Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2014 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_TYPE_FEEDBACK_VECTOR_H_ |
| 6 | #define V8_TYPE_FEEDBACK_VECTOR_H_ |
| 7 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 8 | #include <vector> |
| 9 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 10 | #include "src/checks.h" |
| 11 | #include "src/elements-kind.h" |
| 12 | #include "src/heap/heap.h" |
| 13 | #include "src/isolate.h" |
| 14 | #include "src/objects.h" |
| 15 | |
| 16 | namespace v8 { |
| 17 | namespace internal { |
| 18 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 19 | class FeedbackVectorSpec { |
| 20 | public: |
| 21 | FeedbackVectorSpec() : slots_(0), ic_slots_(0) {} |
| 22 | FeedbackVectorSpec(int slots, int ic_slots) |
| 23 | : slots_(slots), ic_slots_(ic_slots) { |
| 24 | if (FLAG_vector_ics) ic_slot_kinds_.resize(ic_slots); |
| 25 | } |
| 26 | |
| 27 | int slots() const { return slots_; } |
| 28 | void increase_slots(int count) { slots_ += count; } |
| 29 | |
| 30 | int ic_slots() const { return ic_slots_; } |
| 31 | void increase_ic_slots(int count) { |
| 32 | ic_slots_ += count; |
| 33 | if (FLAG_vector_ics) ic_slot_kinds_.resize(ic_slots_); |
| 34 | } |
| 35 | |
| 36 | void SetKind(int ic_slot, Code::Kind kind) { |
| 37 | DCHECK(FLAG_vector_ics); |
| 38 | ic_slot_kinds_[ic_slot] = kind; |
| 39 | } |
| 40 | |
| 41 | Code::Kind GetKind(int ic_slot) const { |
| 42 | DCHECK(FLAG_vector_ics); |
| 43 | return static_cast<Code::Kind>(ic_slot_kinds_.at(ic_slot)); |
| 44 | } |
| 45 | |
| 46 | private: |
| 47 | int slots_; |
| 48 | int ic_slots_; |
| 49 | std::vector<unsigned char> ic_slot_kinds_; |
| 50 | }; |
| 51 | |
| 52 | |
| 53 | // The shape of the TypeFeedbackVector is an array with: |
| 54 | // 0: first_ic_slot_index (== length() if no ic slots are present) |
| 55 | // 1: ics_with_types |
| 56 | // 2: ics_with_generic_info |
| 57 | // 3: type information for ic slots, if any |
| 58 | // ... |
| 59 | // N: first feedback slot (N >= 3) |
| 60 | // ... |
| 61 | // [<first_ic_slot_index>: feedback slot] |
| 62 | // ...to length() - 1 |
| 63 | // |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 64 | class TypeFeedbackVector : public FixedArray { |
| 65 | public: |
| 66 | // Casting. |
| 67 | static TypeFeedbackVector* cast(Object* obj) { |
| 68 | DCHECK(obj->IsTypeFeedbackVector()); |
| 69 | return reinterpret_cast<TypeFeedbackVector*>(obj); |
| 70 | } |
| 71 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 72 | static const int kReservedIndexCount = 3; |
| 73 | static const int kFirstICSlotIndex = 0; |
| 74 | static const int kWithTypesIndex = 1; |
| 75 | static const int kGenericCountIndex = 2; |
| 76 | |
| 77 | int first_ic_slot_index() const { |
| 78 | DCHECK(length() >= kReservedIndexCount); |
| 79 | return Smi::cast(get(kFirstICSlotIndex))->value(); |
| 80 | } |
| 81 | |
| 82 | int ic_with_type_info_count() { |
| 83 | return length() > 0 ? Smi::cast(get(kWithTypesIndex))->value() : 0; |
| 84 | } |
| 85 | |
| 86 | void change_ic_with_type_info_count(int delta) { |
| 87 | if (delta == 0) return; |
| 88 | int value = ic_with_type_info_count() + delta; |
| 89 | // Could go negative because of the debugger. |
| 90 | if (value >= 0) { |
| 91 | set(kWithTypesIndex, Smi::FromInt(value)); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | int ic_generic_count() { |
| 96 | return length() > 0 ? Smi::cast(get(kGenericCountIndex))->value() : 0; |
| 97 | } |
| 98 | |
| 99 | void change_ic_generic_count(int delta) { |
| 100 | if (delta == 0) return; |
| 101 | int value = ic_generic_count() + delta; |
| 102 | if (value >= 0) { |
| 103 | set(kGenericCountIndex, Smi::FromInt(value)); |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | inline int ic_metadata_length() const; |
