| File: | llvm/lib/Transforms/Vectorize/LoopVectorize.cpp |
| Warning: | line 7321, column 35 Potential leak of memory pointed to by 'BlockMask' |
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| 1 | //===- LoopVectorize.cpp - A Loop Vectorizer ------------------------------===// |
| 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 | // This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops |
| 10 | // and generates target-independent LLVM-IR. |
| 11 | // The vectorizer uses the TargetTransformInfo analysis to estimate the costs |
| 12 | // of instructions in order to estimate the profitability of vectorization. |
| 13 | // |
| 14 | // The loop vectorizer combines consecutive loop iterations into a single |
| 15 | // 'wide' iteration. After this transformation the index is incremented |
| 16 | // by the SIMD vector width, and not by one. |
| 17 | // |
| 18 | // This pass has three parts: |
| 19 | // 1. The main loop pass that drives the different parts. |
| 20 | // 2. LoopVectorizationLegality - A unit that checks for the legality |
| 21 | // of the vectorization. |
| 22 | // 3. InnerLoopVectorizer - A unit that performs the actual |
| 23 | // widening of instructions. |
| 24 | // 4. LoopVectorizationCostModel - A unit that checks for the profitability |
| 25 | // of vectorization. It decides on the optimal vector width, which |
| 26 | // can be one, if vectorization is not profitable. |
| 27 | // |
| 28 | // There is a development effort going on to migrate loop vectorizer to the |
| 29 | // VPlan infrastructure and to introduce outer loop vectorization support (see |
| 30 | // docs/Proposal/VectorizationPlan.rst and |
| 31 | // http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html). For this |
| 32 | // purpose, we temporarily introduced the VPlan-native vectorization path: an |
| 33 | // alternative vectorization path that is natively implemented on top of the |
| 34 | // VPlan infrastructure. See EnableVPlanNativePath for enabling. |
| 35 | // |
| 36 | //===----------------------------------------------------------------------===// |
| 37 | // |
| 38 | // The reduction-variable vectorization is based on the paper: |
| 39 | // D. Nuzman and R. Henderson. Multi-platform Auto-vectorization. |
| 40 | // |
| 41 | // Variable uniformity checks are inspired by: |
| 42 | // Karrenberg, R. and Hack, S. Whole Function Vectorization. |
| 43 | // |
| 44 | // The interleaved access vectorization is based on the paper: |
| 45 | // Dorit Nuzman, Ira Rosen and Ayal Zaks. Auto-Vectorization of Interleaved |
| 46 | // Data for SIMD |
| 47 | // |
| 48 | // Other ideas/concepts are from: |
| 49 | // A. Zaks and D. Nuzman. Autovectorization in GCC-two years later. |
| 50 | // |
| 51 | // S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of |
| 52 | // Vectorizing Compilers. |
| 53 | // |
| 54 | //===----------------------------------------------------------------------===// |
| 55 | |
| 56 | #include "llvm/Transforms/Vectorize/LoopVectorize.h" |
| 57 | #include "LoopVectorizationPlanner.h" |
| 58 | #include "VPRecipeBuilder.h" |
| 59 | #include "VPlan.h" |
| 60 | #include "VPlanHCFGBuilder.h" |
| 61 | #include "VPlanPredicator.h" |
| 62 | #include "VPlanTransforms.h" |
| 63 | #include "llvm/ADT/APInt.h" |
| 64 | #include "llvm/ADT/ArrayRef.h" |
| 65 | #include "llvm/ADT/DenseMap.h" |
| 66 | #include "llvm/ADT/DenseMapInfo.h" |
| 67 | #include "llvm/ADT/Hashing.h" |
| 68 | #include "llvm/ADT/MapVector.h" |
| 69 | #include "llvm/ADT/None.h" |
| 70 | #include "llvm/ADT/Optional.h" |
| 71 | #include "llvm/ADT/STLExtras.h" |
| 72 | #include "llvm/ADT/SetVector.h" |
| 73 | #include "llvm/ADT/SmallPtrSet.h" |
| 74 | #include "llvm/ADT/SmallVector.h" |
| 75 | #include "llvm/ADT/Statistic.h" |
| 76 | #include "llvm/ADT/StringRef.h" |
| 77 | #include "llvm/ADT/Twine.h" |
| 78 | #include "llvm/ADT/iterator_range.h" |
| 79 | #include "llvm/Analysis/AssumptionCache.h" |
| 80 | #include "llvm/Analysis/BasicAliasAnalysis.h" |
| 81 | #include "llvm/Analysis/BlockFrequencyInfo.h" |
| 82 | #include "llvm/Analysis/CFG.h" |
| 83 | #include "llvm/Analysis/CodeMetrics.h" |
| 84 | #include "llvm/Analysis/DemandedBits.h" |
| 85 | #include "llvm/Analysis/GlobalsModRef.h" |
| 86 | #include "llvm/Analysis/LoopAccessAnalysis.h" |
| 87 | #include "llvm/Analysis/LoopAnalysisManager.h" |
| 88 | #include "llvm/Analysis/LoopInfo.h" |
| 89 | #include "llvm/Analysis/LoopIterator.h" |
| 90 | #include "llvm/Analysis/MemorySSA.h" |
| 91 | #include "llvm/Analysis/OptimizationRemarkEmitter.h" |
| 92 | #include "llvm/Analysis/ProfileSummaryInfo.h" |
| 93 | #include "llvm/Analysis/ScalarEvolution.h" |
| 94 | #include "llvm/Analysis/ScalarEvolutionExpressions.h" |
| 95 | #include "llvm/Analysis/TargetLibraryInfo.h" |
| 96 | #include "llvm/Analysis/TargetTransformInfo.h" |
| 97 | #include "llvm/Analysis/VectorUtils.h" |
| 98 | #include "llvm/IR/Attributes.h" |
| 99 | #include "llvm/IR/BasicBlock.h" |
| 100 | #include "llvm/IR/CFG.h" |
| 101 | #include "llvm/IR/Constant.h" |
| 102 | #include "llvm/IR/Constants.h" |
| 103 | #include "llvm/IR/DataLayout.h" |
| 104 | #include "llvm/IR/DebugInfoMetadata.h" |
| 105 | #include "llvm/IR/DebugLoc.h" |
| 106 | #include "llvm/IR/DerivedTypes.h" |
| 107 | #include "llvm/IR/DiagnosticInfo.h" |
| 108 | #include "llvm/IR/Dominators.h" |
| 109 | #include "llvm/IR/Function.h" |
| 110 | #include "llvm/IR/IRBuilder.h" |
| 111 | #include "llvm/IR/InstrTypes.h" |
| 112 | #include "llvm/IR/Instruction.h" |
| 113 | #include "llvm/IR/Instructions.h" |
| 114 | #include "llvm/IR/IntrinsicInst.h" |
| 115 | #include "llvm/IR/Intrinsics.h" |
| 116 | #include "llvm/IR/LLVMContext.h" |
| 117 | #include "llvm/IR/Metadata.h" |
| 118 | #include "llvm/IR/Module.h" |
| 119 | #include "llvm/IR/Operator.h" |
| 120 | #include "llvm/IR/Type.h" |
| 121 | #include "llvm/IR/Use.h" |
| 122 | #include "llvm/IR/User.h" |
| 123 | #include "llvm/IR/Value.h" |
| 124 | #include "llvm/IR/ValueHandle.h" |
| 125 | #include "llvm/IR/Verifier.h" |
| 126 | #include "llvm/InitializePasses.h" |
| 127 | #include "llvm/Pass.h" |
| 128 | #include "llvm/Support/Casting.h" |
| 129 | #include "llvm/Support/CommandLine.h" |
| 130 | #include "llvm/Support/Compiler.h" |
| 131 | #include "llvm/Support/Debug.h" |
| 132 | #include "llvm/Support/ErrorHandling.h" |
| 133 | #include "llvm/Support/MathExtras.h" |
| 134 | #include "llvm/Support/raw_ostream.h" |
| 135 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" |
| 136 | #include "llvm/Transforms/Utils/InjectTLIMappings.h" |
| 137 | #include "llvm/Transforms/Utils/LoopSimplify.h" |
| 138 | #include "llvm/Transforms/Utils/LoopUtils.h" |
| 139 | #include "llvm/Transforms/Utils/LoopVersioning.h" |
| 140 | #include "llvm/Transforms/Utils/ScalarEvolutionExpander.h" |
| 141 | #include "llvm/Transforms/Utils/SizeOpts.h" |
| 142 | #include "llvm/Transforms/Vectorize/LoopVectorizationLegality.h" |
| 143 | #include <algorithm> |
| 144 | #include <cassert> |
| 145 | #include <cstdint> |
| 146 | #include <cstdlib> |
| 147 | #include <functional> |
| 148 | #include <iterator> |
| 149 | #include <limits> |
| 150 | #include <memory> |
| 151 | #include <string> |
| 152 | #include <tuple> |
| 153 | #include <utility> |
| 154 | |
| 155 | using namespace llvm; |
| 156 | |
| 157 | #define LV_NAME"loop-vectorize" "loop-vectorize" |
| 158 | #define DEBUG_TYPE"loop-vectorize" LV_NAME"loop-vectorize" |
| 159 | |
| 160 | /// @{ |
| 161 | /// Metadata attribute names |
| 162 | static const char *const LLVMLoopVectorizeFollowupAll = |
| 163 | "llvm.loop.vectorize.followup_all"; |
| 164 | static const char *const LLVMLoopVectorizeFollowupVectorized = |
| 165 | "llvm.loop.vectorize.followup_vectorized"; |
| 166 | static const char *const LLVMLoopVectorizeFollowupEpilogue = |
| 167 | "llvm.loop.vectorize.followup_epilogue"; |
| 168 | /// @} |
| 169 | |
| 170 | STATISTIC(LoopsVectorized, "Number of loops vectorized")static llvm::Statistic LoopsVectorized = {"loop-vectorize", "LoopsVectorized" , "Number of loops vectorized"}; |
| 171 | STATISTIC(LoopsAnalyzed, "Number of loops analyzed for vectorization")static llvm::Statistic LoopsAnalyzed = {"loop-vectorize", "LoopsAnalyzed" , "Number of loops analyzed for vectorization"}; |
| 172 | |
| 173 | /// Loops with a known constant trip count below this number are vectorized only |
| 174 | /// if no scalar iteration overheads are incurred. |
| 175 | static cl::opt<unsigned> TinyTripCountVectorThreshold( |
| 176 | "vectorizer-min-trip-count", cl::init(16), cl::Hidden, |
| 177 | cl::desc("Loops with a constant trip count that is smaller than this " |
| 178 | "value are vectorized only if no scalar iteration overheads " |
| 179 | "are incurred.")); |
| 180 | |
| 181 | // Option prefer-predicate-over-epilogue indicates that an epilogue is undesired, |
| 182 | // that predication is preferred, and this lists all options. I.e., the |
| 183 | // vectorizer will try to fold the tail-loop (epilogue) into the vector body |
| 184 | // and predicate the instructions accordingly. If tail-folding fails, there are |
| 185 | // different fallback strategies depending on these values: |
| 186 | namespace PreferPredicateTy { |
| 187 | enum Option { |
| 188 | ScalarEpilogue = 0, |
| 189 | PredicateElseScalarEpilogue, |
| 190 | PredicateOrDontVectorize |
| 191 | }; |
| 192 | } // namespace PreferPredicateTy |
| 193 | |
| 194 | static cl::opt<PreferPredicateTy::Option> PreferPredicateOverEpilogue( |
| 195 | "prefer-predicate-over-epilogue", |
| 196 | cl::init(PreferPredicateTy::ScalarEpilogue), |
| 197 | cl::Hidden, |
| 198 | cl::desc("Tail-folding and predication preferences over creating a scalar " |
| 199 | "epilogue loop."), |
| 200 | cl::values(clEnumValN(PreferPredicateTy::ScalarEpilogue,llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy ::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue" } |
| 201 | "scalar-epilogue",llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy ::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue" } |
| 202 | "Don't tail-predicate loops, create scalar epilogue")llvm::cl::OptionEnumValue { "scalar-epilogue", int(PreferPredicateTy ::ScalarEpilogue), "Don't tail-predicate loops, create scalar epilogue" }, |
| 203 | clEnumValN(PreferPredicateTy::PredicateElseScalarEpilogue,llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue", int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail " "folding fails." } |
| 204 | "predicate-else-scalar-epilogue",llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue", int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail " "folding fails." } |
| 205 | "prefer tail-folding, create scalar epilogue if tail "llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue", int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail " "folding fails." } |
| 206 | "folding fails.")llvm::cl::OptionEnumValue { "predicate-else-scalar-epilogue", int(PreferPredicateTy::PredicateElseScalarEpilogue), "prefer tail-folding, create scalar epilogue if tail " "folding fails." }, |
| 207 | clEnumValN(PreferPredicateTy::PredicateOrDontVectorize,llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy ::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if " "tail-folding fails." } |
| 208 | "predicate-dont-vectorize",llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy ::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if " "tail-folding fails." } |
| 209 | "prefers tail-folding, don't attempt vectorization if "llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy ::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if " "tail-folding fails." } |
| 210 | "tail-folding fails.")llvm::cl::OptionEnumValue { "predicate-dont-vectorize", int(PreferPredicateTy ::PredicateOrDontVectorize), "prefers tail-folding, don't attempt vectorization if " "tail-folding fails." })); |
| 211 | |
| 212 | static cl::opt<bool> MaximizeBandwidth( |
| 213 | "vectorizer-maximize-bandwidth", cl::init(false), cl::Hidden, |
| 214 | cl::desc("Maximize bandwidth when selecting vectorization factor which " |
| 215 | "will be determined by the smallest type in loop.")); |
| 216 | |
| 217 | static cl::opt<bool> EnableInterleavedMemAccesses( |
| 218 | "enable-interleaved-mem-accesses", cl::init(false), cl::Hidden, |
| 219 | cl::desc("Enable vectorization on interleaved memory accesses in a loop")); |
| 220 | |
| 221 | /// An interleave-group may need masking if it resides in a block that needs |
| 222 | /// predication, or in order to mask away gaps. |
| 223 | static cl::opt<bool> EnableMaskedInterleavedMemAccesses( |
| 224 | "enable-masked-interleaved-mem-accesses", cl::init(false), cl::Hidden, |
| 225 | cl::desc("Enable vectorization on masked interleaved memory accesses in a loop")); |
| 226 | |
| 227 | static cl::opt<unsigned> TinyTripCountInterleaveThreshold( |
| 228 | "tiny-trip-count-interleave-threshold", cl::init(128), cl::Hidden, |
| 229 | cl::desc("We don't interleave loops with a estimated constant trip count " |
| 230 | "below this number")); |
| 231 | |
| 232 | static cl::opt<unsigned> ForceTargetNumScalarRegs( |
| 233 | "force-target-num-scalar-regs", cl::init(0), cl::Hidden, |
| 234 | cl::desc("A flag that overrides the target's number of scalar registers.")); |
| 235 | |
| 236 | static cl::opt<unsigned> ForceTargetNumVectorRegs( |
| 237 | "force-target-num-vector-regs", cl::init(0), cl::Hidden, |
| 238 | cl::desc("A flag that overrides the target's number of vector registers.")); |
| 239 | |
| 240 | static cl::opt<unsigned> ForceTargetMaxScalarInterleaveFactor( |
| 241 | "force-target-max-scalar-interleave", cl::init(0), cl::Hidden, |
| 242 | cl::desc("A flag that overrides the target's max interleave factor for " |
| 243 | "scalar loops.")); |
| 244 | |
| 245 | static cl::opt<unsigned> ForceTargetMaxVectorInterleaveFactor( |
| 246 | "force-target-max-vector-interleave", cl::init(0), cl::Hidden, |
| 247 | cl::desc("A flag that overrides the target's max interleave factor for " |
| 248 | "vectorized loops.")); |
| 249 | |
| 250 | static cl::opt<unsigned> ForceTargetInstructionCost( |
| 251 | "force-target-instruction-cost", cl::init(0), cl::Hidden, |
| 252 | cl::desc("A flag that overrides the target's expected cost for " |
| 253 | "an instruction to a single constant value. Mostly " |
| 254 | "useful for getting consistent testing.")); |
| 255 | |
| 256 | static cl::opt<unsigned> SmallLoopCost( |
| 257 | "small-loop-cost", cl::init(20), cl::Hidden, |
| 258 | cl::desc( |
| 259 | "The cost of a loop that is considered 'small' by the interleaver.")); |
| 260 | |
| 261 | static cl::opt<bool> LoopVectorizeWithBlockFrequency( |
| 262 | "loop-vectorize-with-block-frequency", cl::init(true), cl::Hidden, |
| 263 | cl::desc("Enable the use of the block frequency analysis to access PGO " |
| 264 | "heuristics minimizing code growth in cold regions and being more " |
| 265 | "aggressive in hot regions.")); |
| 266 | |
| 267 | // Runtime interleave loops for load/store throughput. |
| 268 | static cl::opt<bool> EnableLoadStoreRuntimeInterleave( |
| 269 | "enable-loadstore-runtime-interleave", cl::init(true), cl::Hidden, |
| 270 | cl::desc( |
| 271 | "Enable runtime interleaving until load/store ports are saturated")); |
| 272 | |
| 273 | /// Interleave small loops with scalar reductions. |
| 274 | static cl::opt<bool> InterleaveSmallLoopScalarReduction( |
| 275 | "interleave-small-loop-scalar-reduction", cl::init(false), cl::Hidden, |
| 276 | cl::desc("Enable interleaving for loops with small iteration counts that " |
| 277 | "contain scalar reductions to expose ILP.")); |
| 278 | |
| 279 | /// The number of stores in a loop that are allowed to need predication. |
| 280 | static cl::opt<unsigned> NumberOfStoresToPredicate( |
| 281 | "vectorize-num-stores-pred", cl::init(1), cl::Hidden, |
| 282 | cl::desc("Max number of stores to be predicated behind an if.")); |
| 283 | |
| 284 | static cl::opt<bool> EnableIndVarRegisterHeur( |
| 285 | "enable-ind-var-reg-heur", cl::init(true), cl::Hidden, |
| 286 | cl::desc("Count the induction variable only once when interleaving")); |
| 287 | |
| 288 | static cl::opt<bool> EnableCondStoresVectorization( |
| 289 | "enable-cond-stores-vec", cl::init(true), cl::Hidden, |
| 290 | cl::desc("Enable if predication of stores during vectorization.")); |
| 291 | |
| 292 | static cl::opt<unsigned> MaxNestedScalarReductionIC( |
| 293 | "max-nested-scalar-reduction-interleave", cl::init(2), cl::Hidden, |
| 294 | cl::desc("The maximum interleave count to use when interleaving a scalar " |
| 295 | "reduction in a nested loop.")); |
| 296 | |
| 297 | static cl::opt<bool> |
| 298 | PreferInLoopReductions("prefer-inloop-reductions", cl::init(false), |
| 299 | cl::Hidden, |
| 300 | cl::desc("Prefer in-loop vector reductions, " |
| 301 | "overriding the targets preference.")); |
| 302 | |
| 303 | static cl::opt<bool> PreferPredicatedReductionSelect( |
| 304 | "prefer-predicated-reduction-select", cl::init(false), cl::Hidden, |
| 305 | cl::desc( |
| 306 | "Prefer predicating a reduction operation over an after loop select.")); |
| 307 | |
| 308 | cl::opt<bool> EnableVPlanNativePath( |
| 309 | "enable-vplan-native-path", cl::init(false), cl::Hidden, |
| 310 | cl::desc("Enable VPlan-native vectorization path with " |
| 311 | "support for outer loop vectorization.")); |
| 312 | |
| 313 | // FIXME: Remove this switch once we have divergence analysis. Currently we |
| 314 | // assume divergent non-backedge branches when this switch is true. |
| 315 | cl::opt<bool> EnableVPlanPredication( |
| 316 | "enable-vplan-predication", cl::init(false), cl::Hidden, |
| 317 | cl::desc("Enable VPlan-native vectorization path predicator with " |
| 318 | "support for outer loop vectorization.")); |
| 319 | |
| 320 | // This flag enables the stress testing of the VPlan H-CFG construction in the |
| 321 | // VPlan-native vectorization path. It must be used in conjuction with |
| 322 | // -enable-vplan-native-path. -vplan-verify-hcfg can also be used to enable the |
| 323 | // verification of the H-CFGs built. |
| 324 | static cl::opt<bool> VPlanBuildStressTest( |
| 325 | "vplan-build-stress-test", cl::init(false), cl::Hidden, |
| 326 | cl::desc( |
| 327 | "Build VPlan for every supported loop nest in the function and bail " |
| 328 | "out right after the build (stress test the VPlan H-CFG construction " |
| 329 | "in the VPlan-native vectorization path).")); |
| 330 | |
| 331 | cl::opt<bool> llvm::EnableLoopInterleaving( |
| 332 | "interleave-loops", cl::init(true), cl::Hidden, |
| 333 | cl::desc("Enable loop interleaving in Loop vectorization passes")); |
| 334 | cl::opt<bool> llvm::EnableLoopVectorization( |
| 335 | "vectorize-loops", cl::init(true), cl::Hidden, |
| 336 | cl::desc("Run the Loop vectorization passes")); |
| 337 | |
| 338 | /// A helper function that returns the type of loaded or stored value. |
| 339 | static Type *getMemInstValueType(Value *I) { |
| 340 | assert((isa<LoadInst>(I) || isa<StoreInst>(I)) &&(((isa<LoadInst>(I) || isa<StoreInst>(I)) && "Expected Load or Store instruction") ? static_cast<void> (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Expected Load or Store instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 341, __PRETTY_FUNCTION__)) |
| 341 | "Expected Load or Store instruction")(((isa<LoadInst>(I) || isa<StoreInst>(I)) && "Expected Load or Store instruction") ? static_cast<void> (0) : __assert_fail ("(isa<LoadInst>(I) || isa<StoreInst>(I)) && \"Expected Load or Store instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 341, __PRETTY_FUNCTION__)); |
| 342 | if (auto *LI = dyn_cast<LoadInst>(I)) |
| 343 | return LI->getType(); |
| 344 | return cast<StoreInst>(I)->getValueOperand()->getType(); |
| 345 | } |
| 346 | |
| 347 | /// A helper function that returns true if the given type is irregular. The |
| 348 | /// type is irregular if its allocated size doesn't equal the store size of an |
| 349 | /// element of the corresponding vector type at the given vectorization factor. |
| 350 | static bool hasIrregularType(Type *Ty, const DataLayout &DL, ElementCount VF) { |
| 351 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 351, __PRETTY_FUNCTION__)); |
| 352 | // Determine if an array of VF elements of type Ty is "bitcast compatible" |
| 353 | // with a <VF x Ty> vector. |
| 354 | if (VF.isVector()) { |
| 355 | auto *VectorTy = VectorType::get(Ty, VF); |
| 356 | return TypeSize::get(VF.getKnownMinValue() * |
| 357 | DL.getTypeAllocSize(Ty).getFixedValue(), |
| 358 | VF.isScalable()) != DL.getTypeStoreSize(VectorTy); |
| 359 | } |
| 360 | |
| 361 | // If the vectorization factor is one, we just check if an array of type Ty |
| 362 | // requires padding between elements. |
| 363 | return DL.getTypeAllocSizeInBits(Ty) != DL.getTypeSizeInBits(Ty); |
| 364 | } |
| 365 | |
| 366 | /// A helper function that returns the reciprocal of the block probability of |
| 367 | /// predicated blocks. If we return X, we are assuming the predicated block |
| 368 | /// will execute once for every X iterations of the loop header. |
| 369 | /// |
| 370 | /// TODO: We should use actual block probability here, if available. Currently, |
| 371 | /// we always assume predicated blocks have a 50% chance of executing. |
| 372 | static unsigned getReciprocalPredBlockProb() { return 2; } |
| 373 | |
| 374 | /// A helper function that adds a 'fast' flag to floating-point operations. |
| 375 | static Value *addFastMathFlag(Value *V) { |
| 376 | if (isa<FPMathOperator>(V)) |
| 377 | cast<Instruction>(V)->setFastMathFlags(FastMathFlags::getFast()); |
| 378 | return V; |
| 379 | } |
| 380 | |
| 381 | static Value *addFastMathFlag(Value *V, FastMathFlags FMF) { |
| 382 | if (isa<FPMathOperator>(V)) |
| 383 | cast<Instruction>(V)->setFastMathFlags(FMF); |
| 384 | return V; |
| 385 | } |
| 386 | |
| 387 | /// A helper function that returns an integer or floating-point constant with |
| 388 | /// value C. |
| 389 | static Constant *getSignedIntOrFpConstant(Type *Ty, int64_t C) { |
| 390 | return Ty->isIntegerTy() ? ConstantInt::getSigned(Ty, C) |
| 391 | : ConstantFP::get(Ty, C); |
| 392 | } |
| 393 | |
| 394 | /// Returns "best known" trip count for the specified loop \p L as defined by |
| 395 | /// the following procedure: |
| 396 | /// 1) Returns exact trip count if it is known. |
| 397 | /// 2) Returns expected trip count according to profile data if any. |
| 398 | /// 3) Returns upper bound estimate if it is known. |
| 399 | /// 4) Returns None if all of the above failed. |
| 400 | static Optional<unsigned> getSmallBestKnownTC(ScalarEvolution &SE, Loop *L) { |
| 401 | // Check if exact trip count is known. |
| 402 | if (unsigned ExpectedTC = SE.getSmallConstantTripCount(L)) |
| 403 | return ExpectedTC; |
| 404 | |
| 405 | // Check if there is an expected trip count available from profile data. |
| 406 | if (LoopVectorizeWithBlockFrequency) |
| 407 | if (auto EstimatedTC = getLoopEstimatedTripCount(L)) |
| 408 | return EstimatedTC; |
| 409 | |
| 410 | // Check if upper bound estimate is known. |
| 411 | if (unsigned ExpectedTC = SE.getSmallConstantMaxTripCount(L)) |
| 412 | return ExpectedTC; |
| 413 | |
| 414 | return None; |
| 415 | } |
| 416 | |
| 417 | namespace llvm { |
| 418 | |
| 419 | /// InnerLoopVectorizer vectorizes loops which contain only one basic |
| 420 | /// block to a specified vectorization factor (VF). |
| 421 | /// This class performs the widening of scalars into vectors, or multiple |
| 422 | /// scalars. This class also implements the following features: |
| 423 | /// * It inserts an epilogue loop for handling loops that don't have iteration |
| 424 | /// counts that are known to be a multiple of the vectorization factor. |
| 425 | /// * It handles the code generation for reduction variables. |
| 426 | /// * Scalarization (implementation using scalars) of un-vectorizable |
| 427 | /// instructions. |
| 428 | /// InnerLoopVectorizer does not perform any vectorization-legality |
| 429 | /// checks, and relies on the caller to check for the different legality |
| 430 | /// aspects. The InnerLoopVectorizer relies on the |
| 431 | /// LoopVectorizationLegality class to provide information about the induction |
| 432 | /// and reduction variables that were found to a given vectorization factor. |
| 433 | class InnerLoopVectorizer { |
| 434 | public: |
| 435 | InnerLoopVectorizer(Loop *OrigLoop, PredicatedScalarEvolution &PSE, |
| 436 | LoopInfo *LI, DominatorTree *DT, |
| 437 | const TargetLibraryInfo *TLI, |
| 438 | const TargetTransformInfo *TTI, AssumptionCache *AC, |
| 439 | OptimizationRemarkEmitter *ORE, ElementCount VecWidth, |
| 440 | unsigned UnrollFactor, LoopVectorizationLegality *LVL, |
| 441 | LoopVectorizationCostModel *CM, BlockFrequencyInfo *BFI, |
| 442 | ProfileSummaryInfo *PSI) |
| 443 | : OrigLoop(OrigLoop), PSE(PSE), LI(LI), DT(DT), TLI(TLI), TTI(TTI), |
| 444 | AC(AC), ORE(ORE), VF(VecWidth), UF(UnrollFactor), |
| 445 | Builder(PSE.getSE()->getContext()), |
| 446 | VectorLoopValueMap(UnrollFactor, VecWidth), Legal(LVL), Cost(CM), |
| 447 | BFI(BFI), PSI(PSI) { |
| 448 | // Query this against the original loop and save it here because the profile |
| 449 | // of the original loop header may change as the transformation happens. |
| 450 | OptForSizeBasedOnProfile = llvm::shouldOptimizeForSize( |
| 451 | OrigLoop->getHeader(), PSI, BFI, PGSOQueryType::IRPass); |
| 452 | } |
| 453 | |
| 454 | virtual ~InnerLoopVectorizer() = default; |
| 455 | |
| 456 | /// Create a new empty loop that will contain vectorized instructions later |
| 457 | /// on, while the old loop will be used as the scalar remainder. Control flow |
| 458 | /// is generated around the vectorized (and scalar epilogue) loops consisting |
| 459 | /// of various checks and bypasses. Return the pre-header block of the new |
| 460 | /// loop. |
| 461 | BasicBlock *createVectorizedLoopSkeleton(); |
| 462 | |
| 463 | /// Widen a single instruction within the innermost loop. |
| 464 | void widenInstruction(Instruction &I, VPUser &Operands, |
| 465 | VPTransformState &State); |
| 466 | |
| 467 | /// Widen a single call instruction within the innermost loop. |
| 468 | void widenCallInstruction(CallInst &I, VPValue *Def, VPUser &ArgOperands, |
| 469 | VPTransformState &State); |
| 470 | |
| 471 | /// Widen a single select instruction within the innermost loop. |
| 472 | void widenSelectInstruction(SelectInst &I, VPValue *VPDef, VPUser &Operands, |
| 473 | bool InvariantCond, VPTransformState &State); |
| 474 | |
| 475 | /// Fix the vectorized code, taking care of header phi's, live-outs, and more. |
| 476 | void fixVectorizedLoop(); |
| 477 | |
| 478 | // Return true if any runtime check is added. |
| 479 | bool areSafetyChecksAdded() { return AddedSafetyChecks; } |
| 480 | |
| 481 | /// A type for vectorized values in the new loop. Each value from the |
| 482 | /// original loop, when vectorized, is represented by UF vector values in the |
| 483 | /// new unrolled loop, where UF is the unroll factor. |
| 484 | using VectorParts = SmallVector<Value *, 2>; |
| 485 | |
| 486 | /// Vectorize a single GetElementPtrInst based on information gathered and |
| 487 | /// decisions taken during planning. |
| 488 | void widenGEP(GetElementPtrInst *GEP, VPValue *VPDef, VPUser &Indices, |
| 489 | unsigned UF, ElementCount VF, bool IsPtrLoopInvariant, |
| 490 | SmallBitVector &IsIndexLoopInvariant, VPTransformState &State); |
| 491 | |
| 492 | /// Vectorize a single PHINode in a block. This method handles the induction |
| 493 | /// variable canonicalization. It supports both VF = 1 for unrolled loops and |
| 494 | /// arbitrary length vectors. |
| 495 | void widenPHIInstruction(Instruction *PN, unsigned UF, ElementCount VF); |
| 496 | |
| 497 | /// A helper function to scalarize a single Instruction in the innermost loop. |
| 498 | /// Generates a sequence of scalar instances for each lane between \p MinLane |
| 499 | /// and \p MaxLane, times each part between \p MinPart and \p MaxPart, |
| 500 | /// inclusive. Uses the VPValue operands from \p Operands instead of \p |
| 501 | /// Instr's operands. |
| 502 | void scalarizeInstruction(Instruction *Instr, VPUser &Operands, |
| 503 | const VPIteration &Instance, bool IfPredicateInstr, |
| 504 | VPTransformState &State); |
| 505 | |
| 506 | /// Widen an integer or floating-point induction variable \p IV. If \p Trunc |
| 507 | /// is provided, the integer induction variable will first be truncated to |
| 508 | /// the corresponding type. |
| 509 | void widenIntOrFpInduction(PHINode *IV, TruncInst *Trunc = nullptr); |
| 510 | |
| 511 | /// getOrCreateVectorValue and getOrCreateScalarValue coordinate to generate a |
| 512 | /// vector or scalar value on-demand if one is not yet available. When |
| 513 | /// vectorizing a loop, we visit the definition of an instruction before its |
| 514 | /// uses. When visiting the definition, we either vectorize or scalarize the |
| 515 | /// instruction, creating an entry for it in the corresponding map. (In some |
| 516 | /// cases, such as induction variables, we will create both vector and scalar |
| 517 | /// entries.) Then, as we encounter uses of the definition, we derive values |
| 518 | /// for each scalar or vector use unless such a value is already available. |
| 519 | /// For example, if we scalarize a definition and one of its uses is vector, |
| 520 | /// we build the required vector on-demand with an insertelement sequence |
| 521 | /// when visiting the use. Otherwise, if the use is scalar, we can use the |
| 522 | /// existing scalar definition. |
| 523 | /// |
| 524 | /// Return a value in the new loop corresponding to \p V from the original |
| 525 | /// loop at unroll index \p Part. If the value has already been vectorized, |
| 526 | /// the corresponding vector entry in VectorLoopValueMap is returned. If, |
| 527 | /// however, the value has a scalar entry in VectorLoopValueMap, we construct |
| 528 | /// a new vector value on-demand by inserting the scalar values into a vector |
| 529 | /// with an insertelement sequence. If the value has been neither vectorized |
| 530 | /// nor scalarized, it must be loop invariant, so we simply broadcast the |
| 531 | /// value into a vector. |
| 532 | Value *getOrCreateVectorValue(Value *V, unsigned Part); |
| 533 | |
| 534 | void setVectorValue(Value *Scalar, unsigned Part, Value *Vector) { |
| 535 | VectorLoopValueMap.setVectorValue(Scalar, Part, Vector); |
| 536 | } |
| 537 | |
| 538 | /// Return a value in the new loop corresponding to \p V from the original |
| 539 | /// loop at unroll and vector indices \p Instance. If the value has been |
| 540 | /// vectorized but not scalarized, the necessary extractelement instruction |
| 541 | /// will be generated. |
| 542 | Value *getOrCreateScalarValue(Value *V, const VPIteration &Instance); |
| 543 | |
| 544 | /// Construct the vector value of a scalarized value \p V one lane at a time. |
| 545 | void packScalarIntoVectorValue(Value *V, const VPIteration &Instance); |
| 546 | |
| 547 | /// Try to vectorize interleaved access group \p Group with the base address |
| 548 | /// given in \p Addr, optionally masking the vector operations if \p |
| 549 | /// BlockInMask is non-null. Use \p State to translate given VPValues to IR |
| 550 | /// values in the vectorized loop. |
| 551 | void vectorizeInterleaveGroup(const InterleaveGroup<Instruction> *Group, |
| 552 | VPTransformState &State, VPValue *Addr, |
| 553 | VPValue *BlockInMask = nullptr); |
| 554 | |
| 555 | /// Vectorize Load and Store instructions with the base address given in \p |
| 556 | /// Addr, optionally masking the vector operations if \p BlockInMask is |
| 557 | /// non-null. Use \p State to translate given VPValues to IR values in the |
| 558 | /// vectorized loop. |
| 559 | void vectorizeMemoryInstruction(Instruction *Instr, VPTransformState &State, |
| 560 | VPValue *Def, VPValue *Addr, |
| 561 | VPValue *StoredValue, VPValue *BlockInMask); |
| 562 | |
| 563 | /// Set the debug location in the builder using the debug location in |
| 564 | /// the instruction. |
| 565 | void setDebugLocFromInst(IRBuilder<> &B, const Value *Ptr); |
| 566 | |
| 567 | /// Fix the non-induction PHIs in the OrigPHIsToFix vector. |
| 568 | void fixNonInductionPHIs(void); |
| 569 | |
| 570 | protected: |
| 571 | friend class LoopVectorizationPlanner; |
| 572 | |
| 573 | /// A small list of PHINodes. |
| 574 | using PhiVector = SmallVector<PHINode *, 4>; |
| 575 | |
| 576 | /// A type for scalarized values in the new loop. Each value from the |
| 577 | /// original loop, when scalarized, is represented by UF x VF scalar values |
| 578 | /// in the new unrolled loop, where UF is the unroll factor and VF is the |
