| 1 | //===- LoopVectorizationPlanner.h - Planner for LoopVectorization ---------===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | /// |
| 9 | /// \file |
| 10 | /// This file provides a LoopVectorizationPlanner class. |
| 11 | /// InnerLoopVectorizer vectorizes loops which contain only one basic |
| 12 | /// LoopVectorizationPlanner - drives the vectorization process after having |
| 13 | /// passed Legality checks. |
| 14 | /// The planner builds and optimizes the Vectorization Plans which record the |
| 15 | /// decisions how to vectorize the given loop. In particular, represent the |
| 16 | /// control-flow of the vectorized version, the replication of instructions that |
| 17 | /// are to be scalarized, and interleave access groups. |
| 18 | /// |
| 19 | /// Also provides a VPlan-based builder utility analogous to IRBuilder. |
| 20 | /// It provides an instruction-level API for generating VPInstructions while |
| 21 | /// abstracting away the Recipe manipulation details. |
| 22 | //===----------------------------------------------------------------------===// |
| 23 | |
| 24 | #ifndef LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZATIONPLANNER_H |
| 25 | #define LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZATIONPLANNER_H |
| 26 | |
| 27 | #include "VPlan.h" |
| 28 | #include "llvm/ADT/SmallSet.h" |
| 29 | #include "llvm/Analysis/TargetTransformInfo.h" |
| 30 | #include "llvm/Support/InstructionCost.h" |
| 31 | #include <optional> |
| 32 | |
| 33 | namespace { |
| 34 | class GeneratedRTChecks; |
| 35 | } |
| 36 | |
| 37 | namespace llvm { |
| 38 | |
| 39 | class BranchProbabilityInfo; |
| 40 | class LoopInfo; |
| 41 | class DominatorTree; |
| 42 | class LoopVectorizationLegality; |
| 43 | class LoopVectorizationCostModel; |
| 44 | class PredicatedScalarEvolution; |
| 45 | class LoopVectorizeHints; |
| 46 | class RecurrenceDescriptor; |
| 47 | class LoopVersioning; |
| 48 | class ; |
| 49 | class TargetLibraryInfo; |
| 50 | class VPRecipeBuilder; |
| 51 | struct VPRegisterUsage; |
| 52 | struct VFRange; |
| 53 | |
| 54 | /// \return An upper bound for vscale based on TTI or the vscale_range |
| 55 | /// attribute. |
| 56 | std::optional<unsigned> getMaxVScale(const Function &F); |
| 57 | |
| 58 | /// \return The upper bound for the runtime value of \p EC, or std::nullopt |
| 59 | /// if the upper bound is unknown. |
| 60 | std::optional<uint64_t> |
| 61 | getMaxRuntimeElementCount(ElementCount EC, const Function &F); |
| 62 | |
| 63 | // Utility functions that are used by different vectorization classes |
| 64 | namespace LoopVectorizationUtils { |
| 65 | |
| 66 | /// Reports a vectorization failure: print \p DebugMsg for debugging |
| 67 | /// purposes along with the corresponding optimization remark \p RemarkName. |
| 68 | /// If \p I is passed, it is an instruction that prevents vectorization. |
| 69 | /// Otherwise, the loop \p TheLoop is used for the location of the remark. |
| 70 | void (const StringRef DebugMsg, |
| 71 | const StringRef OREMsg, const StringRef ORETag, |
| 72 | OptimizationRemarkEmitter *ORE, |
| 73 | const Loop *TheLoop, Instruction *I = nullptr); |
| 74 | |
| 75 | /// Same as above, but the debug message and optimization remark are identical |
| 76 | inline void (const StringRef DebugMsg, |
| 77 | const StringRef ORETag, |
| 78 | OptimizationRemarkEmitter *ORE, |
| 79 | const Loop *TheLoop, |
| 80 | Instruction *I = nullptr) { |
| 81 | reportVectorizationFailure(DebugMsg, OREMsg: DebugMsg, ORETag, ORE, TheLoop, I); |
| 82 | } |
| 83 | |
| 84 | /// Reports an informative message: print \p Msg for debugging purposes as well |
| 85 | /// as an optimization remark. Uses either \p I as location of the remark, or |
| 86 | /// otherwise \p TheLoop. If \p DL is passed, use it as debug location for the |
| 87 | /// remark. |
| 88 | void (const StringRef Msg, const StringRef ORETag, |
| 89 | OptimizationRemarkEmitter *ORE, |
| 90 | const Loop *TheLoop, Instruction *I = nullptr, |
| 91 | DebugLoc DL = {}); |
| 92 | |
| 93 | /// Report successful vectorization of the loop. In case an outer loop is |
| 94 | /// vectorized, prepend "outer" to the vectorization remark. |
| 95 | void (OptimizationRemarkEmitter *ORE, Loop *TheLoop, |
| 96 | ElementCount VFWidth, unsigned IC); |
| 97 | |
| 98 | } // namespace LoopVectorizationUtils |
| 99 | |
| 100 | /// VPlan-based builder utility analogous to IRBuilder. |
| 101 | class VPBuilder { |
| 102 | private: |
| 103 | class VPInsertPoint { |
| 104 | VPBasicBlock *Block = nullptr; |
| 105 | VPBasicBlock::iterator Point; |
| 106 | |
| 107 | public: |
| 108 | /// Creates a new insertion point which doesn't point to anything. |
| 109 | VPInsertPoint() = default; |
| 110 | |
| 111 | /// Creates a new insertion point to insert at \p Point in \p Block. |
| 112 | VPInsertPoint(VPBasicBlock *Block, VPBasicBlock::iterator Point) |
| 113 | : Block(Block), Point(Point) {} |
| 114 | |
| 115 | /// Creates a new insertion point to insert before \p R. |
| 116 | VPInsertPoint(VPRecipeBase *R) |
| 117 | : Block(R->getParent()), Point(R->getIterator()) {} |
| 118 | |
| 119 | /// Creates a new insertion point to insert at the end of \p Block. |
| 120 | VPInsertPoint(VPBasicBlock *Block) : Block(Block), Point(Block->end()) {} |
| 121 | |
| 122 | /// Returns true if this insert point is set. |
| 123 | operator bool() const { return Block; } |
| 124 | |
| 125 | VPBasicBlock *getBlock() const { return Block; } |
| 126 | |
| 127 | operator VPRecipeBase *() const { |
| 128 | return Point == Block->end() ? nullptr : &*Point; |
| 129 | } |
| 130 | |
| 131 | template <typename T> void insert(T &R) { return Block->insert(Recipe: R, InsertPt: Point); } |
| 132 | }; |
| 133 | |
| 134 | VPInsertPoint InsertPt; |
| 135 | |
| 136 | /// Insert \p VPI in BB at InsertPt if BB is set. |
| 137 | template <typename T> T *tryInsertInstruction(T *R) { |
| 138 | if (InsertPt) |
| 139 | InsertPt.insert(R); |
| 140 | return R; |
| 141 | } |
| 142 | |
| 143 | VPInstruction *createInstruction(unsigned Opcode, |
| 144 | ArrayRef<VPValue *> Operands, |
| 145 | const VPIRMetadata &MD, DebugLoc DL, |
| 146 | const Twine &Name = "" ) { |
| 147 | return tryInsertInstruction( |
| 148 | R: new VPInstruction(Opcode, Operands, {}, MD, DL, Name)); |
| 149 | } |
| 150 | |
| 151 | public: |
| 152 | VPlan &getPlan() const { |
| 153 | assert(InsertPt && "Insert block must be set" ); |
| 154 | return *InsertPt.getBlock()->getPlan(); |
| 155 | } |
