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_REGISTER_ALLOCATOR_H_ |
| 6 | #define V8_REGISTER_ALLOCATOR_H_ |
| 7 | |
| 8 | #include "src/allocation.h" |
| 9 | #include "src/compiler/instruction.h" |
| 10 | #include "src/compiler/node.h" |
| 11 | #include "src/compiler/schedule.h" |
| 12 | #include "src/macro-assembler.h" |
| 13 | #include "src/zone.h" |
| 14 | |
| 15 | namespace v8 { |
| 16 | namespace internal { |
| 17 | |
| 18 | // Forward declarations. |
| 19 | class BitVector; |
| 20 | class InstructionOperand; |
| 21 | class UnallocatedOperand; |
| 22 | class ParallelMove; |
| 23 | class PointerMap; |
| 24 | |
| 25 | namespace compiler { |
| 26 | |
| 27 | enum RegisterKind { |
| 28 | UNALLOCATED_REGISTERS, |
| 29 | GENERAL_REGISTERS, |
| 30 | DOUBLE_REGISTERS |
| 31 | }; |
| 32 | |
| 33 | |
| 34 | // This class represents a single point of a InstructionOperand's lifetime. For |
| 35 | // each instruction there are exactly two lifetime positions: the beginning and |
| 36 | // the end of the instruction. Lifetime positions for different instructions are |
| 37 | // disjoint. |
| 38 | class LifetimePosition { |
| 39 | public: |
| 40 | // Return the lifetime position that corresponds to the beginning of |
| 41 | // the instruction with the given index. |
| 42 | static LifetimePosition FromInstructionIndex(int index) { |
| 43 | return LifetimePosition(index * kStep); |
| 44 | } |
| 45 | |
| 46 | // Returns a numeric representation of this lifetime position. |
| 47 | int Value() const { return value_; } |
| 48 | |
| 49 | // Returns the index of the instruction to which this lifetime position |
| 50 | // corresponds. |
| 51 | int InstructionIndex() const { |
| 52 | DCHECK(IsValid()); |
| 53 | return value_ / kStep; |
| 54 | } |
| 55 | |
| 56 | // Returns true if this lifetime position corresponds to the instruction |
| 57 | // start. |
| 58 | bool IsInstructionStart() const { return (value_ & (kStep - 1)) == 0; } |
| 59 | |
| 60 | // Returns the lifetime position for the start of the instruction which |
| 61 | // corresponds to this lifetime position. |
| 62 | LifetimePosition InstructionStart() const { |
| 63 | DCHECK(IsValid()); |
| 64 | return LifetimePosition(value_ & ~(kStep - 1)); |
| 65 | } |
| 66 | |
| 67 | // Returns the lifetime position for the end of the instruction which |
| 68 | // corresponds to this lifetime position. |
| 69 | LifetimePosition InstructionEnd() const { |
| 70 | DCHECK(IsValid()); |
| 71 | return LifetimePosition(InstructionStart().Value() + kStep / 2); |
| 72 | } |
| 73 | |
| 74 | // Returns the lifetime position for the beginning of the next instruction. |
| 75 | LifetimePosition NextInstruction() const { |
| 76 | DCHECK(IsValid()); |
| 77 | return LifetimePosition(InstructionStart().Value() + kStep); |
| 78 | } |
| 79 | |
| 80 | // Returns the lifetime position for the beginning of the previous |
| 81 | // instruction. |
| 82 | LifetimePosition PrevInstruction() const { |
| 83 | DCHECK(IsValid()); |
| 84 | DCHECK(value_ > 1); |
| 85 | return LifetimePosition(InstructionStart().Value() - kStep); |
| 86 | } |
| 87 | |
| 88 | // Constructs the lifetime position which does not correspond to any |
| 89 | // instruction. |
| 90 | LifetimePosition() : value_(-1) {} |
| 91 | |
| 92 | // Returns true if this lifetime positions corrensponds to some |
| 93 | // instruction. |
| 94 | bool IsValid() const { return value_ != -1; } |
| 95 | |
| 96 | static inline LifetimePosition Invalid() { return LifetimePosition(); } |
| 97 | |
| 98 | static inline LifetimePosition MaxPosition() { |
| 99 | // We have to use this kind of getter instead of static member due to |
| 100 | // crash bug in GDB. |
| 101 | return LifetimePosition(kMaxInt); |
| 102 | } |
| 103 | |
| 104 | private: |
| 105 | static const int kStep = 2; |
| 106 | |