| 579 | /// vectorization factor. |
| 580 | using ScalarParts = SmallVector<SmallVector<Value *, 4>, 2>; |
| 581 | |
| 582 | /// Set up the values of the IVs correctly when exiting the vector loop. |
| 583 | void fixupIVUsers(PHINode *OrigPhi, const InductionDescriptor &II, |
| 584 | Value *CountRoundDown, Value *EndValue, |
| 585 | BasicBlock *MiddleBlock); |
| 586 | |
| 587 | /// Create a new induction variable inside L. |
| 588 | PHINode *createInductionVariable(Loop *L, Value *Start, Value *End, |
| 589 | Value *Step, Instruction *DL); |
| 590 | |
| 591 | /// Handle all cross-iteration phis in the header. |
| 592 | void fixCrossIterationPHIs(); |
| 593 | |
| 594 | /// Fix a first-order recurrence. This is the second phase of vectorizing |
| 595 | /// this phi node. |
| 596 | void fixFirstOrderRecurrence(PHINode *Phi); |
| 597 | |
| 598 | /// Fix a reduction cross-iteration phi. This is the second phase of |
| 599 | /// vectorizing this phi node. |
| 600 | void fixReduction(PHINode *Phi); |
| 601 | |
| 602 | /// Clear NSW/NUW flags from reduction instructions if necessary. |
| 603 | void clearReductionWrapFlags(RecurrenceDescriptor &RdxDesc); |
| 604 | |
| 605 | /// The Loop exit block may have single value PHI nodes with some |
| 606 | /// incoming value. While vectorizing we only handled real values |
| 607 | /// that were defined inside the loop and we should have one value for |
| 608 | /// each predecessor of its parent basic block. See PR14725. |
| 609 | void fixLCSSAPHIs(); |
| 610 | |
| 611 | /// Iteratively sink the scalarized operands of a predicated instruction into |
| 612 | /// the block that was created for it. |
| 613 | void sinkScalarOperands(Instruction *PredInst); |
| 614 | |
| 615 | /// Shrinks vector element sizes to the smallest bitwidth they can be legally |
| 616 | /// represented as. |
| 617 | void truncateToMinimalBitwidths(); |
| 618 | |
| 619 | /// Create a broadcast instruction. This method generates a broadcast |
| 620 | /// instruction (shuffle) for loop invariant values and for the induction |
| 621 | /// value. If this is the induction variable then we extend it to N, N+1, ... |
| 622 | /// this is needed because each iteration in the loop corresponds to a SIMD |
| 623 | /// element. |
| 624 | virtual Value *getBroadcastInstrs(Value *V); |
| 625 | |
| 626 | /// This function adds (StartIdx, StartIdx + Step, StartIdx + 2*Step, ...) |
| 627 | /// to each vector element of Val. The sequence starts at StartIndex. |
| 628 | /// \p Opcode is relevant for FP induction variable. |
| 629 | virtual Value *getStepVector(Value *Val, int StartIdx, Value *Step, |
| 630 | Instruction::BinaryOps Opcode = |
| 631 | Instruction::BinaryOpsEnd); |
| 632 | |
| 633 | /// Compute scalar induction steps. \p ScalarIV is the scalar induction |
| 634 | /// variable on which to base the steps, \p Step is the size of the step, and |
| 635 | /// \p EntryVal is the value from the original loop that maps to the steps. |
| 636 | /// Note that \p EntryVal doesn't have to be an induction variable - it |
| 637 | /// can also be a truncate instruction. |
| 638 | void buildScalarSteps(Value *ScalarIV, Value *Step, Instruction *EntryVal, |
| 639 | const InductionDescriptor &ID); |
| 640 | |
| 641 | /// Create a vector induction phi node based on an existing scalar one. \p |
| 642 | /// EntryVal is the value from the original loop that maps to the vector phi |
| 643 | /// node, and \p Step is the loop-invariant step. If \p EntryVal is a |
| 644 | /// truncate instruction, instead of widening the original IV, we widen a |
| 645 | /// version of the IV truncated to \p EntryVal's type. |
| 646 | void createVectorIntOrFpInductionPHI(const InductionDescriptor &II, |
| 647 | Value *Step, Instruction *EntryVal); |
| 648 | |
| 649 | /// Returns true if an instruction \p I should be scalarized instead of |
| 650 | /// vectorized for the chosen vectorization factor. |
| 651 | bool shouldScalarizeInstruction(Instruction *I) const; |
| 652 | |
| 653 | /// Returns true if we should generate a scalar version of \p IV. |
| 654 | bool needsScalarInduction(Instruction *IV) const; |
| 655 | |
| 656 | /// If there is a cast involved in the induction variable \p ID, which should |
| 657 | /// be ignored in the vectorized loop body, this function records the |
| 658 | /// VectorLoopValue of the respective Phi also as the VectorLoopValue of the |
| 659 | /// cast. We had already proved that the casted Phi is equal to the uncasted |
| 660 | /// Phi in the vectorized loop (under a runtime guard), and therefore |
| 661 | /// there is no need to vectorize the cast - the same value can be used in the |
| 662 | /// vector loop for both the Phi and the cast. |
| 663 | /// If \p VectorLoopValue is a scalarized value, \p Lane is also specified, |
| 664 | /// Otherwise, \p VectorLoopValue is a widened/vectorized value. |
| 665 | /// |
| 666 | /// \p EntryVal is the value from the original loop that maps to the vector |
| 667 | /// phi node and is used to distinguish what is the IV currently being |
| 668 | /// processed - original one (if \p EntryVal is a phi corresponding to the |
| 669 | /// original IV) or the "newly-created" one based on the proof mentioned above |
| 670 | /// (see also buildScalarSteps() and createVectorIntOrFPInductionPHI()). In the |
| 671 | /// latter case \p EntryVal is a TruncInst and we must not record anything for |
| 672 | /// that IV, but it's error-prone to expect callers of this routine to care |
| 673 | /// about that, hence this explicit parameter. |
| 674 | void recordVectorLoopValueForInductionCast(const InductionDescriptor &ID, |
| 675 | const Instruction *EntryVal, |
| 676 | Value *VectorLoopValue, |
| 677 | unsigned Part, |
| 678 | unsigned Lane = UINT_MAX(2147483647 *2U +1U)); |
| 679 | |
| 680 | /// Generate a shuffle sequence that will reverse the vector Vec. |
| 681 | virtual Value *reverseVector(Value *Vec); |
| 682 | |
| 683 | /// Returns (and creates if needed) the original loop trip count. |
| 684 | Value *getOrCreateTripCount(Loop *NewLoop); |
| 685 | |
| 686 | /// Returns (and creates if needed) the trip count of the widened loop. |
| 687 | Value *getOrCreateVectorTripCount(Loop *NewLoop); |
| 688 | |
| 689 | /// Returns a bitcasted value to the requested vector type. |
| 690 | /// Also handles bitcasts of vector<float> <-> vector<pointer> types. |
| 691 | Value *createBitOrPointerCast(Value *V, VectorType *DstVTy, |
| 692 | const DataLayout &DL); |
| 693 | |
| 694 | /// Emit a bypass check to see if the vector trip count is zero, including if |
| 695 | /// it overflows. |
| 696 | void emitMinimumIterationCountCheck(Loop *L, BasicBlock *Bypass); |
| 697 | |
| 698 | /// Emit a bypass check to see if all of the SCEV assumptions we've |
| 699 | /// had to make are correct. |
| 700 | void emitSCEVChecks(Loop *L, BasicBlock *Bypass); |
| 701 | |
| 702 | /// Emit bypass checks to check any memory assumptions we may have made. |
| 703 | void emitMemRuntimeChecks(Loop *L, BasicBlock *Bypass); |
| 704 | |
| 705 | /// Compute the transformed value of Index at offset StartValue using step |
| 706 | /// StepValue. |
| 707 | /// For integer induction, returns StartValue + Index * StepValue. |
| 708 | /// For pointer induction, returns StartValue[Index * StepValue]. |
| 709 | /// FIXME: The newly created binary instructions should contain nsw/nuw |
| 710 | /// flags, which can be found from the original scalar operations. |
| 711 | Value *emitTransformedIndex(IRBuilder<> &B, Value *Index, ScalarEvolution *SE, |
| 712 | const DataLayout &DL, |
| 713 | const InductionDescriptor &ID) const; |
| 714 | |
| 715 | /// Emit basic blocks (prefixed with \p Prefix) for the iteration check, |
| 716 | /// vector loop preheader, middle block and scalar preheader. Also |
| 717 | /// allocate a loop object for the new vector loop and return it. |
| 718 | Loop *createVectorLoopSkeleton(StringRef Prefix); |
| 719 | |
| 720 | /// Create new phi nodes for the induction variables to resume iteration count |
| 721 | /// in the scalar epilogue, from where the vectorized loop left off (given by |
| 722 | /// \p VectorTripCount). |
| 723 | void createInductionResumeValues(Loop *L, Value *VectorTripCount); |
| 724 | |
| 725 | /// Complete the loop skeleton by adding debug MDs, creating appropriate |
| 726 | /// conditional branches in the middle block, preparing the builder and |
| 727 | /// running the verifier. Take in the vector loop \p L as argument, and return |
| 728 | /// the preheader of the completed vector loop. |
| 729 | BasicBlock *completeLoopSkeleton(Loop *L, MDNode *OrigLoopID); |
| 730 | |
| 731 | /// Add additional metadata to \p To that was not present on \p Orig. |
| 732 | /// |
| 733 | /// Currently this is used to add the noalias annotations based on the |
| 734 | /// inserted memchecks. Use this for instructions that are *cloned* into the |
| 735 | /// vector loop. |
| 736 | void addNewMetadata(Instruction *To, const Instruction *Orig); |
| 737 | |
| 738 | /// Add metadata from one instruction to another. |
| 739 | /// |
| 740 | /// This includes both the original MDs from \p From and additional ones (\see |
| 741 | /// addNewMetadata). Use this for *newly created* instructions in the vector |
| 742 | /// loop. |
| 743 | void addMetadata(Instruction *To, Instruction *From); |
| 744 | |
| 745 | /// Similar to the previous function but it adds the metadata to a |
| 746 | /// vector of instructions. |
| 747 | void addMetadata(ArrayRef<Value *> To, Instruction *From); |
| 748 | |
| 749 | /// The original loop. |
| 750 | Loop *OrigLoop; |
| 751 | |
| 752 | /// A wrapper around ScalarEvolution used to add runtime SCEV checks. Applies |
| 753 | /// dynamic knowledge to simplify SCEV expressions and converts them to a |
| 754 | /// more usable form. |
| 755 | PredicatedScalarEvolution &PSE; |
| 756 | |
| 757 | /// Loop Info. |
| 758 | LoopInfo *LI; |
| 759 | |
| 760 | /// Dominator Tree. |
| 761 | DominatorTree *DT; |
| 762 | |
| 763 | /// Alias Analysis. |
| 764 | AAResults *AA; |
| 765 | |
| 766 | /// Target Library Info. |
| 767 | const TargetLibraryInfo *TLI; |
| 768 | |
| 769 | /// Target Transform Info. |
| 770 | const TargetTransformInfo *TTI; |
| 771 | |
| 772 | /// Assumption Cache. |
| 773 | AssumptionCache *AC; |
| 774 | |
| 775 | /// Interface to emit optimization remarks. |
| 776 | OptimizationRemarkEmitter *ORE; |
| 777 | |
| 778 | /// LoopVersioning. It's only set up (non-null) if memchecks were |
| 779 | /// used. |
| 780 | /// |
| 781 | /// This is currently only used to add no-alias metadata based on the |
| 782 | /// memchecks. The actually versioning is performed manually. |
| 783 | std::unique_ptr<LoopVersioning> LVer; |
| 784 | |
| 785 | /// The vectorization SIMD factor to use. Each vector will have this many |
| 786 | /// vector elements. |
| 787 | ElementCount VF; |
| 788 | |
| 789 | /// The vectorization unroll factor to use. Each scalar is vectorized to this |
| 790 | /// many different vector instructions. |
| 791 | unsigned UF; |
| 792 | |
| 793 | /// The builder that we use |
| 794 | IRBuilder<> Builder; |
| 795 | |
| 796 | // --- Vectorization state --- |
| 797 | |
| 798 | /// The vector-loop preheader. |
| 799 | BasicBlock *LoopVectorPreHeader; |
| 800 | |
| 801 | /// The scalar-loop preheader. |
| 802 | BasicBlock *LoopScalarPreHeader; |
| 803 | |
| 804 | /// Middle Block between the vector and the scalar. |
| 805 | BasicBlock *LoopMiddleBlock; |
| 806 | |
| 807 | /// The ExitBlock of the scalar loop. |
| 808 | BasicBlock *LoopExitBlock; |
| 809 | |
| 810 | /// The vector loop body. |
| 811 | BasicBlock *LoopVectorBody; |
| 812 | |
| 813 | /// The scalar loop body. |
| 814 | BasicBlock *LoopScalarBody; |
| 815 | |
| 816 | /// A list of all bypass blocks. The first block is the entry of the loop. |
| 817 | SmallVector<BasicBlock *, 4> LoopBypassBlocks; |
| 818 | |
| 819 | /// The new Induction variable which was added to the new block. |
| 820 | PHINode *Induction = nullptr; |
| 821 | |
| 822 | /// The induction variable of the old basic block. |
| 823 | PHINode *OldInduction = nullptr; |
| 824 | |
| 825 | /// Maps values from the original loop to their corresponding values in the |
| 826 | /// vectorized loop. A key value can map to either vector values, scalar |
| 827 | /// values or both kinds of values, depending on whether the key was |
| 828 | /// vectorized and scalarized. |
| 829 | VectorizerValueMap VectorLoopValueMap; |
| 830 | |
| 831 | /// Store instructions that were predicated. |
| 832 | SmallVector<Instruction *, 4> PredicatedInstructions; |
| 833 | |
| 834 | /// Trip count of the original loop. |
| 835 | Value *TripCount = nullptr; |
| 836 | |
| 837 | /// Trip count of the widened loop (TripCount - TripCount % (VF*UF)) |
| 838 | Value *VectorTripCount = nullptr; |
| 839 | |
| 840 | /// The legality analysis. |
| 841 | LoopVectorizationLegality *Legal; |
| 842 | |
| 843 | /// The profitablity analysis. |
| 844 | LoopVectorizationCostModel *Cost; |
| 845 | |
| 846 | // Record whether runtime checks are added. |
| 847 | bool AddedSafetyChecks = false; |
| 848 | |
| 849 | // Holds the end values for each induction variable. We save the end values |
| 850 | // so we can later fix-up the external users of the induction variables. |
| 851 | DenseMap<PHINode *, Value *> IVEndValues; |
| 852 | |
| 853 | // Vector of original scalar PHIs whose corresponding widened PHIs need to be |
| 854 | // fixed up at the end of vector code generation. |
| 855 | SmallVector<PHINode *, 8> OrigPHIsToFix; |
| 856 | |
| 857 | /// BFI and PSI are used to check for profile guided size optimizations. |
| 858 | BlockFrequencyInfo *BFI; |
| 859 | ProfileSummaryInfo *PSI; |
| 860 | |
| 861 | // Whether this loop should be optimized for size based on profile guided size |
| 862 | // optimizatios. |
| 863 | bool OptForSizeBasedOnProfile; |
| 864 | }; |
| 865 | |
| 866 | class InnerLoopUnroller : public InnerLoopVectorizer { |
| 867 | public: |
| 868 | InnerLoopUnroller(Loop *OrigLoop, PredicatedScalarEvolution &PSE, |
| 869 | LoopInfo *LI, DominatorTree *DT, |
| 870 | const TargetLibraryInfo *TLI, |
| 871 | const TargetTransformInfo *TTI, AssumptionCache *AC, |
| 872 | OptimizationRemarkEmitter *ORE, unsigned UnrollFactor, |
| 873 | LoopVectorizationLegality *LVL, |
| 874 | LoopVectorizationCostModel *CM, BlockFrequencyInfo *BFI, |
| 875 | ProfileSummaryInfo *PSI) |
| 876 | : InnerLoopVectorizer(OrigLoop, PSE, LI, DT, TLI, TTI, AC, ORE, |
| 877 | ElementCount::getFixed(1), UnrollFactor, LVL, CM, |
| 878 | BFI, PSI) {} |
| 879 | |
| 880 | private: |
| 881 | Value *getBroadcastInstrs(Value *V) override; |
| 882 | Value *getStepVector(Value *Val, int StartIdx, Value *Step, |
| 883 | Instruction::BinaryOps Opcode = |
| 884 | Instruction::BinaryOpsEnd) override; |
| 885 | Value *reverseVector(Value *Vec) override; |
| 886 | }; |
| 887 | |
| 888 | } // end namespace llvm |
| 889 | |
| 890 | /// Look for a meaningful debug location on the instruction or it's |
| 891 | /// operands. |
| 892 | static Instruction *getDebugLocFromInstOrOperands(Instruction *I) { |
| 893 | if (!I) |
| 894 | return I; |
| 895 | |
| 896 | DebugLoc Empty; |
| 897 | if (I->getDebugLoc() != Empty) |
| 898 | return I; |
| 899 | |
| 900 | for (User::op_iterator OI = I->op_begin(), OE = I->op_end(); OI != OE; ++OI) { |
| 901 | if (Instruction *OpInst = dyn_cast<Instruction>(*OI)) |
| 902 | if (OpInst->getDebugLoc() != Empty) |
| 903 | return OpInst; |
| 904 | } |
| 905 | |
| 906 | return I; |
| 907 | } |
| 908 | |
| 909 | void InnerLoopVectorizer::setDebugLocFromInst(IRBuilder<> &B, const Value *Ptr) { |
| 910 | if (const Instruction *Inst = dyn_cast_or_null<Instruction>(Ptr)) { |
| 911 | const DILocation *DIL = Inst->getDebugLoc(); |
| 912 | if (DIL && Inst->getFunction()->isDebugInfoForProfiling() && |
| 913 | !isa<DbgInfoIntrinsic>(Inst)) { |
| 914 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 914, __PRETTY_FUNCTION__)); |
| 915 | auto NewDIL = |
| 916 | DIL->cloneByMultiplyingDuplicationFactor(UF * VF.getKnownMinValue()); |
| 917 | if (NewDIL) |
| 918 | B.SetCurrentDebugLocation(NewDIL.getValue()); |
| 919 | else |
| 920 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "Failed to create new discriminator: " << DIL->getFilename() << " Line: " << DIL ->getLine(); } } while (false) |
| 921 | << "Failed to create new discriminator: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "Failed to create new discriminator: " << DIL->getFilename() << " Line: " << DIL ->getLine(); } } while (false) |
| 922 | << DIL->getFilename() << " Line: " << DIL->getLine())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "Failed to create new discriminator: " << DIL->getFilename() << " Line: " << DIL ->getLine(); } } while (false); |
| 923 | } |
| 924 | else |
| 925 | B.SetCurrentDebugLocation(DIL); |
| 926 | } else |
| 927 | B.SetCurrentDebugLocation(DebugLoc()); |
| 928 | } |
| 929 | |
| 930 | /// Write a record \p DebugMsg about vectorization failure to the debug |
| 931 | /// output stream. If \p I is passed, it is an instruction that prevents |
| 932 | /// vectorization. |
| 933 | #ifndef NDEBUG |
| 934 | static void debugVectorizationFailure(const StringRef DebugMsg, |
| 935 | Instruction *I) { |
| 936 | dbgs() << "LV: Not vectorizing: " << DebugMsg; |
| 937 | if (I != nullptr) |
| 938 | dbgs() << " " << *I; |
| 939 | else |
| 940 | dbgs() << '.'; |
| 941 | dbgs() << '\n'; |
| 942 | } |
| 943 | #endif |
| 944 | |
| 945 | /// Create an analysis remark that explains why vectorization failed |
| 946 | /// |
| 947 | /// \p PassName is the name of the pass (e.g. can be AlwaysPrint). \p |
| 948 | /// RemarkName is the identifier for the remark. If \p I is passed it is an |
| 949 | /// instruction that prevents vectorization. Otherwise \p TheLoop is used for |
| 950 | /// the location of the remark. \return the remark object that can be |
| 951 | /// streamed to. |
| 952 | static OptimizationRemarkAnalysis createLVAnalysis(const char *PassName, |
| 953 | StringRef RemarkName, Loop *TheLoop, Instruction *I) { |
| 954 | Value *CodeRegion = TheLoop->getHeader(); |
| 955 | DebugLoc DL = TheLoop->getStartLoc(); |
| 956 | |
| 957 | if (I) { |
| 958 | CodeRegion = I->getParent(); |
| 959 | // If there is no debug location attached to the instruction, revert back to |
| 960 | // using the loop's. |
| 961 | if (I->getDebugLoc()) |
| 962 | DL = I->getDebugLoc(); |
| 963 | } |
| 964 | |
| 965 | OptimizationRemarkAnalysis R(PassName, RemarkName, DL, CodeRegion); |
| 966 | R << "loop not vectorized: "; |
| 967 | return R; |
| 968 | } |
| 969 | |
| 970 | namespace llvm { |
| 971 | |
| 972 | void reportVectorizationFailure(const StringRef DebugMsg, |
| 973 | const StringRef OREMsg, const StringRef ORETag, |
| 974 | OptimizationRemarkEmitter *ORE, Loop *TheLoop, Instruction *I) { |
| 975 | LLVM_DEBUG(debugVectorizationFailure(DebugMsg, I))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { debugVectorizationFailure(DebugMsg, I); } } while (false); |
| 976 | LoopVectorizeHints Hints(TheLoop, true /* doesn't matter */, *ORE); |
| 977 | ORE->emit(createLVAnalysis(Hints.vectorizeAnalysisPassName(), |
| 978 | ORETag, TheLoop, I) << OREMsg); |
| 979 | } |
| 980 | |
| 981 | } // end namespace llvm |
| 982 | |
| 983 | #ifndef NDEBUG |
| 984 | /// \return string containing a file name and a line # for the given loop. |
| 985 | static std::string getDebugLocString(const Loop *L) { |
| 986 | std::string Result; |
| 987 | if (L) { |
| 988 | raw_string_ostream OS(Result); |
| 989 | if (const DebugLoc LoopDbgLoc = L->getStartLoc()) |
| 990 | LoopDbgLoc.print(OS); |
| 991 | else |
| 992 | // Just print the module name. |
| 993 | OS << L->getHeader()->getParent()->getParent()->getModuleIdentifier(); |
| 994 | OS.flush(); |
| 995 | } |
| 996 | return Result; |
| 997 | } |
| 998 | #endif |
| 999 | |
| 1000 | void InnerLoopVectorizer::addNewMetadata(Instruction *To, |
| 1001 | const Instruction *Orig) { |
| 1002 | // If the loop was versioned with memchecks, add the corresponding no-alias |
| 1003 | // metadata. |
| 1004 | if (LVer && (isa<LoadInst>(Orig) || isa<StoreInst>(Orig))) |
| 1005 | LVer->annotateInstWithNoAlias(To, Orig); |
| 1006 | } |
| 1007 | |
| 1008 | void InnerLoopVectorizer::addMetadata(Instruction *To, |
| 1009 | Instruction *From) { |
| 1010 | propagateMetadata(To, From); |
| 1011 | addNewMetadata(To, From); |
| 1012 | } |
| 1013 | |
| 1014 | void InnerLoopVectorizer::addMetadata(ArrayRef<Value *> To, |
| 1015 | Instruction *From) { |
| 1016 | for (Value *V : To) { |
| 1017 | if (Instruction *I = dyn_cast<Instruction>(V)) |
| 1018 | addMetadata(I, From); |
| 1019 | } |
| 1020 | } |
| 1021 | |
| 1022 | namespace llvm { |
| 1023 | |
| 1024 | // Loop vectorization cost-model hints how the scalar epilogue loop should be |
| 1025 | // lowered. |
| 1026 | enum ScalarEpilogueLowering { |
| 1027 | |
| 1028 | // The default: allowing scalar epilogues. |
| 1029 | CM_ScalarEpilogueAllowed, |
| 1030 | |
| 1031 | // Vectorization with OptForSize: don't allow epilogues. |
| 1032 | CM_ScalarEpilogueNotAllowedOptSize, |
| 1033 | |
| 1034 | // A special case of vectorisation with OptForSize: loops with a very small |
| 1035 | // trip count are considered for vectorization under OptForSize, thereby |
| 1036 | // making sure the cost of their loop body is dominant, free of runtime |
| 1037 | // guards and scalar iteration overheads. |
| 1038 | CM_ScalarEpilogueNotAllowedLowTripLoop, |
| 1039 | |
| 1040 | // Loop hint predicate indicating an epilogue is undesired. |
| 1041 | CM_ScalarEpilogueNotNeededUsePredicate |
| 1042 | }; |
| 1043 | |
| 1044 | /// LoopVectorizationCostModel - estimates the expected speedups due to |
| 1045 | /// vectorization. |
| 1046 | /// In many cases vectorization is not profitable. This can happen because of |
| 1047 | /// a number of reasons. In this class we mainly attempt to predict the |
| 1048 | /// expected speedup/slowdowns due to the supported instruction set. We use the |
| 1049 | /// TargetTransformInfo to query the different backends for the cost of |
| 1050 | /// different operations. |
| 1051 | class LoopVectorizationCostModel { |
| 1052 | public: |
| 1053 | LoopVectorizationCostModel(ScalarEpilogueLowering SEL, Loop *L, |
| 1054 | PredicatedScalarEvolution &PSE, LoopInfo *LI, |
| 1055 | LoopVectorizationLegality *Legal, |
| 1056 | const TargetTransformInfo &TTI, |
| 1057 | const TargetLibraryInfo *TLI, DemandedBits *DB, |
| 1058 | AssumptionCache *AC, |
| 1059 | OptimizationRemarkEmitter *ORE, const Function *F, |
| 1060 | const LoopVectorizeHints *Hints, |
| 1061 | InterleavedAccessInfo &IAI) |
| 1062 | : ScalarEpilogueStatus(SEL), TheLoop(L), PSE(PSE), LI(LI), Legal(Legal), |
| 1063 | TTI(TTI), TLI(TLI), DB(DB), AC(AC), ORE(ORE), TheFunction(F), |
| 1064 | Hints(Hints), InterleaveInfo(IAI) {} |
| 1065 | |
| 1066 | /// \return An upper bound for the vectorization factor, or None if |
| 1067 | /// vectorization and interleaving should be avoided up front. |
| 1068 | Optional<ElementCount> computeMaxVF(ElementCount UserVF, unsigned UserIC); |
| 1069 | |
| 1070 | /// \return True if runtime checks are required for vectorization, and false |
| 1071 | /// otherwise. |
| 1072 | bool runtimeChecksRequired(); |
| 1073 | |
| 1074 | /// \return The most profitable vectorization factor and the cost of that VF. |
| 1075 | /// This method checks every power of two up to MaxVF. If UserVF is not ZERO |
| 1076 | /// then this vectorization factor will be selected if vectorization is |
| 1077 | /// possible. |
| 1078 | VectorizationFactor selectVectorizationFactor(ElementCount MaxVF); |
| 1079 | |
| 1080 | /// Setup cost-based decisions for user vectorization factor. |
| 1081 | void selectUserVectorizationFactor(ElementCount UserVF) { |
| 1082 | collectUniformsAndScalars(UserVF); |
| 1083 | collectInstsToScalarize(UserVF); |
| 1084 | } |
| 1085 | |
| 1086 | /// \return The size (in bits) of the smallest and widest types in the code |
| 1087 | /// that needs to be vectorized. We ignore values that remain scalar such as |
| 1088 | /// 64 bit loop indices. |
| 1089 | std::pair<unsigned, unsigned> getSmallestAndWidestTypes(); |
| 1090 | |
| 1091 | /// \return The desired interleave count. |
| 1092 | /// If interleave count has been specified by metadata it will be returned. |
| 1093 | /// Otherwise, the interleave count is computed and returned. VF and LoopCost |
| 1094 | /// are the selected vectorization factor and the cost of the selected VF. |
| 1095 | unsigned selectInterleaveCount(ElementCount VF, unsigned LoopCost); |
| 1096 | |
| 1097 | /// Memory access instruction may be vectorized in more than one way. |
| 1098 | /// Form of instruction after vectorization depends on cost. |
| 1099 | /// This function takes cost-based decisions for Load/Store instructions |
| 1100 | /// and collects them in a map. This decisions map is used for building |
| 1101 | /// the lists of loop-uniform and loop-scalar instructions. |
| 1102 | /// The calculated cost is saved with widening decision in order to |
| 1103 | /// avoid redundant calculations. |
| 1104 | void setCostBasedWideningDecision(ElementCount VF); |
| 1105 | |
| 1106 | /// A struct that represents some properties of the register usage |
| 1107 | /// of a loop. |
| 1108 | struct RegisterUsage { |
| 1109 | /// Holds the number of loop invariant values that are used in the loop. |
| 1110 | /// The key is ClassID of target-provided register class. |
| 1111 | SmallMapVector<unsigned, unsigned, 4> LoopInvariantRegs; |
| 1112 | /// Holds the maximum number of concurrent live intervals in the loop. |
| 1113 | /// The key is ClassID of target-provided register class. |
| 1114 | SmallMapVector<unsigned, unsigned, 4> MaxLocalUsers; |
| 1115 | }; |
| 1116 | |
| 1117 | /// \return Returns information about the register usages of the loop for the |
| 1118 | /// given vectorization factors. |
| 1119 | SmallVector<RegisterUsage, 8> |
| 1120 | calculateRegisterUsage(ArrayRef<ElementCount> VFs); |
| 1121 | |
| 1122 | /// Collect values we want to ignore in the cost model. |
| 1123 | void collectValuesToIgnore(); |
| 1124 | |
| 1125 | /// Split reductions into those that happen in the loop, and those that happen |
| 1126 | /// outside. In loop reductions are collected into InLoopReductionChains. |
| 1127 | void collectInLoopReductions(); |
| 1128 | |
| 1129 | /// \returns The smallest bitwidth each instruction can be represented with. |
| 1130 | /// The vector equivalents of these instructions should be truncated to this |
| 1131 | /// type. |
| 1132 | const MapVector<Instruction *, uint64_t> &getMinimalBitwidths() const { |
| 1133 | return MinBWs; |
| 1134 | } |
| 1135 | |
| 1136 | /// \returns True if it is more profitable to scalarize instruction \p I for |
| 1137 | /// vectorization factor \p VF. |
| 1138 | bool isProfitableToScalarize(Instruction *I, ElementCount VF) const { |
| 1139 | assert(VF.isVector() &&((VF.isVector() && "Profitable to scalarize relevant only for VF > 1." ) ? static_cast<void> (0) : __assert_fail ("VF.isVector() && \"Profitable to scalarize relevant only for VF > 1.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1140, __PRETTY_FUNCTION__)) |
| 1140 | "Profitable to scalarize relevant only for VF > 1.")((VF.isVector() && "Profitable to scalarize relevant only for VF > 1." ) ? static_cast<void> (0) : __assert_fail ("VF.isVector() && \"Profitable to scalarize relevant only for VF > 1.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1140, __PRETTY_FUNCTION__)); |
| 1141 | |
| 1142 | // Cost model is not run in the VPlan-native path - return conservative |
| 1143 | // result until this changes. |
| 1144 | if (EnableVPlanNativePath) |
| 1145 | return false; |
| 1146 | |
| 1147 | auto Scalars = InstsToScalarize.find(VF); |
| 1148 | assert(Scalars != InstsToScalarize.end() &&((Scalars != InstsToScalarize.end() && "VF not yet analyzed for scalarization profitability" ) ? static_cast<void> (0) : __assert_fail ("Scalars != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1149, __PRETTY_FUNCTION__)) |
| 1149 | "VF not yet analyzed for scalarization profitability")((Scalars != InstsToScalarize.end() && "VF not yet analyzed for scalarization profitability" ) ? static_cast<void> (0) : __assert_fail ("Scalars != InstsToScalarize.end() && \"VF not yet analyzed for scalarization profitability\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1149, __PRETTY_FUNCTION__)); |
| 1150 | return Scalars->second.find(I) != Scalars->second.end(); |
| 1151 | } |
| 1152 | |
| 1153 | /// Returns true if \p I is known to be uniform after vectorization. |
| 1154 | bool isUniformAfterVectorization(Instruction *I, ElementCount VF) const { |
| 1155 | if (VF.isScalar()) |
| 1156 | return true; |
| 1157 | |
| 1158 | // Cost model is not run in the VPlan-native path - return conservative |
| 1159 | // result until this changes. |
| 1160 | if (EnableVPlanNativePath) |
| 1161 | return false; |
| 1162 | |
| 1163 | auto UniformsPerVF = Uniforms.find(VF); |
| 1164 | assert(UniformsPerVF != Uniforms.end() &&((UniformsPerVF != Uniforms.end() && "VF not yet analyzed for uniformity" ) ? static_cast<void> (0) : __assert_fail ("UniformsPerVF != Uniforms.end() && \"VF not yet analyzed for uniformity\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1165, __PRETTY_FUNCTION__)) |
| 1165 | "VF not yet analyzed for uniformity")((UniformsPerVF != Uniforms.end() && "VF not yet analyzed for uniformity" ) ? static_cast<void> (0) : __assert_fail ("UniformsPerVF != Uniforms.end() && \"VF not yet analyzed for uniformity\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1165, __PRETTY_FUNCTION__)); |
| 1166 | return UniformsPerVF->second.count(I); |
| 1167 | } |
| 1168 | |
| 1169 | /// Returns true if \p I is known to be scalar after vectorization. |
| 1170 | bool isScalarAfterVectorization(Instruction *I, ElementCount VF) const { |
| 1171 | if (VF.isScalar()) |
| 1172 | return true; |
| 1173 | |
| 1174 | // Cost model is not run in the VPlan-native path - return conservative |
| 1175 | // result until this changes. |
| 1176 | if (EnableVPlanNativePath) |
| 1177 | return false; |
| 1178 | |
| 1179 | auto ScalarsPerVF = Scalars.find(VF); |
| 1180 | assert(ScalarsPerVF != Scalars.end() &&((ScalarsPerVF != Scalars.end() && "Scalar values are not calculated for VF" ) ? static_cast<void> (0) : __assert_fail ("ScalarsPerVF != Scalars.end() && \"Scalar values are not calculated for VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1181, __PRETTY_FUNCTION__)) |
| 1181 | "Scalar values are not calculated for VF")((ScalarsPerVF != Scalars.end() && "Scalar values are not calculated for VF" ) ? static_cast<void> (0) : __assert_fail ("ScalarsPerVF != Scalars.end() && \"Scalar values are not calculated for VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1181, __PRETTY_FUNCTION__)); |
| 1182 | return ScalarsPerVF->second.count(I); |
| 1183 | } |
| 1184 | |
| 1185 | /// \returns True if instruction \p I can be truncated to a smaller bitwidth |
| 1186 | /// for vectorization factor \p VF. |
| 1187 | bool canTruncateToMinimalBitwidth(Instruction *I, ElementCount VF) const { |
| 1188 | return VF.isVector() && MinBWs.find(I) != MinBWs.end() && |
| 1189 | !isProfitableToScalarize(I, VF) && |
| 1190 | !isScalarAfterVectorization(I, VF); |
| 1191 | } |
| 1192 | |
| 1193 | /// Decision that was taken during cost calculation for memory instruction. |
| 1194 | enum InstWidening { |
| 1195 | CM_Unknown, |
| 1196 | CM_Widen, // For consecutive accesses with stride +1. |
| 1197 | CM_Widen_Reverse, // For consecutive accesses with stride -1. |
| 1198 | CM_Interleave, |
| 1199 | CM_GatherScatter, |
| 1200 | CM_Scalarize |
| 1201 | }; |
| 1202 | |
| 1203 | /// Save vectorization decision \p W and \p Cost taken by the cost model for |
| 1204 | /// instruction \p I and vector width \p VF. |
| 1205 | void setWideningDecision(Instruction *I, ElementCount VF, InstWidening W, |
| 1206 | unsigned Cost) { |
| 1207 | assert(VF.isVector() && "Expected VF >=2")((VF.isVector() && "Expected VF >=2") ? static_cast <void> (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1207, __PRETTY_FUNCTION__)); |
| 1208 | WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, Cost); |
| 1209 | } |
| 1210 | |
| 1211 | /// Save vectorization decision \p W and \p Cost taken by the cost model for |
| 1212 | /// interleaving group \p Grp and vector width \p VF. |
| 1213 | void setWideningDecision(const InterleaveGroup<Instruction> *Grp, |
| 1214 | ElementCount VF, InstWidening W, unsigned Cost) { |
| 1215 | assert(VF.isVector() && "Expected VF >=2")((VF.isVector() && "Expected VF >=2") ? static_cast <void> (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1215, __PRETTY_FUNCTION__)); |