| 108 | |
| 109 | int Slots() const { |
| 110 | if (length() == 0) return 0; |
| 111 | return Max( |
| 112 | 0, first_ic_slot_index() - ic_metadata_length() - kReservedIndexCount); |
| 113 | } |
| 114 | |
| 115 | int ICSlots() const { |
| 116 | if (length() == 0) return 0; |
| 117 | return length() - first_ic_slot_index(); |
| 118 | } |
| 119 | |
| 120 | // Conversion from a slot or ic slot to an integer index to the underlying |
| 121 | // array. |
| 122 | int GetIndex(FeedbackVectorSlot slot) const { |
| 123 | return kReservedIndexCount + ic_metadata_length() + slot.ToInt(); |
| 124 | } |
| 125 | |
| 126 | int GetIndex(FeedbackVectorICSlot slot) const { |
| 127 | int first_ic_slot = first_ic_slot_index(); |
| 128 | DCHECK(slot.ToInt() < ICSlots()); |
| 129 | return first_ic_slot + slot.ToInt(); |
| 130 | } |
| 131 | |
| 132 | // Conversion from an integer index to either a slot or an ic slot. The caller |
| 133 | // should know what kind she expects. |
| 134 | FeedbackVectorSlot ToSlot(int index) const { |
| 135 | DCHECK(index >= kReservedIndexCount && index < first_ic_slot_index()); |
| 136 | return FeedbackVectorSlot(index - ic_metadata_length() - |
| 137 | kReservedIndexCount); |
| 138 | } |
| 139 | |
| 140 | FeedbackVectorICSlot ToICSlot(int index) const { |
| 141 | DCHECK(index >= first_ic_slot_index() && index < length()); |
| 142 | return FeedbackVectorICSlot(index - first_ic_slot_index()); |
| 143 | } |
| 144 | |
| 145 | Object* Get(FeedbackVectorSlot slot) const { return get(GetIndex(slot)); } |
| 146 | void Set(FeedbackVectorSlot slot, Object* value, |
| 147 | WriteBarrierMode mode = UPDATE_WRITE_BARRIER) { |
| 148 | set(GetIndex(slot), value, mode); |
| 149 | } |
| 150 | |
| 151 | Object* Get(FeedbackVectorICSlot slot) const { return get(GetIndex(slot)); } |
| 152 | void Set(FeedbackVectorICSlot slot, Object* value, |
| 153 | WriteBarrierMode mode = UPDATE_WRITE_BARRIER) { |
| 154 | set(GetIndex(slot), value, mode); |
| 155 | } |
| 156 | |
| 157 | // IC slots need metadata to recognize the type of IC. |
| 158 | Code::Kind GetKind(FeedbackVectorICSlot slot) const; |
| 159 | |
| 160 | static Handle<TypeFeedbackVector> Allocate(Isolate* isolate, |
| 161 | const FeedbackVectorSpec& spec); |
| 162 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 163 | static Handle<TypeFeedbackVector> Copy(Isolate* isolate, |
| 164 | Handle<TypeFeedbackVector> vector); |
| 165 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 166 | // Clears the vector slots and the vector ic slots. |
| 167 | void ClearSlots(SharedFunctionInfo* shared); |
| 168 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 169 | // The object that indicates an uninitialized cache. |
| 170 | static inline Handle<Object> UninitializedSentinel(Isolate* isolate); |
| 171 | |
| 172 | // The object that indicates a megamorphic state. |
| 173 | static inline Handle<Object> MegamorphicSentinel(Isolate* isolate); |
| 174 | |
| 175 | // The object that indicates a premonomorphic state. |
| 176 | static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate); |
| 177 | |
| 178 | // The object that indicates a generic state. |
| 179 | static inline Handle<Object> GenericSentinel(Isolate* isolate); |
| 180 | |
| 181 | // The object that indicates a monomorphic state of Array with |
| 182 | // ElementsKind |
| 183 | static inline Handle<Object> MonomorphicArraySentinel( |
| 184 | Isolate* isolate, ElementsKind elements_kind); |
| 185 | |
| 186 | // A raw version of the uninitialized sentinel that's safe to read during |
| 187 | // garbage collection (e.g., for patching the cache). |
| 188 | static inline Object* RawUninitializedSentinel(Heap* heap); |
| 189 | |
| 190 | private: |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 191 | enum VectorICKind { |