| 156 | |
| 157 | VPBuilder() = default; |
| 158 | VPBuilder(const VPInsertPoint &IP) : InsertPt(IP) {} |
| 159 | VPBuilder(VPBasicBlock *TheBB, VPBasicBlock::iterator IP) |
| 160 | : InsertPt(TheBB, IP) {} |
| 161 | |
| 162 | /// Get the recipe at the current insert point or nullptr if the insert point |
| 163 | /// is the end of the block. |
| 164 | VPRecipeBase *getRecipeAtInsertPoint() const { return InsertPt; } |
| 165 | |
| 166 | /// Create a VPBuilder to insert after \p R. |
| 167 | static VPBuilder getToInsertAfter(VPRecipeBase *R) { |
| 168 | return {R->getParent(), std::next(x: R->getIterator())}; |
| 169 | } |
| 170 | |
| 171 | /// Sets the current insert point to a previously-saved location. |
| 172 | void restoreIP(VPInsertPoint IP) { InsertPt = IP; } |
| 173 | |
| 174 | /// Set the current insert point. |
| 175 | void setInsertPoint(const VPInsertPoint &IP) { |
| 176 | assert(IP && "Attempting to set a null insert point" ); |
| 177 | InsertPt = IP; |
| 178 | } |
| 179 | void setInsertPoint(VPBasicBlock *TheBB, VPBasicBlock::iterator IP) { |
| 180 | assert(TheBB && "Attempting to set a null insert point" ); |
| 181 | InsertPt = VPInsertPoint(TheBB, IP); |
| 182 | } |
| 183 | |
| 184 | /// Insert \p R at the current insertion point. Returns \p R unchanged. |
| 185 | template <typename T> [[maybe_unused]] T *insert(T *R) { |
| 186 | InsertPt.insert(R); |
| 187 | return R; |
| 188 | } |
| 189 | |
| 190 | /// Create an N-ary operation with \p Opcode, \p Operands and set \p Inst as |
| 191 | /// its underlying Instruction. |
| 192 | VPInstruction *createNaryOp(unsigned Opcode, ArrayRef<VPValue *> Operands, |
| 193 | Instruction *Inst = nullptr, |
| 194 | const VPIRFlags &Flags = {}, |
| 195 | const VPIRMetadata &MD = {}, |
| 196 | DebugLoc DL = DebugLoc::getUnknown(), |
| 197 | const Twine &Name = "" , |
| 198 | Type *ResultTy = nullptr) { |
| 199 | VPInstruction *NewVPInst = tryInsertInstruction( |
| 200 | R: new VPInstruction(Opcode, Operands, Flags, MD, DL, Name, ResultTy)); |
| 201 | NewVPInst->setUnderlyingValue(Inst); |
| 202 | return NewVPInst; |
| 203 | } |
| 204 | VPInstruction *createNaryOp(unsigned Opcode, ArrayRef<VPValue *> Operands, |
| 205 | DebugLoc DL, const Twine &Name = "" ) { |
| 206 | return createInstruction(Opcode, Operands, MD: {}, DL, Name); |
| 207 | } |
| 208 | VPInstruction *createNaryOp(unsigned Opcode, ArrayRef<VPValue *> Operands, |
| 209 | const VPIRFlags &Flags, |
| 210 | DebugLoc DL = DebugLoc::getUnknown(), |
| 211 | const Twine &Name = "" ) { |
| 212 | return tryInsertInstruction( |
| 213 | R: new VPInstruction(Opcode, Operands, Flags, {}, DL, Name)); |
| 214 | } |
| 215 | |
| 216 | VPInstruction *createNaryOp(unsigned Opcode, ArrayRef<VPValue *> Operands, |
| 217 | Type *ResultTy, const VPIRFlags &Flags = {}, |
| 218 | DebugLoc DL = DebugLoc::getUnknown(), |
| 219 | const Twine &Name = "" ) { |
| 220 | return tryInsertInstruction( |
| 221 | R: new VPInstruction(Opcode, Operands, Flags, {}, DL, Name, ResultTy)); |
| 222 | } |
| 223 | |
| 224 | VPInstruction *createFirstActiveLane(ArrayRef<VPValue *> Masks, |
| 225 | DebugLoc DL = DebugLoc::getUnknown(), |
| 226 | const Twine &Name = "" ) { |
| 227 | // Assume that the maximum possible number of elements in a vector fits |
| 228 | // within the index type for the default address space. |
| 229 | VPlan &Plan = getPlan(); |
| 230 | Type *IndexTy = Plan.getDataLayout().getIndexType(C&: Plan.getContext(), AddressSpace: 0); |
| 231 | return tryInsertInstruction(R: new VPInstruction( |
| 232 | VPInstruction::FirstActiveLane, Masks, {}, {}, DL, Name, IndexTy)); |
| 233 | } |
| 234 | |
| 235 | VPInstruction *createLastActiveLane(ArrayRef<VPValue *> Masks, |
| 236 | DebugLoc DL = DebugLoc::getUnknown(), |
| 237 | const Twine &Name = "" ) { |
| 238 | // Assume that the maximum possible number of elements in a vector fits |
| 239 | // within the index type for the default address space. |
| 240 | VPlan &Plan = getPlan(); |
| 241 | Type *IndexTy = Plan.getDataLayout().getIndexType(C&: Plan.getContext(), AddressSpace: 0); |
| 242 | return tryInsertInstruction(R: new VPInstruction( |
| 243 | VPInstruction::LastActiveLane, Masks, {}, {}, DL, Name, IndexTy)); |
| 244 | } |
| 245 | |
| 246 | VPInstruction *createOverflowingOp( |
| 247 | unsigned Opcode, ArrayRef<VPValue *> Operands, |
| 248 | VPRecipeWithIRFlags::WrapFlagsTy WrapFlags = {false, false}, |
| 249 | DebugLoc DL = DebugLoc::getUnknown(), const Twine &Name = "" ) { |
| 250 | return tryInsertInstruction( |
| 251 | R: new VPInstruction(Opcode, Operands, WrapFlags, {}, DL, Name)); |
| 252 | } |
| 253 | |
| 254 | VPInstruction *createNot(VPValue *Operand, |
| 255 | DebugLoc DL = DebugLoc::getUnknown(), |
| 256 | const Twine &Name = "" ) { |
| 257 | return createInstruction(Opcode: VPInstruction::Not, Operands: {Operand}, MD: {}, DL, Name); |
| 258 | } |
| 259 | |
| 260 | VPInstruction *createAnd(VPValue *LHS, VPValue *RHS, |
| 261 | DebugLoc DL = DebugLoc::getUnknown(), |
| 262 | const Twine &Name = "" ) { |
| 263 | return createInstruction(Opcode: Instruction::BinaryOps::And, Operands: {LHS, RHS}, MD: {}, DL, |
| 264 | Name); |
| 265 | } |
| 266 | |
| 267 | VPInstruction *createOr(VPValue *LHS, VPValue *RHS, |
| 268 | DebugLoc DL = DebugLoc::getUnknown(), |
| 269 | const Twine &Name = "" ) { |
| 270 | |
| 271 | return tryInsertInstruction(R: new VPInstruction( |
| 272 | Instruction::BinaryOps::Or, {LHS, RHS}, |
| 273 | VPRecipeWithIRFlags::DisjointFlagsTy(false), {}, DL, Name)); |
| 274 | } |
| 275 | |
| 276 | VPInstruction * |
| 277 | createAdd(VPValue *LHS, VPValue *RHS, DebugLoc DL = DebugLoc::getUnknown(), |
| 278 | const Twine &Name = "" , |
| 279 | VPRecipeWithIRFlags::WrapFlagsTy WrapFlags = {false, false}) { |
| 280 | return createOverflowingOp(Opcode: Instruction::Add, Operands: {LHS, RHS}, WrapFlags, DL, |
| 281 | Name); |
| 282 | } |
| 283 | |
| 284 | VPInstruction * |
| 285 | createSub(VPValue *LHS, VPValue *RHS, DebugLoc DL = DebugLoc::getUnknown(), |
| 286 | const Twine &Name = "" , |
| 287 | VPRecipeWithIRFlags::WrapFlagsTy WrapFlags = {false, false}) { |
| 288 | return createOverflowingOp(Opcode: Instruction::Sub, Operands: {LHS, RHS}, WrapFlags, DL, |
| 289 | Name); |
| 290 | } |
| 291 | |
| 292 | VPInstruction *createLogicalAnd(VPValue *LHS, VPValue *RHS, |
| 293 | DebugLoc DL = DebugLoc::getUnknown(), |
| 294 | const Twine &Name = "" ) { |
| 295 | return createNaryOp(Opcode: VPInstruction::LogicalAnd, Operands: {LHS, RHS}, DL, Name); |