| 1216 | /// Broadcast this decicion to all instructions inside the group. |
| 1217 | /// But the cost will be assigned to one instruction only. |
| 1218 | for (unsigned i = 0; i < Grp->getFactor(); ++i) { |
| 1219 | if (auto *I = Grp->getMember(i)) { |
| 1220 | if (Grp->getInsertPos() == I) |
| 1221 | WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, Cost); |
| 1222 | else |
| 1223 | WideningDecisions[std::make_pair(I, VF)] = std::make_pair(W, 0); |
| 1224 | } |
| 1225 | } |
| 1226 | } |
| 1227 | |
| 1228 | /// Return the cost model decision for the given instruction \p I and vector |
| 1229 | /// width \p VF. Return CM_Unknown if this instruction did not pass |
| 1230 | /// through the cost modeling. |
| 1231 | InstWidening getWideningDecision(Instruction *I, ElementCount VF) { |
| 1232 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1232, __PRETTY_FUNCTION__)); |
| 1233 | assert(VF.isVector() && "Expected VF >=2")((VF.isVector() && "Expected VF >=2") ? static_cast <void> (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1233, __PRETTY_FUNCTION__)); |
| 1234 | |
| 1235 | // Cost model is not run in the VPlan-native path - return conservative |
| 1236 | // result until this changes. |
| 1237 | if (EnableVPlanNativePath) |
| 1238 | return CM_GatherScatter; |
| 1239 | |
| 1240 | std::pair<Instruction *, ElementCount> InstOnVF = std::make_pair(I, VF); |
| 1241 | auto Itr = WideningDecisions.find(InstOnVF); |
| 1242 | if (Itr == WideningDecisions.end()) |
| 1243 | return CM_Unknown; |
| 1244 | return Itr->second.first; |
| 1245 | } |
| 1246 | |
| 1247 | /// Return the vectorization cost for the given instruction \p I and vector |
| 1248 | /// width \p VF. |
| 1249 | unsigned getWideningCost(Instruction *I, ElementCount VF) { |
| 1250 | assert(VF.isVector() && "Expected VF >=2")((VF.isVector() && "Expected VF >=2") ? static_cast <void> (0) : __assert_fail ("VF.isVector() && \"Expected VF >=2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1250, __PRETTY_FUNCTION__)); |
| 1251 | std::pair<Instruction *, ElementCount> InstOnVF = std::make_pair(I, VF); |
| 1252 | assert(WideningDecisions.find(InstOnVF) != WideningDecisions.end() &&((WideningDecisions.find(InstOnVF) != WideningDecisions.end() && "The cost is not calculated") ? static_cast<void > (0) : __assert_fail ("WideningDecisions.find(InstOnVF) != WideningDecisions.end() && \"The cost is not calculated\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1253, __PRETTY_FUNCTION__)) |
| 1253 | "The cost is not calculated")((WideningDecisions.find(InstOnVF) != WideningDecisions.end() && "The cost is not calculated") ? static_cast<void > (0) : __assert_fail ("WideningDecisions.find(InstOnVF) != WideningDecisions.end() && \"The cost is not calculated\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1253, __PRETTY_FUNCTION__)); |
| 1254 | return WideningDecisions[InstOnVF].second; |
| 1255 | } |
| 1256 | |
| 1257 | /// Return True if instruction \p I is an optimizable truncate whose operand |
| 1258 | /// is an induction variable. Such a truncate will be removed by adding a new |
| 1259 | /// induction variable with the destination type. |
| 1260 | bool isOptimizableIVTruncate(Instruction *I, ElementCount VF) { |
| 1261 | // If the instruction is not a truncate, return false. |
| 1262 | auto *Trunc = dyn_cast<TruncInst>(I); |
| 1263 | if (!Trunc) |
| 1264 | return false; |
| 1265 | |
| 1266 | // Get the source and destination types of the truncate. |
| 1267 | Type *SrcTy = ToVectorTy(cast<CastInst>(I)->getSrcTy(), VF); |
| 1268 | Type *DestTy = ToVectorTy(cast<CastInst>(I)->getDestTy(), VF); |
| 1269 | |
| 1270 | // If the truncate is free for the given types, return false. Replacing a |
| 1271 | // free truncate with an induction variable would add an induction variable |
| 1272 | // update instruction to each iteration of the loop. We exclude from this |
| 1273 | // check the primary induction variable since it will need an update |
| 1274 | // instruction regardless. |
| 1275 | Value *Op = Trunc->getOperand(0); |
| 1276 | if (Op != Legal->getPrimaryInduction() && TTI.isTruncateFree(SrcTy, DestTy)) |
| 1277 | return false; |
| 1278 | |
| 1279 | // If the truncated value is not an induction variable, return false. |
| 1280 | return Legal->isInductionPhi(Op); |
| 1281 | } |
| 1282 | |
| 1283 | /// Collects the instructions to scalarize for each predicated instruction in |
| 1284 | /// the loop. |
| 1285 | void collectInstsToScalarize(ElementCount VF); |
| 1286 | |
| 1287 | /// Collect Uniform and Scalar values for the given \p VF. |
| 1288 | /// The sets depend on CM decision for Load/Store instructions |
| 1289 | /// that may be vectorized as interleave, gather-scatter or scalarized. |
| 1290 | void collectUniformsAndScalars(ElementCount VF) { |
| 1291 | // Do the analysis once. |
| 1292 | if (VF.isScalar() || Uniforms.find(VF) != Uniforms.end()) |
| 1293 | return; |
| 1294 | setCostBasedWideningDecision(VF); |
| 1295 | collectLoopUniforms(VF); |
| 1296 | collectLoopScalars(VF); |
| 1297 | } |
| 1298 | |
| 1299 | /// Returns true if the target machine supports masked store operation |
| 1300 | /// for the given \p DataType and kind of access to \p Ptr. |
| 1301 | bool isLegalMaskedStore(Type *DataType, Value *Ptr, Align Alignment) { |
| 1302 | return Legal->isConsecutivePtr(Ptr) && |
| 1303 | TTI.isLegalMaskedStore(DataType, Alignment); |
| 1304 | } |
| 1305 | |
| 1306 | /// Returns true if the target machine supports masked load operation |
| 1307 | /// for the given \p DataType and kind of access to \p Ptr. |
| 1308 | bool isLegalMaskedLoad(Type *DataType, Value *Ptr, Align Alignment) { |
| 1309 | return Legal->isConsecutivePtr(Ptr) && |
| 1310 | TTI.isLegalMaskedLoad(DataType, Alignment); |
| 1311 | } |
| 1312 | |
| 1313 | /// Returns true if the target machine supports masked scatter operation |
| 1314 | /// for the given \p DataType. |
| 1315 | bool isLegalMaskedScatter(Type *DataType, Align Alignment) { |
| 1316 | return TTI.isLegalMaskedScatter(DataType, Alignment); |
| 1317 | } |
| 1318 | |
| 1319 | /// Returns true if the target machine supports masked gather operation |
| 1320 | /// for the given \p DataType. |
| 1321 | bool isLegalMaskedGather(Type *DataType, Align Alignment) { |
| 1322 | return TTI.isLegalMaskedGather(DataType, Alignment); |
| 1323 | } |
| 1324 | |
| 1325 | /// Returns true if the target machine can represent \p V as a masked gather |
| 1326 | /// or scatter operation. |
| 1327 | bool isLegalGatherOrScatter(Value *V) { |
| 1328 | bool LI = isa<LoadInst>(V); |
| 1329 | bool SI = isa<StoreInst>(V); |
| 1330 | if (!LI && !SI) |
| 1331 | return false; |
| 1332 | auto *Ty = getMemInstValueType(V); |
| 1333 | Align Align = getLoadStoreAlignment(V); |
| 1334 | return (LI && isLegalMaskedGather(Ty, Align)) || |
| 1335 | (SI && isLegalMaskedScatter(Ty, Align)); |
| 1336 | } |
| 1337 | |
| 1338 | /// Returns true if \p I is an instruction that will be scalarized with |
| 1339 | /// predication. Such instructions include conditional stores and |
| 1340 | /// instructions that may divide by zero. |
| 1341 | /// If a non-zero VF has been calculated, we check if I will be scalarized |
| 1342 | /// predication for that VF. |
| 1343 | bool isScalarWithPredication(Instruction *I, |
| 1344 | ElementCount VF = ElementCount::getFixed(1)); |
| 1345 | |
| 1346 | // Returns true if \p I is an instruction that will be predicated either |
| 1347 | // through scalar predication or masked load/store or masked gather/scatter. |
| 1348 | // Superset of instructions that return true for isScalarWithPredication. |
| 1349 | bool isPredicatedInst(Instruction *I) { |
| 1350 | if (!blockNeedsPredication(I->getParent())) |
| 1351 | return false; |
| 1352 | // Loads and stores that need some form of masked operation are predicated |
| 1353 | // instructions. |
| 1354 | if (isa<LoadInst>(I) || isa<StoreInst>(I)) |
| 1355 | return Legal->isMaskRequired(I); |
| 1356 | return isScalarWithPredication(I); |
| 1357 | } |
| 1358 | |
| 1359 | /// Returns true if \p I is a memory instruction with consecutive memory |
| 1360 | /// access that can be widened. |
| 1361 | bool |
| 1362 | memoryInstructionCanBeWidened(Instruction *I, |
| 1363 | ElementCount VF = ElementCount::getFixed(1)); |
| 1364 | |
| 1365 | /// Returns true if \p I is a memory instruction in an interleaved-group |
| 1366 | /// of memory accesses that can be vectorized with wide vector loads/stores |
| 1367 | /// and shuffles. |
| 1368 | bool |
| 1369 | interleavedAccessCanBeWidened(Instruction *I, |
| 1370 | ElementCount VF = ElementCount::getFixed(1)); |
| 1371 | |
| 1372 | /// Check if \p Instr belongs to any interleaved access group. |
| 1373 | bool isAccessInterleaved(Instruction *Instr) { |
| 1374 | return InterleaveInfo.isInterleaved(Instr); |
| 1375 | } |
| 1376 | |
| 1377 | /// Get the interleaved access group that \p Instr belongs to. |
| 1378 | const InterleaveGroup<Instruction> * |
| 1379 | getInterleavedAccessGroup(Instruction *Instr) { |
| 1380 | return InterleaveInfo.getInterleaveGroup(Instr); |
| 1381 | } |
| 1382 | |
| 1383 | /// Returns true if an interleaved group requires a scalar iteration |
| 1384 | /// to handle accesses with gaps, and there is nothing preventing us from |
| 1385 | /// creating a scalar epilogue. |
| 1386 | bool requiresScalarEpilogue() const { |
| 1387 | return isScalarEpilogueAllowed() && InterleaveInfo.requiresScalarEpilogue(); |
| 1388 | } |
| 1389 | |
| 1390 | /// Returns true if a scalar epilogue is not allowed due to optsize or a |
| 1391 | /// loop hint annotation. |
| 1392 | bool isScalarEpilogueAllowed() const { |
| 1393 | return ScalarEpilogueStatus == CM_ScalarEpilogueAllowed; |
| 1394 | } |
| 1395 | |
| 1396 | /// Returns true if all loop blocks should be masked to fold tail loop. |
| 1397 | bool foldTailByMasking() const { return FoldTailByMasking; } |
| 1398 | |
| 1399 | bool blockNeedsPredication(BasicBlock *BB) { |
| 1400 | return foldTailByMasking() || Legal->blockNeedsPredication(BB); |
| 1401 | } |
| 1402 | |
| 1403 | /// A SmallMapVector to store the InLoop reduction op chains, mapping phi |
| 1404 | /// nodes to the chain of instructions representing the reductions. Uses a |
| 1405 | /// MapVector to ensure deterministic iteration order. |
| 1406 | using ReductionChainMap = |
| 1407 | SmallMapVector<PHINode *, SmallVector<Instruction *, 4>, 4>; |
| 1408 | |
| 1409 | /// Return the chain of instructions representing an inloop reduction. |
| 1410 | const ReductionChainMap &getInLoopReductionChains() const { |
| 1411 | return InLoopReductionChains; |
| 1412 | } |
| 1413 | |
| 1414 | /// Returns true if the Phi is part of an inloop reduction. |
| 1415 | bool isInLoopReduction(PHINode *Phi) const { |
| 1416 | return InLoopReductionChains.count(Phi); |
| 1417 | } |
| 1418 | |
| 1419 | /// Estimate cost of an intrinsic call instruction CI if it were vectorized |
| 1420 | /// with factor VF. Return the cost of the instruction, including |
| 1421 | /// scalarization overhead if it's needed. |
| 1422 | unsigned getVectorIntrinsicCost(CallInst *CI, ElementCount VF); |
| 1423 | |
| 1424 | /// Estimate cost of a call instruction CI if it were vectorized with factor |
| 1425 | /// VF. Return the cost of the instruction, including scalarization overhead |
| 1426 | /// if it's needed. The flag NeedToScalarize shows if the call needs to be |
| 1427 | /// scalarized - |
| 1428 | /// i.e. either vector version isn't available, or is too expensive. |
| 1429 | unsigned getVectorCallCost(CallInst *CI, ElementCount VF, |
| 1430 | bool &NeedToScalarize); |
| 1431 | |
| 1432 | /// Invalidates decisions already taken by the cost model. |
| 1433 | void invalidateCostModelingDecisions() { |
| 1434 | WideningDecisions.clear(); |
| 1435 | Uniforms.clear(); |
| 1436 | Scalars.clear(); |
| 1437 | } |
| 1438 | |
| 1439 | private: |
| 1440 | unsigned NumPredStores = 0; |
| 1441 | |
| 1442 | /// \return An upper bound for the vectorization factor, a power-of-2 larger |
| 1443 | /// than zero. One is returned if vectorization should best be avoided due |
| 1444 | /// to cost. |
| 1445 | ElementCount computeFeasibleMaxVF(unsigned ConstTripCount); |
| 1446 | |
| 1447 | /// The vectorization cost is a combination of the cost itself and a boolean |
| 1448 | /// indicating whether any of the contributing operations will actually |
| 1449 | /// operate on |
| 1450 | /// vector values after type legalization in the backend. If this latter value |
| 1451 | /// is |
| 1452 | /// false, then all operations will be scalarized (i.e. no vectorization has |
| 1453 | /// actually taken place). |
| 1454 | using VectorizationCostTy = std::pair<unsigned, bool>; |
| 1455 | |
| 1456 | /// Returns the expected execution cost. The unit of the cost does |
| 1457 | /// not matter because we use the 'cost' units to compare different |
| 1458 | /// vector widths. The cost that is returned is *not* normalized by |
| 1459 | /// the factor width. |
| 1460 | VectorizationCostTy expectedCost(ElementCount VF); |
| 1461 | |
| 1462 | /// Returns the execution time cost of an instruction for a given vector |
| 1463 | /// width. Vector width of one means scalar. |
| 1464 | VectorizationCostTy getInstructionCost(Instruction *I, ElementCount VF); |
| 1465 | |
| 1466 | /// The cost-computation logic from getInstructionCost which provides |
| 1467 | /// the vector type as an output parameter. |
| 1468 | unsigned getInstructionCost(Instruction *I, ElementCount VF, Type *&VectorTy); |
| 1469 | |
| 1470 | /// Calculate vectorization cost of memory instruction \p I. |
| 1471 | unsigned getMemoryInstructionCost(Instruction *I, ElementCount VF); |
| 1472 | |
| 1473 | /// The cost computation for scalarized memory instruction. |
| 1474 | unsigned getMemInstScalarizationCost(Instruction *I, ElementCount VF); |
| 1475 | |
| 1476 | /// The cost computation for interleaving group of memory instructions. |
| 1477 | unsigned getInterleaveGroupCost(Instruction *I, ElementCount VF); |
| 1478 | |
| 1479 | /// The cost computation for Gather/Scatter instruction. |
| 1480 | unsigned getGatherScatterCost(Instruction *I, ElementCount VF); |
| 1481 | |
| 1482 | /// The cost computation for widening instruction \p I with consecutive |
| 1483 | /// memory access. |
| 1484 | unsigned getConsecutiveMemOpCost(Instruction *I, ElementCount VF); |
| 1485 | |
| 1486 | /// The cost calculation for Load/Store instruction \p I with uniform pointer - |
| 1487 | /// Load: scalar load + broadcast. |
| 1488 | /// Store: scalar store + (loop invariant value stored? 0 : extract of last |
| 1489 | /// element) |
| 1490 | unsigned getUniformMemOpCost(Instruction *I, ElementCount VF); |
| 1491 | |
| 1492 | /// Estimate the overhead of scalarizing an instruction. This is a |
| 1493 | /// convenience wrapper for the type-based getScalarizationOverhead API. |
| 1494 | unsigned getScalarizationOverhead(Instruction *I, ElementCount VF); |
| 1495 | |
| 1496 | /// Returns whether the instruction is a load or store and will be a emitted |
| 1497 | /// as a vector operation. |
| 1498 | bool isConsecutiveLoadOrStore(Instruction *I); |
| 1499 | |
| 1500 | /// Returns true if an artificially high cost for emulated masked memrefs |
| 1501 | /// should be used. |
| 1502 | bool useEmulatedMaskMemRefHack(Instruction *I); |
| 1503 | |
| 1504 | /// Map of scalar integer values to the smallest bitwidth they can be legally |
| 1505 | /// represented as. The vector equivalents of these values should be truncated |
| 1506 | /// to this type. |
| 1507 | MapVector<Instruction *, uint64_t> MinBWs; |
| 1508 | |
| 1509 | /// A type representing the costs for instructions if they were to be |
| 1510 | /// scalarized rather than vectorized. The entries are Instruction-Cost |
| 1511 | /// pairs. |
| 1512 | using ScalarCostsTy = DenseMap<Instruction *, unsigned>; |
| 1513 | |
| 1514 | /// A set containing all BasicBlocks that are known to present after |
| 1515 | /// vectorization as a predicated block. |
| 1516 | SmallPtrSet<BasicBlock *, 4> PredicatedBBsAfterVectorization; |
| 1517 | |
| 1518 | /// Records whether it is allowed to have the original scalar loop execute at |
| 1519 | /// least once. This may be needed as a fallback loop in case runtime |
| 1520 | /// aliasing/dependence checks fail, or to handle the tail/remainder |
| 1521 | /// iterations when the trip count is unknown or doesn't divide by the VF, |
| 1522 | /// or as a peel-loop to handle gaps in interleave-groups. |
| 1523 | /// Under optsize and when the trip count is very small we don't allow any |
| 1524 | /// iterations to execute in the scalar loop. |
| 1525 | ScalarEpilogueLowering ScalarEpilogueStatus = CM_ScalarEpilogueAllowed; |
| 1526 | |
| 1527 | /// All blocks of loop are to be masked to fold tail of scalar iterations. |
| 1528 | bool FoldTailByMasking = false; |
| 1529 | |
| 1530 | /// A map holding scalar costs for different vectorization factors. The |
| 1531 | /// presence of a cost for an instruction in the mapping indicates that the |
| 1532 | /// instruction will be scalarized when vectorizing with the associated |
| 1533 | /// vectorization factor. The entries are VF-ScalarCostTy pairs. |
| 1534 | DenseMap<ElementCount, ScalarCostsTy> InstsToScalarize; |
| 1535 | |
| 1536 | /// Holds the instructions known to be uniform after vectorization. |
| 1537 | /// The data is collected per VF. |
| 1538 | DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> Uniforms; |
| 1539 | |
| 1540 | /// Holds the instructions known to be scalar after vectorization. |
| 1541 | /// The data is collected per VF. |
| 1542 | DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> Scalars; |
| 1543 | |
| 1544 | /// Holds the instructions (address computations) that are forced to be |
| 1545 | /// scalarized. |
| 1546 | DenseMap<ElementCount, SmallPtrSet<Instruction *, 4>> ForcedScalars; |
| 1547 | |
| 1548 | /// PHINodes of the reductions that should be expanded in-loop along with |
| 1549 | /// their associated chains of reduction operations, in program order from top |
| 1550 | /// (PHI) to bottom |
| 1551 | ReductionChainMap InLoopReductionChains; |
| 1552 | |
| 1553 | /// Returns the expected difference in cost from scalarizing the expression |
| 1554 | /// feeding a predicated instruction \p PredInst. The instructions to |
| 1555 | /// scalarize and their scalar costs are collected in \p ScalarCosts. A |
| 1556 | /// non-negative return value implies the expression will be scalarized. |
| 1557 | /// Currently, only single-use chains are considered for scalarization. |
| 1558 | int computePredInstDiscount(Instruction *PredInst, ScalarCostsTy &ScalarCosts, |
| 1559 | ElementCount VF); |
| 1560 | |
| 1561 | /// Collect the instructions that are uniform after vectorization. An |
| 1562 | /// instruction is uniform if we represent it with a single scalar value in |
| 1563 | /// the vectorized loop corresponding to each vector iteration. Examples of |
| 1564 | /// uniform instructions include pointer operands of consecutive or |
| 1565 | /// interleaved memory accesses. Note that although uniformity implies an |
| 1566 | /// instruction will be scalar, the reverse is not true. In general, a |
| 1567 | /// scalarized instruction will be represented by VF scalar values in the |
| 1568 | /// vectorized loop, each corresponding to an iteration of the original |
| 1569 | /// scalar loop. |
| 1570 | void collectLoopUniforms(ElementCount VF); |
| 1571 | |
| 1572 | /// Collect the instructions that are scalar after vectorization. An |
| 1573 | /// instruction is scalar if it is known to be uniform or will be scalarized |
| 1574 | /// during vectorization. Non-uniform scalarized instructions will be |
| 1575 | /// represented by VF values in the vectorized loop, each corresponding to an |
| 1576 | /// iteration of the original scalar loop. |
| 1577 | void collectLoopScalars(ElementCount VF); |
| 1578 | |
| 1579 | /// Keeps cost model vectorization decision and cost for instructions. |
| 1580 | /// Right now it is used for memory instructions only. |
| 1581 | using DecisionList = DenseMap<std::pair<Instruction *, ElementCount>, |
| 1582 | std::pair<InstWidening, unsigned>>; |
| 1583 | |
| 1584 | DecisionList WideningDecisions; |
| 1585 | |
| 1586 | /// Returns true if \p V is expected to be vectorized and it needs to be |
| 1587 | /// extracted. |
| 1588 | bool needsExtract(Value *V, ElementCount VF) const { |
| 1589 | Instruction *I = dyn_cast<Instruction>(V); |
| 1590 | if (VF.isScalar() || !I || !TheLoop->contains(I) || |
| 1591 | TheLoop->isLoopInvariant(I)) |
| 1592 | return false; |
| 1593 | |
| 1594 | // Assume we can vectorize V (and hence we need extraction) if the |
| 1595 | // scalars are not computed yet. This can happen, because it is called |
| 1596 | // via getScalarizationOverhead from setCostBasedWideningDecision, before |
| 1597 | // the scalars are collected. That should be a safe assumption in most |
| 1598 | // cases, because we check if the operands have vectorizable types |
| 1599 | // beforehand in LoopVectorizationLegality. |
| 1600 | return Scalars.find(VF) == Scalars.end() || |
| 1601 | !isScalarAfterVectorization(I, VF); |
| 1602 | }; |
| 1603 | |
| 1604 | /// Returns a range containing only operands needing to be extracted. |
| 1605 | SmallVector<Value *, 4> filterExtractingOperands(Instruction::op_range Ops, |
| 1606 | ElementCount VF) { |
| 1607 | return SmallVector<Value *, 4>(make_filter_range( |
| 1608 | Ops, [this, VF](Value *V) { return this->needsExtract(V, VF); })); |
| 1609 | } |
| 1610 | |
| 1611 | public: |
| 1612 | /// The loop that we evaluate. |
| 1613 | Loop *TheLoop; |
| 1614 | |
| 1615 | /// Predicated scalar evolution analysis. |
| 1616 | PredicatedScalarEvolution &PSE; |
| 1617 | |
| 1618 | /// Loop Info analysis. |
| 1619 | LoopInfo *LI; |
| 1620 | |
| 1621 | /// Vectorization legality. |
| 1622 | LoopVectorizationLegality *Legal; |
| 1623 | |
| 1624 | /// Vector target information. |
| 1625 | const TargetTransformInfo &TTI; |
| 1626 | |
| 1627 | /// Target Library Info. |
| 1628 | const TargetLibraryInfo *TLI; |
| 1629 | |
| 1630 | /// Demanded bits analysis. |
| 1631 | DemandedBits *DB; |
| 1632 | |
| 1633 | /// Assumption cache. |
| 1634 | AssumptionCache *AC; |
| 1635 | |
| 1636 | /// Interface to emit optimization remarks. |
| 1637 | OptimizationRemarkEmitter *ORE; |
| 1638 | |
| 1639 | const Function *TheFunction; |
| 1640 | |
| 1641 | /// Loop Vectorize Hint. |
| 1642 | const LoopVectorizeHints *Hints; |
| 1643 | |
| 1644 | /// The interleave access information contains groups of interleaved accesses |
| 1645 | /// with the same stride and close to each other. |
| 1646 | InterleavedAccessInfo &InterleaveInfo; |
| 1647 | |
| 1648 | /// Values to ignore in the cost model. |
| 1649 | SmallPtrSet<const Value *, 16> ValuesToIgnore; |
| 1650 | |
| 1651 | /// Values to ignore in the cost model when VF > 1. |
| 1652 | SmallPtrSet<const Value *, 16> VecValuesToIgnore; |
| 1653 | }; |
| 1654 | |
| 1655 | } // end namespace llvm |
| 1656 | |
| 1657 | // Return true if \p OuterLp is an outer loop annotated with hints for explicit |
| 1658 | // vectorization. The loop needs to be annotated with #pragma omp simd |
| 1659 | // simdlen(#) or #pragma clang vectorize(enable) vectorize_width(#). If the |
| 1660 | // vector length information is not provided, vectorization is not considered |
| 1661 | // explicit. Interleave hints are not allowed either. These limitations will be |
| 1662 | // relaxed in the future. |
| 1663 | // Please, note that we are currently forced to abuse the pragma 'clang |
| 1664 | // vectorize' semantics. This pragma provides *auto-vectorization hints* |
| 1665 | // (i.e., LV must check that vectorization is legal) whereas pragma 'omp simd' |
| 1666 | // provides *explicit vectorization hints* (LV can bypass legal checks and |
| 1667 | // assume that vectorization is legal). However, both hints are implemented |
| 1668 | // using the same metadata (llvm.loop.vectorize, processed by |
| 1669 | // LoopVectorizeHints). This will be fixed in the future when the native IR |
| 1670 | // representation for pragma 'omp simd' is introduced. |
| 1671 | static bool isExplicitVecOuterLoop(Loop *OuterLp, |
| 1672 | OptimizationRemarkEmitter *ORE) { |
| 1673 | assert(!OuterLp->isInnermost() && "This is not an outer loop")((!OuterLp->isInnermost() && "This is not an outer loop" ) ? static_cast<void> (0) : __assert_fail ("!OuterLp->isInnermost() && \"This is not an outer loop\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1673, __PRETTY_FUNCTION__)); |
| 1674 | LoopVectorizeHints Hints(OuterLp, true /*DisableInterleaving*/, *ORE); |
| 1675 | |
| 1676 | // Only outer loops with an explicit vectorization hint are supported. |
| 1677 | // Unannotated outer loops are ignored. |
| 1678 | if (Hints.getForce() == LoopVectorizeHints::FK_Undefined) |
| 1679 | return false; |
| 1680 | |
| 1681 | Function *Fn = OuterLp->getHeader()->getParent(); |
| 1682 | if (!Hints.allowVectorization(Fn, OuterLp, |
| 1683 | true /*VectorizeOnlyWhenForced*/)) { |
| 1684 | LLVM_DEBUG(dbgs() << "LV: Loop hints prevent outer loop vectorization.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Loop hints prevent outer loop vectorization.\n" ; } } while (false); |
| 1685 | return false; |
| 1686 | } |
| 1687 | |
| 1688 | if (Hints.getInterleave() > 1) { |
| 1689 | // TODO: Interleave support is future work. |
| 1690 | LLVM_DEBUG(dbgs() << "LV: Not vectorizing: Interleave is not supported for "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Interleave is not supported for " "outer loops.\n"; } } while (false) |
| 1691 | "outer loops.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not vectorizing: Interleave is not supported for " "outer loops.\n"; } } while (false); |
| 1692 | Hints.emitRemarkWithHints(); |
| 1693 | return false; |
| 1694 | } |
| 1695 | |
| 1696 | return true; |
| 1697 | } |
| 1698 | |
| 1699 | static void collectSupportedLoops(Loop &L, LoopInfo *LI, |
| 1700 | OptimizationRemarkEmitter *ORE, |
| 1701 | SmallVectorImpl<Loop *> &V) { |
| 1702 | // Collect inner loops and outer loops without irreducible control flow. For |
| 1703 | // now, only collect outer loops that have explicit vectorization hints. If we |
| 1704 | // are stress testing the VPlan H-CFG construction, we collect the outermost |
| 1705 | // loop of every loop nest. |
| 1706 | if (L.isInnermost() || VPlanBuildStressTest || |
| 1707 | (EnableVPlanNativePath && isExplicitVecOuterLoop(&L, ORE))) { |
| 1708 | LoopBlocksRPO RPOT(&L); |
| 1709 | RPOT.perform(LI); |
| 1710 | if (!containsIrreducibleCFG<const BasicBlock *>(RPOT, *LI)) { |
| 1711 | V.push_back(&L); |
| 1712 | // TODO: Collect inner loops inside marked outer loops in case |
| 1713 | // vectorization fails for the outer loop. Do not invoke |
| 1714 | // 'containsIrreducibleCFG' again for inner loops when the outer loop is |
| 1715 | // already known to be reducible. We can use an inherited attribute for |
| 1716 | // that. |
| 1717 | return; |
| 1718 | } |
| 1719 | } |
| 1720 | for (Loop *InnerL : L) |
| 1721 | collectSupportedLoops(*InnerL, LI, ORE, V); |
| 1722 | } |
| 1723 | |
| 1724 | namespace { |
| 1725 | |
| 1726 | /// The LoopVectorize Pass. |
| 1727 | struct LoopVectorize : public FunctionPass { |
| 1728 | /// Pass identification, replacement for typeid |
| 1729 | static char ID; |
| 1730 | |
| 1731 | LoopVectorizePass Impl; |
| 1732 | |
| 1733 | explicit LoopVectorize(bool InterleaveOnlyWhenForced = false, |
| 1734 | bool VectorizeOnlyWhenForced = false) |
| 1735 | : FunctionPass(ID), |
| 1736 | Impl({InterleaveOnlyWhenForced, VectorizeOnlyWhenForced}) { |
| 1737 | initializeLoopVectorizePass(*PassRegistry::getPassRegistry()); |
| 1738 | } |
| 1739 | |
| 1740 | bool runOnFunction(Function &F) override { |
| 1741 | if (skipFunction(F)) |
| 1742 | return false; |
| 1743 | |
| 1744 | auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE(); |
| 1745 | auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); |
| 1746 | auto *TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F); |
| 1747 | auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); |
| 1748 | auto *BFI = &getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI(); |
| 1749 | auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>(); |
| 1750 | auto *TLI = TLIP ? &TLIP->getTLI(F) : nullptr; |
| 1751 | auto *AA = &getAnalysis<AAResultsWrapperPass>().getAAResults(); |
| 1752 | auto *AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); |
| 1753 | auto *LAA = &getAnalysis<LoopAccessLegacyAnalysis>(); |
| 1754 | auto *DB = &getAnalysis<DemandedBitsWrapperPass>().getDemandedBits(); |
| 1755 | auto *ORE = &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE(); |
| 1756 | auto *PSI = &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI(); |
| 1757 | |
| 1758 | std::function<const LoopAccessInfo &(Loop &)> GetLAA = |
| 1759 | [&](Loop &L) -> const LoopAccessInfo & { return LAA->getInfo(&L); }; |
| 1760 | |
| 1761 | return Impl.runImpl(F, *SE, *LI, *TTI, *DT, *BFI, TLI, *DB, *AA, *AC, |
| 1762 | GetLAA, *ORE, PSI).MadeAnyChange; |
| 1763 | } |
| 1764 | |
| 1765 | void getAnalysisUsage(AnalysisUsage &AU) const override { |
| 1766 | AU.addRequired<AssumptionCacheTracker>(); |
| 1767 | AU.addRequired<BlockFrequencyInfoWrapperPass>(); |
| 1768 | AU.addRequired<DominatorTreeWrapperPass>(); |
| 1769 | AU.addRequired<LoopInfoWrapperPass>(); |
| 1770 | AU.addRequired<ScalarEvolutionWrapperPass>(); |
| 1771 | AU.addRequired<TargetTransformInfoWrapperPass>(); |
| 1772 | AU.addRequired<AAResultsWrapperPass>(); |
| 1773 | AU.addRequired<LoopAccessLegacyAnalysis>(); |
| 1774 | AU.addRequired<DemandedBitsWrapperPass>(); |
| 1775 | AU.addRequired<OptimizationRemarkEmitterWrapperPass>(); |
| 1776 | AU.addRequired<InjectTLIMappingsLegacy>(); |
| 1777 | |
| 1778 | // We currently do not preserve loopinfo/dominator analyses with outer loop |
| 1779 | // vectorization. Until this is addressed, mark these analyses as preserved |
| 1780 | // only for non-VPlan-native path. |
| 1781 | // TODO: Preserve Loop and Dominator analyses for VPlan-native path. |
| 1782 | if (!EnableVPlanNativePath) { |
| 1783 | AU.addPreserved<LoopInfoWrapperPass>(); |
| 1784 | AU.addPreserved<DominatorTreeWrapperPass>(); |
| 1785 | } |
| 1786 | |
| 1787 | AU.addPreserved<BasicAAWrapperPass>(); |
| 1788 | AU.addPreserved<GlobalsAAWrapperPass>(); |
| 1789 | AU.addRequired<ProfileSummaryInfoWrapperPass>(); |
| 1790 | } |
| 1791 | }; |
| 1792 | |
| 1793 | } // end anonymous namespace |
| 1794 | |
| 1795 | //===----------------------------------------------------------------------===// |
| 1796 | // Implementation of LoopVectorizationLegality, InnerLoopVectorizer and |
| 1797 | // LoopVectorizationCostModel and LoopVectorizationPlanner. |
| 1798 | //===----------------------------------------------------------------------===// |
| 1799 | |
| 1800 | Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { |
| 1801 | // We need to place the broadcast of invariant variables outside the loop, |
| 1802 | // but only if it's proven safe to do so. Else, broadcast will be inside |
| 1803 | // vector loop body. |
| 1804 | Instruction *Instr = dyn_cast<Instruction>(V); |
| 1805 | bool SafeToHoist = OrigLoop->isLoopInvariant(V) && |
| 1806 | (!Instr || |
| 1807 | DT->dominates(Instr->getParent(), LoopVectorPreHeader)); |
| 1808 | // Place the code for broadcasting invariant variables in the new preheader. |
| 1809 | IRBuilder<>::InsertPointGuard Guard(Builder); |
| 1810 | if (SafeToHoist) |
| 1811 | Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); |
| 1812 | |
| 1813 | // Broadcast the scalar into all locations in the vector. |
| 1814 | Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast"); |
| 1815 | |
| 1816 | return Shuf; |
| 1817 | } |
| 1818 | |
| 1819 | void InnerLoopVectorizer::createVectorIntOrFpInductionPHI( |
| 1820 | const InductionDescriptor &II, Value *Step, Instruction *EntryVal) { |
| 1821 | assert((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) &&(((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal )) && "Expected either an induction phi-node or a truncate of it!" ) ? static_cast<void> (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1822, __PRETTY_FUNCTION__)) |
| 1822 | "Expected either an induction phi-node or a truncate of it!")(((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal )) && "Expected either an induction phi-node or a truncate of it!" ) ? static_cast<void> (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1822, __PRETTY_FUNCTION__)); |
| 1823 | Value *Start = II.getStartValue(); |
| 1824 | |
| 1825 | // Construct the initial value of the vector IV in the vector loop preheader |