| 107 | // Code relies on kStep being a power of two. |
| 108 | STATIC_ASSERT(IS_POWER_OF_TWO(kStep)); |
| 109 | |
| 110 | explicit LifetimePosition(int value) : value_(value) {} |
| 111 | |
| 112 | int value_; |
| 113 | }; |
| 114 | |
| 115 | |
| 116 | // Representation of the non-empty interval [start,end[. |
| 117 | class UseInterval : public ZoneObject { |
| 118 | public: |
| 119 | UseInterval(LifetimePosition start, LifetimePosition end) |
| 120 | : start_(start), end_(end), next_(NULL) { |
| 121 | DCHECK(start.Value() < end.Value()); |
| 122 | } |
| 123 | |
| 124 | LifetimePosition start() const { return start_; } |
| 125 | LifetimePosition end() const { return end_; } |
| 126 | UseInterval* next() const { return next_; } |
| 127 | |
| 128 | // Split this interval at the given position without effecting the |
| 129 | // live range that owns it. The interval must contain the position. |
| 130 | void SplitAt(LifetimePosition pos, Zone* zone); |
| 131 | |
| 132 | // If this interval intersects with other return smallest position |
| 133 | // that belongs to both of them. |
| 134 | LifetimePosition Intersect(const UseInterval* other) const { |
| 135 | if (other->start().Value() < start_.Value()) return other->Intersect(this); |
| 136 | if (other->start().Value() < end_.Value()) return other->start(); |
| 137 | return LifetimePosition::Invalid(); |
| 138 | } |
| 139 | |
| 140 | bool Contains(LifetimePosition point) const { |
| 141 | return start_.Value() <= point.Value() && point.Value() < end_.Value(); |
| 142 | } |
| 143 | |
| 144 | void set_start(LifetimePosition start) { start_ = start; } |
| 145 | void set_next(UseInterval* next) { next_ = next; } |
| 146 | |
| 147 | LifetimePosition start_; |
| 148 | LifetimePosition end_; |
| 149 | UseInterval* next_; |
| 150 | }; |
| 151 | |
| 152 | // Representation of a use position. |
| 153 | class UsePosition : public ZoneObject { |
| 154 | public: |
| 155 | UsePosition(LifetimePosition pos, InstructionOperand* operand, |
| 156 | InstructionOperand* hint); |
| 157 | |
| 158 | InstructionOperand* operand() const { return operand_; } |
| 159 | bool HasOperand() const { return operand_ != NULL; } |
| 160 | |
| 161 | InstructionOperand* hint() const { return hint_; } |
| 162 | bool HasHint() const; |
| 163 | bool RequiresRegister() const; |
| 164 | bool RegisterIsBeneficial() const; |
| 165 | |
| 166 | LifetimePosition pos() const { return pos_; } |
| 167 | UsePosition* next() const { return next_; } |
| 168 | |
| 169 | void set_next(UsePosition* next) { next_ = next; } |
| 170 | |
| 171 | InstructionOperand* const operand_; |
| 172 | InstructionOperand* const hint_; |
| 173 | LifetimePosition const pos_; |
| 174 | UsePosition* next_; |
| 175 | bool requires_reg_; |
| 176 | bool register_beneficial_; |
| 177 | }; |
| 178 | |
| 179 | // Representation of SSA values' live ranges as a collection of (continuous) |
| 180 | // intervals over the instruction ordering. |
| 181 | class LiveRange : public ZoneObject { |
| 182 | public: |
| 183 | static const int kInvalidAssignment = 0x7fffffff; |
| 184 | |
| 185 | LiveRange(int id, Zone* zone); |
| 186 | |
| 187 | UseInterval* first_interval() const { return first_interval_; } |
| 188 | UsePosition* first_pos() const { return first_pos_; } |
| 189 | LiveRange* parent() const { return parent_; } |
| 190 | LiveRange* TopLevel() { return (parent_ == NULL) ? this : parent_; } |
| 191 | LiveRange* next() const { return next_; } |
| 192 | bool IsChild() const { return parent() != NULL; } |
| 193 | int id() const { return id_; } |
| 194 | bool IsFixed() const { return id_ < 0; } |
| 195 | bool IsEmpty() const { return first_interval() == NULL; } |
| 196 | InstructionOperand* CreateAssignedOperand(Zone* zone); |
| 197 | int assigned_register() const { return assigned_register_; } |