| 192 | KindUnused = 0x0, |
| 193 | KindCallIC = 0x1, |
| 194 | KindLoadIC = 0x2, |
| 195 | KindKeyedLoadIC = 0x3 |
| 196 | }; |
| 197 | |
| 198 | static const int kVectorICKindBits = 2; |
| 199 | static VectorICKind FromCodeKind(Code::Kind kind); |
| 200 | static Code::Kind FromVectorICKind(VectorICKind kind); |
| 201 | void SetKind(FeedbackVectorICSlot slot, Code::Kind kind); |
| 202 | |
| 203 | typedef BitSetComputer<VectorICKind, kVectorICKindBits, kSmiValueSize, |
| 204 | uint32_t> VectorICComputer; |
| 205 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 206 | DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackVector); |
| 207 | }; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 208 | |
| 209 | |
| 210 | // A FeedbackNexus is the combination of a TypeFeedbackVector and a slot. |
| 211 | // Derived classes customize the update and retrieval of feedback. |
| 212 | class FeedbackNexus { |
| 213 | public: |
| 214 | FeedbackNexus(Handle<TypeFeedbackVector> vector, FeedbackVectorICSlot slot) |
| 215 | : vector_handle_(vector), vector_(NULL), slot_(slot) {} |
| 216 | FeedbackNexus(TypeFeedbackVector* vector, FeedbackVectorICSlot slot) |
| 217 | : vector_(vector), slot_(slot) {} |
| 218 | virtual ~FeedbackNexus() {} |
| 219 | |
| 220 | Handle<TypeFeedbackVector> vector_handle() const { |
| 221 | DCHECK(vector_ == NULL); |
| 222 | return vector_handle_; |
| 223 | } |
| 224 | TypeFeedbackVector* vector() const { |
| 225 | return vector_handle_.is_null() ? vector_ : *vector_handle_; |
| 226 | } |
| 227 | FeedbackVectorICSlot slot() const { return slot_; } |
| 228 | |
| 229 | InlineCacheState ic_state() const { return StateFromFeedback(); } |
| 230 | Map* FindFirstMap() const { |
| 231 | MapHandleList maps; |
| 232 | ExtractMaps(&maps); |
| 233 | if (maps.length() > 0) return *maps.at(0); |
| 234 | return NULL; |
| 235 | } |
| 236 | |
| 237 | // TODO(mvstanton): remove FindAllMaps, it didn't survive a code review. |
| 238 | void FindAllMaps(MapHandleList* maps) const { ExtractMaps(maps); } |
| 239 | |
| 240 | virtual InlineCacheState StateFromFeedback() const = 0; |
| 241 | virtual int ExtractMaps(MapHandleList* maps) const = 0; |
| 242 | virtual MaybeHandle<Code> FindHandlerForMap(Handle<Map> map) const = 0; |
| 243 | virtual bool FindHandlers(CodeHandleList* code_list, int length = -1) const { |
| 244 | return length == 0; |
| 245 | } |
| 246 | virtual Name* FindFirstName() const { return NULL; } |
| 247 | |
| 248 | Object* GetFeedback() const { return vector()->Get(slot()); } |
| 249 | |
| 250 | protected: |
| 251 | Isolate* GetIsolate() const { return vector()->GetIsolate(); } |
| 252 | |
| 253 | void SetFeedback(Object* feedback, |
| 254 | WriteBarrierMode mode = UPDATE_WRITE_BARRIER) { |
| 255 | vector()->Set(slot(), feedback, mode); |
| 256 | } |
| 257 | |
| 258 | Handle<FixedArray> EnsureArrayOfSize(int length); |
| 259 | void InstallHandlers(int start_index, TypeHandleList* types, |
| 260 | CodeHandleList* handlers); |
| 261 | int ExtractMaps(int start_index, MapHandleList* maps) const; |
| 262 | MaybeHandle<Code> FindHandlerForMap(int start_index, Handle<Map> map) const; |
| 263 | bool FindHandlers(int start_index, CodeHandleList* code_list, |
| 264 | int length) const; |
| 265 | |
| 266 | private: |
| 267 | // The reason for having a vector handle and a raw pointer is that we can and |
| 268 | // should use handles during IC miss, but not during GC when we clear ICs. If |
| 269 | // you have a handle to the vector that is better because more operations can |
| 270 | // be done, like allocation. |
| 271 | Handle<TypeFeedbackVector> vector_handle_; |
| 272 | TypeFeedbackVector* vector_; |
| 273 | FeedbackVectorICSlot slot_; |
| 274 | }; |
| 275 | |
| 276 | |