| 1826 | auto CurrIP = Builder.saveIP(); |
| 1827 | Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); |
| 1828 | if (isa<TruncInst>(EntryVal)) { |
| 1829 | assert(Start->getType()->isIntegerTy() &&((Start->getType()->isIntegerTy() && "Truncation requires an integer type" ) ? static_cast<void> (0) : __assert_fail ("Start->getType()->isIntegerTy() && \"Truncation requires an integer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1830, __PRETTY_FUNCTION__)) |
| 1830 | "Truncation requires an integer type")((Start->getType()->isIntegerTy() && "Truncation requires an integer type" ) ? static_cast<void> (0) : __assert_fail ("Start->getType()->isIntegerTy() && \"Truncation requires an integer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1830, __PRETTY_FUNCTION__)); |
| 1831 | auto *TruncType = cast<IntegerType>(EntryVal->getType()); |
| 1832 | Step = Builder.CreateTrunc(Step, TruncType); |
| 1833 | Start = Builder.CreateCast(Instruction::Trunc, Start, TruncType); |
| 1834 | } |
| 1835 | Value *SplatStart = Builder.CreateVectorSplat(VF, Start); |
| 1836 | Value *SteppedStart = |
| 1837 | getStepVector(SplatStart, 0, Step, II.getInductionOpcode()); |
| 1838 | |
| 1839 | // We create vector phi nodes for both integer and floating-point induction |
| 1840 | // variables. Here, we determine the kind of arithmetic we will perform. |
| 1841 | Instruction::BinaryOps AddOp; |
| 1842 | Instruction::BinaryOps MulOp; |
| 1843 | if (Step->getType()->isIntegerTy()) { |
| 1844 | AddOp = Instruction::Add; |
| 1845 | MulOp = Instruction::Mul; |
| 1846 | } else { |
| 1847 | AddOp = II.getInductionOpcode(); |
| 1848 | MulOp = Instruction::FMul; |
| 1849 | } |
| 1850 | |
| 1851 | // Multiply the vectorization factor by the step using integer or |
| 1852 | // floating-point arithmetic as appropriate. |
| 1853 | Value *ConstVF = |
| 1854 | getSignedIntOrFpConstant(Step->getType(), VF.getKnownMinValue()); |
| 1855 | Value *Mul = addFastMathFlag(Builder.CreateBinOp(MulOp, Step, ConstVF)); |
| 1856 | |
| 1857 | // Create a vector splat to use in the induction update. |
| 1858 | // |
| 1859 | // FIXME: If the step is non-constant, we create the vector splat with |
| 1860 | // IRBuilder. IRBuilder can constant-fold the multiply, but it doesn't |
| 1861 | // handle a constant vector splat. |
| 1862 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1862, __PRETTY_FUNCTION__)); |
| 1863 | Value *SplatVF = isa<Constant>(Mul) |
| 1864 | ? ConstantVector::getSplat(VF, cast<Constant>(Mul)) |
| 1865 | : Builder.CreateVectorSplat(VF, Mul); |
| 1866 | Builder.restoreIP(CurrIP); |
| 1867 | |
| 1868 | // We may need to add the step a number of times, depending on the unroll |
| 1869 | // factor. The last of those goes into the PHI. |
| 1870 | PHINode *VecInd = PHINode::Create(SteppedStart->getType(), 2, "vec.ind", |
| 1871 | &*LoopVectorBody->getFirstInsertionPt()); |
| 1872 | VecInd->setDebugLoc(EntryVal->getDebugLoc()); |
| 1873 | Instruction *LastInduction = VecInd; |
| 1874 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 1875 | VectorLoopValueMap.setVectorValue(EntryVal, Part, LastInduction); |
| 1876 | |
| 1877 | if (isa<TruncInst>(EntryVal)) |
| 1878 | addMetadata(LastInduction, EntryVal); |
| 1879 | recordVectorLoopValueForInductionCast(II, EntryVal, LastInduction, Part); |
| 1880 | |
| 1881 | LastInduction = cast<Instruction>(addFastMathFlag( |
| 1882 | Builder.CreateBinOp(AddOp, LastInduction, SplatVF, "step.add"))); |
| 1883 | LastInduction->setDebugLoc(EntryVal->getDebugLoc()); |
| 1884 | } |
| 1885 | |
| 1886 | // Move the last step to the end of the latch block. This ensures consistent |
| 1887 | // placement of all induction updates. |
| 1888 | auto *LoopVectorLatch = LI->getLoopFor(LoopVectorBody)->getLoopLatch(); |
| 1889 | auto *Br = cast<BranchInst>(LoopVectorLatch->getTerminator()); |
| 1890 | auto *ICmp = cast<Instruction>(Br->getCondition()); |
| 1891 | LastInduction->moveBefore(ICmp); |
| 1892 | LastInduction->setName("vec.ind.next"); |
| 1893 | |
| 1894 | VecInd->addIncoming(SteppedStart, LoopVectorPreHeader); |
| 1895 | VecInd->addIncoming(LastInduction, LoopVectorLatch); |
| 1896 | } |
| 1897 | |
| 1898 | bool InnerLoopVectorizer::shouldScalarizeInstruction(Instruction *I) const { |
| 1899 | return Cost->isScalarAfterVectorization(I, VF) || |
| 1900 | Cost->isProfitableToScalarize(I, VF); |
| 1901 | } |
| 1902 | |
| 1903 | bool InnerLoopVectorizer::needsScalarInduction(Instruction *IV) const { |
| 1904 | if (shouldScalarizeInstruction(IV)) |
| 1905 | return true; |
| 1906 | auto isScalarInst = [&](User *U) -> bool { |
| 1907 | auto *I = cast<Instruction>(U); |
| 1908 | return (OrigLoop->contains(I) && shouldScalarizeInstruction(I)); |
| 1909 | }; |
| 1910 | return llvm::any_of(IV->users(), isScalarInst); |
| 1911 | } |
| 1912 | |
| 1913 | void InnerLoopVectorizer::recordVectorLoopValueForInductionCast( |
| 1914 | const InductionDescriptor &ID, const Instruction *EntryVal, |
| 1915 | Value *VectorLoopVal, unsigned Part, unsigned Lane) { |
| 1916 | assert((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) &&(((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal )) && "Expected either an induction phi-node or a truncate of it!" ) ? static_cast<void> (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1917, __PRETTY_FUNCTION__)) |
| 1917 | "Expected either an induction phi-node or a truncate of it!")(((isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal )) && "Expected either an induction phi-node or a truncate of it!" ) ? static_cast<void> (0) : __assert_fail ("(isa<PHINode>(EntryVal) || isa<TruncInst>(EntryVal)) && \"Expected either an induction phi-node or a truncate of it!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1917, __PRETTY_FUNCTION__)); |
| 1918 | |
| 1919 | // This induction variable is not the phi from the original loop but the |
| 1920 | // newly-created IV based on the proof that casted Phi is equal to the |
| 1921 | // uncasted Phi in the vectorized loop (under a runtime guard possibly). It |
| 1922 | // re-uses the same InductionDescriptor that original IV uses but we don't |
| 1923 | // have to do any recording in this case - that is done when original IV is |
| 1924 | // processed. |
| 1925 | if (isa<TruncInst>(EntryVal)) |
| 1926 | return; |
| 1927 | |
| 1928 | const SmallVectorImpl<Instruction *> &Casts = ID.getCastInsts(); |
| 1929 | if (Casts.empty()) |
| 1930 | return; |
| 1931 | // Only the first Cast instruction in the Casts vector is of interest. |
| 1932 | // The rest of the Casts (if exist) have no uses outside the |
| 1933 | // induction update chain itself. |
| 1934 | Instruction *CastInst = *Casts.begin(); |
| 1935 | if (Lane < UINT_MAX(2147483647 *2U +1U)) |
| 1936 | VectorLoopValueMap.setScalarValue(CastInst, {Part, Lane}, VectorLoopVal); |
| 1937 | else |
| 1938 | VectorLoopValueMap.setVectorValue(CastInst, Part, VectorLoopVal); |
| 1939 | } |
| 1940 | |
| 1941 | void InnerLoopVectorizer::widenIntOrFpInduction(PHINode *IV, TruncInst *Trunc) { |
| 1942 | assert((IV->getType()->isIntegerTy() || IV != OldInduction) &&(((IV->getType()->isIntegerTy() || IV != OldInduction) && "Primary induction variable must have an integer type") ? static_cast <void> (0) : __assert_fail ("(IV->getType()->isIntegerTy() || IV != OldInduction) && \"Primary induction variable must have an integer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1943, __PRETTY_FUNCTION__)) |
| 1943 | "Primary induction variable must have an integer type")(((IV->getType()->isIntegerTy() || IV != OldInduction) && "Primary induction variable must have an integer type") ? static_cast <void> (0) : __assert_fail ("(IV->getType()->isIntegerTy() || IV != OldInduction) && \"Primary induction variable must have an integer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1943, __PRETTY_FUNCTION__)); |
| 1944 | |
| 1945 | auto II = Legal->getInductionVars().find(IV); |
| 1946 | assert(II != Legal->getInductionVars().end() && "IV is not an induction")((II != Legal->getInductionVars().end() && "IV is not an induction" ) ? static_cast<void> (0) : __assert_fail ("II != Legal->getInductionVars().end() && \"IV is not an induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1946, __PRETTY_FUNCTION__)); |
| 1947 | |
| 1948 | auto ID = II->second; |
| 1949 | assert(IV->getType() == ID.getStartValue()->getType() && "Types must match")((IV->getType() == ID.getStartValue()->getType() && "Types must match") ? static_cast<void> (0) : __assert_fail ("IV->getType() == ID.getStartValue()->getType() && \"Types must match\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1949, __PRETTY_FUNCTION__)); |
| 1950 | |
| 1951 | // The value from the original loop to which we are mapping the new induction |
| 1952 | // variable. |
| 1953 | Instruction *EntryVal = Trunc ? cast<Instruction>(Trunc) : IV; |
| 1954 | |
| 1955 | auto &DL = OrigLoop->getHeader()->getModule()->getDataLayout(); |
| 1956 | |
| 1957 | // Generate code for the induction step. Note that induction steps are |
| 1958 | // required to be loop-invariant |
| 1959 | auto CreateStepValue = [&](const SCEV *Step) -> Value * { |
| 1960 | assert(PSE.getSE()->isLoopInvariant(Step, OrigLoop) &&((PSE.getSE()->isLoopInvariant(Step, OrigLoop) && "Induction step should be loop invariant" ) ? static_cast<void> (0) : __assert_fail ("PSE.getSE()->isLoopInvariant(Step, OrigLoop) && \"Induction step should be loop invariant\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1961, __PRETTY_FUNCTION__)) |
| 1961 | "Induction step should be loop invariant")((PSE.getSE()->isLoopInvariant(Step, OrigLoop) && "Induction step should be loop invariant" ) ? static_cast<void> (0) : __assert_fail ("PSE.getSE()->isLoopInvariant(Step, OrigLoop) && \"Induction step should be loop invariant\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1961, __PRETTY_FUNCTION__)); |
| 1962 | if (PSE.getSE()->isSCEVable(IV->getType())) { |
| 1963 | SCEVExpander Exp(*PSE.getSE(), DL, "induction"); |
| 1964 | return Exp.expandCodeFor(Step, Step->getType(), |
| 1965 | LoopVectorPreHeader->getTerminator()); |
| 1966 | } |
| 1967 | return cast<SCEVUnknown>(Step)->getValue(); |
| 1968 | }; |
| 1969 | |
| 1970 | // The scalar value to broadcast. This is derived from the canonical |
| 1971 | // induction variable. If a truncation type is given, truncate the canonical |
| 1972 | // induction variable and step. Otherwise, derive these values from the |
| 1973 | // induction descriptor. |
| 1974 | auto CreateScalarIV = [&](Value *&Step) -> Value * { |
| 1975 | Value *ScalarIV = Induction; |
| 1976 | if (IV != OldInduction) { |
| 1977 | ScalarIV = IV->getType()->isIntegerTy() |
| 1978 | ? Builder.CreateSExtOrTrunc(Induction, IV->getType()) |
| 1979 | : Builder.CreateCast(Instruction::SIToFP, Induction, |
| 1980 | IV->getType()); |
| 1981 | ScalarIV = emitTransformedIndex(Builder, ScalarIV, PSE.getSE(), DL, ID); |
| 1982 | ScalarIV->setName("offset.idx"); |
| 1983 | } |
| 1984 | if (Trunc) { |
| 1985 | auto *TruncType = cast<IntegerType>(Trunc->getType()); |
| 1986 | assert(Step->getType()->isIntegerTy() &&((Step->getType()->isIntegerTy() && "Truncation requires an integer step" ) ? static_cast<void> (0) : __assert_fail ("Step->getType()->isIntegerTy() && \"Truncation requires an integer step\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1987, __PRETTY_FUNCTION__)) |
| 1987 | "Truncation requires an integer step")((Step->getType()->isIntegerTy() && "Truncation requires an integer step" ) ? static_cast<void> (0) : __assert_fail ("Step->getType()->isIntegerTy() && \"Truncation requires an integer step\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1987, __PRETTY_FUNCTION__)); |
| 1988 | ScalarIV = Builder.CreateTrunc(ScalarIV, TruncType); |
| 1989 | Step = Builder.CreateTrunc(Step, TruncType); |
| 1990 | } |
| 1991 | return ScalarIV; |
| 1992 | }; |
| 1993 | |
| 1994 | // Create the vector values from the scalar IV, in the absence of creating a |
| 1995 | // vector IV. |
| 1996 | auto CreateSplatIV = [&](Value *ScalarIV, Value *Step) { |
| 1997 | Value *Broadcasted = getBroadcastInstrs(ScalarIV); |
| 1998 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 1999 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 1999, __PRETTY_FUNCTION__)); |
| 2000 | Value *EntryPart = |
| 2001 | getStepVector(Broadcasted, VF.getKnownMinValue() * Part, Step, |
| 2002 | ID.getInductionOpcode()); |
| 2003 | VectorLoopValueMap.setVectorValue(EntryVal, Part, EntryPart); |
| 2004 | if (Trunc) |
| 2005 | addMetadata(EntryPart, Trunc); |
| 2006 | recordVectorLoopValueForInductionCast(ID, EntryVal, EntryPart, Part); |
| 2007 | } |
| 2008 | }; |
| 2009 | |
| 2010 | // Now do the actual transformations, and start with creating the step value. |
| 2011 | Value *Step = CreateStepValue(ID.getStep()); |
| 2012 | if (VF.isZero() || VF.isScalar()) { |
| 2013 | Value *ScalarIV = CreateScalarIV(Step); |
| 2014 | CreateSplatIV(ScalarIV, Step); |
| 2015 | return; |
| 2016 | } |
| 2017 | |
| 2018 | // Determine if we want a scalar version of the induction variable. This is |
| 2019 | // true if the induction variable itself is not widened, or if it has at |
| 2020 | // least one user in the loop that is not widened. |
| 2021 | auto NeedsScalarIV = needsScalarInduction(EntryVal); |
| 2022 | if (!NeedsScalarIV) { |
| 2023 | createVectorIntOrFpInductionPHI(ID, Step, EntryVal); |
| 2024 | return; |
| 2025 | } |
| 2026 | |
| 2027 | // Try to create a new independent vector induction variable. If we can't |
| 2028 | // create the phi node, we will splat the scalar induction variable in each |
| 2029 | // loop iteration. |
| 2030 | if (!shouldScalarizeInstruction(EntryVal)) { |
| 2031 | createVectorIntOrFpInductionPHI(ID, Step, EntryVal); |
| 2032 | Value *ScalarIV = CreateScalarIV(Step); |
| 2033 | // Create scalar steps that can be used by instructions we will later |
| 2034 | // scalarize. Note that the addition of the scalar steps will not increase |
| 2035 | // the number of instructions in the loop in the common case prior to |
| 2036 | // InstCombine. We will be trading one vector extract for each scalar step. |
| 2037 | buildScalarSteps(ScalarIV, Step, EntryVal, ID); |
| 2038 | return; |
| 2039 | } |
| 2040 | |
| 2041 | // All IV users are scalar instructions, so only emit a scalar IV, not a |
| 2042 | // vectorised IV. Except when we tail-fold, then the splat IV feeds the |
| 2043 | // predicate used by the masked loads/stores. |
| 2044 | Value *ScalarIV = CreateScalarIV(Step); |
| 2045 | if (!Cost->isScalarEpilogueAllowed()) |
| 2046 | CreateSplatIV(ScalarIV, Step); |
| 2047 | buildScalarSteps(ScalarIV, Step, EntryVal, ID); |
| 2048 | } |
| 2049 | |
| 2050 | Value *InnerLoopVectorizer::getStepVector(Value *Val, int StartIdx, Value *Step, |
| 2051 | Instruction::BinaryOps BinOp) { |
| 2052 | // Create and check the types. |
| 2053 | auto *ValVTy = cast<FixedVectorType>(Val->getType()); |
| 2054 | int VLen = ValVTy->getNumElements(); |
| 2055 | |
| 2056 | Type *STy = Val->getType()->getScalarType(); |
| 2057 | assert((STy->isIntegerTy() || STy->isFloatingPointTy()) &&(((STy->isIntegerTy() || STy->isFloatingPointTy()) && "Induction Step must be an integer or FP") ? static_cast< void> (0) : __assert_fail ("(STy->isIntegerTy() || STy->isFloatingPointTy()) && \"Induction Step must be an integer or FP\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2058, __PRETTY_FUNCTION__)) |
| 2058 | "Induction Step must be an integer or FP")(((STy->isIntegerTy() || STy->isFloatingPointTy()) && "Induction Step must be an integer or FP") ? static_cast< void> (0) : __assert_fail ("(STy->isIntegerTy() || STy->isFloatingPointTy()) && \"Induction Step must be an integer or FP\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2058, __PRETTY_FUNCTION__)); |
| 2059 | assert(Step->getType() == STy && "Step has wrong type")((Step->getType() == STy && "Step has wrong type") ? static_cast<void> (0) : __assert_fail ("Step->getType() == STy && \"Step has wrong type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2059, __PRETTY_FUNCTION__)); |
| 2060 | |
| 2061 | SmallVector<Constant *, 8> Indices; |
| 2062 | |
| 2063 | if (STy->isIntegerTy()) { |
| 2064 | // Create a vector of consecutive numbers from zero to VF. |
| 2065 | for (int i = 0; i < VLen; ++i) |
| 2066 | Indices.push_back(ConstantInt::get(STy, StartIdx + i)); |
| 2067 | |
| 2068 | // Add the consecutive indices to the vector value. |
| 2069 | Constant *Cv = ConstantVector::get(Indices); |
| 2070 | assert(Cv->getType() == Val->getType() && "Invalid consecutive vec")((Cv->getType() == Val->getType() && "Invalid consecutive vec" ) ? static_cast<void> (0) : __assert_fail ("Cv->getType() == Val->getType() && \"Invalid consecutive vec\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2070, __PRETTY_FUNCTION__)); |
| 2071 | Step = Builder.CreateVectorSplat(VLen, Step); |
| 2072 | assert(Step->getType() == Val->getType() && "Invalid step vec")((Step->getType() == Val->getType() && "Invalid step vec" ) ? static_cast<void> (0) : __assert_fail ("Step->getType() == Val->getType() && \"Invalid step vec\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2072, __PRETTY_FUNCTION__)); |
| 2073 | // FIXME: The newly created binary instructions should contain nsw/nuw flags, |
| 2074 | // which can be found from the original scalar operations. |
| 2075 | Step = Builder.CreateMul(Cv, Step); |
| 2076 | return Builder.CreateAdd(Val, Step, "induction"); |
| 2077 | } |
| 2078 | |
| 2079 | // Floating point induction. |
| 2080 | assert((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) &&(((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && "Binary Opcode should be specified for FP induction") ? static_cast <void> (0) : __assert_fail ("(BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && \"Binary Opcode should be specified for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2081, __PRETTY_FUNCTION__)) |
| 2081 | "Binary Opcode should be specified for FP induction")(((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && "Binary Opcode should be specified for FP induction") ? static_cast <void> (0) : __assert_fail ("(BinOp == Instruction::FAdd || BinOp == Instruction::FSub) && \"Binary Opcode should be specified for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2081, __PRETTY_FUNCTION__)); |
| 2082 | // Create a vector of consecutive numbers from zero to VF. |
| 2083 | for (int i = 0; i < VLen; ++i) |
| 2084 | Indices.push_back(ConstantFP::get(STy, (double)(StartIdx + i))); |
| 2085 | |
| 2086 | // Add the consecutive indices to the vector value. |
| 2087 | Constant *Cv = ConstantVector::get(Indices); |
| 2088 | |
| 2089 | Step = Builder.CreateVectorSplat(VLen, Step); |
| 2090 | |
| 2091 | // Floating point operations had to be 'fast' to enable the induction. |
| 2092 | FastMathFlags Flags; |
| 2093 | Flags.setFast(); |
| 2094 | |
| 2095 | Value *MulOp = Builder.CreateFMul(Cv, Step); |
| 2096 | if (isa<Instruction>(MulOp)) |
| 2097 | // Have to check, MulOp may be a constant |
| 2098 | cast<Instruction>(MulOp)->setFastMathFlags(Flags); |
| 2099 | |
| 2100 | Value *BOp = Builder.CreateBinOp(BinOp, Val, MulOp, "induction"); |
| 2101 | if (isa<Instruction>(BOp)) |
| 2102 | cast<Instruction>(BOp)->setFastMathFlags(Flags); |
| 2103 | return BOp; |
| 2104 | } |
| 2105 | |
| 2106 | void InnerLoopVectorizer::buildScalarSteps(Value *ScalarIV, Value *Step, |
| 2107 | Instruction *EntryVal, |
| 2108 | const InductionDescriptor &ID) { |
| 2109 | // We shouldn't have to build scalar steps if we aren't vectorizing. |
| 2110 | assert(VF.isVector() && "VF should be greater than one")((VF.isVector() && "VF should be greater than one") ? static_cast<void> (0) : __assert_fail ("VF.isVector() && \"VF should be greater than one\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2110, __PRETTY_FUNCTION__)); |
| 2111 | assert(!VF.isScalable() &&((!VF.isScalable() && "the code below assumes a fixed number of elements at compile time" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"the code below assumes a fixed number of elements at compile time\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2112, __PRETTY_FUNCTION__)) |
| 2112 | "the code below assumes a fixed number of elements at compile time")((!VF.isScalable() && "the code below assumes a fixed number of elements at compile time" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"the code below assumes a fixed number of elements at compile time\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2112, __PRETTY_FUNCTION__)); |
| 2113 | // Get the value type and ensure it and the step have the same integer type. |
| 2114 | Type *ScalarIVTy = ScalarIV->getType()->getScalarType(); |
| 2115 | assert(ScalarIVTy == Step->getType() &&((ScalarIVTy == Step->getType() && "Val and Step should have the same type" ) ? static_cast<void> (0) : __assert_fail ("ScalarIVTy == Step->getType() && \"Val and Step should have the same type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2116, __PRETTY_FUNCTION__)) |
| 2116 | "Val and Step should have the same type")((ScalarIVTy == Step->getType() && "Val and Step should have the same type" ) ? static_cast<void> (0) : __assert_fail ("ScalarIVTy == Step->getType() && \"Val and Step should have the same type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2116, __PRETTY_FUNCTION__)); |
| 2117 | |
| 2118 | // We build scalar steps for both integer and floating-point induction |
| 2119 | // variables. Here, we determine the kind of arithmetic we will perform. |
| 2120 | Instruction::BinaryOps AddOp; |
| 2121 | Instruction::BinaryOps MulOp; |
| 2122 | if (ScalarIVTy->isIntegerTy()) { |
| 2123 | AddOp = Instruction::Add; |
| 2124 | MulOp = Instruction::Mul; |
| 2125 | } else { |
| 2126 | AddOp = ID.getInductionOpcode(); |
| 2127 | MulOp = Instruction::FMul; |
| 2128 | } |
| 2129 | |
| 2130 | // Determine the number of scalars we need to generate for each unroll |
| 2131 | // iteration. If EntryVal is uniform, we only need to generate the first |
| 2132 | // lane. Otherwise, we generate all VF values. |
| 2133 | unsigned Lanes = |
| 2134 | Cost->isUniformAfterVectorization(cast<Instruction>(EntryVal), VF) |
| 2135 | ? 1 |
| 2136 | : VF.getKnownMinValue(); |
| 2137 | // Compute the scalar steps and save the results in VectorLoopValueMap. |
| 2138 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 2139 | for (unsigned Lane = 0; Lane < Lanes; ++Lane) { |
| 2140 | auto *StartIdx = getSignedIntOrFpConstant( |
| 2141 | ScalarIVTy, VF.getKnownMinValue() * Part + Lane); |
| 2142 | auto *Mul = addFastMathFlag(Builder.CreateBinOp(MulOp, StartIdx, Step)); |
| 2143 | auto *Add = addFastMathFlag(Builder.CreateBinOp(AddOp, ScalarIV, Mul)); |
| 2144 | VectorLoopValueMap.setScalarValue(EntryVal, {Part, Lane}, Add); |
| 2145 | recordVectorLoopValueForInductionCast(ID, EntryVal, Add, Part, Lane); |
| 2146 | } |
| 2147 | } |
| 2148 | } |
| 2149 | |
| 2150 | Value *InnerLoopVectorizer::getOrCreateVectorValue(Value *V, unsigned Part) { |
| 2151 | assert(V != Induction && "The new induction variable should not be used.")((V != Induction && "The new induction variable should not be used." ) ? static_cast<void> (0) : __assert_fail ("V != Induction && \"The new induction variable should not be used.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2151, __PRETTY_FUNCTION__)); |
| 2152 | assert(!V->getType()->isVectorTy() && "Can't widen a vector")((!V->getType()->isVectorTy() && "Can't widen a vector" ) ? static_cast<void> (0) : __assert_fail ("!V->getType()->isVectorTy() && \"Can't widen a vector\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2152, __PRETTY_FUNCTION__)); |
| 2153 | assert(!V->getType()->isVoidTy() && "Type does not produce a value")((!V->getType()->isVoidTy() && "Type does not produce a value" ) ? static_cast<void> (0) : __assert_fail ("!V->getType()->isVoidTy() && \"Type does not produce a value\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2153, __PRETTY_FUNCTION__)); |
| 2154 | |
| 2155 | // If we have a stride that is replaced by one, do it here. Defer this for |
| 2156 | // the VPlan-native path until we start running Legal checks in that path. |
| 2157 | if (!EnableVPlanNativePath && Legal->hasStride(V)) |
| 2158 | V = ConstantInt::get(V->getType(), 1); |
| 2159 | |
| 2160 | // If we have a vector mapped to this value, return it. |
| 2161 | if (VectorLoopValueMap.hasVectorValue(V, Part)) |
| 2162 | return VectorLoopValueMap.getVectorValue(V, Part); |
| 2163 | |
| 2164 | // If the value has not been vectorized, check if it has been scalarized |
| 2165 | // instead. If it has been scalarized, and we actually need the value in |
| 2166 | // vector form, we will construct the vector values on demand. |
| 2167 | if (VectorLoopValueMap.hasAnyScalarValue(V)) { |
| 2168 | Value *ScalarValue = VectorLoopValueMap.getScalarValue(V, {Part, 0}); |
| 2169 | |
| 2170 | // If we've scalarized a value, that value should be an instruction. |
| 2171 | auto *I = cast<Instruction>(V); |
| 2172 | |
| 2173 | // If we aren't vectorizing, we can just copy the scalar map values over to |
| 2174 | // the vector map. |
| 2175 | if (VF.isScalar()) { |
| 2176 | VectorLoopValueMap.setVectorValue(V, Part, ScalarValue); |
| 2177 | return ScalarValue; |
| 2178 | } |
| 2179 | |
| 2180 | // Get the last scalar instruction we generated for V and Part. If the value |
| 2181 | // is known to be uniform after vectorization, this corresponds to lane zero |
| 2182 | // of the Part unroll iteration. Otherwise, the last instruction is the one |
| 2183 | // we created for the last vector lane of the Part unroll iteration. |
| 2184 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2184, __PRETTY_FUNCTION__)); |
| 2185 | unsigned LastLane = Cost->isUniformAfterVectorization(I, VF) |
| 2186 | ? 0 |
| 2187 | : VF.getKnownMinValue() - 1; |
| 2188 | auto *LastInst = cast<Instruction>( |
| 2189 | VectorLoopValueMap.getScalarValue(V, {Part, LastLane})); |
| 2190 | |
| 2191 | // Set the insert point after the last scalarized instruction. This ensures |
| 2192 | // the insertelement sequence will directly follow the scalar definitions. |
| 2193 | auto OldIP = Builder.saveIP(); |
| 2194 | auto NewIP = std::next(BasicBlock::iterator(LastInst)); |
| 2195 | Builder.SetInsertPoint(&*NewIP); |
| 2196 | |
| 2197 | // However, if we are vectorizing, we need to construct the vector values. |
| 2198 | // If the value is known to be uniform after vectorization, we can just |
| 2199 | // broadcast the scalar value corresponding to lane zero for each unroll |
| 2200 | // iteration. Otherwise, we construct the vector values using insertelement |
| 2201 | // instructions. Since the resulting vectors are stored in |
| 2202 | // VectorLoopValueMap, we will only generate the insertelements once. |
| 2203 | Value *VectorValue = nullptr; |
| 2204 | if (Cost->isUniformAfterVectorization(I, VF)) { |
| 2205 | VectorValue = getBroadcastInstrs(ScalarValue); |
| 2206 | VectorLoopValueMap.setVectorValue(V, Part, VectorValue); |
| 2207 | } else { |
| 2208 | // Initialize packing with insertelements to start from undef. |
| 2209 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2209, __PRETTY_FUNCTION__)); |
| 2210 | Value *Undef = UndefValue::get(VectorType::get(V->getType(), VF)); |
| 2211 | VectorLoopValueMap.setVectorValue(V, Part, Undef); |
| 2212 | for (unsigned Lane = 0; Lane < VF.getKnownMinValue(); ++Lane) |
| 2213 | packScalarIntoVectorValue(V, {Part, Lane}); |
| 2214 | VectorValue = VectorLoopValueMap.getVectorValue(V, Part); |
| 2215 | } |
| 2216 | Builder.restoreIP(OldIP); |
| 2217 | return VectorValue; |
| 2218 | } |
| 2219 | |
| 2220 | // If this scalar is unknown, assume that it is a constant or that it is |
| 2221 | // loop invariant. Broadcast V and save the value for future uses. |
| 2222 | Value *B = getBroadcastInstrs(V); |
| 2223 | VectorLoopValueMap.setVectorValue(V, Part, B); |
| 2224 | return B; |
| 2225 | } |
| 2226 | |
| 2227 | Value * |
| 2228 | InnerLoopVectorizer::getOrCreateScalarValue(Value *V, |
| 2229 | const VPIteration &Instance) { |
| 2230 | // If the value is not an instruction contained in the loop, it should |
| 2231 | // already be scalar. |
| 2232 | if (OrigLoop->isLoopInvariant(V)) |
| 2233 | return V; |
| 2234 | |
| 2235 | assert(Instance.Lane > 0((Instance.Lane > 0 ? !Cost->isUniformAfterVectorization (cast<Instruction>(V), VF) : true && "Uniform values only have lane zero" ) ? static_cast<void> (0) : __assert_fail ("Instance.Lane > 0 ? !Cost->isUniformAfterVectorization(cast<Instruction>(V), VF) : true && \"Uniform values only have lane zero\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2237, __PRETTY_FUNCTION__)) |
| 2236 | ? !Cost->isUniformAfterVectorization(cast<Instruction>(V), VF)((Instance.Lane > 0 ? !Cost->isUniformAfterVectorization (cast<Instruction>(V), VF) : true && "Uniform values only have lane zero" ) ? static_cast<void> (0) : __assert_fail ("Instance.Lane > 0 ? !Cost->isUniformAfterVectorization(cast<Instruction>(V), VF) : true && \"Uniform values only have lane zero\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2237, __PRETTY_FUNCTION__)) |
| 2237 | : true && "Uniform values only have lane zero")((Instance.Lane > 0 ? !Cost->isUniformAfterVectorization (cast<Instruction>(V), VF) : true && "Uniform values only have lane zero" ) ? static_cast<void> (0) : __assert_fail ("Instance.Lane > 0 ? !Cost->isUniformAfterVectorization(cast<Instruction>(V), VF) : true && \"Uniform values only have lane zero\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2237, __PRETTY_FUNCTION__)); |
| 2238 | |
| 2239 | // If the value from the original loop has not been vectorized, it is |
| 2240 | // represented by UF x VF scalar values in the new loop. Return the requested |
| 2241 | // scalar value. |
| 2242 | if (VectorLoopValueMap.hasScalarValue(V, Instance)) |
| 2243 | return VectorLoopValueMap.getScalarValue(V, Instance); |
| 2244 | |
| 2245 | // If the value has not been scalarized, get its entry in VectorLoopValueMap |
| 2246 | // for the given unroll part. If this entry is not a vector type (i.e., the |
| 2247 | // vectorization factor is one), there is no need to generate an |
| 2248 | // extractelement instruction. |
| 2249 | auto *U = getOrCreateVectorValue(V, Instance.Part); |
| 2250 | if (!U->getType()->isVectorTy()) { |
| 2251 | assert(VF.isScalar() && "Value not scalarized has non-vector type")((VF.isScalar() && "Value not scalarized has non-vector type" ) ? static_cast<void> (0) : __assert_fail ("VF.isScalar() && \"Value not scalarized has non-vector type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2251, __PRETTY_FUNCTION__)); |
| 2252 | return U; |
| 2253 | } |
| 2254 | |
| 2255 | // Otherwise, the value from the original loop has been vectorized and is |
| 2256 | // represented by UF vector values. Extract and return the requested scalar |
| 2257 | // value from the appropriate vector lane. |
| 2258 | return Builder.CreateExtractElement(U, Builder.getInt32(Instance.Lane)); |
| 2259 | } |
| 2260 | |
| 2261 | void InnerLoopVectorizer::packScalarIntoVectorValue( |
| 2262 | Value *V, const VPIteration &Instance) { |
| 2263 | assert(V != Induction && "The new induction variable should not be used.")((V != Induction && "The new induction variable should not be used." ) ? static_cast<void> (0) : __assert_fail ("V != Induction && \"The new induction variable should not be used.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2263, __PRETTY_FUNCTION__)); |
| 2264 | assert(!V->getType()->isVectorTy() && "Can't pack a vector")((!V->getType()->isVectorTy() && "Can't pack a vector" ) ? static_cast<void> (0) : __assert_fail ("!V->getType()->isVectorTy() && \"Can't pack a vector\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2264, __PRETTY_FUNCTION__)); |
| 2265 | assert(!V->getType()->isVoidTy() && "Type does not produce a value")((!V->getType()->isVoidTy() && "Type does not produce a value" ) ? static_cast<void> (0) : __assert_fail ("!V->getType()->isVoidTy() && \"Type does not produce a value\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2265, __PRETTY_FUNCTION__)); |
| 2266 | |
| 2267 | Value *ScalarInst = VectorLoopValueMap.getScalarValue(V, Instance); |
| 2268 | Value *VectorValue = VectorLoopValueMap.getVectorValue(V, Instance.Part); |
| 2269 | VectorValue = Builder.CreateInsertElement(VectorValue, ScalarInst, |
| 2270 | Builder.getInt32(Instance.Lane)); |
| 2271 | VectorLoopValueMap.resetVectorValue(V, Instance.Part, VectorValue); |
| 2272 | } |
| 2273 | |
| 2274 | Value *InnerLoopVectorizer::reverseVector(Value *Vec) { |