| 198 | int spill_start_index() const { return spill_start_index_; } |
| 199 | void set_assigned_register(int reg, Zone* zone); |
| 200 | void MakeSpilled(Zone* zone); |
| 201 | bool is_phi() const { return is_phi_; } |
| 202 | void set_is_phi(bool is_phi) { is_phi_ = is_phi; } |
| 203 | bool is_non_loop_phi() const { return is_non_loop_phi_; } |
| 204 | void set_is_non_loop_phi(bool is_non_loop_phi) { |
| 205 | is_non_loop_phi_ = is_non_loop_phi; |
| 206 | } |
| 207 | |
| 208 | // Returns use position in this live range that follows both start |
| 209 | // and last processed use position. |
| 210 | // Modifies internal state of live range! |
| 211 | UsePosition* NextUsePosition(LifetimePosition start); |
| 212 | |
| 213 | // Returns use position for which register is required in this live |
| 214 | // range and which follows both start and last processed use position |
| 215 | // Modifies internal state of live range! |
| 216 | UsePosition* NextRegisterPosition(LifetimePosition start); |
| 217 | |
| 218 | // Returns use position for which register is beneficial in this live |
| 219 | // range and which follows both start and last processed use position |
| 220 | // Modifies internal state of live range! |
| 221 | UsePosition* NextUsePositionRegisterIsBeneficial(LifetimePosition start); |
| 222 | |
| 223 | // Returns use position for which register is beneficial in this live |
| 224 | // range and which precedes start. |
| 225 | UsePosition* PreviousUsePositionRegisterIsBeneficial(LifetimePosition start); |
| 226 | |
| 227 | // Can this live range be spilled at this position. |
| 228 | bool CanBeSpilled(LifetimePosition pos); |
| 229 | |
| 230 | // Split this live range at the given position which must follow the start of |
| 231 | // the range. |
| 232 | // All uses following the given position will be moved from this |
| 233 | // live range to the result live range. |
| 234 | void SplitAt(LifetimePosition position, LiveRange* result, Zone* zone); |
| 235 | |
| 236 | RegisterKind Kind() const { return kind_; } |
| 237 | bool HasRegisterAssigned() const { |
| 238 | return assigned_register_ != kInvalidAssignment; |
| 239 | } |
| 240 | bool IsSpilled() const { return spilled_; } |
| 241 | |
| 242 | InstructionOperand* current_hint_operand() const { |
| 243 | DCHECK(current_hint_operand_ == FirstHint()); |
| 244 | return current_hint_operand_; |
| 245 | } |
| 246 | InstructionOperand* FirstHint() const { |
| 247 | UsePosition* pos = first_pos_; |
| 248 | while (pos != NULL && !pos->HasHint()) pos = pos->next(); |
| 249 | if (pos != NULL) return pos->hint(); |
| 250 | return NULL; |
| 251 | } |
| 252 | |
| 253 | LifetimePosition Start() const { |
| 254 | DCHECK(!IsEmpty()); |
| 255 | return first_interval()->start(); |
| 256 | } |
| 257 | |
| 258 | LifetimePosition End() const { |
| 259 | DCHECK(!IsEmpty()); |
| 260 | return last_interval_->end(); |
| 261 | } |
| 262 | |
| 263 | bool HasAllocatedSpillOperand() const; |
| 264 | InstructionOperand* GetSpillOperand() const { return spill_operand_; } |
| 265 | void SetSpillOperand(InstructionOperand* operand); |
| 266 | |
| 267 | void SetSpillStartIndex(int start) { |
| 268 | spill_start_index_ = Min(start, spill_start_index_); |
| 269 | } |
| 270 | |
| 271 | bool ShouldBeAllocatedBefore(const LiveRange* other) const; |
| 272 | bool CanCover(LifetimePosition position) const; |
| 273 | bool Covers(LifetimePosition position); |
| 274 | LifetimePosition FirstIntersection(LiveRange* other); |
| 275 | |
| 276 | // Add a new interval or a new use position to this live range. |
| 277 | void EnsureInterval(LifetimePosition start, LifetimePosition end, Zone* zone); |
| 278 | void AddUseInterval(LifetimePosition start, LifetimePosition end, Zone* zone); |
| 279 | void AddUsePosition(LifetimePosition pos, InstructionOperand* operand, |