| 277 | class CallICNexus : public FeedbackNexus { |
| 278 | public: |
| 279 | CallICNexus(Handle<TypeFeedbackVector> vector, FeedbackVectorICSlot slot) |
| 280 | : FeedbackNexus(vector, slot) { |
| 281 | DCHECK(vector->GetKind(slot) == Code::CALL_IC); |
| 282 | } |
| 283 | CallICNexus(TypeFeedbackVector* vector, FeedbackVectorICSlot slot) |
| 284 | : FeedbackNexus(vector, slot) { |
| 285 | DCHECK(vector->GetKind(slot) == Code::CALL_IC); |
| 286 | } |
| 287 | |
| 288 | void Clear(Code* host); |
| 289 | |
| 290 | void ConfigureUninitialized(); |
| 291 | void ConfigureGeneric(); |
| 292 | void ConfigureMonomorphicArray(); |
| 293 | void ConfigureMonomorphic(Handle<JSFunction> function); |
| 294 | |
| 295 | InlineCacheState StateFromFeedback() const OVERRIDE; |
| 296 | |
| 297 | int ExtractMaps(MapHandleList* maps) const OVERRIDE { |
| 298 | // CallICs don't record map feedback. |
| 299 | return 0; |
| 300 | } |
| 301 | MaybeHandle<Code> FindHandlerForMap(Handle<Map> map) const OVERRIDE { |
| 302 | return MaybeHandle<Code>(); |
| 303 | } |
| 304 | virtual bool FindHandlers(CodeHandleList* code_list, |
| 305 | int length = -1) const OVERRIDE { |
| 306 | return length == 0; |
| 307 | } |
| 308 | }; |
| 309 | |
| 310 | |
| 311 | class LoadICNexus : public FeedbackNexus { |
| 312 | public: |
| 313 | LoadICNexus(Handle<TypeFeedbackVector> vector, FeedbackVectorICSlot slot) |
| 314 | : FeedbackNexus(vector, slot) { |
| 315 | DCHECK(vector->GetKind(slot) == Code::LOAD_IC); |
| 316 | } |
| 317 | LoadICNexus(TypeFeedbackVector* vector, FeedbackVectorICSlot slot) |
| 318 | : FeedbackNexus(vector, slot) { |
| 319 | DCHECK(vector->GetKind(slot) == Code::LOAD_IC); |
| 320 | } |
| 321 | |
| 322 | void Clear(Code* host); |
| 323 | |
| 324 | void ConfigureMegamorphic(); |
| 325 | void ConfigurePremonomorphic(); |
| 326 | void ConfigureMonomorphic(Handle<HeapType> type, Handle<Code> handler); |
| 327 | |
| 328 | void ConfigurePolymorphic(TypeHandleList* types, CodeHandleList* handlers); |
| 329 | |
| 330 | InlineCacheState StateFromFeedback() const OVERRIDE; |
| 331 | int ExtractMaps(MapHandleList* maps) const OVERRIDE; |
| 332 | MaybeHandle<Code> FindHandlerForMap(Handle<Map> map) const OVERRIDE; |
| 333 | virtual bool FindHandlers(CodeHandleList* code_list, |
| 334 | int length = -1) const OVERRIDE; |
| 335 | }; |
| 336 | |
| 337 | |
| 338 | class KeyedLoadICNexus : public FeedbackNexus { |
| 339 | public: |
| 340 | KeyedLoadICNexus(Handle<TypeFeedbackVector> vector, FeedbackVectorICSlot slot) |
| 341 | : FeedbackNexus(vector, slot) { |
| 342 | DCHECK(vector->GetKind(slot) == Code::KEYED_LOAD_IC); |
| 343 | } |
| 344 | KeyedLoadICNexus(TypeFeedbackVector* vector, FeedbackVectorICSlot slot) |
| 345 | : FeedbackNexus(vector, slot) { |
| 346 | DCHECK(vector->GetKind(slot) == Code::KEYED_LOAD_IC); |
| 347 | } |
| 348 | |
| 349 | void Clear(Code* host); |
| 350 | |
| 351 | void ConfigureGeneric(); |
| 352 | void ConfigurePremonomorphic(); |
| 353 | // name can be a null handle for element loads. |
| 354 | void ConfigureMonomorphic(Handle<Name> name, Handle<HeapType> type, |
| 355 | Handle<Code> handler); |
| 356 | // name can be null. |
| 357 | void ConfigurePolymorphic(Handle<Name> name, TypeHandleList* types, |
| 358 | CodeHandleList* handlers); |
| 359 | |
| 360 | InlineCacheState StateFromFeedback() const OVERRIDE; |
| 361 | int ExtractMaps(MapHandleList* maps) const OVERRIDE; |
| 362 | MaybeHandle<Code> FindHandlerForMap(Handle<Map> map) const OVERRIDE; |
| 363 | virtual bool FindHandlers(CodeHandleList* code_list, |
| 364 | int length = -1) const OVERRIDE; |
| 365 | Name* FindFirstName() const OVERRIDE; |
| 366 | }; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 367 | } |
| 368 | } // namespace v8::internal |
| 369 | |
| 370 | #endif // V8_TRANSITIONS_H_ |