| 2275 | assert(Vec->getType()->isVectorTy() && "Invalid type")((Vec->getType()->isVectorTy() && "Invalid type" ) ? static_cast<void> (0) : __assert_fail ("Vec->getType()->isVectorTy() && \"Invalid type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2275, __PRETTY_FUNCTION__)); |
| 2276 | assert(!VF.isScalable() && "Cannot reverse scalable vectors")((!VF.isScalable() && "Cannot reverse scalable vectors" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"Cannot reverse scalable vectors\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2276, __PRETTY_FUNCTION__)); |
| 2277 | SmallVector<int, 8> ShuffleMask; |
| 2278 | for (unsigned i = 0; i < VF.getKnownMinValue(); ++i) |
| 2279 | ShuffleMask.push_back(VF.getKnownMinValue() - i - 1); |
| 2280 | |
| 2281 | return Builder.CreateShuffleVector(Vec, ShuffleMask, "reverse"); |
| 2282 | } |
| 2283 | |
| 2284 | // Return whether we allow using masked interleave-groups (for dealing with |
| 2285 | // strided loads/stores that reside in predicated blocks, or for dealing |
| 2286 | // with gaps). |
| 2287 | static bool useMaskedInterleavedAccesses(const TargetTransformInfo &TTI) { |
| 2288 | // If an override option has been passed in for interleaved accesses, use it. |
| 2289 | if (EnableMaskedInterleavedMemAccesses.getNumOccurrences() > 0) |
| 2290 | return EnableMaskedInterleavedMemAccesses; |
| 2291 | |
| 2292 | return TTI.enableMaskedInterleavedAccessVectorization(); |
| 2293 | } |
| 2294 | |
| 2295 | // Try to vectorize the interleave group that \p Instr belongs to. |
| 2296 | // |
| 2297 | // E.g. Translate following interleaved load group (factor = 3): |
| 2298 | // for (i = 0; i < N; i+=3) { |
| 2299 | // R = Pic[i]; // Member of index 0 |
| 2300 | // G = Pic[i+1]; // Member of index 1 |
| 2301 | // B = Pic[i+2]; // Member of index 2 |
| 2302 | // ... // do something to R, G, B |
| 2303 | // } |
| 2304 | // To: |
| 2305 | // %wide.vec = load <12 x i32> ; Read 4 tuples of R,G,B |
| 2306 | // %R.vec = shuffle %wide.vec, undef, <0, 3, 6, 9> ; R elements |
| 2307 | // %G.vec = shuffle %wide.vec, undef, <1, 4, 7, 10> ; G elements |
| 2308 | // %B.vec = shuffle %wide.vec, undef, <2, 5, 8, 11> ; B elements |
| 2309 | // |
| 2310 | // Or translate following interleaved store group (factor = 3): |
| 2311 | // for (i = 0; i < N; i+=3) { |
| 2312 | // ... do something to R, G, B |
| 2313 | // Pic[i] = R; // Member of index 0 |
| 2314 | // Pic[i+1] = G; // Member of index 1 |
| 2315 | // Pic[i+2] = B; // Member of index 2 |
| 2316 | // } |
| 2317 | // To: |
| 2318 | // %R_G.vec = shuffle %R.vec, %G.vec, <0, 1, 2, ..., 7> |
| 2319 | // %B_U.vec = shuffle %B.vec, undef, <0, 1, 2, 3, u, u, u, u> |
| 2320 | // %interleaved.vec = shuffle %R_G.vec, %B_U.vec, |
| 2321 | // <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11> ; Interleave R,G,B elements |
| 2322 | // store <12 x i32> %interleaved.vec ; Write 4 tuples of R,G,B |
| 2323 | void InnerLoopVectorizer::vectorizeInterleaveGroup( |
| 2324 | const InterleaveGroup<Instruction> *Group, VPTransformState &State, |
| 2325 | VPValue *Addr, VPValue *BlockInMask) { |
| 2326 | Instruction *Instr = Group->getInsertPos(); |
| 2327 | const DataLayout &DL = Instr->getModule()->getDataLayout(); |
| 2328 | |
| 2329 | // Prepare for the vector type of the interleaved load/store. |
| 2330 | Type *ScalarTy = getMemInstValueType(Instr); |
| 2331 | unsigned InterleaveFactor = Group->getFactor(); |
| 2332 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2332, __PRETTY_FUNCTION__)); |
| 2333 | auto *VecTy = VectorType::get(ScalarTy, VF * InterleaveFactor); |
| 2334 | |
| 2335 | // Prepare for the new pointers. |
| 2336 | SmallVector<Value *, 2> AddrParts; |
| 2337 | unsigned Index = Group->getIndex(Instr); |
| 2338 | |
| 2339 | // TODO: extend the masked interleaved-group support to reversed access. |
| 2340 | assert((!BlockInMask || !Group->isReverse()) &&(((!BlockInMask || !Group->isReverse()) && "Reversed masked interleave-group not supported." ) ? static_cast<void> (0) : __assert_fail ("(!BlockInMask || !Group->isReverse()) && \"Reversed masked interleave-group not supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2341, __PRETTY_FUNCTION__)) |
| 2341 | "Reversed masked interleave-group not supported.")(((!BlockInMask || !Group->isReverse()) && "Reversed masked interleave-group not supported." ) ? static_cast<void> (0) : __assert_fail ("(!BlockInMask || !Group->isReverse()) && \"Reversed masked interleave-group not supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2341, __PRETTY_FUNCTION__)); |
| 2342 | |
| 2343 | // If the group is reverse, adjust the index to refer to the last vector lane |
| 2344 | // instead of the first. We adjust the index from the first vector lane, |
| 2345 | // rather than directly getting the pointer for lane VF - 1, because the |
| 2346 | // pointer operand of the interleaved access is supposed to be uniform. For |
| 2347 | // uniform instructions, we're only required to generate a value for the |
| 2348 | // first vector lane in each unroll iteration. |
| 2349 | assert(!VF.isScalable() &&((!VF.isScalable() && "scalable vector reverse operation is not implemented" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vector reverse operation is not implemented\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2350, __PRETTY_FUNCTION__)) |
| 2350 | "scalable vector reverse operation is not implemented")((!VF.isScalable() && "scalable vector reverse operation is not implemented" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vector reverse operation is not implemented\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2350, __PRETTY_FUNCTION__)); |
| 2351 | if (Group->isReverse()) |
| 2352 | Index += (VF.getKnownMinValue() - 1) * Group->getFactor(); |
| 2353 | |
| 2354 | for (unsigned Part = 0; Part < UF; Part++) { |
| 2355 | Value *AddrPart = State.get(Addr, {Part, 0}); |
| 2356 | setDebugLocFromInst(Builder, AddrPart); |
| 2357 | |
| 2358 | // Notice current instruction could be any index. Need to adjust the address |
| 2359 | // to the member of index 0. |
| 2360 | // |
| 2361 | // E.g. a = A[i+1]; // Member of index 1 (Current instruction) |
| 2362 | // b = A[i]; // Member of index 0 |
| 2363 | // Current pointer is pointed to A[i+1], adjust it to A[i]. |
| 2364 | // |
| 2365 | // E.g. A[i+1] = a; // Member of index 1 |
| 2366 | // A[i] = b; // Member of index 0 |
| 2367 | // A[i+2] = c; // Member of index 2 (Current instruction) |
| 2368 | // Current pointer is pointed to A[i+2], adjust it to A[i]. |
| 2369 | |
| 2370 | bool InBounds = false; |
| 2371 | if (auto *gep = dyn_cast<GetElementPtrInst>(AddrPart->stripPointerCasts())) |
| 2372 | InBounds = gep->isInBounds(); |
| 2373 | AddrPart = Builder.CreateGEP(ScalarTy, AddrPart, Builder.getInt32(-Index)); |
| 2374 | cast<GetElementPtrInst>(AddrPart)->setIsInBounds(InBounds); |
| 2375 | |
| 2376 | // Cast to the vector pointer type. |
| 2377 | unsigned AddressSpace = AddrPart->getType()->getPointerAddressSpace(); |
| 2378 | Type *PtrTy = VecTy->getPointerTo(AddressSpace); |
| 2379 | AddrParts.push_back(Builder.CreateBitCast(AddrPart, PtrTy)); |
| 2380 | } |
| 2381 | |
| 2382 | setDebugLocFromInst(Builder, Instr); |
| 2383 | Value *UndefVec = UndefValue::get(VecTy); |
| 2384 | |
| 2385 | Value *MaskForGaps = nullptr; |
| 2386 | if (Group->requiresScalarEpilogue() && !Cost->isScalarEpilogueAllowed()) { |
| 2387 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2387, __PRETTY_FUNCTION__)); |
| 2388 | MaskForGaps = createBitMaskForGaps(Builder, VF.getKnownMinValue(), *Group); |
| 2389 | assert(MaskForGaps && "Mask for Gaps is required but it is null")((MaskForGaps && "Mask for Gaps is required but it is null" ) ? static_cast<void> (0) : __assert_fail ("MaskForGaps && \"Mask for Gaps is required but it is null\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2389, __PRETTY_FUNCTION__)); |
| 2390 | } |
| 2391 | |
| 2392 | // Vectorize the interleaved load group. |
| 2393 | if (isa<LoadInst>(Instr)) { |
| 2394 | // For each unroll part, create a wide load for the group. |
| 2395 | SmallVector<Value *, 2> NewLoads; |
| 2396 | for (unsigned Part = 0; Part < UF; Part++) { |
| 2397 | Instruction *NewLoad; |
| 2398 | if (BlockInMask || MaskForGaps) { |
| 2399 | assert(useMaskedInterleavedAccesses(*TTI) &&((useMaskedInterleavedAccesses(*TTI) && "masked interleaved groups are not allowed." ) ? static_cast<void> (0) : __assert_fail ("useMaskedInterleavedAccesses(*TTI) && \"masked interleaved groups are not allowed.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2400, __PRETTY_FUNCTION__)) |
| 2400 | "masked interleaved groups are not allowed.")((useMaskedInterleavedAccesses(*TTI) && "masked interleaved groups are not allowed." ) ? static_cast<void> (0) : __assert_fail ("useMaskedInterleavedAccesses(*TTI) && \"masked interleaved groups are not allowed.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2400, __PRETTY_FUNCTION__)); |
| 2401 | Value *GroupMask = MaskForGaps; |
| 2402 | if (BlockInMask) { |
| 2403 | Value *BlockInMaskPart = State.get(BlockInMask, Part); |
| 2404 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2404, __PRETTY_FUNCTION__)); |
| 2405 | Value *ShuffledMask = Builder.CreateShuffleVector( |
| 2406 | BlockInMaskPart, |
| 2407 | createReplicatedMask(InterleaveFactor, VF.getKnownMinValue()), |
| 2408 | "interleaved.mask"); |
| 2409 | GroupMask = MaskForGaps |
| 2410 | ? Builder.CreateBinOp(Instruction::And, ShuffledMask, |
| 2411 | MaskForGaps) |
| 2412 | : ShuffledMask; |
| 2413 | } |
| 2414 | NewLoad = |
| 2415 | Builder.CreateMaskedLoad(AddrParts[Part], Group->getAlign(), |
| 2416 | GroupMask, UndefVec, "wide.masked.vec"); |
| 2417 | } |
| 2418 | else |
| 2419 | NewLoad = Builder.CreateAlignedLoad(VecTy, AddrParts[Part], |
| 2420 | Group->getAlign(), "wide.vec"); |
| 2421 | Group->addMetadata(NewLoad); |
| 2422 | NewLoads.push_back(NewLoad); |
| 2423 | } |
| 2424 | |
| 2425 | // For each member in the group, shuffle out the appropriate data from the |
| 2426 | // wide loads. |
| 2427 | for (unsigned I = 0; I < InterleaveFactor; ++I) { |
| 2428 | Instruction *Member = Group->getMember(I); |
| 2429 | |
| 2430 | // Skip the gaps in the group. |
| 2431 | if (!Member) |
| 2432 | continue; |
| 2433 | |
| 2434 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2434, __PRETTY_FUNCTION__)); |
| 2435 | auto StrideMask = |
| 2436 | createStrideMask(I, InterleaveFactor, VF.getKnownMinValue()); |
| 2437 | for (unsigned Part = 0; Part < UF; Part++) { |
| 2438 | Value *StridedVec = Builder.CreateShuffleVector( |
| 2439 | NewLoads[Part], StrideMask, "strided.vec"); |
| 2440 | |
| 2441 | // If this member has different type, cast the result type. |
| 2442 | if (Member->getType() != ScalarTy) { |
| 2443 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2443, __PRETTY_FUNCTION__)); |
| 2444 | VectorType *OtherVTy = VectorType::get(Member->getType(), VF); |
| 2445 | StridedVec = createBitOrPointerCast(StridedVec, OtherVTy, DL); |
| 2446 | } |
| 2447 | |
| 2448 | if (Group->isReverse()) |
| 2449 | StridedVec = reverseVector(StridedVec); |
| 2450 | |
| 2451 | VectorLoopValueMap.setVectorValue(Member, Part, StridedVec); |
| 2452 | } |
| 2453 | } |
| 2454 | return; |
| 2455 | } |
| 2456 | |
| 2457 | // The sub vector type for current instruction. |
| 2458 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2458, __PRETTY_FUNCTION__)); |
| 2459 | auto *SubVT = VectorType::get(ScalarTy, VF); |
| 2460 | |
| 2461 | // Vectorize the interleaved store group. |
| 2462 | for (unsigned Part = 0; Part < UF; Part++) { |
| 2463 | // Collect the stored vector from each member. |
| 2464 | SmallVector<Value *, 4> StoredVecs; |
| 2465 | for (unsigned i = 0; i < InterleaveFactor; i++) { |
| 2466 | // Interleaved store group doesn't allow a gap, so each index has a member |
| 2467 | Instruction *Member = Group->getMember(i); |
| 2468 | assert(Member && "Fail to get a member from an interleaved store group")((Member && "Fail to get a member from an interleaved store group" ) ? static_cast<void> (0) : __assert_fail ("Member && \"Fail to get a member from an interleaved store group\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2468, __PRETTY_FUNCTION__)); |
| 2469 | |
| 2470 | Value *StoredVec = getOrCreateVectorValue( |
| 2471 | cast<StoreInst>(Member)->getValueOperand(), Part); |
| 2472 | if (Group->isReverse()) |
| 2473 | StoredVec = reverseVector(StoredVec); |
| 2474 | |
| 2475 | // If this member has different type, cast it to a unified type. |
| 2476 | |
| 2477 | if (StoredVec->getType() != SubVT) |
| 2478 | StoredVec = createBitOrPointerCast(StoredVec, SubVT, DL); |
| 2479 | |
| 2480 | StoredVecs.push_back(StoredVec); |
| 2481 | } |
| 2482 | |
| 2483 | // Concatenate all vectors into a wide vector. |
| 2484 | Value *WideVec = concatenateVectors(Builder, StoredVecs); |
| 2485 | |
| 2486 | // Interleave the elements in the wide vector. |
| 2487 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2487, __PRETTY_FUNCTION__)); |
| 2488 | Value *IVec = Builder.CreateShuffleVector( |
| 2489 | WideVec, createInterleaveMask(VF.getKnownMinValue(), InterleaveFactor), |
| 2490 | "interleaved.vec"); |
| 2491 | |
| 2492 | Instruction *NewStoreInstr; |
| 2493 | if (BlockInMask) { |
| 2494 | Value *BlockInMaskPart = State.get(BlockInMask, Part); |
| 2495 | Value *ShuffledMask = Builder.CreateShuffleVector( |
| 2496 | BlockInMaskPart, |
| 2497 | createReplicatedMask(InterleaveFactor, VF.getKnownMinValue()), |
| 2498 | "interleaved.mask"); |
| 2499 | NewStoreInstr = Builder.CreateMaskedStore( |
| 2500 | IVec, AddrParts[Part], Group->getAlign(), ShuffledMask); |
| 2501 | } |
| 2502 | else |
| 2503 | NewStoreInstr = |
| 2504 | Builder.CreateAlignedStore(IVec, AddrParts[Part], Group->getAlign()); |
| 2505 | |
| 2506 | Group->addMetadata(NewStoreInstr); |
| 2507 | } |
| 2508 | } |
| 2509 | |
| 2510 | void InnerLoopVectorizer::vectorizeMemoryInstruction( |
| 2511 | Instruction *Instr, VPTransformState &State, VPValue *Def, VPValue *Addr, |
| 2512 | VPValue *StoredValue, VPValue *BlockInMask) { |
| 2513 | // Attempt to issue a wide load. |
| 2514 | LoadInst *LI = dyn_cast<LoadInst>(Instr); |
| 2515 | StoreInst *SI = dyn_cast<StoreInst>(Instr); |
| 2516 | |
| 2517 | assert((LI || SI) && "Invalid Load/Store instruction")(((LI || SI) && "Invalid Load/Store instruction") ? static_cast <void> (0) : __assert_fail ("(LI || SI) && \"Invalid Load/Store instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2517, __PRETTY_FUNCTION__)); |
| 2518 | assert((!SI || StoredValue) && "No stored value provided for widened store")(((!SI || StoredValue) && "No stored value provided for widened store" ) ? static_cast<void> (0) : __assert_fail ("(!SI || StoredValue) && \"No stored value provided for widened store\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2518, __PRETTY_FUNCTION__)); |
| 2519 | assert((!LI || !StoredValue) && "Stored value provided for widened load")(((!LI || !StoredValue) && "Stored value provided for widened load" ) ? static_cast<void> (0) : __assert_fail ("(!LI || !StoredValue) && \"Stored value provided for widened load\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2519, __PRETTY_FUNCTION__)); |
| 2520 | |
| 2521 | LoopVectorizationCostModel::InstWidening Decision = |
| 2522 | Cost->getWideningDecision(Instr, VF); |
| 2523 | assert((Decision == LoopVectorizationCostModel::CM_Widen ||(((Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && "CM decision is not to widen the memory instruction" ) ? static_cast<void> (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2526, __PRETTY_FUNCTION__)) |
| 2524 | Decision == LoopVectorizationCostModel::CM_Widen_Reverse ||(((Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && "CM decision is not to widen the memory instruction" ) ? static_cast<void> (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2526, __PRETTY_FUNCTION__)) |
| 2525 | Decision == LoopVectorizationCostModel::CM_GatherScatter) &&(((Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && "CM decision is not to widen the memory instruction" ) ? static_cast<void> (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2526, __PRETTY_FUNCTION__)) |
| 2526 | "CM decision is not to widen the memory instruction")(((Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && "CM decision is not to widen the memory instruction" ) ? static_cast<void> (0) : __assert_fail ("(Decision == LoopVectorizationCostModel::CM_Widen || Decision == LoopVectorizationCostModel::CM_Widen_Reverse || Decision == LoopVectorizationCostModel::CM_GatherScatter) && \"CM decision is not to widen the memory instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2526, __PRETTY_FUNCTION__)); |
| 2527 | |
| 2528 | Type *ScalarDataTy = getMemInstValueType(Instr); |
| 2529 | |
| 2530 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2530, __PRETTY_FUNCTION__)); |
| 2531 | auto *DataTy = VectorType::get(ScalarDataTy, VF); |
| 2532 | const Align Alignment = getLoadStoreAlignment(Instr); |
| 2533 | |
| 2534 | // Determine if the pointer operand of the access is either consecutive or |
| 2535 | // reverse consecutive. |
| 2536 | bool Reverse = (Decision == LoopVectorizationCostModel::CM_Widen_Reverse); |
| 2537 | bool ConsecutiveStride = |
| 2538 | Reverse || (Decision == LoopVectorizationCostModel::CM_Widen); |
| 2539 | bool CreateGatherScatter = |
| 2540 | (Decision == LoopVectorizationCostModel::CM_GatherScatter); |
| 2541 | |
| 2542 | // Either Ptr feeds a vector load/store, or a vector GEP should feed a vector |
| 2543 | // gather/scatter. Otherwise Decision should have been to Scalarize. |
| 2544 | assert((ConsecutiveStride || CreateGatherScatter) &&(((ConsecutiveStride || CreateGatherScatter) && "The instruction should be scalarized" ) ? static_cast<void> (0) : __assert_fail ("(ConsecutiveStride || CreateGatherScatter) && \"The instruction should be scalarized\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2545, __PRETTY_FUNCTION__)) |
| 2545 | "The instruction should be scalarized")(((ConsecutiveStride || CreateGatherScatter) && "The instruction should be scalarized" ) ? static_cast<void> (0) : __assert_fail ("(ConsecutiveStride || CreateGatherScatter) && \"The instruction should be scalarized\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2545, __PRETTY_FUNCTION__)); |
| 2546 | (void)ConsecutiveStride; |
| 2547 | |
| 2548 | VectorParts BlockInMaskParts(UF); |
| 2549 | bool isMaskRequired = BlockInMask; |
| 2550 | if (isMaskRequired) |
| 2551 | for (unsigned Part = 0; Part < UF; ++Part) |
| 2552 | BlockInMaskParts[Part] = State.get(BlockInMask, Part); |
| 2553 | |
| 2554 | const auto CreateVecPtr = [&](unsigned Part, Value *Ptr) -> Value * { |
| 2555 | // Calculate the pointer for the specific unroll-part. |
| 2556 | GetElementPtrInst *PartPtr = nullptr; |
| 2557 | |
| 2558 | bool InBounds = false; |
| 2559 | if (auto *gep = dyn_cast<GetElementPtrInst>(Ptr->stripPointerCasts())) |
| 2560 | InBounds = gep->isInBounds(); |
| 2561 | |
| 2562 | if (Reverse) { |
| 2563 | // If the address is consecutive but reversed, then the |
| 2564 | // wide store needs to start at the last vector element. |
| 2565 | PartPtr = cast<GetElementPtrInst>(Builder.CreateGEP( |
| 2566 | ScalarDataTy, Ptr, Builder.getInt32(-Part * VF.getKnownMinValue()))); |
| 2567 | PartPtr->setIsInBounds(InBounds); |
| 2568 | PartPtr = cast<GetElementPtrInst>(Builder.CreateGEP( |
| 2569 | ScalarDataTy, PartPtr, Builder.getInt32(1 - VF.getKnownMinValue()))); |
| 2570 | PartPtr->setIsInBounds(InBounds); |
| 2571 | if (isMaskRequired) // Reverse of a null all-one mask is a null mask. |
| 2572 | BlockInMaskParts[Part] = reverseVector(BlockInMaskParts[Part]); |
| 2573 | } else { |
| 2574 | PartPtr = cast<GetElementPtrInst>(Builder.CreateGEP( |
| 2575 | ScalarDataTy, Ptr, Builder.getInt32(Part * VF.getKnownMinValue()))); |
| 2576 | PartPtr->setIsInBounds(InBounds); |
| 2577 | } |
| 2578 | |
| 2579 | unsigned AddressSpace = Ptr->getType()->getPointerAddressSpace(); |
| 2580 | return Builder.CreateBitCast(PartPtr, DataTy->getPointerTo(AddressSpace)); |
| 2581 | }; |
| 2582 | |
| 2583 | // Handle Stores: |
| 2584 | if (SI) { |
| 2585 | setDebugLocFromInst(Builder, SI); |
| 2586 | |
| 2587 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 2588 | Instruction *NewSI = nullptr; |
| 2589 | Value *StoredVal = State.get(StoredValue, Part); |
| 2590 | if (CreateGatherScatter) { |
| 2591 | Value *MaskPart = isMaskRequired ? BlockInMaskParts[Part] : nullptr; |
| 2592 | Value *VectorGep = State.get(Addr, Part); |
| 2593 | NewSI = Builder.CreateMaskedScatter(StoredVal, VectorGep, Alignment, |
| 2594 | MaskPart); |
| 2595 | } else { |
| 2596 | if (Reverse) { |
| 2597 | // If we store to reverse consecutive memory locations, then we need |
| 2598 | // to reverse the order of elements in the stored value. |
| 2599 | StoredVal = reverseVector(StoredVal); |
| 2600 | // We don't want to update the value in the map as it might be used in |
| 2601 | // another expression. So don't call resetVectorValue(StoredVal). |
| 2602 | } |
| 2603 | auto *VecPtr = CreateVecPtr(Part, State.get(Addr, {0, 0})); |
| 2604 | if (isMaskRequired) |
| 2605 | NewSI = Builder.CreateMaskedStore(StoredVal, VecPtr, Alignment, |
| 2606 | BlockInMaskParts[Part]); |
| 2607 | else |
| 2608 | NewSI = Builder.CreateAlignedStore(StoredVal, VecPtr, Alignment); |
| 2609 | } |
| 2610 | addMetadata(NewSI, SI); |
| 2611 | } |
| 2612 | return; |
| 2613 | } |
| 2614 | |
| 2615 | // Handle loads. |
| 2616 | assert(LI && "Must have a load instruction")((LI && "Must have a load instruction") ? static_cast <void> (0) : __assert_fail ("LI && \"Must have a load instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2616, __PRETTY_FUNCTION__)); |
| 2617 | setDebugLocFromInst(Builder, LI); |
| 2618 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 2619 | Value *NewLI; |
| 2620 | if (CreateGatherScatter) { |
| 2621 | Value *MaskPart = isMaskRequired ? BlockInMaskParts[Part] : nullptr; |
| 2622 | Value *VectorGep = State.get(Addr, Part); |
| 2623 | NewLI = Builder.CreateMaskedGather(VectorGep, Alignment, MaskPart, |
| 2624 | nullptr, "wide.masked.gather"); |
| 2625 | addMetadata(NewLI, LI); |
| 2626 | } else { |
| 2627 | auto *VecPtr = CreateVecPtr(Part, State.get(Addr, {0, 0})); |
| 2628 | if (isMaskRequired) |
| 2629 | NewLI = Builder.CreateMaskedLoad( |
| 2630 | VecPtr, Alignment, BlockInMaskParts[Part], UndefValue::get(DataTy), |
| 2631 | "wide.masked.load"); |
| 2632 | else |
| 2633 | NewLI = |
| 2634 | Builder.CreateAlignedLoad(DataTy, VecPtr, Alignment, "wide.load"); |
| 2635 | |
| 2636 | // Add metadata to the load, but setVectorValue to the reverse shuffle. |
| 2637 | addMetadata(NewLI, LI); |
| 2638 | if (Reverse) |
| 2639 | NewLI = reverseVector(NewLI); |
| 2640 | } |
| 2641 | |
| 2642 | State.set(Def, Instr, NewLI, Part); |
| 2643 | } |
| 2644 | } |
| 2645 | |
| 2646 | void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr, VPUser &User, |
| 2647 | const VPIteration &Instance, |
| 2648 | bool IfPredicateInstr, |
| 2649 | VPTransformState &State) { |
| 2650 | assert(!Instr->getType()->isAggregateType() && "Can't handle vectors")((!Instr->getType()->isAggregateType() && "Can't handle vectors" ) ? static_cast<void> (0) : __assert_fail ("!Instr->getType()->isAggregateType() && \"Can't handle vectors\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2650, __PRETTY_FUNCTION__)); |
| 2651 | |
| 2652 | setDebugLocFromInst(Builder, Instr); |
| 2653 | |
| 2654 | // Does this instruction return a value ? |
| 2655 | bool IsVoidRetTy = Instr->getType()->isVoidTy(); |
| 2656 | |
| 2657 | Instruction *Cloned = Instr->clone(); |
| 2658 | if (!IsVoidRetTy) |
| 2659 | Cloned->setName(Instr->getName() + ".cloned"); |
| 2660 | |
| 2661 | // Replace the operands of the cloned instructions with their scalar |
| 2662 | // equivalents in the new loop. |
| 2663 | for (unsigned op = 0, e = User.getNumOperands(); op != e; ++op) { |
| 2664 | auto *Operand = dyn_cast<Instruction>(Instr->getOperand(op)); |
| 2665 | auto InputInstance = Instance; |
| 2666 | if (!Operand || !OrigLoop->contains(Operand) || |
| 2667 | (Cost->isUniformAfterVectorization(Operand, State.VF))) |
| 2668 | InputInstance.Lane = 0; |
| 2669 | auto *NewOp = State.get(User.getOperand(op), InputInstance); |
| 2670 | Cloned->setOperand(op, NewOp); |
| 2671 | } |
| 2672 | addNewMetadata(Cloned, Instr); |
| 2673 | |
| 2674 | // Place the cloned scalar in the new loop. |
| 2675 | Builder.Insert(Cloned); |
| 2676 | |
| 2677 | // Add the cloned scalar to the scalar map entry. |
| 2678 | VectorLoopValueMap.setScalarValue(Instr, Instance, Cloned); |
| 2679 | |
| 2680 | // If we just cloned a new assumption, add it the assumption cache. |
| 2681 | if (auto *II = dyn_cast<IntrinsicInst>(Cloned)) |
| 2682 | if (II->getIntrinsicID() == Intrinsic::assume) |
| 2683 | AC->registerAssumption(II); |
| 2684 | |
| 2685 | // End if-block. |
| 2686 | if (IfPredicateInstr) |
| 2687 | PredicatedInstructions.push_back(Cloned); |
| 2688 | } |
| 2689 | |
| 2690 | PHINode *InnerLoopVectorizer::createInductionVariable(Loop *L, Value *Start, |
| 2691 | Value *End, Value *Step, |
| 2692 | Instruction *DL) { |
| 2693 | BasicBlock *Header = L->getHeader(); |
| 2694 | BasicBlock *Latch = L->getLoopLatch(); |
| 2695 | // As we're just creating this loop, it's possible no latch exists |
| 2696 | // yet. If so, use the header as this will be a single block loop. |
| 2697 | if (!Latch) |
| 2698 | Latch = Header; |
| 2699 | |
| 2700 | IRBuilder<> Builder(&*Header->getFirstInsertionPt()); |
| 2701 | Instruction *OldInst = getDebugLocFromInstOrOperands(OldInduction); |
| 2702 | setDebugLocFromInst(Builder, OldInst); |
| 2703 | auto *Induction = Builder.CreatePHI(Start->getType(), 2, "index"); |
| 2704 | |
| 2705 | Builder.SetInsertPoint(Latch->getTerminator()); |
| 2706 | setDebugLocFromInst(Builder, OldInst); |
| 2707 | |
| 2708 | // Create i+1 and fill the PHINode. |
| 2709 | Value *Next = Builder.CreateAdd(Induction, Step, "index.next"); |
| 2710 | Induction->addIncoming(Start, L->getLoopPreheader()); |
| 2711 | Induction->addIncoming(Next, Latch); |
| 2712 | // Create the compare. |
| 2713 | Value *ICmp = Builder.CreateICmpEQ(Next, End); |
| 2714 | Builder.CreateCondBr(ICmp, L->getExitBlock(), Header); |
| 2715 | |
| 2716 | // Now we have two terminators. Remove the old one from the block. |
| 2717 | Latch->getTerminator()->eraseFromParent(); |
| 2718 | |
| 2719 | return Induction; |
| 2720 | } |
| 2721 | |
| 2722 | Value *InnerLoopVectorizer::getOrCreateTripCount(Loop *L) { |
| 2723 | if (TripCount) |
| 2724 | return TripCount; |
| 2725 | |
| 2726 | assert(L && "Create Trip Count for null loop.")((L && "Create Trip Count for null loop.") ? static_cast <void> (0) : __assert_fail ("L && \"Create Trip Count for null loop.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2726, __PRETTY_FUNCTION__)); |
| 2727 | IRBuilder<> Builder(L->getLoopPreheader()->getTerminator()); |
| 2728 | // Find the loop boundaries. |
| 2729 | ScalarEvolution *SE = PSE.getSE(); |
| 2730 | const SCEV *BackedgeTakenCount = PSE.getBackedgeTakenCount(); |
| 2731 | assert(BackedgeTakenCount != SE->getCouldNotCompute() &&((BackedgeTakenCount != SE->getCouldNotCompute() && "Invalid loop count") ? static_cast<void> (0) : __assert_fail ("BackedgeTakenCount != SE->getCouldNotCompute() && \"Invalid loop count\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2732, __PRETTY_FUNCTION__)) |
| 2732 | "Invalid loop count")((BackedgeTakenCount != SE->getCouldNotCompute() && "Invalid loop count") ? static_cast<void> (0) : __assert_fail ("BackedgeTakenCount != SE->getCouldNotCompute() && \"Invalid loop count\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2732, __PRETTY_FUNCTION__)); |
| 2733 | |
| 2734 | Type *IdxTy = Legal->getWidestInductionType(); |
| 2735 | assert(IdxTy && "No type for induction")((IdxTy && "No type for induction") ? static_cast< void> (0) : __assert_fail ("IdxTy && \"No type for induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2735, __PRETTY_FUNCTION__)); |
| 2736 | |
| 2737 | // The exit count might have the type of i64 while the phi is i32. This can |
| 2738 | // happen if we have an induction variable that is sign extended before the |
| 2739 | // compare. The only way that we get a backedge taken count is that the |
| 2740 | // induction variable was signed and as such will not overflow. In such a case |
| 2741 | // truncation is legal. |
| 2742 | if (SE->getTypeSizeInBits(BackedgeTakenCount->getType()) > |
| 2743 | IdxTy->getPrimitiveSizeInBits()) |
| 2744 | BackedgeTakenCount = SE->getTruncateOrNoop(BackedgeTakenCount, IdxTy); |
| 2745 | BackedgeTakenCount = SE->getNoopOrZeroExtend(BackedgeTakenCount, IdxTy); |
| 2746 | |
| 2747 | // Get the total trip count from the count by adding 1. |
| 2748 | const SCEV *ExitCount = SE->getAddExpr( |
| 2749 | BackedgeTakenCount, SE->getOne(BackedgeTakenCount->getType())); |
| 2750 | |
| 2751 | const DataLayout &DL = L->getHeader()->getModule()->getDataLayout(); |
| 2752 | |
| 2753 | // Expand the trip count and place the new instructions in the preheader. |
| 2754 | // Notice that the pre-header does not change, only the loop body. |
| 2755 | SCEVExpander Exp(*SE, DL, "induction"); |
| 2756 | |
| 2757 | // Count holds the overall loop count (N). |
| 2758 | TripCount = Exp.expandCodeFor(ExitCount, ExitCount->getType(), |
| 2759 | L->getLoopPreheader()->getTerminator()); |
| 2760 | |
| 2761 | if (TripCount->getType()->isPointerTy()) |
| 2762 | TripCount = |
| 2763 | CastInst::CreatePointerCast(TripCount, IdxTy, "exitcount.ptrcnt.to.int", |
| 2764 | L->getLoopPreheader()->getTerminator()); |
| 2765 | |
| 2766 | return TripCount; |
| 2767 | } |
| 2768 | |
| 2769 | Value *InnerLoopVectorizer::getOrCreateVectorTripCount(Loop *L) { |
| 2770 | if (VectorTripCount) |
| 2771 | return VectorTripCount; |
| 2772 | |
| 2773 | Value *TC = getOrCreateTripCount(L); |
| 2774 | IRBuilder<> Builder(L->getLoopPreheader()->getTerminator()); |
| 2775 | |
| 2776 | Type *Ty = TC->getType(); |
| 2777 | // This is where we can make the step a runtime constant. |
| 2778 | assert(!VF.isScalable() && "scalable vectorization is not supported yet")((!VF.isScalable() && "scalable vectorization is not supported yet" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectorization is not supported yet\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2778, __PRETTY_FUNCTION__)); |
| 2779 | Constant *Step = ConstantInt::get(Ty, VF.getKnownMinValue() * UF); |
| 2780 | |
| 2781 | // If the tail is to be folded by masking, round the number of iterations N |
| 2782 | // up to a multiple of Step instead of rounding down. This is done by first |
| 2783 | // adding Step-1 and then rounding down. Note that it's ok if this addition |
| 2784 | // overflows: the vector induction variable will eventually wrap to zero given |
| 2785 | // that it starts at zero and its Step is a power of two; the loop will then |
| 2786 | // exit, with the last early-exit vector comparison also producing all-true. |
| 2787 | if (Cost->foldTailByMasking()) { |
| 2788 | assert(isPowerOf2_32(VF.getKnownMinValue() * UF) &&((isPowerOf2_32(VF.getKnownMinValue() * UF) && "VF*UF must be a power of 2 when folding tail by masking" ) ? static_cast<void> (0) : __assert_fail ("isPowerOf2_32(VF.getKnownMinValue() * UF) && \"VF*UF must be a power of 2 when folding tail by masking\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2789, __PRETTY_FUNCTION__)) |
| 2789 | "VF*UF must be a power of 2 when folding tail by masking")((isPowerOf2_32(VF.getKnownMinValue() * UF) && "VF*UF must be a power of 2 when folding tail by masking" ) ? static_cast<void> (0) : __assert_fail ("isPowerOf2_32(VF.getKnownMinValue() * UF) && \"VF*UF must be a power of 2 when folding tail by masking\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2789, __PRETTY_FUNCTION__)); |
| 2790 | TC = Builder.CreateAdd( |
| 2791 | TC, ConstantInt::get(Ty, VF.getKnownMinValue() * UF - 1), "n.rnd.up"); |
| 2792 | } |
| 2793 | |
| 2794 | // Now we need to generate the expression for the part of the loop that the |
| 2795 | // vectorized body will execute. This is equal to N - (N % Step) if scalar |
| 2796 | // iterations are not required for correctness, or N - Step, otherwise. Step |
| 2797 | // is equal to the vectorization factor (number of SIMD elements) times the |
| 2798 | // unroll factor (number of SIMD instructions). |
| 2799 | Value *R = Builder.CreateURem(TC, Step, "n.mod.vf"); |
| 2800 | |
| 2801 | // If there is a non-reversed interleaved group that may speculatively access |
| 2802 | // memory out-of-bounds, we need to ensure that there will be at least one |
| 2803 | // iteration of the scalar epilogue loop. Thus, if the step evenly divides |
| 2804 | // the trip count, we set the remainder to be equal to the step. If the step |