| 280 | InstructionOperand* hint, Zone* zone); |
| 281 | |
| 282 | // Shorten the most recently added interval by setting a new start. |
| 283 | void ShortenTo(LifetimePosition start); |
| 284 | |
| 285 | #ifdef DEBUG |
| 286 | // True if target overlaps an existing interval. |
| 287 | bool HasOverlap(UseInterval* target) const; |
| 288 | void Verify() const; |
| 289 | #endif |
| 290 | |
| 291 | private: |
| 292 | void ConvertOperands(Zone* zone); |
| 293 | UseInterval* FirstSearchIntervalForPosition(LifetimePosition position) const; |
| 294 | void AdvanceLastProcessedMarker(UseInterval* to_start_of, |
| 295 | LifetimePosition but_not_past) const; |
| 296 | |
| 297 | int id_; |
| 298 | bool spilled_; |
| 299 | bool is_phi_; |
| 300 | bool is_non_loop_phi_; |
| 301 | RegisterKind kind_; |
| 302 | int assigned_register_; |
| 303 | UseInterval* last_interval_; |
| 304 | UseInterval* first_interval_; |
| 305 | UsePosition* first_pos_; |
| 306 | LiveRange* parent_; |
| 307 | LiveRange* next_; |
| 308 | // This is used as a cache, it doesn't affect correctness. |
| 309 | mutable UseInterval* current_interval_; |
| 310 | UsePosition* last_processed_use_; |
| 311 | // This is used as a cache, it's invalid outside of BuildLiveRanges. |
| 312 | InstructionOperand* current_hint_operand_; |
| 313 | InstructionOperand* spill_operand_; |
| 314 | int spill_start_index_; |
| 315 | |
| 316 | friend class RegisterAllocator; // Assigns to kind_. |
| 317 | }; |
| 318 | |
| 319 | |
| 320 | class RegisterAllocator BASE_EMBEDDED { |
| 321 | public: |
| 322 | explicit RegisterAllocator(InstructionSequence* code); |
| 323 | |
| 324 | static void TraceAlloc(const char* msg, ...); |
| 325 | |
| 326 | // Checks whether the value of a given virtual register is a reference. |
| 327 | // TODO(titzer): rename this to IsReference. |
| 328 | bool HasTaggedValue(int virtual_register) const; |
| 329 | |
| 330 | // Returns the register kind required by the given virtual register. |
| 331 | RegisterKind RequiredRegisterKind(int virtual_register) const; |
| 332 | |
| 333 | bool Allocate(); |
| 334 | |
| 335 | const ZoneList<LiveRange*>* live_ranges() const { return &live_ranges_; } |
| 336 | const Vector<LiveRange*>* fixed_live_ranges() const { |
| 337 | return &fixed_live_ranges_; |
| 338 | } |
| 339 | const Vector<LiveRange*>* fixed_double_live_ranges() const { |
| 340 | return &fixed_double_live_ranges_; |
| 341 | } |
| 342 | |
| 343 | inline InstructionSequence* code() const { return code_; } |
| 344 | |
| 345 | // This zone is for datastructures only needed during register allocation. |
| 346 | inline Zone* zone() { return &zone_; } |
| 347 | |
| 348 | // This zone is for InstructionOperands and moves that live beyond register |
| 349 | // allocation. |
| 350 | inline Zone* code_zone() { return code()->zone(); } |
| 351 | |
| 352 | int GetVirtualRegister() { |
| 353 | int vreg = code()->NextVirtualRegister(); |
| 354 | if (vreg >= UnallocatedOperand::kMaxVirtualRegisters) { |
| 355 | allocation_ok_ = false; |
| 356 | // Maintain the invariant that we return something below the maximum. |
| 357 | return 0; |
| 358 | } |
| 359 | return vreg; |
| 360 | } |
| 361 | |
| 362 | bool AllocationOk() { return allocation_ok_; } |
| 363 | |
| 364 | #ifdef DEBUG |
| 365 | void Verify() const; |
| 366 | #endif |
| 367 | |
| 368 | BitVector* assigned_registers() { return assigned_registers_; } |
| 369 | BitVector* assigned_double_registers() { return assigned_double_registers_; } |
| 370 | |
| 371 | private: |
| 372 | void MeetRegisterConstraints(); |
| 373 | void ResolvePhis(); |
| 374 | void BuildLiveRanges(); |
| 375 | void AllocateGeneralRegisters(); |
| 376 | void AllocateDoubleRegisters(); |
| 377 | void ConnectRanges(); |
| 378 | void ResolveControlFlow(); |
