKey() { return CompareNilIC; }
+  virtual int NotMissMinorKey() { return bit_field_; }
+
+  int bit_field_;
+
+  DISALLOW_COPY_AND_ASSIGN(CompareNilICStub);
+};
+
+
 class CEntryStub : public PlatformCodeStub {
  public:
   explicit CEntryStub(int result_size,
                       SaveFPRegsMode save_doubles = kDontSaveFPRegs)
       : result_size_(result_size), save_doubles_(save_doubles) { }
 
   void Generate(MacroAssembler* masm);
 
   // The version of this stub that doesn't save doubles is generated ahead of
   // time, so it's OK to call it from other stubs that can't cope with GC during
@@ skipping 768 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_