| 2805 | // does not evenly divide the trip count, no adjustment is necessary since |
| 2806 | // there will already be scalar iterations. Note that the minimum iterations |
| 2807 | // check ensures that N >= Step. |
| 2808 | if (VF.isVector() && Cost->requiresScalarEpilogue()) { |
| 2809 | auto *IsZero = Builder.CreateICmpEQ(R, ConstantInt::get(R->getType(), 0)); |
| 2810 | R = Builder.CreateSelect(IsZero, Step, R); |
| 2811 | } |
| 2812 | |
| 2813 | VectorTripCount = Builder.CreateSub(TC, R, "n.vec"); |
| 2814 | |
| 2815 | return VectorTripCount; |
| 2816 | } |
| 2817 | |
| 2818 | Value *InnerLoopVectorizer::createBitOrPointerCast(Value *V, VectorType *DstVTy, |
| 2819 | const DataLayout &DL) { |
| 2820 | // Verify that V is a vector type with same number of elements as DstVTy. |
| 2821 | auto *DstFVTy = cast<FixedVectorType>(DstVTy); |
| 2822 | unsigned VF = DstFVTy->getNumElements(); |
| 2823 | auto *SrcVecTy = cast<FixedVectorType>(V->getType()); |
| 2824 | assert((VF == SrcVecTy->getNumElements()) && "Vector dimensions do not match")(((VF == SrcVecTy->getNumElements()) && "Vector dimensions do not match" ) ? static_cast<void> (0) : __assert_fail ("(VF == SrcVecTy->getNumElements()) && \"Vector dimensions do not match\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2824, __PRETTY_FUNCTION__)); |
| 2825 | Type *SrcElemTy = SrcVecTy->getElementType(); |
| 2826 | Type *DstElemTy = DstFVTy->getElementType(); |
| 2827 | assert((DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) &&(((DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy )) && "Vector elements must have same size") ? static_cast <void> (0) : __assert_fail ("(DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) && \"Vector elements must have same size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2828, __PRETTY_FUNCTION__)) |
| 2828 | "Vector elements must have same size")(((DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy )) && "Vector elements must have same size") ? static_cast <void> (0) : __assert_fail ("(DL.getTypeSizeInBits(SrcElemTy) == DL.getTypeSizeInBits(DstElemTy)) && \"Vector elements must have same size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2828, __PRETTY_FUNCTION__)); |
| 2829 | |
| 2830 | // Do a direct cast if element types are castable. |
| 2831 | if (CastInst::isBitOrNoopPointerCastable(SrcElemTy, DstElemTy, DL)) { |
| 2832 | return Builder.CreateBitOrPointerCast(V, DstFVTy); |
| 2833 | } |
| 2834 | // V cannot be directly casted to desired vector type. |
| 2835 | // May happen when V is a floating point vector but DstVTy is a vector of |
| 2836 | // pointers or vice-versa. Handle this using a two-step bitcast using an |
| 2837 | // intermediate Integer type for the bitcast i.e. Ptr <-> Int <-> Float. |
| 2838 | assert((DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) &&(((DstElemTy->isPointerTy() != SrcElemTy->isPointerTy() ) && "Only one type should be a pointer type") ? static_cast <void> (0) : __assert_fail ("(DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) && \"Only one type should be a pointer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2839, __PRETTY_FUNCTION__)) |
| 2839 | "Only one type should be a pointer type")(((DstElemTy->isPointerTy() != SrcElemTy->isPointerTy() ) && "Only one type should be a pointer type") ? static_cast <void> (0) : __assert_fail ("(DstElemTy->isPointerTy() != SrcElemTy->isPointerTy()) && \"Only one type should be a pointer type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2839, __PRETTY_FUNCTION__)); |
| 2840 | assert((DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) &&(((DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy ()) && "Only one type should be a floating point type" ) ? static_cast<void> (0) : __assert_fail ("(DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) && \"Only one type should be a floating point type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2841, __PRETTY_FUNCTION__)) |
| 2841 | "Only one type should be a floating point type")(((DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy ()) && "Only one type should be a floating point type" ) ? static_cast<void> (0) : __assert_fail ("(DstElemTy->isFloatingPointTy() != SrcElemTy->isFloatingPointTy()) && \"Only one type should be a floating point type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2841, __PRETTY_FUNCTION__)); |
| 2842 | Type *IntTy = |
| 2843 | IntegerType::getIntNTy(V->getContext(), DL.getTypeSizeInBits(SrcElemTy)); |
| 2844 | auto *VecIntTy = FixedVectorType::get(IntTy, VF); |
| 2845 | Value *CastVal = Builder.CreateBitOrPointerCast(V, VecIntTy); |
| 2846 | return Builder.CreateBitOrPointerCast(CastVal, DstFVTy); |
| 2847 | } |
| 2848 | |
| 2849 | void InnerLoopVectorizer::emitMinimumIterationCountCheck(Loop *L, |
| 2850 | BasicBlock *Bypass) { |
| 2851 | Value *Count = getOrCreateTripCount(L); |
| 2852 | // Reuse existing vector loop preheader for TC checks. |
| 2853 | // Note that new preheader block is generated for vector loop. |
| 2854 | BasicBlock *const TCCheckBlock = LoopVectorPreHeader; |
| 2855 | IRBuilder<> Builder(TCCheckBlock->getTerminator()); |
| 2856 | |
| 2857 | // Generate code to check if the loop's trip count is less than VF * UF, or |
| 2858 | // equal to it in case a scalar epilogue is required; this implies that the |
| 2859 | // vector trip count is zero. This check also covers the case where adding one |
| 2860 | // to the backedge-taken count overflowed leading to an incorrect trip count |
| 2861 | // of zero. In this case we will also jump to the scalar loop. |
| 2862 | auto P = Cost->requiresScalarEpilogue() ? ICmpInst::ICMP_ULE |
| 2863 | : ICmpInst::ICMP_ULT; |
| 2864 | |
| 2865 | // If tail is to be folded, vector loop takes care of all iterations. |
| 2866 | Value *CheckMinIters = Builder.getFalse(); |
| 2867 | if (!Cost->foldTailByMasking()) { |
| 2868 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2868, __PRETTY_FUNCTION__)); |
| 2869 | CheckMinIters = Builder.CreateICmp( |
| 2870 | P, Count, |
| 2871 | ConstantInt::get(Count->getType(), VF.getKnownMinValue() * UF), |
| 2872 | "min.iters.check"); |
| 2873 | } |
| 2874 | // Create new preheader for vector loop. |
| 2875 | LoopVectorPreHeader = |
| 2876 | SplitBlock(TCCheckBlock, TCCheckBlock->getTerminator(), DT, LI, nullptr, |
| 2877 | "vector.ph"); |
| 2878 | |
| 2879 | assert(DT->properlyDominates(DT->getNode(TCCheckBlock),((DT->properlyDominates(DT->getNode(TCCheckBlock), DT-> getNode(Bypass)->getIDom()) && "TC check is expected to dominate Bypass" ) ? static_cast<void> (0) : __assert_fail ("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2881, __PRETTY_FUNCTION__)) |
| 2880 | DT->getNode(Bypass)->getIDom()) &&((DT->properlyDominates(DT->getNode(TCCheckBlock), DT-> getNode(Bypass)->getIDom()) && "TC check is expected to dominate Bypass" ) ? static_cast<void> (0) : __assert_fail ("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2881, __PRETTY_FUNCTION__)) |
| 2881 | "TC check is expected to dominate Bypass")((DT->properlyDominates(DT->getNode(TCCheckBlock), DT-> getNode(Bypass)->getIDom()) && "TC check is expected to dominate Bypass" ) ? static_cast<void> (0) : __assert_fail ("DT->properlyDominates(DT->getNode(TCCheckBlock), DT->getNode(Bypass)->getIDom()) && \"TC check is expected to dominate Bypass\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2881, __PRETTY_FUNCTION__)); |
| 2882 | |
| 2883 | // Update dominator for Bypass & LoopExit. |
| 2884 | DT->changeImmediateDominator(Bypass, TCCheckBlock); |
| 2885 | DT->changeImmediateDominator(LoopExitBlock, TCCheckBlock); |
| 2886 | |
| 2887 | ReplaceInstWithInst( |
| 2888 | TCCheckBlock->getTerminator(), |
| 2889 | BranchInst::Create(Bypass, LoopVectorPreHeader, CheckMinIters)); |
| 2890 | LoopBypassBlocks.push_back(TCCheckBlock); |
| 2891 | } |
| 2892 | |
| 2893 | void InnerLoopVectorizer::emitSCEVChecks(Loop *L, BasicBlock *Bypass) { |
| 2894 | // Reuse existing vector loop preheader for SCEV checks. |
| 2895 | // Note that new preheader block is generated for vector loop. |
| 2896 | BasicBlock *const SCEVCheckBlock = LoopVectorPreHeader; |
| 2897 | |
| 2898 | // Generate the code to check that the SCEV assumptions that we made. |
| 2899 | // We want the new basic block to start at the first instruction in a |
| 2900 | // sequence of instructions that form a check. |
| 2901 | SCEVExpander Exp(*PSE.getSE(), Bypass->getModule()->getDataLayout(), |
| 2902 | "scev.check"); |
| 2903 | Value *SCEVCheck = Exp.expandCodeForPredicate( |
| 2904 | &PSE.getUnionPredicate(), SCEVCheckBlock->getTerminator()); |
| 2905 | |
| 2906 | if (auto *C = dyn_cast<ConstantInt>(SCEVCheck)) |
| 2907 | if (C->isZero()) |
| 2908 | return; |
| 2909 | |
| 2910 | assert(!(SCEVCheckBlock->getParent()->hasOptSize() ||((!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints ::FK_Enabled)) && "Cannot SCEV check stride or overflow when optimizing for size" ) ? static_cast<void> (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2913, __PRETTY_FUNCTION__)) |
| 2911 | (OptForSizeBasedOnProfile &&((!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints ::FK_Enabled)) && "Cannot SCEV check stride or overflow when optimizing for size" ) ? static_cast<void> (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2913, __PRETTY_FUNCTION__)) |
| 2912 | Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) &&((!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints ::FK_Enabled)) && "Cannot SCEV check stride or overflow when optimizing for size" ) ? static_cast<void> (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2913, __PRETTY_FUNCTION__)) |
| 2913 | "Cannot SCEV check stride or overflow when optimizing for size")((!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints ::FK_Enabled)) && "Cannot SCEV check stride or overflow when optimizing for size" ) ? static_cast<void> (0) : __assert_fail ("!(SCEVCheckBlock->getParent()->hasOptSize() || (OptForSizeBasedOnProfile && Cost->Hints->getForce() != LoopVectorizeHints::FK_Enabled)) && \"Cannot SCEV check stride or overflow when optimizing for size\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2913, __PRETTY_FUNCTION__)); |
| 2914 | |
| 2915 | SCEVCheckBlock->setName("vector.scevcheck"); |
| 2916 | // Create new preheader for vector loop. |
| 2917 | LoopVectorPreHeader = |
| 2918 | SplitBlock(SCEVCheckBlock, SCEVCheckBlock->getTerminator(), DT, LI, |
| 2919 | nullptr, "vector.ph"); |
| 2920 | |
| 2921 | // Update dominator only if this is first RT check. |
| 2922 | if (LoopBypassBlocks.empty()) { |
| 2923 | DT->changeImmediateDominator(Bypass, SCEVCheckBlock); |
| 2924 | DT->changeImmediateDominator(LoopExitBlock, SCEVCheckBlock); |
| 2925 | } |
| 2926 | |
| 2927 | ReplaceInstWithInst( |
| 2928 | SCEVCheckBlock->getTerminator(), |
| 2929 | BranchInst::Create(Bypass, LoopVectorPreHeader, SCEVCheck)); |
| 2930 | LoopBypassBlocks.push_back(SCEVCheckBlock); |
| 2931 | AddedSafetyChecks = true; |
| 2932 | } |
| 2933 | |
| 2934 | void InnerLoopVectorizer::emitMemRuntimeChecks(Loop *L, BasicBlock *Bypass) { |
| 2935 | // VPlan-native path does not do any analysis for runtime checks currently. |
| 2936 | if (EnableVPlanNativePath) |
| 2937 | return; |
| 2938 | |
| 2939 | // Reuse existing vector loop preheader for runtime memory checks. |
| 2940 | // Note that new preheader block is generated for vector loop. |
| 2941 | BasicBlock *const MemCheckBlock = L->getLoopPreheader(); |
| 2942 | |
| 2943 | // Generate the code that checks in runtime if arrays overlap. We put the |
| 2944 | // checks into a separate block to make the more common case of few elements |
| 2945 | // faster. |
| 2946 | auto *LAI = Legal->getLAI(); |
| 2947 | const auto &RtPtrChecking = *LAI->getRuntimePointerChecking(); |
| 2948 | if (!RtPtrChecking.Need) |
| 2949 | return; |
| 2950 | |
| 2951 | if (MemCheckBlock->getParent()->hasOptSize() || OptForSizeBasedOnProfile) { |
| 2952 | assert(Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled &&((Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced " "to vectorize.") ? static_cast<void> (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2954, __PRETTY_FUNCTION__)) |
| 2953 | "Cannot emit memory checks when optimizing for size, unless forced "((Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced " "to vectorize.") ? static_cast<void> (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2954, __PRETTY_FUNCTION__)) |
| 2954 | "to vectorize.")((Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && "Cannot emit memory checks when optimizing for size, unless forced " "to vectorize.") ? static_cast<void> (0) : __assert_fail ("Cost->Hints->getForce() == LoopVectorizeHints::FK_Enabled && \"Cannot emit memory checks when optimizing for size, unless forced \" \"to vectorize.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2954, __PRETTY_FUNCTION__)); |
| 2955 | ORE->emit([&]() { |
| 2956 | return OptimizationRemarkAnalysis(DEBUG_TYPE"loop-vectorize", "VectorizationCodeSize", |
| 2957 | L->getStartLoc(), L->getHeader()) |
| 2958 | << "Code-size may be reduced by not forcing " |
| 2959 | "vectorization, or by source-code modifications " |
| 2960 | "eliminating the need for runtime checks " |
| 2961 | "(e.g., adding 'restrict')."; |
| 2962 | }); |
| 2963 | } |
| 2964 | |
| 2965 | MemCheckBlock->setName("vector.memcheck"); |
| 2966 | // Create new preheader for vector loop. |
| 2967 | LoopVectorPreHeader = |
| 2968 | SplitBlock(MemCheckBlock, MemCheckBlock->getTerminator(), DT, LI, nullptr, |
| 2969 | "vector.ph"); |
| 2970 | |
| 2971 | auto *CondBranch = cast<BranchInst>( |
| 2972 | Builder.CreateCondBr(Builder.getTrue(), Bypass, LoopVectorPreHeader)); |
| 2973 | ReplaceInstWithInst(MemCheckBlock->getTerminator(), CondBranch); |
| 2974 | LoopBypassBlocks.push_back(MemCheckBlock); |
| 2975 | AddedSafetyChecks = true; |
| 2976 | |
| 2977 | // Update dominator only if this is first RT check. |
| 2978 | if (LoopBypassBlocks.empty()) { |
| 2979 | DT->changeImmediateDominator(Bypass, MemCheckBlock); |
| 2980 | DT->changeImmediateDominator(LoopExitBlock, MemCheckBlock); |
| 2981 | } |
| 2982 | |
| 2983 | Instruction *FirstCheckInst; |
| 2984 | Instruction *MemRuntimeCheck; |
| 2985 | std::tie(FirstCheckInst, MemRuntimeCheck) = |
| 2986 | addRuntimeChecks(MemCheckBlock->getTerminator(), OrigLoop, |
| 2987 | RtPtrChecking.getChecks(), RtPtrChecking.getSE()); |
| 2988 | assert(MemRuntimeCheck && "no RT checks generated although RtPtrChecking "((MemRuntimeCheck && "no RT checks generated although RtPtrChecking " "claimed checks are required") ? static_cast<void> (0) : __assert_fail ("MemRuntimeCheck && \"no RT checks generated although RtPtrChecking \" \"claimed checks are required\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2989, __PRETTY_FUNCTION__)) |
| 2989 | "claimed checks are required")((MemRuntimeCheck && "no RT checks generated although RtPtrChecking " "claimed checks are required") ? static_cast<void> (0) : __assert_fail ("MemRuntimeCheck && \"no RT checks generated although RtPtrChecking \" \"claimed checks are required\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 2989, __PRETTY_FUNCTION__)); |
| 2990 | CondBranch->setCondition(MemRuntimeCheck); |
| 2991 | |
| 2992 | // We currently don't use LoopVersioning for the actual loop cloning but we |
| 2993 | // still use it to add the noalias metadata. |
| 2994 | LVer = std::make_unique<LoopVersioning>( |
| 2995 | *Legal->getLAI(), |
| 2996 | Legal->getLAI()->getRuntimePointerChecking()->getChecks(), OrigLoop, LI, |
| 2997 | DT, PSE.getSE()); |
| 2998 | LVer->prepareNoAliasMetadata(); |
| 2999 | } |
| 3000 | |
| 3001 | Value *InnerLoopVectorizer::emitTransformedIndex( |
| 3002 | IRBuilder<> &B, Value *Index, ScalarEvolution *SE, const DataLayout &DL, |
| 3003 | const InductionDescriptor &ID) const { |
| 3004 | |
| 3005 | SCEVExpander Exp(*SE, DL, "induction"); |
| 3006 | auto Step = ID.getStep(); |
| 3007 | auto StartValue = ID.getStartValue(); |
| 3008 | assert(Index->getType() == Step->getType() &&((Index->getType() == Step->getType() && "Index type does not match StepValue type" ) ? static_cast<void> (0) : __assert_fail ("Index->getType() == Step->getType() && \"Index type does not match StepValue type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3009, __PRETTY_FUNCTION__)) |
| 3009 | "Index type does not match StepValue type")((Index->getType() == Step->getType() && "Index type does not match StepValue type" ) ? static_cast<void> (0) : __assert_fail ("Index->getType() == Step->getType() && \"Index type does not match StepValue type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3009, __PRETTY_FUNCTION__)); |
| 3010 | |
| 3011 | // Note: the IR at this point is broken. We cannot use SE to create any new |
| 3012 | // SCEV and then expand it, hoping that SCEV's simplification will give us |
| 3013 | // a more optimal code. Unfortunately, attempt of doing so on invalid IR may |
| 3014 | // lead to various SCEV crashes. So all we can do is to use builder and rely |
| 3015 | // on InstCombine for future simplifications. Here we handle some trivial |
| 3016 | // cases only. |
| 3017 | auto CreateAdd = [&B](Value *X, Value *Y) { |
| 3018 | assert(X->getType() == Y->getType() && "Types don't match!")((X->getType() == Y->getType() && "Types don't match!" ) ? static_cast<void> (0) : __assert_fail ("X->getType() == Y->getType() && \"Types don't match!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3018, __PRETTY_FUNCTION__)); |
| 3019 | if (auto *CX = dyn_cast<ConstantInt>(X)) |
| 3020 | if (CX->isZero()) |
| 3021 | return Y; |
| 3022 | if (auto *CY = dyn_cast<ConstantInt>(Y)) |
| 3023 | if (CY->isZero()) |
| 3024 | return X; |
| 3025 | return B.CreateAdd(X, Y); |
| 3026 | }; |
| 3027 | |
| 3028 | auto CreateMul = [&B](Value *X, Value *Y) { |
| 3029 | assert(X->getType() == Y->getType() && "Types don't match!")((X->getType() == Y->getType() && "Types don't match!" ) ? static_cast<void> (0) : __assert_fail ("X->getType() == Y->getType() && \"Types don't match!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3029, __PRETTY_FUNCTION__)); |
| 3030 | if (auto *CX = dyn_cast<ConstantInt>(X)) |
| 3031 | if (CX->isOne()) |
| 3032 | return Y; |
| 3033 | if (auto *CY = dyn_cast<ConstantInt>(Y)) |
| 3034 | if (CY->isOne()) |
| 3035 | return X; |
| 3036 | return B.CreateMul(X, Y); |
| 3037 | }; |
| 3038 | |
| 3039 | // Get a suitable insert point for SCEV expansion. For blocks in the vector |
| 3040 | // loop, choose the end of the vector loop header (=LoopVectorBody), because |
| 3041 | // the DomTree is not kept up-to-date for additional blocks generated in the |
| 3042 | // vector loop. By using the header as insertion point, we guarantee that the |
| 3043 | // expanded instructions dominate all their uses. |
| 3044 | auto GetInsertPoint = [this, &B]() { |
| 3045 | BasicBlock *InsertBB = B.GetInsertPoint()->getParent(); |
| 3046 | if (InsertBB != LoopVectorBody && |
| 3047 | LI->getLoopFor(LoopVectorBody) == LI->getLoopFor(InsertBB)) |
| 3048 | return LoopVectorBody->getTerminator(); |
| 3049 | return &*B.GetInsertPoint(); |
| 3050 | }; |
| 3051 | switch (ID.getKind()) { |
| 3052 | case InductionDescriptor::IK_IntInduction: { |
| 3053 | assert(Index->getType() == StartValue->getType() &&((Index->getType() == StartValue->getType() && "Index type does not match StartValue type" ) ? static_cast<void> (0) : __assert_fail ("Index->getType() == StartValue->getType() && \"Index type does not match StartValue type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3054, __PRETTY_FUNCTION__)) |
| 3054 | "Index type does not match StartValue type")((Index->getType() == StartValue->getType() && "Index type does not match StartValue type" ) ? static_cast<void> (0) : __assert_fail ("Index->getType() == StartValue->getType() && \"Index type does not match StartValue type\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3054, __PRETTY_FUNCTION__)); |
| 3055 | if (ID.getConstIntStepValue() && ID.getConstIntStepValue()->isMinusOne()) |
| 3056 | return B.CreateSub(StartValue, Index); |
| 3057 | auto *Offset = CreateMul( |
| 3058 | Index, Exp.expandCodeFor(Step, Index->getType(), GetInsertPoint())); |
| 3059 | return CreateAdd(StartValue, Offset); |
| 3060 | } |
| 3061 | case InductionDescriptor::IK_PtrInduction: { |
| 3062 | assert(isa<SCEVConstant>(Step) &&((isa<SCEVConstant>(Step) && "Expected constant step for pointer induction" ) ? static_cast<void> (0) : __assert_fail ("isa<SCEVConstant>(Step) && \"Expected constant step for pointer induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3063, __PRETTY_FUNCTION__)) |
| 3063 | "Expected constant step for pointer induction")((isa<SCEVConstant>(Step) && "Expected constant step for pointer induction" ) ? static_cast<void> (0) : __assert_fail ("isa<SCEVConstant>(Step) && \"Expected constant step for pointer induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3063, __PRETTY_FUNCTION__)); |
| 3064 | return B.CreateGEP( |
| 3065 | StartValue->getType()->getPointerElementType(), StartValue, |
| 3066 | CreateMul(Index, |
| 3067 | Exp.expandCodeFor(Step, Index->getType(), GetInsertPoint()))); |
| 3068 | } |
| 3069 | case InductionDescriptor::IK_FpInduction: { |
| 3070 | assert(Step->getType()->isFloatingPointTy() && "Expected FP Step value")((Step->getType()->isFloatingPointTy() && "Expected FP Step value" ) ? static_cast<void> (0) : __assert_fail ("Step->getType()->isFloatingPointTy() && \"Expected FP Step value\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3070, __PRETTY_FUNCTION__)); |
| 3071 | auto InductionBinOp = ID.getInductionBinOp(); |
| 3072 | assert(InductionBinOp &&((InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction ::FSub) && "Original bin op should be defined for FP induction" ) ? static_cast<void> (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3075, __PRETTY_FUNCTION__)) |
| 3073 | (InductionBinOp->getOpcode() == Instruction::FAdd ||((InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction ::FSub) && "Original bin op should be defined for FP induction" ) ? static_cast<void> (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3075, __PRETTY_FUNCTION__)) |
| 3074 | InductionBinOp->getOpcode() == Instruction::FSub) &&((InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction ::FSub) && "Original bin op should be defined for FP induction" ) ? static_cast<void> (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3075, __PRETTY_FUNCTION__)) |
| 3075 | "Original bin op should be defined for FP induction")((InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction ::FSub) && "Original bin op should be defined for FP induction" ) ? static_cast<void> (0) : __assert_fail ("InductionBinOp && (InductionBinOp->getOpcode() == Instruction::FAdd || InductionBinOp->getOpcode() == Instruction::FSub) && \"Original bin op should be defined for FP induction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3075, __PRETTY_FUNCTION__)); |
| 3076 | |
| 3077 | Value *StepValue = cast<SCEVUnknown>(Step)->getValue(); |
| 3078 | |
| 3079 | // Floating point operations had to be 'fast' to enable the induction. |
| 3080 | FastMathFlags Flags; |
| 3081 | Flags.setFast(); |
| 3082 | |
| 3083 | Value *MulExp = B.CreateFMul(StepValue, Index); |
| 3084 | if (isa<Instruction>(MulExp)) |
| 3085 | // We have to check, the MulExp may be a constant. |
| 3086 | cast<Instruction>(MulExp)->setFastMathFlags(Flags); |
| 3087 | |
| 3088 | Value *BOp = B.CreateBinOp(InductionBinOp->getOpcode(), StartValue, MulExp, |
| 3089 | "induction"); |
| 3090 | if (isa<Instruction>(BOp)) |
| 3091 | cast<Instruction>(BOp)->setFastMathFlags(Flags); |
| 3092 | |
| 3093 | return BOp; |
| 3094 | } |
| 3095 | case InductionDescriptor::IK_NoInduction: |
| 3096 | return nullptr; |
| 3097 | } |
| 3098 | llvm_unreachable("invalid enum")::llvm::llvm_unreachable_internal("invalid enum", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3098); |
| 3099 | } |
| 3100 | |
| 3101 | Loop *InnerLoopVectorizer::createVectorLoopSkeleton(StringRef Prefix) { |
| 3102 | LoopScalarBody = OrigLoop->getHeader(); |
| 3103 | LoopVectorPreHeader = OrigLoop->getLoopPreheader(); |
| 3104 | LoopExitBlock = OrigLoop->getExitBlock(); |
| 3105 | assert(LoopExitBlock && "Must have an exit block")((LoopExitBlock && "Must have an exit block") ? static_cast <void> (0) : __assert_fail ("LoopExitBlock && \"Must have an exit block\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3105, __PRETTY_FUNCTION__)); |
| 3106 | assert(LoopVectorPreHeader && "Invalid loop structure")((LoopVectorPreHeader && "Invalid loop structure") ? static_cast <void> (0) : __assert_fail ("LoopVectorPreHeader && \"Invalid loop structure\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3106, __PRETTY_FUNCTION__)); |
| 3107 | |
| 3108 | LoopMiddleBlock = |
| 3109 | SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT, |
| 3110 | LI, nullptr, Twine(Prefix) + "middle.block"); |
| 3111 | LoopScalarPreHeader = |
| 3112 | SplitBlock(LoopMiddleBlock, LoopMiddleBlock->getTerminator(), DT, LI, |
| 3113 | nullptr, Twine(Prefix) + "scalar.ph"); |
| 3114 | // We intentionally don't let SplitBlock to update LoopInfo since |
| 3115 | // LoopVectorBody should belong to another loop than LoopVectorPreHeader. |
| 3116 | // LoopVectorBody is explicitly added to the correct place few lines later. |
| 3117 | LoopVectorBody = |
| 3118 | SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT, |
| 3119 | nullptr, nullptr, Twine(Prefix) + "vector.body"); |
| 3120 | |
| 3121 | // Update dominator for loop exit. |
| 3122 | DT->changeImmediateDominator(LoopExitBlock, LoopMiddleBlock); |
| 3123 | |
| 3124 | // Create and register the new vector loop. |
| 3125 | Loop *Lp = LI->AllocateLoop(); |
| 3126 | Loop *ParentLoop = OrigLoop->getParentLoop(); |
| 3127 | |
| 3128 | // Insert the new loop into the loop nest and register the new basic blocks |
| 3129 | // before calling any utilities such as SCEV that require valid LoopInfo. |
| 3130 | if (ParentLoop) { |
| 3131 | ParentLoop->addChildLoop(Lp); |
| 3132 | } else { |
| 3133 | LI->addTopLevelLoop(Lp); |
| 3134 | } |
| 3135 | Lp->addBasicBlockToLoop(LoopVectorBody, *LI); |
| 3136 | return Lp; |
| 3137 | } |
| 3138 | |
| 3139 | void InnerLoopVectorizer::createInductionResumeValues(Loop *L, |
| 3140 | Value *VectorTripCount) { |
| 3141 | assert(VectorTripCount && L && "Expected valid arguments")((VectorTripCount && L && "Expected valid arguments" ) ? static_cast<void> (0) : __assert_fail ("VectorTripCount && L && \"Expected valid arguments\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3141, __PRETTY_FUNCTION__)); |
| 3142 | // We are going to resume the execution of the scalar loop. |
| 3143 | // Go over all of the induction variables that we found and fix the |
| 3144 | // PHIs that are left in the scalar version of the loop. |
| 3145 | // The starting values of PHI nodes depend on the counter of the last |
| 3146 | // iteration in the vectorized loop. |
| 3147 | // If we come from a bypass edge then we need to start from the original |
| 3148 | // start value. |
| 3149 | for (auto &InductionEntry : Legal->getInductionVars()) { |
| 3150 | PHINode *OrigPhi = InductionEntry.first; |
| 3151 | InductionDescriptor II = InductionEntry.second; |
| 3152 | |
| 3153 | // Create phi nodes to merge from the backedge-taken check block. |
| 3154 | PHINode *BCResumeVal = |
| 3155 | PHINode::Create(OrigPhi->getType(), 3, "bc.resume.val", |
| 3156 | LoopScalarPreHeader->getTerminator()); |
| 3157 | // Copy original phi DL over to the new one. |
| 3158 | BCResumeVal->setDebugLoc(OrigPhi->getDebugLoc()); |
| 3159 | Value *&EndValue = IVEndValues[OrigPhi]; |
| 3160 | if (OrigPhi == OldInduction) { |
| 3161 | // We know what the end value is. |
| 3162 | EndValue = VectorTripCount; |
| 3163 | } else { |
| 3164 | IRBuilder<> B(L->getLoopPreheader()->getTerminator()); |
| 3165 | Type *StepType = II.getStep()->getType(); |
| 3166 | Instruction::CastOps CastOp = |
| 3167 | CastInst::getCastOpcode(VectorTripCount, true, StepType, true); |
| 3168 | Value *CRD = B.CreateCast(CastOp, VectorTripCount, StepType, "cast.crd"); |
| 3169 | const DataLayout &DL = LoopScalarBody->getModule()->getDataLayout(); |
| 3170 | EndValue = emitTransformedIndex(B, CRD, PSE.getSE(), DL, II); |
| 3171 | EndValue->setName("ind.end"); |
| 3172 | } |
| 3173 | |
| 3174 | // The new PHI merges the original incoming value, in case of a bypass, |
| 3175 | // or the value at the end of the vectorized loop. |
| 3176 | BCResumeVal->addIncoming(EndValue, LoopMiddleBlock); |
| 3177 | |
| 3178 | // Fix the scalar body counter (PHI node). |
| 3179 | // The old induction's phi node in the scalar body needs the truncated |
| 3180 | // value. |
| 3181 | for (BasicBlock *BB : LoopBypassBlocks) |
| 3182 | BCResumeVal->addIncoming(II.getStartValue(), BB); |
| 3183 | OrigPhi->setIncomingValueForBlock(LoopScalarPreHeader, BCResumeVal); |
| 3184 | } |
| 3185 | } |
| 3186 | |
| 3187 | BasicBlock *InnerLoopVectorizer::completeLoopSkeleton(Loop *L, |
| 3188 | MDNode *OrigLoopID) { |
| 3189 | assert(L && "Expected valid loop.")((L && "Expected valid loop.") ? static_cast<void> (0) : __assert_fail ("L && \"Expected valid loop.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3189, __PRETTY_FUNCTION__)); |
| 3190 | |
| 3191 | // The trip counts should be cached by now. |
| 3192 | Value *Count = getOrCreateTripCount(L); |
| 3193 | Value *VectorTripCount = getOrCreateVectorTripCount(L); |
| 3194 | |
| 3195 | // We need the OrigLoop (scalar loop part) latch terminator to help |
| 3196 | // produce correct debug info for the middle block BB instructions. |
| 3197 | // The legality check stage guarantees that the loop will have a single |
| 3198 | // latch. |
| 3199 | assert(isa<BranchInst>(OrigLoop->getLoopLatch()->getTerminator()) &&((isa<BranchInst>(OrigLoop->getLoopLatch()->getTerminator ()) && "Scalar loop latch terminator isn't a branch") ? static_cast<void> (0) : __assert_fail ("isa<BranchInst>(OrigLoop->getLoopLatch()->getTerminator()) && \"Scalar loop latch terminator isn't a branch\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3200, __PRETTY_FUNCTION__)) |
| 3200 | "Scalar loop latch terminator isn't a branch")((isa<BranchInst>(OrigLoop->getLoopLatch()->getTerminator ()) && "Scalar loop latch terminator isn't a branch") ? static_cast<void> (0) : __assert_fail ("isa<BranchInst>(OrigLoop->getLoopLatch()->getTerminator()) && \"Scalar loop latch terminator isn't a branch\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3200, __PRETTY_FUNCTION__)); |
| 3201 | BranchInst *ScalarLatchBr = |
| 3202 | cast<BranchInst>(OrigLoop->getLoopLatch()->getTerminator()); |
| 3203 | |
| 3204 | // Add a check in the middle block to see if we have completed |
| 3205 | // all of the iterations in the first vector loop. |
| 3206 | // If (N - N%VF) == N, then we *don't* need to run the remainder. |
| 3207 | // If tail is to be folded, we know we don't need to run the remainder. |
| 3208 | Value *CmpN = Builder.getTrue(); |
| 3209 | if (!Cost->foldTailByMasking()) { |
| 3210 | CmpN = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, Count, |
| 3211 | VectorTripCount, "cmp.n", |
| 3212 | LoopMiddleBlock->getTerminator()); |
| 3213 | |
| 3214 | // Here we use the same DebugLoc as the scalar loop latch branch instead |
| 3215 | // of the corresponding compare because they may have ended up with |
| 3216 | // different line numbers and we want to avoid awkward line stepping while |
| 3217 | // debugging. Eg. if the compare has got a line number inside the loop. |
| 3218 | cast<Instruction>(CmpN)->setDebugLoc(ScalarLatchBr->getDebugLoc()); |
| 3219 | } |
| 3220 | |
| 3221 | BranchInst *BrInst = |
| 3222 | BranchInst::Create(LoopExitBlock, LoopScalarPreHeader, CmpN); |
| 3223 | BrInst->setDebugLoc(ScalarLatchBr->getDebugLoc()); |
| 3224 | ReplaceInstWithInst(LoopMiddleBlock->getTerminator(), BrInst); |
| 3225 | |
| 3226 | // Get ready to start creating new instructions into the vectorized body. |
| 3227 | assert(LoopVectorPreHeader == L->getLoopPreheader() &&((LoopVectorPreHeader == L->getLoopPreheader() && "Inconsistent vector loop preheader" ) ? static_cast<void> (0) : __assert_fail ("LoopVectorPreHeader == L->getLoopPreheader() && \"Inconsistent vector loop preheader\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3228, __PRETTY_FUNCTION__)) |
| 3228 | "Inconsistent vector loop preheader")((LoopVectorPreHeader == L->getLoopPreheader() && "Inconsistent vector loop preheader" ) ? static_cast<void> (0) : __assert_fail ("LoopVectorPreHeader == L->getLoopPreheader() && \"Inconsistent vector loop preheader\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3228, __PRETTY_FUNCTION__)); |