| 379 | void PopulatePointerMaps(); // TODO(titzer): rename to PopulateReferenceMaps. |
| 380 | void AllocateRegisters(); |
| 381 | bool CanEagerlyResolveControlFlow(BasicBlock* block) const; |
| 382 | inline bool SafePointsAreInOrder() const; |
| 383 | |
| 384 | // Liveness analysis support. |
| 385 | void InitializeLivenessAnalysis(); |
| 386 | BitVector* ComputeLiveOut(BasicBlock* block); |
| 387 | void AddInitialIntervals(BasicBlock* block, BitVector* live_out); |
| 388 | bool IsOutputRegisterOf(Instruction* instr, int index); |
| 389 | bool IsOutputDoubleRegisterOf(Instruction* instr, int index); |
| 390 | void ProcessInstructions(BasicBlock* block, BitVector* live); |
| 391 | void MeetRegisterConstraints(BasicBlock* block); |
| 392 | void MeetConstraintsBetween(Instruction* first, Instruction* second, |
| 393 | int gap_index); |
| 394 | void MeetRegisterConstraintsForLastInstructionInBlock(BasicBlock* block); |
| 395 | void ResolvePhis(BasicBlock* block); |
| 396 | |
| 397 | // Helper methods for building intervals. |
| 398 | InstructionOperand* AllocateFixed(UnallocatedOperand* operand, int pos, |
| 399 | bool is_tagged); |
| 400 | LiveRange* LiveRangeFor(InstructionOperand* operand); |
| 401 | void Define(LifetimePosition position, InstructionOperand* operand, |
| 402 | InstructionOperand* hint); |
| 403 | void Use(LifetimePosition block_start, LifetimePosition position, |
| 404 | InstructionOperand* operand, InstructionOperand* hint); |
| 405 | void AddConstraintsGapMove(int index, InstructionOperand* from, |
| 406 | InstructionOperand* to); |
| 407 | |
| 408 | // Helper methods for updating the life range lists. |
| 409 | void AddToActive(LiveRange* range); |
| 410 | void AddToInactive(LiveRange* range); |
| 411 | void AddToUnhandledSorted(LiveRange* range); |
| 412 | void AddToUnhandledUnsorted(LiveRange* range); |
| 413 | void SortUnhandled(); |
| 414 | bool UnhandledIsSorted(); |
| 415 | void ActiveToHandled(LiveRange* range); |
| 416 | void ActiveToInactive(LiveRange* range); |
| 417 | void InactiveToHandled(LiveRange* range); |
| 418 | void InactiveToActive(LiveRange* range); |
| 419 | void FreeSpillSlot(LiveRange* range); |
| 420 | InstructionOperand* TryReuseSpillSlot(LiveRange* range); |
| 421 | |
| 422 | // Helper methods for allocating registers. |
| 423 | bool TryAllocateFreeReg(LiveRange* range); |
| 424 | void AllocateBlockedReg(LiveRange* range); |
| 425 | |
| 426 | // Live range splitting helpers. |
| 427 | |
| 428 | // Split the given range at the given position. |
| 429 | // If range starts at or after the given position then the |
| 430 | // original range is returned. |
| 431 | // Otherwise returns the live range that starts at pos and contains |
| 432 | // all uses from the original range that follow pos. Uses at pos will |
| 433 | // still be owned by the original range after splitting. |
| 434 | LiveRange* SplitRangeAt(LiveRange* range, LifetimePosition pos); |
| 435 | |
| 436 | // Split the given range in a position from the interval [start, end]. |
| 437 | LiveRange* SplitBetween(LiveRange* range, LifetimePosition start, |
| 438 | LifetimePosition end); |
| 439 | |
| 440 | // Find a lifetime position in the interval [start, end] which |
| 441 | // is optimal for splitting: it is either header of the outermost |
| 442 | // loop covered by this interval or the latest possible position. |
| 443 | LifetimePosition FindOptimalSplitPos(LifetimePosition start, |
| 444 | LifetimePosition end); |
| 445 | |
| 446 | // Spill the given life range after position pos. |
| 447 | void SpillAfter(LiveRange* range, LifetimePosition pos); |
| 448 | |
| 449 | // Spill the given life range after position [start] and up to position [end]. |
| 450 | void SpillBetween(LiveRange* range, LifetimePosition start, |