| 296 | } |
| 297 | |
| 298 | VPInstruction *createLogicalOr(VPValue *LHS, VPValue *RHS, |
| 299 | DebugLoc DL = DebugLoc::getUnknown(), |
| 300 | const Twine &Name = "" ) { |
| 301 | return createNaryOp(Opcode: VPInstruction::LogicalOr, Operands: {LHS, RHS}, DL, Name); |
| 302 | } |
| 303 | |
| 304 | /// Create a select of \p TrueVal and \p FalseVal based on \p Cond, using the |
| 305 | /// default flags for the result type, unless \p Flags is set. |
| 306 | VPInstruction *createSelect(VPValue *Cond, VPValue *TrueVal, |
| 307 | VPValue *FalseVal, |
| 308 | DebugLoc DL = DebugLoc::getUnknown(), |
| 309 | const Twine &Name = "" , |
| 310 | std::optional<VPIRFlags> Flags = std::nullopt) { |
| 311 | return tryInsertInstruction( |
| 312 | R: new VPInstruction(Instruction::Select, {Cond, TrueVal, FalseVal}, |
| 313 | Flags.value_or(u: VPIRFlags::getDefaultFlags( |
| 314 | Opcode: Instruction::Select, ResultTy: TrueVal->getScalarType())), |
| 315 | {}, DL, Name)); |
| 316 | } |
| 317 | |
| 318 | /// Create a new ICmp VPInstruction with predicate \p Pred and operands \p A |
| 319 | /// and \p B. |
| 320 | VPInstruction *createICmp(CmpInst::Predicate Pred, VPValue *A, VPValue *B, |
| 321 | DebugLoc DL = DebugLoc::getUnknown(), |
| 322 | const Twine &Name = "" ) { |
| 323 | assert(Pred >= CmpInst::FIRST_ICMP_PREDICATE && |
| 324 | Pred <= CmpInst::LAST_ICMP_PREDICATE && "invalid predicate" ); |
| 325 | return tryInsertInstruction( |
| 326 | R: new VPInstruction(Instruction::ICmp, {A, B}, Pred, {}, DL, Name)); |
| 327 | } |
| 328 | |
| 329 | /// Create a new FCmp VPInstruction with predicate \p Pred and operands \p A |
| 330 | /// and \p B. |
| 331 | VPInstruction *createFCmp(CmpInst::Predicate Pred, VPValue *A, VPValue *B, |
| 332 | DebugLoc DL = DebugLoc::getUnknown(), |
| 333 | const Twine &Name = "" ) { |
| 334 | assert(Pred >= CmpInst::FIRST_FCMP_PREDICATE && |
| 335 | Pred <= CmpInst::LAST_FCMP_PREDICATE && "invalid predicate" ); |
| 336 | return tryInsertInstruction( |
| 337 | R: new VPInstruction(Instruction::FCmp, {A, B}, |
| 338 | VPIRFlags(Pred, FastMathFlags()), {}, DL, Name)); |
| 339 | } |
| 340 | |
| 341 | /// Create an AnyOf reduction pattern: or-reduce \p ChainOp, freeze the |
| 342 | /// result, then select between \p TrueVal and \p FalseVal. |
| 343 | VPInstruction *createAnyOfReduction(VPValue *ChainOp, VPValue *TrueVal, |
| 344 | VPValue *FalseVal, |
| 345 | DebugLoc DL = DebugLoc::getUnknown()); |
| 346 | |
| 347 | VPInstruction *createPtrAdd(VPValue *Ptr, VPValue *Offset, |
| 348 | DebugLoc DL = DebugLoc::getUnknown(), |
| 349 | const Twine &Name = "" ) { |
| 350 | return createNoWrapPtrAdd(Ptr, Offset, GEPFlags: GEPNoWrapFlags::none(), DL, Name); |
| 351 | } |
| 352 | |
| 353 | VPInstruction *createNoWrapPtrAdd(VPValue *Ptr, VPValue *Offset, |
| 354 | GEPNoWrapFlags GEPFlags, |
| 355 | DebugLoc DL = DebugLoc::getUnknown(), |
| 356 | const Twine &Name = "" ) { |
| 357 | return tryInsertInstruction(R: new VPInstruction( |
| 358 | VPInstruction::PtrAdd, {Ptr, Offset}, GEPFlags, {}, DL, Name)); |
| 359 | } |
| 360 | |
| 361 | VPInstruction *createWidePtrAdd(VPValue *Ptr, VPValue *Offset, |
| 362 | DebugLoc DL = DebugLoc::getUnknown(), |
| 363 | const Twine &Name = "" ) { |
| 364 | return tryInsertInstruction( |
| 365 | R: new VPInstruction(VPInstruction::WidePtrAdd, {Ptr, Offset}, |
| 366 | GEPNoWrapFlags::none(), {}, DL, Name)); |
| 367 | } |
| 368 | |
| 369 | /// Create a phi with \p IncomingValues, using the default flags for the |
| 370 | /// result type, unless \p Flags is set. |
| 371 | VPPhi *createScalarPhi(ArrayRef<VPValue *> IncomingValues, |
| 372 | DebugLoc DL = DebugLoc::getUnknown(), |
| 373 | const Twine &Name = "" , |
| 374 | std::optional<VPIRFlags> Flags = std::nullopt, |
| 375 | Type *ResultTy = nullptr) { |
| 376 | Type *ScalarTy = ResultTy ? ResultTy : IncomingValues[0]->getScalarType(); |
| 377 | return tryInsertInstruction(R: new VPPhi( |
| 378 | IncomingValues, |
| 379 | Flags.value_or(u: VPIRFlags::getDefaultFlags(Opcode: Instruction::PHI, ResultTy: ScalarTy)), |
| 380 | DL, Name, ResultTy)); |
| 381 | } |
| 382 | |
| 383 | VPWidenPHIRecipe *createWidenPhi(ArrayRef<VPValue *> IncomingValues, |
| 384 | DebugLoc DL = DebugLoc::getUnknown(), |
| 385 | const Twine &Name = "" ) { |
| 386 | return tryInsertInstruction(R: new VPWidenPHIRecipe(IncomingValues, DL, Name)); |
| 387 | } |
| 388 | |
| 389 | VPValue *createElementCount(Type *Ty, ElementCount EC) { |
| 390 | VPlan &Plan = getPlan(); |
| 391 | unsigned MinEC = EC.getKnownMinValue(); |
| 392 | if (EC.isScalable()) { |
| 393 | VPValue *VScale = createVScale(ResultTy: Ty); |
| 394 | if (MinEC == 1) |
| 395 | return VScale; |
| 396 | // TODO: Move this optimization into createOverflowingOp directly. |
| 397 | if (isPowerOf2_32(Value: MinEC)) { |
| 398 | VPValue *ShtAmt = Plan.getConstantInt(Ty, Val: Log2_32(Value: MinEC)); |
| 399 | return createOverflowingOp(Opcode: Instruction::Shl, Operands: {VScale, ShtAmt}, |
| 400 | WrapFlags: {true, false}); |
| 401 | } |
| 402 | VPValue *MulAmt = Plan.getConstantInt(Ty, Val: MinEC); |
| 403 | return createOverflowingOp(Opcode: Instruction::Mul, Operands: {VScale, MulAmt}, |
| 404 | WrapFlags: {true, false}); |
| 405 | } |
| 406 | return Plan.getConstantInt(Ty, Val: MinEC); |
| 407 | } |
| 408 | |
| 409 | /// Convert \p Current to \p Start + \p Current * \p Step. |
| 410 | VPDerivedIVRecipe *createDerivedIV(InductionDescriptor::InductionKind Kind, |
| 411 | FPMathOperator *FPBinOp, VPValue *Start, |
| 412 | VPValue *Current, VPValue *Step, |
| 413 | const VPIRFlags::WrapFlagsTy &Flags = {}) { |
| 414 | return tryInsertInstruction( |
| 415 | R: new VPDerivedIVRecipe(Kind, FPBinOp, Start, Current, Step, Flags)); |
| 416 | } |
| 417 | |
| 418 | VPInstruction *createScalarCast(Instruction::CastOps Opcode, VPValue *Op, |
| 419 | Type *ResultTy, DebugLoc DL, |
| 420 | std::optional<VPIRFlags> Flags = std::nullopt, |
| 421 | const VPIRMetadata &Metadata = {}) { |
| 422 | return tryInsertInstruction(R: new VPInstruction( |
| 423 | Opcode, Op, Flags.value_or(u: VPIRFlags::getDefaultFlags(Opcode)), |
| 424 | Metadata, DL, "" , ResultTy)); |
| 425 | } |
| 426 | |
| 427 | /// Create a scalar call to the intrinsic \p IntrinsicID with \p Operands, and |
| 428 | /// result type \p ResultTy |
| 429 | VPInstruction *createScalarIntrinsic(Intrinsic::ID IntrinsicID, |
| 430 | ArrayRef<VPValue *> Operands, |
| 431 | Type *ResultTy, DebugLoc DL) { |