| 3229 | Builder.SetInsertPoint(&*LoopVectorBody->getFirstInsertionPt()); |
| 3230 | |
| 3231 | Optional<MDNode *> VectorizedLoopID = |
| 3232 | makeFollowupLoopID(OrigLoopID, {LLVMLoopVectorizeFollowupAll, |
| 3233 | LLVMLoopVectorizeFollowupVectorized}); |
| 3234 | if (VectorizedLoopID.hasValue()) { |
| 3235 | L->setLoopID(VectorizedLoopID.getValue()); |
| 3236 | |
| 3237 | // Do not setAlreadyVectorized if loop attributes have been defined |
| 3238 | // explicitly. |
| 3239 | return LoopVectorPreHeader; |
| 3240 | } |
| 3241 | |
| 3242 | // Keep all loop hints from the original loop on the vector loop (we'll |
| 3243 | // replace the vectorizer-specific hints below). |
| 3244 | if (MDNode *LID = OrigLoop->getLoopID()) |
| 3245 | L->setLoopID(LID); |
| 3246 | |
| 3247 | LoopVectorizeHints Hints(L, true, *ORE); |
| 3248 | Hints.setAlreadyVectorized(); |
| 3249 | |
| 3250 | #ifdef EXPENSIVE_CHECKS |
| 3251 | assert(DT->verify(DominatorTree::VerificationLevel::Fast))((DT->verify(DominatorTree::VerificationLevel::Fast)) ? static_cast <void> (0) : __assert_fail ("DT->verify(DominatorTree::VerificationLevel::Fast)" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3251, __PRETTY_FUNCTION__)); |
| 3252 | LI->verify(*DT); |
| 3253 | #endif |
| 3254 | |
| 3255 | return LoopVectorPreHeader; |
| 3256 | } |
| 3257 | |
| 3258 | BasicBlock *InnerLoopVectorizer::createVectorizedLoopSkeleton() { |
| 3259 | /* |
| 3260 | In this function we generate a new loop. The new loop will contain |
| 3261 | the vectorized instructions while the old loop will continue to run the |
| 3262 | scalar remainder. |
| 3263 | |
| 3264 | [ ] <-- loop iteration number check. |
| 3265 | / | |
| 3266 | / v |
| 3267 | | [ ] <-- vector loop bypass (may consist of multiple blocks). |
| 3268 | | / | |
| 3269 | | / v |
| 3270 | || [ ] <-- vector pre header. |
| 3271 | |/ | |
| 3272 | | v |
| 3273 | | [ ] \ |
| 3274 | | [ ]_| <-- vector loop. |
| 3275 | | | |
| 3276 | | v |
| 3277 | | -[ ] <--- middle-block. |
| 3278 | | / | |
| 3279 | | / v |
| 3280 | -|- >[ ] <--- new preheader. |
| 3281 | | | |
| 3282 | | v |
| 3283 | | [ ] \ |
| 3284 | | [ ]_| <-- old scalar loop to handle remainder. |
| 3285 | \ | |
| 3286 | \ v |
| 3287 | >[ ] <-- exit block. |
| 3288 | ... |
| 3289 | */ |
| 3290 | |
| 3291 | // Get the metadata of the original loop before it gets modified. |
| 3292 | MDNode *OrigLoopID = OrigLoop->getLoopID(); |
| 3293 | |
| 3294 | // Create an empty vector loop, and prepare basic blocks for the runtime |
| 3295 | // checks. |
| 3296 | Loop *Lp = createVectorLoopSkeleton(""); |
| 3297 | |
| 3298 | // Now, compare the new count to zero. If it is zero skip the vector loop and |
| 3299 | // jump to the scalar loop. This check also covers the case where the |
| 3300 | // backedge-taken count is uint##_max: adding one to it will overflow leading |
| 3301 | // to an incorrect trip count of zero. In this (rare) case we will also jump |
| 3302 | // to the scalar loop. |
| 3303 | emitMinimumIterationCountCheck(Lp, LoopScalarPreHeader); |
| 3304 | |
| 3305 | // Generate the code to check any assumptions that we've made for SCEV |
| 3306 | // expressions. |
| 3307 | emitSCEVChecks(Lp, LoopScalarPreHeader); |
| 3308 | |
| 3309 | // Generate the code that checks in runtime if arrays overlap. We put the |
| 3310 | // checks into a separate block to make the more common case of few elements |
| 3311 | // faster. |
| 3312 | emitMemRuntimeChecks(Lp, LoopScalarPreHeader); |
| 3313 | |
| 3314 | // Some loops have a single integer induction variable, while other loops |
| 3315 | // don't. One example is c++ iterators that often have multiple pointer |
| 3316 | // induction variables. In the code below we also support a case where we |
| 3317 | // don't have a single induction variable. |
| 3318 | // |
| 3319 | // We try to obtain an induction variable from the original loop as hard |
| 3320 | // as possible. However if we don't find one that: |
| 3321 | // - is an integer |
| 3322 | // - counts from zero, stepping by one |
| 3323 | // - is the size of the widest induction variable type |
| 3324 | // then we create a new one. |
| 3325 | OldInduction = Legal->getPrimaryInduction(); |
| 3326 | Type *IdxTy = Legal->getWidestInductionType(); |
| 3327 | Value *StartIdx = ConstantInt::get(IdxTy, 0); |
| 3328 | // The loop step is equal to the vectorization factor (num of SIMD elements) |
| 3329 | // times the unroll factor (num of SIMD instructions). |
| 3330 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3330, __PRETTY_FUNCTION__)); |
| 3331 | Constant *Step = ConstantInt::get(IdxTy, VF.getKnownMinValue() * UF); |
| 3332 | Value *CountRoundDown = getOrCreateVectorTripCount(Lp); |
| 3333 | Induction = |
| 3334 | createInductionVariable(Lp, StartIdx, CountRoundDown, Step, |
| 3335 | getDebugLocFromInstOrOperands(OldInduction)); |
| 3336 | |
| 3337 | // Emit phis for the new starting index of the scalar loop. |
| 3338 | createInductionResumeValues(Lp, CountRoundDown); |
| 3339 | |
| 3340 | return completeLoopSkeleton(Lp, OrigLoopID); |
| 3341 | } |
| 3342 | |
| 3343 | // Fix up external users of the induction variable. At this point, we are |
| 3344 | // in LCSSA form, with all external PHIs that use the IV having one input value, |
| 3345 | // coming from the remainder loop. We need those PHIs to also have a correct |
| 3346 | // value for the IV when arriving directly from the middle block. |
| 3347 | void InnerLoopVectorizer::fixupIVUsers(PHINode *OrigPhi, |
| 3348 | const InductionDescriptor &II, |
| 3349 | Value *CountRoundDown, Value *EndValue, |
| 3350 | BasicBlock *MiddleBlock) { |
| 3351 | // There are two kinds of external IV usages - those that use the value |
| 3352 | // computed in the last iteration (the PHI) and those that use the penultimate |
| 3353 | // value (the value that feeds into the phi from the loop latch). |
| 3354 | // We allow both, but they, obviously, have different values. |
| 3355 | |
| 3356 | assert(OrigLoop->getExitBlock() && "Expected a single exit block")((OrigLoop->getExitBlock() && "Expected a single exit block" ) ? static_cast<void> (0) : __assert_fail ("OrigLoop->getExitBlock() && \"Expected a single exit block\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3356, __PRETTY_FUNCTION__)); |
| 3357 | |
| 3358 | DenseMap<Value *, Value *> MissingVals; |
| 3359 | |
| 3360 | // An external user of the last iteration's value should see the value that |
| 3361 | // the remainder loop uses to initialize its own IV. |
| 3362 | Value *PostInc = OrigPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch()); |
| 3363 | for (User *U : PostInc->users()) { |
| 3364 | Instruction *UI = cast<Instruction>(U); |
| 3365 | if (!OrigLoop->contains(UI)) { |
| 3366 | assert(isa<PHINode>(UI) && "Expected LCSSA form")((isa<PHINode>(UI) && "Expected LCSSA form") ? static_cast <void> (0) : __assert_fail ("isa<PHINode>(UI) && \"Expected LCSSA form\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3366, __PRETTY_FUNCTION__)); |
| 3367 | MissingVals[UI] = EndValue; |
| 3368 | } |
| 3369 | } |
| 3370 | |
| 3371 | // An external user of the penultimate value need to see EndValue - Step. |
| 3372 | // The simplest way to get this is to recompute it from the constituent SCEVs, |
| 3373 | // that is Start + (Step * (CRD - 1)). |
| 3374 | for (User *U : OrigPhi->users()) { |
| 3375 | auto *UI = cast<Instruction>(U); |
| 3376 | if (!OrigLoop->contains(UI)) { |
| 3377 | const DataLayout &DL = |
| 3378 | OrigLoop->getHeader()->getModule()->getDataLayout(); |
| 3379 | assert(isa<PHINode>(UI) && "Expected LCSSA form")((isa<PHINode>(UI) && "Expected LCSSA form") ? static_cast <void> (0) : __assert_fail ("isa<PHINode>(UI) && \"Expected LCSSA form\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3379, __PRETTY_FUNCTION__)); |
| 3380 | |
| 3381 | IRBuilder<> B(MiddleBlock->getTerminator()); |
| 3382 | Value *CountMinusOne = B.CreateSub( |
| 3383 | CountRoundDown, ConstantInt::get(CountRoundDown->getType(), 1)); |
| 3384 | Value *CMO = |
| 3385 | !II.getStep()->getType()->isIntegerTy() |
| 3386 | ? B.CreateCast(Instruction::SIToFP, CountMinusOne, |
| 3387 | II.getStep()->getType()) |
| 3388 | : B.CreateSExtOrTrunc(CountMinusOne, II.getStep()->getType()); |
| 3389 | CMO->setName("cast.cmo"); |
| 3390 | Value *Escape = emitTransformedIndex(B, CMO, PSE.getSE(), DL, II); |
| 3391 | Escape->setName("ind.escape"); |
| 3392 | MissingVals[UI] = Escape; |
| 3393 | } |
| 3394 | } |
| 3395 | |
| 3396 | for (auto &I : MissingVals) { |
| 3397 | PHINode *PHI = cast<PHINode>(I.first); |
| 3398 | // One corner case we have to handle is two IVs "chasing" each-other, |
| 3399 | // that is %IV2 = phi [...], [ %IV1, %latch ] |
| 3400 | // In this case, if IV1 has an external use, we need to avoid adding both |
| 3401 | // "last value of IV1" and "penultimate value of IV2". So, verify that we |
| 3402 | // don't already have an incoming value for the middle block. |
| 3403 | if (PHI->getBasicBlockIndex(MiddleBlock) == -1) |
| 3404 | PHI->addIncoming(I.second, MiddleBlock); |
| 3405 | } |
| 3406 | } |
| 3407 | |
| 3408 | namespace { |
| 3409 | |
| 3410 | struct CSEDenseMapInfo { |
| 3411 | static bool canHandle(const Instruction *I) { |
| 3412 | return isa<InsertElementInst>(I) || isa<ExtractElementInst>(I) || |
| 3413 | isa<ShuffleVectorInst>(I) || isa<GetElementPtrInst>(I); |
| 3414 | } |
| 3415 | |
| 3416 | static inline Instruction *getEmptyKey() { |
| 3417 | return DenseMapInfo<Instruction *>::getEmptyKey(); |
| 3418 | } |
| 3419 | |
| 3420 | static inline Instruction *getTombstoneKey() { |
| 3421 | return DenseMapInfo<Instruction *>::getTombstoneKey(); |
| 3422 | } |
| 3423 | |
| 3424 | static unsigned getHashValue(const Instruction *I) { |
| 3425 | assert(canHandle(I) && "Unknown instruction!")((canHandle(I) && "Unknown instruction!") ? static_cast <void> (0) : __assert_fail ("canHandle(I) && \"Unknown instruction!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3425, __PRETTY_FUNCTION__)); |
| 3426 | return hash_combine(I->getOpcode(), hash_combine_range(I->value_op_begin(), |
| 3427 | I->value_op_end())); |
| 3428 | } |
| 3429 | |
| 3430 | static bool isEqual(const Instruction *LHS, const Instruction *RHS) { |
| 3431 | if (LHS == getEmptyKey() || RHS == getEmptyKey() || |
| 3432 | LHS == getTombstoneKey() || RHS == getTombstoneKey()) |
| 3433 | return LHS == RHS; |
| 3434 | return LHS->isIdenticalTo(RHS); |
| 3435 | } |
| 3436 | }; |
| 3437 | |
| 3438 | } // end anonymous namespace |
| 3439 | |
| 3440 | ///Perform cse of induction variable instructions. |
| 3441 | static void cse(BasicBlock *BB) { |
| 3442 | // Perform simple cse. |
| 3443 | SmallDenseMap<Instruction *, Instruction *, 4, CSEDenseMapInfo> CSEMap; |
| 3444 | for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) { |
| 3445 | Instruction *In = &*I++; |
| 3446 | |
| 3447 | if (!CSEDenseMapInfo::canHandle(In)) |
| 3448 | continue; |
| 3449 | |
| 3450 | // Check if we can replace this instruction with any of the |
| 3451 | // visited instructions. |
| 3452 | if (Instruction *V = CSEMap.lookup(In)) { |
| 3453 | In->replaceAllUsesWith(V); |
| 3454 | In->eraseFromParent(); |
| 3455 | continue; |
| 3456 | } |
| 3457 | |
| 3458 | CSEMap[In] = In; |
| 3459 | } |
| 3460 | } |
| 3461 | |
| 3462 | unsigned LoopVectorizationCostModel::getVectorCallCost(CallInst *CI, |
| 3463 | ElementCount VF, |
| 3464 | bool &NeedToScalarize) { |
| 3465 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3465, __PRETTY_FUNCTION__)); |
| 3466 | Function *F = CI->getCalledFunction(); |
| 3467 | Type *ScalarRetTy = CI->getType(); |
| 3468 | SmallVector<Type *, 4> Tys, ScalarTys; |
| 3469 | for (auto &ArgOp : CI->arg_operands()) |
| 3470 | ScalarTys.push_back(ArgOp->getType()); |
| 3471 | |
| 3472 | // Estimate cost of scalarized vector call. The source operands are assumed |
| 3473 | // to be vectors, so we need to extract individual elements from there, |
| 3474 | // execute VF scalar calls, and then gather the result into the vector return |
| 3475 | // value. |
| 3476 | unsigned ScalarCallCost = TTI.getCallInstrCost(F, ScalarRetTy, ScalarTys, |
| 3477 | TTI::TCK_RecipThroughput); |
| 3478 | if (VF.isScalar()) |
| 3479 | return ScalarCallCost; |
| 3480 | |
| 3481 | // Compute corresponding vector type for return value and arguments. |
| 3482 | Type *RetTy = ToVectorTy(ScalarRetTy, VF); |
| 3483 | for (Type *ScalarTy : ScalarTys) |
| 3484 | Tys.push_back(ToVectorTy(ScalarTy, VF)); |
| 3485 | |
| 3486 | // Compute costs of unpacking argument values for the scalar calls and |
| 3487 | // packing the return values to a vector. |
| 3488 | unsigned ScalarizationCost = getScalarizationOverhead(CI, VF); |
| 3489 | |
| 3490 | unsigned Cost = ScalarCallCost * VF.getKnownMinValue() + ScalarizationCost; |
| 3491 | |
| 3492 | // If we can't emit a vector call for this function, then the currently found |
| 3493 | // cost is the cost we need to return. |
| 3494 | NeedToScalarize = true; |
| 3495 | VFShape Shape = VFShape::get(*CI, VF, false /*HasGlobalPred*/); |
| 3496 | Function *VecFunc = VFDatabase(*CI).getVectorizedFunction(Shape); |
| 3497 | |
| 3498 | if (!TLI || CI->isNoBuiltin() || !VecFunc) |
| 3499 | return Cost; |
| 3500 | |
| 3501 | // If the corresponding vector cost is cheaper, return its cost. |
| 3502 | unsigned VectorCallCost = TTI.getCallInstrCost(nullptr, RetTy, Tys, |
| 3503 | TTI::TCK_RecipThroughput); |
| 3504 | if (VectorCallCost < Cost) { |
| 3505 | NeedToScalarize = false; |
| 3506 | return VectorCallCost; |
| 3507 | } |
| 3508 | return Cost; |
| 3509 | } |
| 3510 | |
| 3511 | unsigned LoopVectorizationCostModel::getVectorIntrinsicCost(CallInst *CI, |
| 3512 | ElementCount VF) { |
| 3513 | Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI); |
| 3514 | assert(ID && "Expected intrinsic call!")((ID && "Expected intrinsic call!") ? static_cast< void> (0) : __assert_fail ("ID && \"Expected intrinsic call!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3514, __PRETTY_FUNCTION__)); |
| 3515 | |
| 3516 | IntrinsicCostAttributes CostAttrs(ID, *CI, VF); |
| 3517 | return TTI.getIntrinsicInstrCost(CostAttrs, |
| 3518 | TargetTransformInfo::TCK_RecipThroughput); |
| 3519 | } |
| 3520 | |
| 3521 | static Type *smallestIntegerVectorType(Type *T1, Type *T2) { |
| 3522 | auto *I1 = cast<IntegerType>(cast<VectorType>(T1)->getElementType()); |
| 3523 | auto *I2 = cast<IntegerType>(cast<VectorType>(T2)->getElementType()); |
| 3524 | return I1->getBitWidth() < I2->getBitWidth() ? T1 : T2; |
| 3525 | } |
| 3526 | |
| 3527 | static Type *largestIntegerVectorType(Type *T1, Type *T2) { |
| 3528 | auto *I1 = cast<IntegerType>(cast<VectorType>(T1)->getElementType()); |
| 3529 | auto *I2 = cast<IntegerType>(cast<VectorType>(T2)->getElementType()); |
| 3530 | return I1->getBitWidth() > I2->getBitWidth() ? T1 : T2; |
| 3531 | } |
| 3532 | |
| 3533 | void InnerLoopVectorizer::truncateToMinimalBitwidths() { |
| 3534 | // For every instruction `I` in MinBWs, truncate the operands, create a |
| 3535 | // truncated version of `I` and reextend its result. InstCombine runs |
| 3536 | // later and will remove any ext/trunc pairs. |
| 3537 | SmallPtrSet<Value *, 4> Erased; |
| 3538 | for (const auto &KV : Cost->getMinimalBitwidths()) { |
| 3539 | // If the value wasn't vectorized, we must maintain the original scalar |
| 3540 | // type. The absence of the value from VectorLoopValueMap indicates that it |
| 3541 | // wasn't vectorized. |
| 3542 | if (!VectorLoopValueMap.hasAnyVectorValue(KV.first)) |
| 3543 | continue; |
| 3544 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 3545 | Value *I = getOrCreateVectorValue(KV.first, Part); |
| 3546 | if (Erased.count(I) || I->use_empty() || !isa<Instruction>(I)) |
| 3547 | continue; |
| 3548 | Type *OriginalTy = I->getType(); |
| 3549 | Type *ScalarTruncatedTy = |
| 3550 | IntegerType::get(OriginalTy->getContext(), KV.second); |
| 3551 | auto *TruncatedTy = FixedVectorType::get( |
| 3552 | ScalarTruncatedTy, |
| 3553 | cast<FixedVectorType>(OriginalTy)->getNumElements()); |
| 3554 | if (TruncatedTy == OriginalTy) |
| 3555 | continue; |
| 3556 | |
| 3557 | IRBuilder<> B(cast<Instruction>(I)); |
| 3558 | auto ShrinkOperand = [&](Value *V) -> Value * { |
| 3559 | if (auto *ZI = dyn_cast<ZExtInst>(V)) |
| 3560 | if (ZI->getSrcTy() == TruncatedTy) |
| 3561 | return ZI->getOperand(0); |
| 3562 | return B.CreateZExtOrTrunc(V, TruncatedTy); |
| 3563 | }; |
| 3564 | |
| 3565 | // The actual instruction modification depends on the instruction type, |
| 3566 | // unfortunately. |
| 3567 | Value *NewI = nullptr; |
| 3568 | if (auto *BO = dyn_cast<BinaryOperator>(I)) { |
| 3569 | NewI = B.CreateBinOp(BO->getOpcode(), ShrinkOperand(BO->getOperand(0)), |
| 3570 | ShrinkOperand(BO->getOperand(1))); |
| 3571 | |
| 3572 | // Any wrapping introduced by shrinking this operation shouldn't be |
| 3573 | // considered undefined behavior. So, we can't unconditionally copy |
| 3574 | // arithmetic wrapping flags to NewI. |
| 3575 | cast<BinaryOperator>(NewI)->copyIRFlags(I, /*IncludeWrapFlags=*/false); |
| 3576 | } else if (auto *CI = dyn_cast<ICmpInst>(I)) { |
| 3577 | NewI = |
| 3578 | B.CreateICmp(CI->getPredicate(), ShrinkOperand(CI->getOperand(0)), |
| 3579 | ShrinkOperand(CI->getOperand(1))); |
| 3580 | } else if (auto *SI = dyn_cast<SelectInst>(I)) { |
| 3581 | NewI = B.CreateSelect(SI->getCondition(), |
| 3582 | ShrinkOperand(SI->getTrueValue()), |
| 3583 | ShrinkOperand(SI->getFalseValue())); |
| 3584 | } else if (auto *CI = dyn_cast<CastInst>(I)) { |
| 3585 | switch (CI->getOpcode()) { |
| 3586 | default: |
| 3587 | llvm_unreachable("Unhandled cast!")::llvm::llvm_unreachable_internal("Unhandled cast!", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3587); |
| 3588 | case Instruction::Trunc: |
| 3589 | NewI = ShrinkOperand(CI->getOperand(0)); |
| 3590 | break; |
| 3591 | case Instruction::SExt: |
| 3592 | NewI = B.CreateSExtOrTrunc( |
| 3593 | CI->getOperand(0), |
| 3594 | smallestIntegerVectorType(OriginalTy, TruncatedTy)); |
| 3595 | break; |
| 3596 | case Instruction::ZExt: |
| 3597 | NewI = B.CreateZExtOrTrunc( |
| 3598 | CI->getOperand(0), |
| 3599 | smallestIntegerVectorType(OriginalTy, TruncatedTy)); |
| 3600 | break; |
| 3601 | } |
| 3602 | } else if (auto *SI = dyn_cast<ShuffleVectorInst>(I)) { |
| 3603 | auto Elements0 = cast<FixedVectorType>(SI->getOperand(0)->getType()) |
| 3604 | ->getNumElements(); |
| 3605 | auto *O0 = B.CreateZExtOrTrunc( |
| 3606 | SI->getOperand(0), |
| 3607 | FixedVectorType::get(ScalarTruncatedTy, Elements0)); |
| 3608 | auto Elements1 = cast<FixedVectorType>(SI->getOperand(1)->getType()) |
| 3609 | ->getNumElements(); |
| 3610 | auto *O1 = B.CreateZExtOrTrunc( |
| 3611 | SI->getOperand(1), |
| 3612 | FixedVectorType::get(ScalarTruncatedTy, Elements1)); |
| 3613 | |
| 3614 | NewI = B.CreateShuffleVector(O0, O1, SI->getShuffleMask()); |
| 3615 | } else if (isa<LoadInst>(I) || isa<PHINode>(I)) { |
| 3616 | // Don't do anything with the operands, just extend the result. |
| 3617 | continue; |
| 3618 | } else if (auto *IE = dyn_cast<InsertElementInst>(I)) { |
| 3619 | auto Elements = cast<FixedVectorType>(IE->getOperand(0)->getType()) |
| 3620 | ->getNumElements(); |
| 3621 | auto *O0 = B.CreateZExtOrTrunc( |
| 3622 | IE->getOperand(0), |
| 3623 | FixedVectorType::get(ScalarTruncatedTy, Elements)); |
| 3624 | auto *O1 = B.CreateZExtOrTrunc(IE->getOperand(1), ScalarTruncatedTy); |
| 3625 | NewI = B.CreateInsertElement(O0, O1, IE->getOperand(2)); |
| 3626 | } else if (auto *EE = dyn_cast<ExtractElementInst>(I)) { |
| 3627 | auto Elements = cast<FixedVectorType>(EE->getOperand(0)->getType()) |
| 3628 | ->getNumElements(); |
| 3629 | auto *O0 = B.CreateZExtOrTrunc( |
| 3630 | EE->getOperand(0), |
| 3631 | FixedVectorType::get(ScalarTruncatedTy, Elements)); |
| 3632 | NewI = B.CreateExtractElement(O0, EE->getOperand(2)); |
| 3633 | } else { |
| 3634 | // If we don't know what to do, be conservative and don't do anything. |
| 3635 | continue; |
| 3636 | } |
| 3637 | |
| 3638 | // Lastly, extend the result. |
| 3639 | NewI->takeName(cast<Instruction>(I)); |
| 3640 | Value *Res = B.CreateZExtOrTrunc(NewI, OriginalTy); |
| 3641 | I->replaceAllUsesWith(Res); |
| 3642 | cast<Instruction>(I)->eraseFromParent(); |
| 3643 | Erased.insert(I); |
| 3644 | VectorLoopValueMap.resetVectorValue(KV.first, Part, Res); |
| 3645 | } |
| 3646 | } |
| 3647 | |
| 3648 | // We'll have created a bunch of ZExts that are now parentless. Clean up. |
| 3649 | for (const auto &KV : Cost->getMinimalBitwidths()) { |
| 3650 | // If the value wasn't vectorized, we must maintain the original scalar |
| 3651 | // type. The absence of the value from VectorLoopValueMap indicates that it |
| 3652 | // wasn't vectorized. |
| 3653 | if (!VectorLoopValueMap.hasAnyVectorValue(KV.first)) |
| 3654 | continue; |
| 3655 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 3656 | Value *I = getOrCreateVectorValue(KV.first, Part); |
| 3657 | ZExtInst *Inst = dyn_cast<ZExtInst>(I); |
| 3658 | if (Inst && Inst->use_empty()) { |
| 3659 | Value *NewI = Inst->getOperand(0); |
| 3660 | Inst->eraseFromParent(); |
| 3661 | VectorLoopValueMap.resetVectorValue(KV.first, Part, NewI); |
| 3662 | } |
| 3663 | } |
| 3664 | } |
| 3665 | } |
| 3666 | |
| 3667 | void InnerLoopVectorizer::fixVectorizedLoop() { |
| 3668 | // Insert truncates and extends for any truncated instructions as hints to |
| 3669 | // InstCombine. |
| 3670 | if (VF.isVector()) |
| 3671 | truncateToMinimalBitwidths(); |
| 3672 | |
| 3673 | // Fix widened non-induction PHIs by setting up the PHI operands. |
| 3674 | if (OrigPHIsToFix.size()) { |
| 3675 | assert(EnableVPlanNativePath &&((EnableVPlanNativePath && "Unexpected non-induction PHIs for fixup in non VPlan-native path" ) ? static_cast<void> (0) : __assert_fail ("EnableVPlanNativePath && \"Unexpected non-induction PHIs for fixup in non VPlan-native path\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3676, __PRETTY_FUNCTION__)) |
| 3676 | "Unexpected non-induction PHIs for fixup in non VPlan-native path")((EnableVPlanNativePath && "Unexpected non-induction PHIs for fixup in non VPlan-native path" ) ? static_cast<void> (0) : __assert_fail ("EnableVPlanNativePath && \"Unexpected non-induction PHIs for fixup in non VPlan-native path\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3676, __PRETTY_FUNCTION__)); |
| 3677 | fixNonInductionPHIs(); |
| 3678 | } |
| 3679 | |
| 3680 | // At this point every instruction in the original loop is widened to a |
| 3681 | // vector form. Now we need to fix the recurrences in the loop. These PHI |
| 3682 | // nodes are currently empty because we did not want to introduce cycles. |
| 3683 | // This is the second stage of vectorizing recurrences. |
| 3684 | fixCrossIterationPHIs(); |
| 3685 | |
| 3686 | // Forget the original basic block. |
| 3687 | PSE.getSE()->forgetLoop(OrigLoop); |
| 3688 | |
| 3689 | // Fix-up external users of the induction variables. |
| 3690 | for (auto &Entry : Legal->getInductionVars()) |
| 3691 | fixupIVUsers(Entry.first, Entry.second, |
| 3692 | getOrCreateVectorTripCount(LI->getLoopFor(LoopVectorBody)), |
| 3693 | IVEndValues[Entry.first], LoopMiddleBlock); |
| 3694 | |
| 3695 | fixLCSSAPHIs(); |
| 3696 | for (Instruction *PI : PredicatedInstructions) |
| 3697 | sinkScalarOperands(&*PI); |
| 3698 | |
| 3699 | // Remove redundant induction instructions. |
| 3700 | cse(LoopVectorBody); |
| 3701 | |
| 3702 | // Set/update profile weights for the vector and remainder loops as original |
| 3703 | // loop iterations are now distributed among them. Note that original loop |
| 3704 | // represented by LoopScalarBody becomes remainder loop after vectorization. |
| 3705 | // |
| 3706 | // For cases like foldTailByMasking() and requiresScalarEpiloque() we may |
| 3707 | // end up getting slightly roughened result but that should be OK since |
| 3708 | // profile is not inherently precise anyway. Note also possible bypass of |
| 3709 | // vector code caused by legality checks is ignored, assigning all the weight |
| 3710 | // to the vector loop, optimistically. |
| 3711 | assert(!VF.isScalable() &&((!VF.isScalable() && "cannot use scalable ElementCount to determine unroll factor" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"cannot use scalable ElementCount to determine unroll factor\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3712, __PRETTY_FUNCTION__)) |
| 3712 | "cannot use scalable ElementCount to determine unroll factor")((!VF.isScalable() && "cannot use scalable ElementCount to determine unroll factor" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"cannot use scalable ElementCount to determine unroll factor\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3712, __PRETTY_FUNCTION__)); |
| 3713 | setProfileInfoAfterUnrolling( |
| 3714 | LI->getLoopFor(LoopScalarBody), LI->getLoopFor(LoopVectorBody), |
| 3715 | LI->getLoopFor(LoopScalarBody), VF.getKnownMinValue() * UF); |
| 3716 | } |
| 3717 | |
| 3718 | void InnerLoopVectorizer::fixCrossIterationPHIs() { |
| 3719 | // In order to support recurrences we need to be able to vectorize Phi nodes. |
| 3720 | // Phi nodes have cycles, so we need to vectorize them in two stages. This is |
| 3721 | // stage #2: We now need to fix the recurrences by adding incoming edges to |
| 3722 | // the currently empty PHI nodes. At this point every instruction in the |
| 3723 | // original loop is widened to a vector form so we can use them to construct |
| 3724 | // the incoming edges. |
| 3725 | for (PHINode &Phi : OrigLoop->getHeader()->phis()) { |
| 3726 | // Handle first-order recurrences and reductions that need to be fixed. |
| 3727 | if (Legal->isFirstOrderRecurrence(&Phi)) |
| 3728 | fixFirstOrderRecurrence(&Phi); |
| 3729 | else if (Legal->isReductionVariable(&Phi)) |
| 3730 | fixReduction(&Phi); |
| 3731 | } |
| 3732 | } |
| 3733 | |
| 3734 | void InnerLoopVectorizer::fixFirstOrderRecurrence(PHINode *Phi) { |
| 3735 | // This is the second phase of vectorizing first-order recurrences. An |
| 3736 | // overview of the transformation is described below. Suppose we have the |
| 3737 | // following loop. |
| 3738 | // |
| 3739 | // for (int i = 0; i < n; ++i) |
| 3740 | // b[i] = a[i] - a[i - 1]; |
| 3741 | // |
| 3742 | // There is a first-order recurrence on "a". For this loop, the shorthand |
| 3743 | // scalar IR looks like: |
| 3744 | // |
| 3745 | // scalar.ph: |
| 3746 | // s_init = a[-1] |
| 3747 | // br scalar.body |
| 3748 | // |
| 3749 | // scalar.body: |
| 3750 | // i = phi [0, scalar.ph], [i+1, scalar.body] |
| 3751 | // s1 = phi [s_init, scalar.ph], [s2, scalar.body] |
| 3752 | // s2 = a[i] |
| 3753 | // b[i] = s2 - s1 |
| 3754 | // br cond, scalar.body, ... |
| 3755 | // |
| 3756 | // In this example, s1 is a recurrence because it's value depends on the |
| 3757 | // previous iteration. In the first phase of vectorization, we created a |
| 3758 | // temporary value for s1. We now complete the vectorization and produce the |
| 3759 | // shorthand vector IR shown below (for VF = 4, UF = 1). |
| 3760 | // |
| 3761 | // vector.ph: |
| 3762 | // v_init = vector(..., ..., ..., a[-1]) |
| 3763 | // br vector.body |
| 3764 | // |
| 3765 | // vector.body |
| 3766 | // i = phi [0, vector.ph], [i+4, vector.body] |
| 3767 | // v1 = phi [v_init, vector.ph], [v2, vector.body] |
| 3768 | // v2 = a[i, i+1, i+2, i+3]; |
| 3769 | // v3 = vector(v1(3), v2(0, 1, 2)) |
| 3770 | // b[i, i+1, i+2, i+3] = v2 - v3 |
| 3771 | // br cond, vector.body, middle.block |
| 3772 | // |
| 3773 | // middle.block: |
| 3774 | // x = v2(3) |
| 3775 | // br scalar.ph |
| 3776 | // |
| 3777 | // scalar.ph: |
| 3778 | // s_init = phi [x, middle.block], [a[-1], otherwise] |
| 3779 | // br scalar.body |
| 3780 | // |
| 3781 | // After execution completes the vector loop, we extract the next value of |
| 3782 | // the recurrence (x) to use as the initial value in the scalar loop. |
| 3783 | |
| 3784 | // Get the original loop preheader and single loop latch. |
| 3785 | auto *Preheader = OrigLoop->getLoopPreheader(); |
| 3786 | auto *Latch = OrigLoop->getLoopLatch(); |
| 3787 | |
| 3788 | // Get the initial and previous values of the scalar recurrence. |
| 3789 | auto *ScalarInit = Phi->getIncomingValueForBlock(Preheader); |
| 3790 | auto *Previous = Phi->getIncomingValueForBlock(Latch); |
| 3791 | |
| 3792 | // Create a vector from the initial value. |
| 3793 | auto *VectorInit = ScalarInit; |
| 3794 | if (VF.isVector()) { |
| 3795 | Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); |
| 3796 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3796, __PRETTY_FUNCTION__)); |
| 3797 | VectorInit = Builder.CreateInsertElement( |
| 3798 | UndefValue::get(VectorType::get(VectorInit->getType(), VF)), VectorInit, |
| 3799 | Builder.getInt32(VF.getKnownMinValue() - 1), "vector.recur.init"); |
| 3800 | } |
| 3801 | |
| 3802 | // We constructed a temporary phi node in the first phase of vectorization. |
| 3803 | // This phi node will eventually be deleted. |
| 3804 | Builder.SetInsertPoint( |
| 3805 | cast<Instruction>(VectorLoopValueMap.getVectorValue(Phi, 0))); |
| 3806 | |
| 3807 | // Create a phi node for the new recurrence. The current value will either be |
| 3808 | // the initial value inserted into a vector or loop-varying vector value. |
| 3809 | auto *VecPhi = Builder.CreatePHI(VectorInit->getType(), 2, "vector.recur"); |
| 3810 | VecPhi->addIncoming(VectorInit, LoopVectorPreHeader); |
| 3811 | |
| 3812 | // Get the vectorized previous value of the last part UF - 1. It appears last |
| 3813 | // among all unrolled iterations, due to the order of their construction. |
| 3814 | Value *PreviousLastPart = getOrCreateVectorValue(Previous, UF - 1); |
| 3815 | |
| 3816 | // Find and set the insertion point after the previous value if it is an |
| 3817 | // instruction. |
| 3818 | BasicBlock::iterator InsertPt; |
| 3819 | // Note that the previous value may have been constant-folded so it is not |
| 3820 | // guaranteed to be an instruction in the vector loop. |
| 3821 | // FIXME: Loop invariant values do not form recurrences. We should deal with |
| 3822 | // them earlier. |
| 3823 | if (LI->getLoopFor(LoopVectorBody)->isLoopInvariant(PreviousLastPart)) |
| 3824 | InsertPt = LoopVectorBody->getFirstInsertionPt(); |
| 3825 | else { |
| 3826 | Instruction *PreviousInst = cast<Instruction>(PreviousLastPart); |
| 3827 | if (isa<PHINode>(PreviousLastPart)) |
| 3828 | // If the previous value is a phi node, we should insert after all the phi |
| 3829 | // nodes in the block containing the PHI to avoid breaking basic block |
| 3830 | // verification. Note that the basic block may be different to |
| 3831 | // LoopVectorBody, in case we predicate the loop. |
| 3832 | InsertPt = PreviousInst->getParent()->getFirstInsertionPt(); |
| 3833 | else |
| 3834 | InsertPt = ++PreviousInst->getIterator(); |
| 3835 | } |
| 3836 | Builder.SetInsertPoint(&*InsertPt); |
| 3837 | |
| 3838 | // We will construct a vector for the recurrence by combining the values for |
| 3839 | // the current and previous iterations. This is the required shuffle mask. |
| 3840 | assert(!VF.isScalable())((!VF.isScalable()) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable()", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3840, __PRETTY_FUNCTION__)); |
| 3841 | SmallVector<int, 8> ShuffleMask(VF.getKnownMinValue()); |
| 3842 | ShuffleMask[0] = VF.getKnownMinValue() - 1; |
| 3843 | for (unsigned I = 1; I < VF.getKnownMinValue(); ++I) |
| 3844 | ShuffleMask[I] = I + VF.getKnownMinValue() - 1; |
| 3845 | |
| 3846 | // The vector from which to take the initial value for the current iteration |
| 3847 | // (actual or unrolled). Initially, this is the vector phi node. |
| 3848 | Value *Incoming = VecPhi; |
| 3849 | |
| 3850 | // Shuffle the current and previous vector and update the vector parts. |
| 3851 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 3852 | Value *PreviousPart = getOrCreateVectorValue(Previous, Part); |
| 3853 | Value *PhiPart = VectorLoopValueMap.getVectorValue(Phi, Part); |
| 3854 | auto *Shuffle = |
| 3855 | VF.isVector() |
| 3856 | ? Builder.CreateShuffleVector(Incoming, PreviousPart, ShuffleMask) |
| 3857 | : Incoming; |
| 3858 | PhiPart->replaceAllUsesWith(Shuffle); |
| 3859 | cast<Instruction>(PhiPart)->eraseFromParent(); |
| 3860 | VectorLoopValueMap.resetVectorValue(Phi, Part, Shuffle); |
| 3861 | Incoming = PreviousPart; |
| 3862 | } |
| 3863 | |
| 3864 | // Fix the latch value of the new recurrence in the vector loop. |
| 3865 | VecPhi->addIncoming(Incoming, LI->getLoopFor(LoopVectorBody)->getLoopLatch()); |
| 3866 | |
| 3867 | // Extract the last vector element in the middle block. This will be the |