| 451 | LifetimePosition end); |
| 452 | |
| 453 | // Spill the given life range after position [start] and up to position [end]. |
| 454 | // Range is guaranteed to be spilled at least until position [until]. |
| 455 | void SpillBetweenUntil(LiveRange* range, LifetimePosition start, |
| 456 | LifetimePosition until, LifetimePosition end); |
| 457 | |
| 458 | void SplitAndSpillIntersecting(LiveRange* range); |
| 459 | |
| 460 | // If we are trying to spill a range inside the loop try to |
| 461 | // hoist spill position out to the point just before the loop. |
| 462 | LifetimePosition FindOptimalSpillingPos(LiveRange* range, |
| 463 | LifetimePosition pos); |
| 464 | |
| 465 | void Spill(LiveRange* range); |
| 466 | bool IsBlockBoundary(LifetimePosition pos); |
| 467 | |
| 468 | // Helper methods for resolving control flow. |
| 469 | void ResolveControlFlow(LiveRange* range, BasicBlock* block, |
| 470 | BasicBlock* pred); |
| 471 | |
| 472 | inline void SetLiveRangeAssignedRegister(LiveRange* range, int reg); |
| 473 | |
| 474 | // Return parallel move that should be used to connect ranges split at the |
| 475 | // given position. |
| 476 | ParallelMove* GetConnectingParallelMove(LifetimePosition pos); |
| 477 | |
| 478 | // Return the block which contains give lifetime position. |
| 479 | BasicBlock* GetBlock(LifetimePosition pos); |
| 480 | |
| 481 | // Helper methods for the fixed registers. |
| 482 | int RegisterCount() const; |
| 483 | static int FixedLiveRangeID(int index) { return -index - 1; } |
| 484 | static int FixedDoubleLiveRangeID(int index); |
| 485 | LiveRange* FixedLiveRangeFor(int index); |
| 486 | LiveRange* FixedDoubleLiveRangeFor(int index); |
| 487 | LiveRange* LiveRangeFor(int index); |
| 488 | GapInstruction* GetLastGap(BasicBlock* block); |
| 489 | |
| 490 | const char* RegisterName(int allocation_index); |
| 491 | |
| 492 | inline Instruction* InstructionAt(int index) { |
| 493 | return code()->InstructionAt(index); |
| 494 | } |
| 495 | |
| 496 | Zone zone_; |
| 497 | InstructionSequence* code_; |
| 498 | |
| 499 | // During liveness analysis keep a mapping from block id to live_in sets |
| 500 | // for blocks already analyzed. |
| 501 | ZoneList<BitVector*> live_in_sets_; |
| 502 | |
| 503 | // Liveness analysis results. |
| 504 | ZoneList<LiveRange*> live_ranges_; |
| 505 | |
| 506 | // Lists of live ranges |
| 507 | EmbeddedVector<LiveRange*, Register::kMaxNumAllocatableRegisters> |
| 508 | fixed_live_ranges_; |
| 509 | EmbeddedVector<LiveRange*, DoubleRegister::kMaxNumAllocatableRegisters> |
| 510 | fixed_double_live_ranges_; |
| 511 | ZoneList<LiveRange*> unhandled_live_ranges_; |
| 512 | ZoneList<LiveRange*> active_live_ranges_; |
| 513 | ZoneList<LiveRange*> inactive_live_ranges_; |
| 514 | ZoneList<LiveRange*> reusable_slots_; |
| 515 | |
| 516 | RegisterKind mode_; |
| 517 | int num_registers_; |
| 518 | |
| 519 | BitVector* assigned_registers_; |
| 520 | BitVector* assigned_double_registers_; |
| 521 | |
| 522 | // Indicates success or failure during register allocation. |
| 523 | bool allocation_ok_; |
| 524 | |
| 525 | #ifdef DEBUG |
| 526 | LifetimePosition allocation_finger_; |
| 527 | #endif |
| 528 | |
| 529 | DISALLOW_COPY_AND_ASSIGN(RegisterAllocator); |
| 530 | }; |
| 531 | |
| 532 | |
| 533 | class RegisterAllocatorPhase : public CompilationPhase { |
| 534 | public: |
| 535 | RegisterAllocatorPhase(const char* name, RegisterAllocator* allocator); |
| 536 | ~RegisterAllocatorPhase(); |
| 537 | |
| 538 | private: |
| 539 | RegisterAllocator* allocator_; |
| 540 | unsigned allocator_zone_start_allocation_size_; |
| 541 | |
| 542 | DISALLOW_COPY_AND_ASSIGN(RegisterAllocatorPhase); |
| 543 | }; |
| 544 | } |
| 545 | } |
| 546 | } // namespace v8::internal::compiler |
| 547 | |
| 548 | #endif // V8_REGISTER_ALLOCATOR_H_ |