| 432 | VPlan &Plan = getPlan(); |
| 433 | SmallVector<VPValue *, 2> Ops(Operands); |
| 434 | Ops.push_back(Elt: Plan.getConstantInt(BitWidth: 8 * sizeof(IntrinsicID), Val: IntrinsicID)); |
| 435 | return tryInsertInstruction(R: new VPInstruction(VPInstruction::Intrinsic, Ops, |
| 436 | {}, {}, DL, "" , ResultTy)); |
| 437 | } |
| 438 | |
| 439 | /// Create a scalar llvm.vscale call. |
| 440 | VPInstruction *createVScale(Type *ResultTy, |
| 441 | DebugLoc DL = DebugLoc::getUnknown()) { |
| 442 | return createScalarIntrinsic(IntrinsicID: Intrinsic::vscale, Operands: {}, ResultTy, DL); |
| 443 | } |
| 444 | |
| 445 | VPValue *createScalarZExtOrTrunc(VPValue *Op, Type *ResultTy, DebugLoc DL) { |
| 446 | Type *SrcTy = Op->getScalarType(); |
| 447 | if (ResultTy == SrcTy) |
| 448 | return Op; |
| 449 | Instruction::CastOps CastOp = |
| 450 | ResultTy->getScalarSizeInBits() < SrcTy->getScalarSizeInBits() |
| 451 | ? Instruction::Trunc |
| 452 | : Instruction::ZExt; |
| 453 | return createScalarCast(Opcode: CastOp, Op, ResultTy, DL); |
| 454 | } |
| 455 | |
| 456 | VPValue *createScalarSExtOrTrunc(VPValue *Op, Type *ResultTy, DebugLoc DL) { |
| 457 | Type *SrcTy = Op->getScalarType(); |
| 458 | if (ResultTy == SrcTy) |
| 459 | return Op; |
| 460 | Instruction::CastOps CastOp = |
| 461 | ResultTy->getScalarSizeInBits() < SrcTy->getScalarSizeInBits() |
| 462 | ? Instruction::Trunc |
| 463 | : Instruction::SExt; |
| 464 | return createScalarCast(Opcode: CastOp, Op, ResultTy, DL); |
| 465 | } |
| 466 | |
| 467 | VPInstruction *createFreeze(VPValue *Op, DebugLoc DL = DebugLoc::getUnknown(), |
| 468 | const Twine &Name = "" ) { |
| 469 | return createNaryOp(Opcode: Instruction::Freeze, Operands: Op, DL, Name); |
| 470 | } |
| 471 | |
| 472 | VPWidenCastRecipe *createWidenCast(Instruction::CastOps Opcode, VPValue *Op, |
| 473 | Type *ResultTy) { |
| 474 | assert(Op->getScalarType() != ResultTy && |
| 475 | "must not create a no-op cast recipe" ); |
| 476 | return tryInsertInstruction(R: new VPWidenCastRecipe( |
| 477 | Opcode, Op, ResultTy, nullptr, VPIRFlags::getDefaultFlags(Opcode))); |
| 478 | } |
| 479 | |
| 480 | /// Create a single-scalar recipe with \p Opcode and \p Operands without |
| 481 | /// inserting it. |
| 482 | static VPSingleDefRecipe *createSingleScalarOp(unsigned Opcode, |
| 483 | ArrayRef<VPValue *> Operands, |
| 484 | VPValue *Mask, |
| 485 | const VPIRFlags &Flags, |
| 486 | const VPIRMetadata &Metadata, |
| 487 | DebugLoc DL, Instruction *UV) { |
| 488 | if (Instruction::isCast(Opcode)) { |
| 489 | assert(!Mask && "Cast cannot be predicated" ); |
| 490 | auto *VPI = new VPInstruction(Opcode, Operands, Flags, Metadata, DL, |
| 491 | UV->getName(), UV->getType()); |
| 492 | VPI->setUnderlyingValue(UV); |
| 493 | return VPI; |
| 494 | } |
| 495 | return new VPReplicateRecipe(UV, Operands, /*IsSingleScalar=*/true, Mask, |
| 496 | Flags, Metadata, DL); |
| 497 | } |
| 498 | |
| 499 | VPScalarIVStepsRecipe * |
| 500 | createScalarIVSteps(Instruction::BinaryOps InductionOpcode, |
| 501 | FPMathOperator *FPBinOp, VPValue *IV, VPValue *Step, |
| 502 | VPValue *VF, DebugLoc DL) { |
| 503 | return tryInsertInstruction(R: new VPScalarIVStepsRecipe( |
| 504 | IV, Step, VF, InductionOpcode, |
| 505 | FPBinOp ? FPBinOp->getFastMathFlags() : FastMathFlags(), DL)); |
| 506 | } |
| 507 | |
| 508 | VPExpandSCEVRecipe *createExpandSCEV(const SCEV *Expr) { |
| 509 | return tryInsertInstruction(R: new VPExpandSCEVRecipe(Expr)); |
| 510 | } |
| 511 | |
| 512 | VPVectorPointerRecipe * |
| 513 | createVectorPointer(VPValue *Ptr, Type *SourceElementTy, VPValue *Stride, |
| 514 | GEPNoWrapFlags GEPFlags, DebugLoc DL) { |
| 515 | return tryInsertInstruction( |
| 516 | R: new VPVectorPointerRecipe(Ptr, SourceElementTy, Stride, GEPFlags, DL)); |
| 517 | } |
| 518 | |
| 519 | /// Create a vector pointer recipe for a consecutive memory access to \p Ptr |
| 520 | /// with element type \p SourceElementTy. |
| 521 | VPSingleDefRecipe *createConsecutiveVectorPointer(VPValue *Ptr, |
| 522 | Type *SourceElementTy, |
| 523 | bool Reverse, DebugLoc DL); |
| 524 | |
| 525 | VPWidenMemIntrinsicRecipe *createWidenMemIntrinsic( |
| 526 | Intrinsic::ID VectorIntrinsicID, ArrayRef<VPValue *> CallArguments, |
| 527 | Type *Ty, Align Alignment, const VPIRMetadata &MD, DebugLoc DL) { |
| 528 | return tryInsertInstruction(R: new VPWidenMemIntrinsicRecipe( |
| 529 | VectorIntrinsicID, CallArguments, Ty, Alignment, MD, DL)); |
| 530 | } |
| 531 | |
| 532 | /// Create a recipe widening \p Load, loading from \p Addr with \p Mask (may |
| 533 | /// be null). |
| 534 | VPWidenLoadRecipe *createWidenLoad(LoadInst &Load, VPValue *Addr, |
| 535 | VPValue *Mask, bool Consecutive, |
| 536 | const VPIRMetadata &Metadata, |
| 537 | DebugLoc DL) { |
| 538 | return tryInsertInstruction( |
| 539 | R: new VPWidenLoadRecipe(Load, Addr, Mask, Consecutive, Metadata, DL)); |
| 540 | } |
| 541 | |
| 542 | /// Create a recipe widening \p Store, storing \p StoredVal to \p Addr with |
| 543 | /// \p Mask (may be null). |
| 544 | VPWidenStoreRecipe *createWidenStore(StoreInst &Store, VPValue *Addr, |
| 545 | VPValue *StoredVal, VPValue *Mask, |
| 546 | bool Consecutive, |
| 547 | const VPIRMetadata &Metadata, |
| 548 | DebugLoc DL) { |
| 549 | return tryInsertInstruction(R: new VPWidenStoreRecipe( |
| 550 | Store, Addr, StoredVal, Mask, Consecutive, Metadata, DL)); |
| 551 | } |
| 552 | |
| 553 | //===--------------------------------------------------------------------===// |
| 554 | // RAII helpers. |
| 555 | //===--------------------------------------------------------------------===// |
| 556 | |
| 557 | /// RAII object that stores the current insertion point and restores it when |
| 558 | /// the object is destroyed. |
| 559 | class InsertPointGuard { |
| 560 | VPBuilder &Builder; |
| 561 | VPInsertPoint InsertPt; |
| 562 | |
| 563 | public: |
| 564 | InsertPointGuard(VPBuilder &B) : Builder(B), InsertPt(B.InsertPt) {} |
| 565 | |
| 566 | InsertPointGuard(const InsertPointGuard &) = delete; |
| 567 | InsertPointGuard &operator=(const InsertPointGuard &) = delete; |
| 568 | |
| 569 | ~InsertPointGuard() { Builder.restoreIP(IP: InsertPt); } |
| 570 | }; |
| 571 | }; |
| 572 | |
| 573 | /// TODO: The following VectorizationFactor was pulled out of |
| 574 | /// LoopVectorizationCostModel class. LV also deals with |
| 575 | /// VectorizerParams::VectorizationFactor. |
| 576 | /// We need to streamline them. |
| 577 | |
| 578 | /// Information about vectorization costs. |
| 579 | struct VectorizationFactor { |
| 580 | /// Vector width with best cost. |
| 581 | ElementCount Width; |
| 582 | |
| 583 | /// Cost of the loop with that width. |
| 584 | InstructionCost Cost; |
| 585 | |
| 586 | /// Cost of the scalar loop. |
| 587 | InstructionCost ScalarCost; |
| 588 | |
| 589 | /// The minimum trip count required to make vectorization profitable, e.g. due |
| 590 | /// to runtime checks. |
| 591 | ElementCount MinProfitableTripCount; |
| 592 | |
| 593 | VectorizationFactor(ElementCount Width, InstructionCost Cost, |
| 594 | InstructionCost ScalarCost) |
| 595 | : Width(Width), Cost(Cost), ScalarCost(ScalarCost) {} |
| 596 | |
| 597 | /// Width 1 means no vectorization, cost 0 means uncomputed cost. |
| 598 | static VectorizationFactor Disabled() { |
| 599 | return {ElementCount::getFixed(MinVal: 1), 0, 0}; |
| 600 | } |
| 601 | |
| 602 | bool operator==(const VectorizationFactor &rhs) const { |
| 603 | return Width == rhs.Width && Cost == rhs.Cost; |
| 604 | } |
| 605 | |
| 606 | bool operator!=(const VectorizationFactor &rhs) const { |
| 607 | return !(*this == rhs); |
| 608 | } |
| 609 | }; |
| 610 | |
| 611 | /// A class that represents two vectorization factors (initialized with 0 by |
| 612 | /// default). One for fixed-width vectorization and one for scalable |
| 613 | /// vectorization. This can be used by the vectorizer to choose from a range of |
| 614 | /// fixed and/or scalable VFs in order to find the most cost-effective VF to |
| 615 | /// vectorize with. |
| 616 | struct FixedScalableVFPair { |
| 617 | ElementCount FixedVF; |
| 618 | ElementCount ScalableVF; |
| 619 | |
| 620 | FixedScalableVFPair() |
| 621 | : FixedVF(ElementCount::getFixed(MinVal: 0)), |
| 622 | ScalableVF(ElementCount::getScalable(MinVal: 0)) {} |
| 623 | FixedScalableVFPair(const ElementCount &Max) : FixedScalableVFPair() { |
| 624 | *(Max.isScalable() ? &ScalableVF : &FixedVF) = Max; |
| 625 | } |
| 626 | FixedScalableVFPair(const ElementCount &FixedVF, |
| 627 | const ElementCount &ScalableVF) |
| 628 | : FixedVF(FixedVF), ScalableVF(ScalableVF) { |
| 629 | assert(!FixedVF.isScalable() && ScalableVF.isScalable() && |
| 630 | "Invalid scalable properties" ); |
| 631 | } |
| 632 | |
| 633 | static FixedScalableVFPair getNone() { return FixedScalableVFPair(); } |
| 634 | |
| 635 | /// \return true if either fixed- or scalable VF is non-zero. |
| 636 | explicit operator bool() const { return FixedVF || ScalableVF; } |
| 637 | |
| 638 | /// \return true if either fixed- or scalable VF is a valid vector VF. |
| 639 | bool hasVector() const { return FixedVF.isVector() || ScalableVF.isVector(); } |
| 640 | }; |
| 641 | |
| 642 | /// Holds state needed to make cost decisions before computing costs per-VF, |
| 643 | /// including the maximum VFs. |
| 644 | class VFSelectionContext { |
| 645 | /// \return True if maximizing vector bandwidth is enabled by the target or |
| 646 | /// user options, for the given register kind (scalable or fixed-width). |
| 647 | bool useMaxBandwidth(bool IsScalable) const; |
| 648 | |
| 649 | /// \return the maximized element count based on the targets vector |
| 650 | /// registers and the loop trip-count, but limited to a maximum safe VF. |
| 651 | /// This is a helper function of computeFeasibleMaxVF. |
| 652 | ElementCount getMaximizedVFForTarget(unsigned MaxTripCount, |
| 653 | unsigned SmallestType, |
| 654 | unsigned WidestType, |
| 655 | ElementCount MaxSafeVF, unsigned UserIC, |
| 656 | bool FoldTailByMasking, |
| 657 | bool RequiresScalarEpilogue); |
| 658 | |
| 659 | /// If \p VF * \p UserIC > MaxTripcount, clamps VF to the next lower VF |
| 660 | /// that results in VF * UserIC <= MaxTripCount. |
| 661 | ElementCount clampVFByMaxTripCount(ElementCount VF, unsigned MaxTripCount, |
| 662 | unsigned UserIC, bool FoldTailByMasking, |
| 663 | bool RequiresScalarEpilogue) const; |
| 664 | |
| 665 | /// Checks if scalable vectorization is supported and enabled. Caches the |
| 666 | /// result to avoid repeated debug dumps for repeated queries. |
| 667 | bool isScalableVectorizationAllowed(); |
| 668 | |
| 669 | /// \return the maximum legal scalable VF, based on the safe max number |
| 670 | /// of elements. |
| 671 | ElementCount getMaxLegalScalableVF(unsigned MaxSafeElements); |
| 672 | |
| 673 | /// Initializes the value of vscale used for tuning the cost model. If |
| 674 | /// vscale_range.min == vscale_range.max then return vscale_range.max, else |
| 675 | /// return the value returned by the corresponding TTI method. |
| 676 | void initializeVScaleForTuning(); |
| 677 | |
| 678 | const TargetTransformInfo &TTI; |
| 679 | const LoopVectorizationLegality *Legal; |
| 680 | const Loop *TheLoop; |
| 681 | const Function &F; |
| 682 | PredicatedScalarEvolution &PSE; |
| 683 | DemandedBits *DB; |
| 684 | OptimizationRemarkEmitter *ORE; |
| 685 | const LoopVectorizeHints *Hints; |
| 686 | |
| 687 | /// Cached result of isScalableVectorizationAllowed. |
| 688 | std::optional<bool> IsScalableVectorizationAllowed; |
| 689 | |
| 690 | /// Used to store the value of vscale used for tuning the cost model. It is |
| 691 | /// initialized during object construction. |
| 692 | std::optional<unsigned> VScaleForTuning; |
| 693 | |
| 694 | /// The highest VF possible for this loop, without using MaxBandwidth. |
| 695 | FixedScalableVFPair MaxPermissibleVFWithoutMaxBW; |
| 696 | |
| 697 | /// All element types found in the loop. |
| 698 | SmallPtrSet<Type *, 16> ElementTypesInLoop; |
| 699 | |
| 700 | /// PHINodes of the reductions that should be expanded in-loop. Set by |
| 701 | /// collectInLoopReductions. |
| 702 | SmallPtrSet<PHINode *, 4> InLoopReductions; |
| 703 | |
| 704 | /// A Map of inloop reduction operations and their immediate chain operand. |
| 705 | /// FIXME: This can be removed once reductions can be costed correctly in |
| 706 | /// VPlan. This was added to allow quick lookup of the inloop operations. |
| 707 | /// Set by collectInLoopReductions. |
| 708 | DenseMap<Instruction *, Instruction *> InLoopReductionImmediateChains; |
| 709 | |
| 710 | /// Maximum safe number of elements to be processed per vector iteration, |
| 711 | /// which do not prevent store-load forwarding and are safe with regard to the |
| 712 | /// memory dependencies. Required for EVL-based vectorization, where this |
| 713 | /// value is used as the upper bound of the safe AVL. Set by |
| 714 | /// computeFeasibleMaxVF. |
| 715 | std::optional<unsigned> MaxSafeElements; |
| 716 | |
| 717 | /// Map of scalar integer values to the smallest bitwidth they can be legally |
| 718 | /// represented as. The vector equivalents of these values should be truncated |
| 719 | /// to this type. |
| 720 | MapVector<Instruction *, uint64_t> MinBWs; |
| 721 | |
| 722 | public: |
| 723 | /// The kind of cost that we are calculating. |
| 724 | const TTI::TargetCostKind CostKind; |
| 725 | |
| 726 | /// Whether this loop should be optimized for size based on function attribute |
| 727 | /// or profile information. |
| 728 | const bool OptForSize; |
| 729 | |
| 730 | VFSelectionContext(const TargetTransformInfo &TTI, |
| 731 | const LoopVectorizationLegality *Legal, |
| 732 | const Loop *TheLoop, const Function &F, |
| 733 | PredicatedScalarEvolution &PSE, DemandedBits *DB, |
| 734 | OptimizationRemarkEmitter *ORE, |
| 735 | const LoopVectorizeHints *Hints, bool OptForSize) |
| 736 | : TTI(TTI), Legal(Legal), TheLoop(TheLoop), F(F), PSE(PSE), DB(DB), |
| 737 | ORE(ORE), Hints(Hints), |
| 738 | CostKind(F.hasMinSize() ? TTI::TCK_CodeSize : TTI::TCK_RecipThroughput), |
| 739 | OptForSize(OptForSize) { |
| 740 | initializeVScaleForTuning(); |
| 741 | } |
| 742 | |
| 743 | /// \return The vscale value used for tuning the cost model. |
| 744 | std::optional<unsigned> getVScaleForTuning() const { return VScaleForTuning; } |
| 745 | |
| 746 | const TargetTransformInfo &getTTI() const { return TTI; } |
| 747 | |
| 748 | PredicatedScalarEvolution &getPSE() const { return PSE; } |
| 749 | |
| 750 | /// \return The loop being analyzed. |
| 751 | const Loop *getLoop() const { return TheLoop; } |
| 752 | |
| 753 | /// \return The vectorization hints for the loop being analyzed. |
| 754 | const LoopVectorizeHints &getHints() const { return *Hints; } |
| 755 | |
| 756 | /// Returns true if epilogue vectorization is considered profitable for a |
| 757 | /// main loop with vectorization factor \p VF and interleave count \p IC. |
| 758 | bool isEpilogueVectorizationProfitable(ElementCount VF, unsigned IC) const; |
| 759 | |
| 760 | /// \return True if register pressure should be considered for the given VF. |
| 761 | bool shouldConsiderRegPressureForVF(ElementCount VF) const; |
| 762 | |
| 763 | /// \return True if scalable vectors are supported by the target or forced. |
| 764 | bool supportsScalableVectors() const; |
| 765 | |
| 766 | /// Collect element types in the loop that need widening. |
| 767 | void collectElementTypesForWidening( |
| 768 | const SmallPtrSetImpl<const Value *> *ValuesToIgnore = nullptr); |
| 769 | |
| 770 | /// \return The size (in bits) of the smallest and widest types in the code |
| 771 | /// that need to be vectorized. We ignore values that remain scalar such as |
| 772 | /// 64 bit loop indices. |
| 773 | std::pair<unsigned, unsigned> getSmallestAndWidestTypes() const; |
| 774 | |
| 775 | /// \return An upper bound for the vectorization factors for both |
| 776 | /// fixed and scalable vectorization, where the minimum-known number of |
| 777 | /// elements is a power-of-2 larger than zero. If scalable vectorization is |
| 778 | /// disabled or unsupported, then the scalable part will be equal to |
| 779 | /// ElementCount::getScalable(0). Also sets MaxSafeElements. |
| 780 | FixedScalableVFPair computeFeasibleMaxVF(unsigned MaxTripCount, |
| 781 | ElementCount UserVF, unsigned UserIC, |
| 782 | bool FoldTailByMasking, |
| 783 | bool RequiresScalarEpilogue); |
| 784 | |
| 785 | /// Return maximum safe number of elements to be processed per vector |
| 786 | /// iteration, which do not prevent store-load forwarding and are safe with |
| 787 | /// regard to the memory dependencies. Required for EVL-based VPlans to |
| 788 | /// correctly calculate AVL (application vector length) as min(remaining AVL, |
| 789 | /// MaxSafeElements). Set by computeFeasibleMaxVF. |
| 790 | /// TODO: need to consider adjusting cost model to use this value as a |
| 791 | /// vectorization factor for EVL-based vectorization. |
| 792 | std::optional<unsigned> getMaxSafeElements() const { return MaxSafeElements; } |
| 793 | |
| 794 | /// Returns true if we should use strict in-order reductions for the given |
| 795 | /// RdxDesc. This is true if the -enable-strict-reductions flag is passed, |
| 796 | /// the IsOrdered flag of RdxDesc is set and we do not allow reordering |
| 797 | /// of FP operations. |
| 798 | bool useOrderedReductions(const RecurrenceDescriptor &RdxDesc) const; |
| 799 | |
| 800 | /// Returns true if the target machine supports a masked load (if \p IsLoad) |
| 801 | /// or masked store of scalar type \p ScalarTy with \p Alignment in address |
| 802 | /// space \p AddressSpace. The caller must ensure the access is consecutive or |
| 803 | /// part of an interleave group. |
| 804 | bool isLegalMaskedLoadOrStore(bool IsLoad, Type *ScalarTy, Align Alignment, |
| 805 | unsigned AddressSpace) const; |
| 806 | |
| 807 | /// Returns true if the target machine supports a gather (if \p IsLoad) |
| 808 | /// or scatter of scalar type \p ScalarTy with \p Alignment for vectorization |
| 809 | /// factor \p VF. |
| 810 | bool isLegalGatherOrScatter(bool IsLoad, Type *ScalarTy, Align Alignment, |
| 811 | ElementCount VF) const; |
| 812 | |
| 813 | /// Split reductions into those that happen in the loop, and those that |
| 814 | /// happen outside. In-loop reductions are collected into InLoopReductions. |
| 815 | /// InLoopReductionImmediateChains is filled with each in-loop reduction |
| 816 | /// operation and its immediate chain operand for use during cost modelling. |
| 817 | void collectInLoopReductions(); |
| 818 | |
| 819 | /// Returns true if the Phi is part of an inloop reduction. |
| 820 | bool isInLoopReduction(PHINode *Phi) const { |
| 821 | return InLoopReductions.contains(Ptr: Phi); |
| 822 | } |
| 823 | |
| 824 | /// Returns the set of in-loop reduction PHIs. |
| 825 | const SmallPtrSetImpl<PHINode *> &getInLoopReductions() const { |
| 826 | return InLoopReductions; |
| 827 | } |
| 828 | |
| 829 | /// Returns the immediate chain operand of in-loop reduction operation \p I, |
| 830 | /// or nullptr if \p I is not an in-loop reduction operation. |
| 831 | Instruction *getInLoopReductionImmediateChain(Instruction *I) const { |
| 832 | return InLoopReductionImmediateChains.lookup(Val: I); |
| 833 | } |
| 834 | |
| 835 | /// Check whether vectorization would require runtime checks. When optimizing |
| 836 | /// for size, returning true here aborts vectorization. |
| 837 | bool runtimeChecksRequired(); |
| 838 | |
| 839 | /// Returns a scalable VF to use for outer-loop vectorization if the target |
| 840 | /// supports it and a fixed VF otherwise. |
| 841 | FixedScalableVFPair computeVPlanOuterloopVF(ElementCount UserVF); |
| 842 | |
| 843 | /// Compute smallest bitwidth each instruction can be represented with. |
| 844 | /// The vector equivalents of these instructions should be truncated to this |
| 845 | /// type. |
| 846 | void computeMinimalBitwidths(); |
| 847 | |
| 848 | /// \returns The smallest bitwidth each instruction can be represented with. |
| 849 | const MapVector<Instruction *, uint64_t> &getMinimalBitwidths() const { |
| 850 | return MinBWs; |
| 851 | } |
| 852 | }; |
| 853 | |
| 854 | /// Planner drives the vectorization process after having passed |
| 855 | /// Legality checks. |
| 856 | class LoopVectorizationPlanner { |
| 857 | /// The loop that we evaluate. |
| 858 | Loop *OrigLoop; |
| 859 | |
| 860 | /// Loop Info analysis. |
| 861 | LoopInfo *LI; |
| 862 | |
| 863 | /// The dominator tree. |
| 864 | DominatorTree *DT; |
| 865 | |
| 866 | /// Target Library Info. |
| 867 | const TargetLibraryInfo *TLI; |
| 868 | |
| 869 | /// Target Transform Info. |
| 870 | const TargetTransformInfo &TTI; |
| 871 | |
| 872 | /// The legality analysis. |
| 873 | LoopVectorizationLegality *Legal; |
| 874 | |
| 875 | /// The profitability analysis. Cleared after making cost based decisions. |
| 876 | std::unique_ptr<LoopVectorizationCostModel> CM; |
| 877 | |
| 878 | /// VF selection state independent of cost-modeling decisions. |
| 879 | VFSelectionContext &Config; |
| 880 | |
| 881 | /// The interleaved access analysis. |
| 882 | InterleavedAccessInfo &IAI; |
| 883 | |
| 884 | PredicatedScalarEvolution &PSE; |
| 885 | |
| 886 | OptimizationRemarkEmitter *ORE; |
| 887 | |
| 888 | /// Lazily fetch BranchProbabilityInfo, independent of BlockFrequencyInfo. |
| 889 | std::function<const BranchProbabilityInfo &()> GetBPI; |
| 890 | |
| 891 | SmallVector<VPlanPtr, 4> VPlans; |
| 892 | |
| 893 | /// Profitable vector factors. |
| 894 | SmallVector<VectorizationFactor, 8> ProfitableVFs; |
| 895 | |
| 896 | /// A builder used to construct the current plan. |
| 897 | VPBuilder Builder; |
| 898 | |
| 899 | /// Computes the cost of \p Plan for vectorization factor \p VF. |
| 900 | /// |
| 901 | /// The current implementation requires access to the |
| 902 | /// LoopVectorizationLegality to handle inductions and reductions, which is |
| 903 | /// why it is kept separate from the VPlan-only cost infrastructure. |
| 904 | /// |
| 905 | /// TODO: Move to VPlan::cost once the use of LoopVectorizationLegality has |
| 906 | /// been retired. |
| 907 | InstructionCost cost(VPlan &Plan, ElementCount VF, VPRegisterUsage *RU) const; |
| 908 | |
| 909 | /// Precompute costs for certain instructions using the legacy cost model. The |
| 910 | /// function is used to bring up the VPlan-based cost model to initially avoid |
| 911 | /// taking different decisions due to inaccuracies in the legacy cost model. |
| 912 | InstructionCost precomputeCosts(VPlan &Plan, ElementCount VF, |
| 913 | VPCostContext &CostCtx) const; |
| 914 | |
| 915 | public: |
| 916 | LoopVectorizationPlanner( |
| 917 | Loop *L, LoopInfo *LI, DominatorTree *DT, const TargetLibraryInfo *TLI, |
| 918 | const TargetTransformInfo &TTI, LoopVectorizationLegality *Legal, |
| 919 | std::unique_ptr<LoopVectorizationCostModel> CM, |
| 920 | VFSelectionContext &Config, InterleavedAccessInfo &IAI, |
| 921 | PredicatedScalarEvolution &PSE, OptimizationRemarkEmitter *ORE, |
| 922 | std::function<const BranchProbabilityInfo &()> GetBPI); |
| 923 | |
| 924 | ~LoopVectorizationPlanner(); |
| 925 | |
| 926 | /// Return the cost model. Must not be called after clearCostModel(). |
| 927 | LoopVectorizationCostModel &getCostModel() { |
| 928 | assert(CM && "Cost model has already been cleared" ); |
| 929 | return *CM; |
| 930 | } |
| 931 | |
| 932 | /// Destroy the cost model. |
| 933 | void clearCostModel(); |
| 934 | |
| 935 | /// Build VPlans for the specified \p UserVF and \p UserIC if they are |
| 936 | /// non-zero or all applicable candidate VFs otherwise. If vectorization and |
| 937 | /// interleaving should be avoided up-front, no plans are generated. |
| 938 | void plan(ElementCount UserVF, unsigned UserIC); |
| 939 | |
| 940 | /// Return the VPlan for \p VF. At the moment, there is always a single VPlan |
| 941 | /// for each VF. |
| 942 | VPlan &getPlanFor(ElementCount VF) const; |
| 943 | |
| 944 | /// Compute and return the most profitable vectorization factor and the |
| 945 | /// corresponding best VPlan. Also collect all profitable VFs in |
| 946 | /// ProfitableVFs. |
| 947 | std::pair<VectorizationFactor, VPlan *> computeBestVF(); |
| 948 | |
| 949 | /// \return The desired interleave count. |
| 950 | /// If interleave count has been specified by metadata it will be returned. |
| 951 | /// Otherwise, the interleave count is computed and returned. VF and LoopCost |
| 952 | /// are the selected vectorization factor and the cost of the selected VF. |
| 953 | unsigned selectInterleaveCount(VPlan &Plan, ElementCount VF, |
| 954 | InstructionCost LoopCost); |
| 955 | |
| 956 | /// Generate the IR code for the vectorized loop captured in VPlan \p BestPlan |
| 957 | /// according to the best selected \p VF and \p UF. |
| 958 | /// |
| 959 | /// TODO: \p EpilogueVecKind should be removed once the re-use issue has been |
| 960 | /// fixed. |
| 961 | /// |
| 962 | /// Returns a mapping of SCEVs to their expanded IR values. |
| 963 | /// Note that this is a temporary workaround needed due to the current |
| 964 | /// epilogue handling. |
| 965 | enum class EpilogueVectorizationKind { |
| 966 | None, ///< Not part of epilogue vectorization. |
| 967 | MainLoop, ///< Vectorizing the main loop of epilogue vectorization. |
| 968 | Epilogue ///< Vectorizing the epilogue loop. |
| 969 | }; |
| 970 | DenseMap<const SCEV *, Value *> |
| 971 | executePlan(ElementCount VF, unsigned UF, VPlan &BestPlan, |
| 972 | InnerLoopVectorizer &LB, DominatorTree *DT, |
| 973 | EpilogueVectorizationKind EpilogueVecKind = |
| 974 | EpilogueVectorizationKind::None); |
| 975 | |
| 976 | #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) |
| 977 | void printPlans(raw_ostream &O); |
| 978 | #endif |
| 979 | |
| 980 | /// Look through the existing plans and return true if we have one with |
| 981 | /// vectorization factor \p VF. |
| 982 | bool hasPlanWithVF(ElementCount VF) const { |
| 983 | return any_of(Range: VPlans, |
| 984 | P: [&](const VPlanPtr &Plan) { return Plan->hasVF(VF); }); |
| 985 | } |
| 986 | |
| 987 | /// Test a \p Predicate on a \p Range of VF's. Return the value of applying |
| 988 | /// \p Predicate on Range.Start, possibly decreasing Range.End such that the |
| 989 | /// returned value holds for the entire \p Range. |
| 990 | static bool |
| 991 | getDecisionAndClampRange(const std::function<bool(ElementCount)> &Predicate, |
| 992 | VFRange &Range); |
| 993 | |
| 994 | /// \return A VPlan for the most profitable epilogue vectorization, with its |
| 995 | /// VF narrowed to the chosen factor. The returned plan is a duplicate. |
| 996 | /// Returns nullptr if epilogue vectorization is not supported or not |
| 997 | /// profitable for the loop. \p ScalarEpilogueAllowed indicates whether the |
| 998 | /// epilogue lowering policy permits creating a scalar epilogue at all. |
| 999 | std::unique_ptr<VPlan> selectBestEpiloguePlan(VPlan &MainPlan, |
| 1000 | ElementCount MainLoopVF, |
| 1001 | unsigned IC, |
| 1002 | bool ScalarEpilogueAllowed); |
| 1003 | |
| 1004 | /// Emit remarks for recipes with invalid costs in the available VPlans. |
| 1005 | void (OptimizationRemarkEmitter *ORE); |
| 1006 | |
| 1007 | /// Create a check to \p Plan to see if the vector loop should be executed |
| 1008 | /// based on its trip count. |
| 1009 | void addMinimumIterationCheck(VPlan &Plan, ElementCount VF, unsigned UF, |
| 1010 | ElementCount MinProfitableTripCount) const; |
| 1011 | |
| 1012 | /// Attach the runtime checks of \p RTChecks to \p Plan. |
| 1013 | void attachRuntimeChecks(VPlan &Plan, GeneratedRTChecks &RTChecks, |
| 1014 | bool HasBranchWeights) const; |
| 1015 | |
| 1016 | /// Update loop metadata and profile info for both the scalar remainder loop |
| 1017 | /// and \p VectorLoop, if it exists. Keeps all loop hints from the original |
| 1018 | /// loop on the vector loop and replaces vectorizer-specific metadata. The |
| 1019 | /// loop ID of the original loop \p OrigLoopID must be passed, together with |
| 1020 | /// the average trip count and invocation weight of the original loop (\p |
| 1021 | /// OrigAverageTripCount and \p OrigLoopInvocationWeight respectively). They |
| 1022 | /// cannot be retrieved after the plan has been executed, as the original loop |
| 1023 | /// may have been removed. \p UnrollVectorizedLoop indicates whether the |
| 1024 | /// target wants the vector loop left eligible for runtime unrolling. |
| 1025 | void updateLoopMetadataAndProfileInfo( |
| 1026 | Loop *VectorLoop, VPBasicBlock *, const VPlan &Plan, |
| 1027 | bool VectorizingEpilogue, MDNode *OrigLoopID, |
| 1028 | std::optional<unsigned> OrigAverageTripCount, |
| 1029 | unsigned OrigLoopInvocationWeight, unsigned EstimatedVFxUF, |
| 1030 | bool DisableRuntimeUnroll, bool UnrollVectorizedLoop); |
| 1031 | |
| 1032 | private: |
| 1033 | /// Build an initial VPlan, with HCFG wrapping the original scalar loop and |
| 1034 | /// scalar transformations applied. Returns null if an initial VPlan cannot |
| 1035 | /// be built. |
| 1036 | VPlanPtr tryToBuildVPlan1(); |
| 1037 | |
| 1038 | /// Build a VPlan using VPRecipes according to the information gathered by |
| 1039 | /// Legal and VPlan-based analysis. For outer loops, performs basic recipe |
| 1040 | /// conversion only. For inner loops, \p Range's largest included VF is |
| 1041 | /// restricted to the maximum VF the returned VPlan is valid for. If no VPlan |
| 1042 | /// can be built for the input range, set the largest included VF to the |
| 1043 | /// maximum VF for which no plan could be built. Each VPlan is built starting |
| 1044 | /// from a copy of \p InitialPlan, which is a plain CFG VPlan wrapping the |
| 1045 | /// original scalar loop. |
| 1046 | VPlanPtr tryToBuildVPlan(VPlanPtr InitialPlan, VFRange &Range); |
| 1047 | |
| 1048 | /// Build VPlans for power-of-2 VF's between \p MinVF and \p MaxVF inclusive, |
| 1049 | /// based on \p VPlan1 and according to the information gathered by Legal |
| 1050 | /// when it checked if it is legal to vectorize the loop. |
| 1051 | void buildVPlans(VPlan &VPlan1, ElementCount MinVF, ElementCount MaxVF); |
| 1052 | |
| 1053 | /// Add ComputeReductionResult recipes to the middle block to compute the |
| 1054 | /// final reduction results. Add Select recipes to the latch block when |
| 1055 | /// folding tail, to feed ComputeReductionResult with the last or penultimate |
| 1056 | /// iteration values according to the header mask. |
| 1057 | void addReductionResultComputation(VPlanPtr &Plan, ElementCount MinVF); |
| 1058 | |
| 1059 | /// Returns true if the per-lane cost of VectorizationFactor A is lower than |
| 1060 | /// that of B. |
| 1061 | bool isMoreProfitable(const VectorizationFactor &A, |
| 1062 | const VectorizationFactor &B, bool HasTail, |
| 1063 | bool IsEpilogue = false) const; |
| 1064 | |
| 1065 | /// Returns true if the per-lane cost of VectorizationFactor A is lower than |
| 1066 | /// that of B in the context of vectorizing a loop with known \p MaxTripCount. |
| 1067 | bool isMoreProfitable(const VectorizationFactor &A, |
| 1068 | const VectorizationFactor &B, |
| 1069 | const unsigned MaxTripCount, bool HasTail, |
| 1070 | bool IsEpilogue = false) const; |
| 1071 | |
| 1072 | /// Determines if we have the infrastructure to vectorize the loop and its |
| 1073 | /// epilogue, assuming the main loop is vectorized by \p MainPlan. |
| 1074 | bool isCandidateForEpilogueVectorization(VPlan &MainPlan) const; |
| 1075 | }; |
| 1076 | |
| 1077 | /// A helper function that returns true if the given type is irregular. The |
| 1078 | /// type is irregular if its allocated size doesn't equal the store size of an |
| 1079 | /// element of the corresponding vector type. |
| 1080 | inline bool hasIrregularType(Type *Ty, const DataLayout &DL) { |
| 1081 | // Determine if an array of N elements of type Ty is "bitcast compatible" |
| 1082 | // with a <N x Ty> vector. |
| 1083 | // This is only true if there is no padding between the array elements. |
| 1084 | return DL.getTypeAllocSizeInBits(Ty) != DL.getTypeSizeInBits(Ty); |
| 1085 | } |
| 1086 | |
| 1087 | } // namespace llvm |
| 1088 | |
| 1089 | #endif // LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZATIONPLANNER_H |
| 1090 | |