| 3868 | // initial value for the recurrence when jumping to the scalar loop. |
| 3869 | auto *ExtractForScalar = Incoming; |
| 3870 | if (VF.isVector()) { |
| 3871 | Builder.SetInsertPoint(LoopMiddleBlock->getTerminator()); |
| 3872 | ExtractForScalar = Builder.CreateExtractElement( |
| 3873 | ExtractForScalar, Builder.getInt32(VF.getKnownMinValue() - 1), |
| 3874 | "vector.recur.extract"); |
| 3875 | } |
| 3876 | // Extract the second last element in the middle block if the |
| 3877 | // Phi is used outside the loop. We need to extract the phi itself |
| 3878 | // and not the last element (the phi update in the current iteration). This |
| 3879 | // will be the value when jumping to the exit block from the LoopMiddleBlock, |
| 3880 | // when the scalar loop is not run at all. |
| 3881 | Value *ExtractForPhiUsedOutsideLoop = nullptr; |
| 3882 | if (VF.isVector()) |
| 3883 | ExtractForPhiUsedOutsideLoop = Builder.CreateExtractElement( |
| 3884 | Incoming, Builder.getInt32(VF.getKnownMinValue() - 2), |
| 3885 | "vector.recur.extract.for.phi"); |
| 3886 | // When loop is unrolled without vectorizing, initialize |
| 3887 | // ExtractForPhiUsedOutsideLoop with the value just prior to unrolled value of |
| 3888 | // `Incoming`. This is analogous to the vectorized case above: extracting the |
| 3889 | // second last element when VF > 1. |
| 3890 | else if (UF > 1) |
| 3891 | ExtractForPhiUsedOutsideLoop = getOrCreateVectorValue(Previous, UF - 2); |
| 3892 | |
| 3893 | // Fix the initial value of the original recurrence in the scalar loop. |
| 3894 | Builder.SetInsertPoint(&*LoopScalarPreHeader->begin()); |
| 3895 | auto *Start = Builder.CreatePHI(Phi->getType(), 2, "scalar.recur.init"); |
| 3896 | for (auto *BB : predecessors(LoopScalarPreHeader)) { |
| 3897 | auto *Incoming = BB == LoopMiddleBlock ? ExtractForScalar : ScalarInit; |
| 3898 | Start->addIncoming(Incoming, BB); |
| 3899 | } |
| 3900 | |
| 3901 | Phi->setIncomingValueForBlock(LoopScalarPreHeader, Start); |
| 3902 | Phi->setName("scalar.recur"); |
| 3903 | |
| 3904 | // Finally, fix users of the recurrence outside the loop. The users will need |
| 3905 | // either the last value of the scalar recurrence or the last value of the |
| 3906 | // vector recurrence we extracted in the middle block. Since the loop is in |
| 3907 | // LCSSA form, we just need to find all the phi nodes for the original scalar |
| 3908 | // recurrence in the exit block, and then add an edge for the middle block. |
| 3909 | for (PHINode &LCSSAPhi : LoopExitBlock->phis()) { |
| 3910 | if (LCSSAPhi.getIncomingValue(0) == Phi) { |
| 3911 | LCSSAPhi.addIncoming(ExtractForPhiUsedOutsideLoop, LoopMiddleBlock); |
| 3912 | } |
| 3913 | } |
| 3914 | } |
| 3915 | |
| 3916 | void InnerLoopVectorizer::fixReduction(PHINode *Phi) { |
| 3917 | Constant *Zero = Builder.getInt32(0); |
| 3918 | |
| 3919 | // Get it's reduction variable descriptor. |
| 3920 | assert(Legal->isReductionVariable(Phi) &&((Legal->isReductionVariable(Phi) && "Unable to find the reduction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->isReductionVariable(Phi) && \"Unable to find the reduction variable\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3921, __PRETTY_FUNCTION__)) |
| 3921 | "Unable to find the reduction variable")((Legal->isReductionVariable(Phi) && "Unable to find the reduction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->isReductionVariable(Phi) && \"Unable to find the reduction variable\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 3921, __PRETTY_FUNCTION__)); |
| 3922 | RecurrenceDescriptor RdxDesc = Legal->getReductionVars()[Phi]; |
| 3923 | |
| 3924 | RecurrenceDescriptor::RecurrenceKind RK = RdxDesc.getRecurrenceKind(); |
| 3925 | TrackingVH<Value> ReductionStartValue = RdxDesc.getRecurrenceStartValue(); |
| 3926 | Instruction *LoopExitInst = RdxDesc.getLoopExitInstr(); |
| 3927 | RecurrenceDescriptor::MinMaxRecurrenceKind MinMaxKind = |
| 3928 | RdxDesc.getMinMaxRecurrenceKind(); |
| 3929 | setDebugLocFromInst(Builder, ReductionStartValue); |
| 3930 | bool IsInLoopReductionPhi = Cost->isInLoopReduction(Phi); |
| 3931 | |
| 3932 | // We need to generate a reduction vector from the incoming scalar. |
| 3933 | // To do so, we need to generate the 'identity' vector and override |
| 3934 | // one of the elements with the incoming scalar reduction. We need |
| 3935 | // to do it in the vector-loop preheader. |
| 3936 | Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); |
| 3937 | |
| 3938 | // This is the vector-clone of the value that leaves the loop. |
| 3939 | Type *VecTy = getOrCreateVectorValue(LoopExitInst, 0)->getType(); |
| 3940 | |
| 3941 | // Find the reduction identity variable. Zero for addition, or, xor, |
| 3942 | // one for multiplication, -1 for And. |
| 3943 | Value *Identity; |
| 3944 | Value *VectorStart; |
| 3945 | if (RK == RecurrenceDescriptor::RK_IntegerMinMax || |
| 3946 | RK == RecurrenceDescriptor::RK_FloatMinMax) { |
| 3947 | // MinMax reduction have the start value as their identify. |
| 3948 | if (VF.isScalar() || IsInLoopReductionPhi) { |
| 3949 | VectorStart = Identity = ReductionStartValue; |
| 3950 | } else { |
| 3951 | VectorStart = Identity = |
| 3952 | Builder.CreateVectorSplat(VF, ReductionStartValue, "minmax.ident"); |
| 3953 | } |
| 3954 | } else { |
| 3955 | // Handle other reduction kinds: |
| 3956 | Constant *Iden = RecurrenceDescriptor::getRecurrenceIdentity( |
| 3957 | RK, MinMaxKind, VecTy->getScalarType()); |
| 3958 | if (VF.isScalar() || IsInLoopReductionPhi) { |
| 3959 | Identity = Iden; |
| 3960 | // This vector is the Identity vector where the first element is the |
| 3961 | // incoming scalar reduction. |
| 3962 | VectorStart = ReductionStartValue; |
| 3963 | } else { |
| 3964 | Identity = ConstantVector::getSplat(VF, Iden); |
| 3965 | |
| 3966 | // This vector is the Identity vector where the first element is the |
| 3967 | // incoming scalar reduction. |
| 3968 | VectorStart = |
| 3969 | Builder.CreateInsertElement(Identity, ReductionStartValue, Zero); |
| 3970 | } |
| 3971 | } |
| 3972 | |
| 3973 | // Wrap flags are in general invalid after vectorization, clear them. |
| 3974 | clearReductionWrapFlags(RdxDesc); |
| 3975 | |
| 3976 | // Fix the vector-loop phi. |
| 3977 | |
| 3978 | // Reductions do not have to start at zero. They can start with |
| 3979 | // any loop invariant values. |
| 3980 | BasicBlock *Latch = OrigLoop->getLoopLatch(); |
| 3981 | Value *LoopVal = Phi->getIncomingValueForBlock(Latch); |
| 3982 | |
| 3983 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 3984 | Value *VecRdxPhi = getOrCreateVectorValue(Phi, Part); |
| 3985 | Value *Val = getOrCreateVectorValue(LoopVal, Part); |
| 3986 | // Make sure to add the reduction start value only to the |
| 3987 | // first unroll part. |
| 3988 | Value *StartVal = (Part == 0) ? VectorStart : Identity; |
| 3989 | cast<PHINode>(VecRdxPhi)->addIncoming(StartVal, LoopVectorPreHeader); |
| 3990 | cast<PHINode>(VecRdxPhi) |
| 3991 | ->addIncoming(Val, LI->getLoopFor(LoopVectorBody)->getLoopLatch()); |
| 3992 | } |
| 3993 | |
| 3994 | // Before each round, move the insertion point right between |
| 3995 | // the PHIs and the values we are going to write. |
| 3996 | // This allows us to write both PHINodes and the extractelement |
| 3997 | // instructions. |
| 3998 | Builder.SetInsertPoint(&*LoopMiddleBlock->getFirstInsertionPt()); |
| 3999 | |
| 4000 | setDebugLocFromInst(Builder, LoopExitInst); |
| 4001 | |
| 4002 | // If tail is folded by masking, the vector value to leave the loop should be |
| 4003 | // a Select choosing between the vectorized LoopExitInst and vectorized Phi, |
| 4004 | // instead of the former. For an inloop reduction the reduction will already |
| 4005 | // be predicated, and does not need to be handled here. |
| 4006 | if (Cost->foldTailByMasking() && !IsInLoopReductionPhi) { |
| 4007 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4008 | Value *VecLoopExitInst = |
| 4009 | VectorLoopValueMap.getVectorValue(LoopExitInst, Part); |
| 4010 | Value *Sel = nullptr; |
| 4011 | for (User *U : VecLoopExitInst->users()) { |
| 4012 | if (isa<SelectInst>(U)) { |
| 4013 | assert(!Sel && "Reduction exit feeding two selects")((!Sel && "Reduction exit feeding two selects") ? static_cast <void> (0) : __assert_fail ("!Sel && \"Reduction exit feeding two selects\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4013, __PRETTY_FUNCTION__)); |
| 4014 | Sel = U; |
| 4015 | } else |
| 4016 | assert(isa<PHINode>(U) && "Reduction exit must feed Phi's or select")((isa<PHINode>(U) && "Reduction exit must feed Phi's or select" ) ? static_cast<void> (0) : __assert_fail ("isa<PHINode>(U) && \"Reduction exit must feed Phi's or select\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4016, __PRETTY_FUNCTION__)); |
| 4017 | } |
| 4018 | assert(Sel && "Reduction exit feeds no select")((Sel && "Reduction exit feeds no select") ? static_cast <void> (0) : __assert_fail ("Sel && \"Reduction exit feeds no select\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4018, __PRETTY_FUNCTION__)); |
| 4019 | VectorLoopValueMap.resetVectorValue(LoopExitInst, Part, Sel); |
| 4020 | |
| 4021 | // If the target can create a predicated operator for the reduction at no |
| 4022 | // extra cost in the loop (for example a predicated vadd), it can be |
| 4023 | // cheaper for the select to remain in the loop than be sunk out of it, |
| 4024 | // and so use the select value for the phi instead of the old |
| 4025 | // LoopExitValue. |
| 4026 | RecurrenceDescriptor RdxDesc = Legal->getReductionVars()[Phi]; |
| 4027 | if (PreferPredicatedReductionSelect || |
| 4028 | TTI->preferPredicatedReductionSelect( |
| 4029 | RdxDesc.getRecurrenceBinOp(), Phi->getType(), |
| 4030 | TargetTransformInfo::ReductionFlags())) { |
| 4031 | auto *VecRdxPhi = cast<PHINode>(getOrCreateVectorValue(Phi, Part)); |
| 4032 | VecRdxPhi->setIncomingValueForBlock( |
| 4033 | LI->getLoopFor(LoopVectorBody)->getLoopLatch(), Sel); |
| 4034 | } |
| 4035 | } |
| 4036 | } |
| 4037 | |
| 4038 | // If the vector reduction can be performed in a smaller type, we truncate |
| 4039 | // then extend the loop exit value to enable InstCombine to evaluate the |
| 4040 | // entire expression in the smaller type. |
| 4041 | if (VF.isVector() && Phi->getType() != RdxDesc.getRecurrenceType()) { |
| 4042 | assert(!IsInLoopReductionPhi && "Unexpected truncated inloop reduction!")((!IsInLoopReductionPhi && "Unexpected truncated inloop reduction!" ) ? static_cast<void> (0) : __assert_fail ("!IsInLoopReductionPhi && \"Unexpected truncated inloop reduction!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4042, __PRETTY_FUNCTION__)); |
| 4043 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4043, __PRETTY_FUNCTION__)); |
| 4044 | Type *RdxVecTy = VectorType::get(RdxDesc.getRecurrenceType(), VF); |
| 4045 | Builder.SetInsertPoint( |
| 4046 | LI->getLoopFor(LoopVectorBody)->getLoopLatch()->getTerminator()); |
| 4047 | VectorParts RdxParts(UF); |
| 4048 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4049 | RdxParts[Part] = VectorLoopValueMap.getVectorValue(LoopExitInst, Part); |
| 4050 | Value *Trunc = Builder.CreateTrunc(RdxParts[Part], RdxVecTy); |
| 4051 | Value *Extnd = RdxDesc.isSigned() ? Builder.CreateSExt(Trunc, VecTy) |
| 4052 | : Builder.CreateZExt(Trunc, VecTy); |
| 4053 | for (Value::user_iterator UI = RdxParts[Part]->user_begin(); |
| 4054 | UI != RdxParts[Part]->user_end();) |
| 4055 | if (*UI != Trunc) { |
| 4056 | (*UI++)->replaceUsesOfWith(RdxParts[Part], Extnd); |
| 4057 | RdxParts[Part] = Extnd; |
| 4058 | } else { |
| 4059 | ++UI; |
| 4060 | } |
| 4061 | } |
| 4062 | Builder.SetInsertPoint(&*LoopMiddleBlock->getFirstInsertionPt()); |
| 4063 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4064 | RdxParts[Part] = Builder.CreateTrunc(RdxParts[Part], RdxVecTy); |
| 4065 | VectorLoopValueMap.resetVectorValue(LoopExitInst, Part, RdxParts[Part]); |
| 4066 | } |
| 4067 | } |
| 4068 | |
| 4069 | // Reduce all of the unrolled parts into a single vector. |
| 4070 | Value *ReducedPartRdx = VectorLoopValueMap.getVectorValue(LoopExitInst, 0); |
| 4071 | unsigned Op = RecurrenceDescriptor::getRecurrenceBinOp(RK); |
| 4072 | |
| 4073 | // The middle block terminator has already been assigned a DebugLoc here (the |
| 4074 | // OrigLoop's single latch terminator). We want the whole middle block to |
| 4075 | // appear to execute on this line because: (a) it is all compiler generated, |
| 4076 | // (b) these instructions are always executed after evaluating the latch |
| 4077 | // conditional branch, and (c) other passes may add new predecessors which |
| 4078 | // terminate on this line. This is the easiest way to ensure we don't |
| 4079 | // accidentally cause an extra step back into the loop while debugging. |
| 4080 | setDebugLocFromInst(Builder, LoopMiddleBlock->getTerminator()); |
| 4081 | for (unsigned Part = 1; Part < UF; ++Part) { |
| 4082 | Value *RdxPart = VectorLoopValueMap.getVectorValue(LoopExitInst, Part); |
| 4083 | if (Op != Instruction::ICmp && Op != Instruction::FCmp) |
| 4084 | // Floating point operations had to be 'fast' to enable the reduction. |
| 4085 | ReducedPartRdx = addFastMathFlag( |
| 4086 | Builder.CreateBinOp((Instruction::BinaryOps)Op, RdxPart, |
| 4087 | ReducedPartRdx, "bin.rdx"), |
| 4088 | RdxDesc.getFastMathFlags()); |
| 4089 | else |
| 4090 | ReducedPartRdx = createMinMaxOp(Builder, MinMaxKind, ReducedPartRdx, |
| 4091 | RdxPart); |
| 4092 | } |
| 4093 | |
| 4094 | // Create the reduction after the loop. Note that inloop reductions create the |
| 4095 | // target reduction in the loop using a Reduction recipe. |
| 4096 | if (VF.isVector() && !IsInLoopReductionPhi) { |
| 4097 | bool NoNaN = Legal->hasFunNoNaNAttr(); |
| 4098 | ReducedPartRdx = |
| 4099 | createTargetReduction(Builder, TTI, RdxDesc, ReducedPartRdx, NoNaN); |
| 4100 | // If the reduction can be performed in a smaller type, we need to extend |
| 4101 | // the reduction to the wider type before we branch to the original loop. |
| 4102 | if (Phi->getType() != RdxDesc.getRecurrenceType()) |
| 4103 | ReducedPartRdx = |
| 4104 | RdxDesc.isSigned() |
| 4105 | ? Builder.CreateSExt(ReducedPartRdx, Phi->getType()) |
| 4106 | : Builder.CreateZExt(ReducedPartRdx, Phi->getType()); |
| 4107 | } |
| 4108 | |
| 4109 | // Create a phi node that merges control-flow from the backedge-taken check |
| 4110 | // block and the middle block. |
| 4111 | PHINode *BCBlockPhi = PHINode::Create(Phi->getType(), 2, "bc.merge.rdx", |
| 4112 | LoopScalarPreHeader->getTerminator()); |
| 4113 | for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) |
| 4114 | BCBlockPhi->addIncoming(ReductionStartValue, LoopBypassBlocks[I]); |
| 4115 | BCBlockPhi->addIncoming(ReducedPartRdx, LoopMiddleBlock); |
| 4116 | |
| 4117 | // Now, we need to fix the users of the reduction variable |
| 4118 | // inside and outside of the scalar remainder loop. |
| 4119 | // We know that the loop is in LCSSA form. We need to update the |
| 4120 | // PHI nodes in the exit blocks. |
| 4121 | for (PHINode &LCSSAPhi : LoopExitBlock->phis()) { |
| 4122 | // All PHINodes need to have a single entry edge, or two if |
| 4123 | // we already fixed them. |
| 4124 | assert(LCSSAPhi.getNumIncomingValues() < 3 && "Invalid LCSSA PHI")((LCSSAPhi.getNumIncomingValues() < 3 && "Invalid LCSSA PHI" ) ? static_cast<void> (0) : __assert_fail ("LCSSAPhi.getNumIncomingValues() < 3 && \"Invalid LCSSA PHI\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4124, __PRETTY_FUNCTION__)); |
| 4125 | |
| 4126 | // We found a reduction value exit-PHI. Update it with the |
| 4127 | // incoming bypass edge. |
| 4128 | if (LCSSAPhi.getIncomingValue(0) == LoopExitInst) |
| 4129 | LCSSAPhi.addIncoming(ReducedPartRdx, LoopMiddleBlock); |
| 4130 | } // end of the LCSSA phi scan. |
| 4131 | |
| 4132 | // Fix the scalar loop reduction variable with the incoming reduction sum |
| 4133 | // from the vector body and from the backedge value. |
| 4134 | int IncomingEdgeBlockIdx = |
| 4135 | Phi->getBasicBlockIndex(OrigLoop->getLoopLatch()); |
| 4136 | assert(IncomingEdgeBlockIdx >= 0 && "Invalid block index")((IncomingEdgeBlockIdx >= 0 && "Invalid block index" ) ? static_cast<void> (0) : __assert_fail ("IncomingEdgeBlockIdx >= 0 && \"Invalid block index\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4136, __PRETTY_FUNCTION__)); |
| 4137 | // Pick the other block. |
| 4138 | int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1); |
| 4139 | Phi->setIncomingValue(SelfEdgeBlockIdx, BCBlockPhi); |
| 4140 | Phi->setIncomingValue(IncomingEdgeBlockIdx, LoopExitInst); |
| 4141 | } |
| 4142 | |
| 4143 | void InnerLoopVectorizer::clearReductionWrapFlags( |
| 4144 | RecurrenceDescriptor &RdxDesc) { |
| 4145 | RecurrenceDescriptor::RecurrenceKind RK = RdxDesc.getRecurrenceKind(); |
| 4146 | if (RK != RecurrenceDescriptor::RK_IntegerAdd && |
| 4147 | RK != RecurrenceDescriptor::RK_IntegerMult) |
| 4148 | return; |
| 4149 | |
| 4150 | Instruction *LoopExitInstr = RdxDesc.getLoopExitInstr(); |
| 4151 | assert(LoopExitInstr && "null loop exit instruction")((LoopExitInstr && "null loop exit instruction") ? static_cast <void> (0) : __assert_fail ("LoopExitInstr && \"null loop exit instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4151, __PRETTY_FUNCTION__)); |
| 4152 | SmallVector<Instruction *, 8> Worklist; |
| 4153 | SmallPtrSet<Instruction *, 8> Visited; |
| 4154 | Worklist.push_back(LoopExitInstr); |
| 4155 | Visited.insert(LoopExitInstr); |
| 4156 | |
| 4157 | while (!Worklist.empty()) { |
| 4158 | Instruction *Cur = Worklist.pop_back_val(); |
| 4159 | if (isa<OverflowingBinaryOperator>(Cur)) |
| 4160 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4161 | Value *V = getOrCreateVectorValue(Cur, Part); |
| 4162 | cast<Instruction>(V)->dropPoisonGeneratingFlags(); |
| 4163 | } |
| 4164 | |
| 4165 | for (User *U : Cur->users()) { |
| 4166 | Instruction *UI = cast<Instruction>(U); |
| 4167 | if ((Cur != LoopExitInstr || OrigLoop->contains(UI->getParent())) && |
| 4168 | Visited.insert(UI).second) |
| 4169 | Worklist.push_back(UI); |
| 4170 | } |
| 4171 | } |
| 4172 | } |
| 4173 | |
| 4174 | void InnerLoopVectorizer::fixLCSSAPHIs() { |
| 4175 | assert(!VF.isScalable() && "the code below assumes fixed width vectors")((!VF.isScalable() && "the code below assumes fixed width vectors" ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"the code below assumes fixed width vectors\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4175, __PRETTY_FUNCTION__)); |
| 4176 | for (PHINode &LCSSAPhi : LoopExitBlock->phis()) { |
| 4177 | if (LCSSAPhi.getNumIncomingValues() == 1) { |
| 4178 | auto *IncomingValue = LCSSAPhi.getIncomingValue(0); |
| 4179 | // Non-instruction incoming values will have only one value. |
| 4180 | unsigned LastLane = 0; |
| 4181 | if (isa<Instruction>(IncomingValue)) |
| 4182 | LastLane = Cost->isUniformAfterVectorization( |
| 4183 | cast<Instruction>(IncomingValue), VF) |
| 4184 | ? 0 |
| 4185 | : VF.getKnownMinValue() - 1; |
| 4186 | // Can be a loop invariant incoming value or the last scalar value to be |
| 4187 | // extracted from the vectorized loop. |
| 4188 | Builder.SetInsertPoint(LoopMiddleBlock->getTerminator()); |
| 4189 | Value *lastIncomingValue = |
| 4190 | getOrCreateScalarValue(IncomingValue, { UF - 1, LastLane }); |
| 4191 | LCSSAPhi.addIncoming(lastIncomingValue, LoopMiddleBlock); |
| 4192 | } |
| 4193 | } |
| 4194 | } |
| 4195 | |
| 4196 | void InnerLoopVectorizer::sinkScalarOperands(Instruction *PredInst) { |
| 4197 | // The basic block and loop containing the predicated instruction. |
| 4198 | auto *PredBB = PredInst->getParent(); |
| 4199 | auto *VectorLoop = LI->getLoopFor(PredBB); |
| 4200 | |
| 4201 | // Initialize a worklist with the operands of the predicated instruction. |
| 4202 | SetVector<Value *> Worklist(PredInst->op_begin(), PredInst->op_end()); |
| 4203 | |
| 4204 | // Holds instructions that we need to analyze again. An instruction may be |
| 4205 | // reanalyzed if we don't yet know if we can sink it or not. |
| 4206 | SmallVector<Instruction *, 8> InstsToReanalyze; |
| 4207 | |
| 4208 | // Returns true if a given use occurs in the predicated block. Phi nodes use |
| 4209 | // their operands in their corresponding predecessor blocks. |
| 4210 | auto isBlockOfUsePredicated = [&](Use &U) -> bool { |
| 4211 | auto *I = cast<Instruction>(U.getUser()); |
| 4212 | BasicBlock *BB = I->getParent(); |
| 4213 | if (auto *Phi = dyn_cast<PHINode>(I)) |
| 4214 | BB = Phi->getIncomingBlock( |
| 4215 | PHINode::getIncomingValueNumForOperand(U.getOperandNo())); |
| 4216 | return BB == PredBB; |
| 4217 | }; |
| 4218 | |
| 4219 | // Iteratively sink the scalarized operands of the predicated instruction |
| 4220 | // into the block we created for it. When an instruction is sunk, it's |
| 4221 | // operands are then added to the worklist. The algorithm ends after one pass |
| 4222 | // through the worklist doesn't sink a single instruction. |
| 4223 | bool Changed; |
| 4224 | do { |
| 4225 | // Add the instructions that need to be reanalyzed to the worklist, and |
| 4226 | // reset the changed indicator. |
| 4227 | Worklist.insert(InstsToReanalyze.begin(), InstsToReanalyze.end()); |
| 4228 | InstsToReanalyze.clear(); |
| 4229 | Changed = false; |
| 4230 | |
| 4231 | while (!Worklist.empty()) { |
| 4232 | auto *I = dyn_cast<Instruction>(Worklist.pop_back_val()); |
| 4233 | |
| 4234 | // We can't sink an instruction if it is a phi node, is already in the |
| 4235 | // predicated block, is not in the loop, or may have side effects. |
| 4236 | if (!I || isa<PHINode>(I) || I->getParent() == PredBB || |
| 4237 | !VectorLoop->contains(I) || I->mayHaveSideEffects()) |
| 4238 | continue; |
| 4239 | |
| 4240 | // It's legal to sink the instruction if all its uses occur in the |
| 4241 | // predicated block. Otherwise, there's nothing to do yet, and we may |
| 4242 | // need to reanalyze the instruction. |
| 4243 | if (!llvm::all_of(I->uses(), isBlockOfUsePredicated)) { |
| 4244 | InstsToReanalyze.push_back(I); |
| 4245 | continue; |
| 4246 | } |
| 4247 | |
| 4248 | // Move the instruction to the beginning of the predicated block, and add |
| 4249 | // it's operands to the worklist. |
| 4250 | I->moveBefore(&*PredBB->getFirstInsertionPt()); |
| 4251 | Worklist.insert(I->op_begin(), I->op_end()); |
| 4252 | |
| 4253 | // The sinking may have enabled other instructions to be sunk, so we will |
| 4254 | // need to iterate. |
| 4255 | Changed = true; |
| 4256 | } |
| 4257 | } while (Changed); |
| 4258 | } |
| 4259 | |
| 4260 | void InnerLoopVectorizer::fixNonInductionPHIs() { |
| 4261 | for (PHINode *OrigPhi : OrigPHIsToFix) { |
| 4262 | PHINode *NewPhi = |
| 4263 | cast<PHINode>(VectorLoopValueMap.getVectorValue(OrigPhi, 0)); |
| 4264 | unsigned NumIncomingValues = OrigPhi->getNumIncomingValues(); |
| 4265 | |
| 4266 | SmallVector<BasicBlock *, 2> ScalarBBPredecessors( |
| 4267 | predecessors(OrigPhi->getParent())); |
| 4268 | SmallVector<BasicBlock *, 2> VectorBBPredecessors( |
| 4269 | predecessors(NewPhi->getParent())); |
| 4270 | assert(ScalarBBPredecessors.size() == VectorBBPredecessors.size() &&((ScalarBBPredecessors.size() == VectorBBPredecessors.size() && "Scalar and Vector BB should have the same number of predecessors" ) ? static_cast<void> (0) : __assert_fail ("ScalarBBPredecessors.size() == VectorBBPredecessors.size() && \"Scalar and Vector BB should have the same number of predecessors\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4271, __PRETTY_FUNCTION__)) |
| 4271 | "Scalar and Vector BB should have the same number of predecessors")((ScalarBBPredecessors.size() == VectorBBPredecessors.size() && "Scalar and Vector BB should have the same number of predecessors" ) ? static_cast<void> (0) : __assert_fail ("ScalarBBPredecessors.size() == VectorBBPredecessors.size() && \"Scalar and Vector BB should have the same number of predecessors\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4271, __PRETTY_FUNCTION__)); |
| 4272 | |
| 4273 | // The insertion point in Builder may be invalidated by the time we get |
| 4274 | // here. Force the Builder insertion point to something valid so that we do |
| 4275 | // not run into issues during insertion point restore in |
| 4276 | // getOrCreateVectorValue calls below. |
| 4277 | Builder.SetInsertPoint(NewPhi); |
| 4278 | |
| 4279 | // The predecessor order is preserved and we can rely on mapping between |
| 4280 | // scalar and vector block predecessors. |
| 4281 | for (unsigned i = 0; i < NumIncomingValues; ++i) { |
| 4282 | BasicBlock *NewPredBB = VectorBBPredecessors[i]; |
| 4283 | |
| 4284 | // When looking up the new scalar/vector values to fix up, use incoming |
| 4285 | // values from original phi. |
| 4286 | Value *ScIncV = |
| 4287 | OrigPhi->getIncomingValueForBlock(ScalarBBPredecessors[i]); |
| 4288 | |
| 4289 | // Scalar incoming value may need a broadcast |
| 4290 | Value *NewIncV = getOrCreateVectorValue(ScIncV, 0); |
| 4291 | NewPhi->addIncoming(NewIncV, NewPredBB); |
| 4292 | } |
| 4293 | } |
| 4294 | } |
| 4295 | |
| 4296 | void InnerLoopVectorizer::widenGEP(GetElementPtrInst *GEP, VPValue *VPDef, |
| 4297 | VPUser &Operands, unsigned UF, |
| 4298 | ElementCount VF, bool IsPtrLoopInvariant, |
| 4299 | SmallBitVector &IsIndexLoopInvariant, |
| 4300 | VPTransformState &State) { |
| 4301 | // Construct a vector GEP by widening the operands of the scalar GEP as |
| 4302 | // necessary. We mark the vector GEP 'inbounds' if appropriate. A GEP |
| 4303 | // results in a vector of pointers when at least one operand of the GEP |
| 4304 | // is vector-typed. Thus, to keep the representation compact, we only use |
| 4305 | // vector-typed operands for loop-varying values. |
| 4306 | |
| 4307 | if (VF.isVector() && IsPtrLoopInvariant && IsIndexLoopInvariant.all()) { |
| 4308 | // If we are vectorizing, but the GEP has only loop-invariant operands, |
| 4309 | // the GEP we build (by only using vector-typed operands for |
| 4310 | // loop-varying values) would be a scalar pointer. Thus, to ensure we |
| 4311 | // produce a vector of pointers, we need to either arbitrarily pick an |
| 4312 | // operand to broadcast, or broadcast a clone of the original GEP. |
| 4313 | // Here, we broadcast a clone of the original. |
| 4314 | // |
| 4315 | // TODO: If at some point we decide to scalarize instructions having |
| 4316 | // loop-invariant operands, this special case will no longer be |
| 4317 | // required. We would add the scalarization decision to |
| 4318 | // collectLoopScalars() and teach getVectorValue() to broadcast |
| 4319 | // the lane-zero scalar value. |
| 4320 | auto *Clone = Builder.Insert(GEP->clone()); |
| 4321 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4322 | Value *EntryPart = Builder.CreateVectorSplat(VF, Clone); |
| 4323 | VectorLoopValueMap.setVectorValue(GEP, Part, EntryPart); |
| 4324 | addMetadata(EntryPart, GEP); |
| 4325 | } |
| 4326 | } else { |
| 4327 | // If the GEP has at least one loop-varying operand, we are sure to |
| 4328 | // produce a vector of pointers. But if we are only unrolling, we want |
| 4329 | // to produce a scalar GEP for each unroll part. Thus, the GEP we |
| 4330 | // produce with the code below will be scalar (if VF == 1) or vector |
| 4331 | // (otherwise). Note that for the unroll-only case, we still maintain |
| 4332 | // values in the vector mapping with initVector, as we do for other |
| 4333 | // instructions. |
| 4334 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4335 | // The pointer operand of the new GEP. If it's loop-invariant, we |
| 4336 | // won't broadcast it. |
| 4337 | auto *Ptr = IsPtrLoopInvariant ? State.get(Operands.getOperand(0), {0, 0}) |
| 4338 | : State.get(Operands.getOperand(0), Part); |
| 4339 | |
| 4340 | // Collect all the indices for the new GEP. If any index is |
| 4341 | // loop-invariant, we won't broadcast it. |
| 4342 | SmallVector<Value *, 4> Indices; |
| 4343 | for (unsigned I = 1, E = Operands.getNumOperands(); I < E; I++) { |
| 4344 | VPValue *Operand = Operands.getOperand(I); |
| 4345 | if (IsIndexLoopInvariant[I - 1]) |
| 4346 | Indices.push_back(State.get(Operand, {0, 0})); |
| 4347 | else |
| 4348 | Indices.push_back(State.get(Operand, Part)); |
| 4349 | } |
| 4350 | |
| 4351 | // Create the new GEP. Note that this GEP may be a scalar if VF == 1, |
| 4352 | // but it should be a vector, otherwise. |
| 4353 | auto *NewGEP = |
| 4354 | GEP->isInBounds() |
| 4355 | ? Builder.CreateInBoundsGEP(GEP->getSourceElementType(), Ptr, |
| 4356 | Indices) |
| 4357 | : Builder.CreateGEP(GEP->getSourceElementType(), Ptr, Indices); |
| 4358 | assert((VF.isScalar() || NewGEP->getType()->isVectorTy()) &&(((VF.isScalar() || NewGEP->getType()->isVectorTy()) && "NewGEP is not a pointer vector") ? static_cast<void> ( 0) : __assert_fail ("(VF.isScalar() || NewGEP->getType()->isVectorTy()) && \"NewGEP is not a pointer vector\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4359, __PRETTY_FUNCTION__)) |
| 4359 | "NewGEP is not a pointer vector")(((VF.isScalar() || NewGEP->getType()->isVectorTy()) && "NewGEP is not a pointer vector") ? static_cast<void> ( 0) : __assert_fail ("(VF.isScalar() || NewGEP->getType()->isVectorTy()) && \"NewGEP is not a pointer vector\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4359, __PRETTY_FUNCTION__)); |
| 4360 | VectorLoopValueMap.setVectorValue(GEP, Part, NewGEP); |
| 4361 | addMetadata(NewGEP, GEP); |
| 4362 | } |
| 4363 | } |
| 4364 | } |
| 4365 | |
| 4366 | void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN, unsigned UF, |
| 4367 | ElementCount VF) { |
| 4368 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4368, __PRETTY_FUNCTION__)); |
| 4369 | PHINode *P = cast<PHINode>(PN); |
| 4370 | if (EnableVPlanNativePath) { |
| 4371 | // Currently we enter here in the VPlan-native path for non-induction |
| 4372 | // PHIs where all control flow is uniform. We simply widen these PHIs. |
| 4373 | // Create a vector phi with no operands - the vector phi operands will be |
| 4374 | // set at the end of vector code generation. |
| 4375 | Type *VecTy = |
| 4376 | (VF.isScalar()) ? PN->getType() : VectorType::get(PN->getType(), VF); |
| 4377 | Value *VecPhi = Builder.CreatePHI(VecTy, PN->getNumOperands(), "vec.phi"); |
| 4378 | VectorLoopValueMap.setVectorValue(P, 0, VecPhi); |
| 4379 | OrigPHIsToFix.push_back(P); |
| 4380 | |
| 4381 | return; |
| 4382 | } |
| 4383 | |
| 4384 | assert(PN->getParent() == OrigLoop->getHeader() &&((PN->getParent() == OrigLoop->getHeader() && "Non-header phis should have been handled elsewhere" ) ? static_cast<void> (0) : __assert_fail ("PN->getParent() == OrigLoop->getHeader() && \"Non-header phis should have been handled elsewhere\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4385, __PRETTY_FUNCTION__)) |
| 4385 | "Non-header phis should have been handled elsewhere")((PN->getParent() == OrigLoop->getHeader() && "Non-header phis should have been handled elsewhere" ) ? static_cast<void> (0) : __assert_fail ("PN->getParent() == OrigLoop->getHeader() && \"Non-header phis should have been handled elsewhere\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4385, __PRETTY_FUNCTION__)); |
| 4386 | |
| 4387 | // In order to support recurrences we need to be able to vectorize Phi nodes. |
| 4388 | // Phi nodes have cycles, so we need to vectorize them in two stages. This is |
| 4389 | // stage #1: We create a new vector PHI node with no incoming edges. We'll use |
| 4390 | // this value when we vectorize all of the instructions that use the PHI. |
| 4391 | if (Legal->isReductionVariable(P) || Legal->isFirstOrderRecurrence(P)) { |
| 4392 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4393 | // This is phase one of vectorizing PHIs. |
| 4394 | bool ScalarPHI = |
| 4395 | (VF.isScalar()) || Cost->isInLoopReduction(cast<PHINode>(PN)); |
| 4396 | Type *VecTy = |
| 4397 | ScalarPHI ? PN->getType() : VectorType::get(PN->getType(), VF); |
| 4398 | Value *EntryPart = PHINode::Create( |
| 4399 | VecTy, 2, "vec.phi", &*LoopVectorBody->getFirstInsertionPt()); |
| 4400 | VectorLoopValueMap.setVectorValue(P, Part, EntryPart); |
| 4401 | } |
| 4402 | return; |
| 4403 | } |
| 4404 | |
| 4405 | setDebugLocFromInst(Builder, P); |
| 4406 | |
| 4407 | // This PHINode must be an induction variable. |
| 4408 | // Make sure that we know about it. |
| 4409 | assert(Legal->getInductionVars().count(P) && "Not an induction variable")((Legal->getInductionVars().count(P) && "Not an induction variable" ) ? static_cast<void> (0) : __assert_fail ("Legal->getInductionVars().count(P) && \"Not an induction variable\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4409, __PRETTY_FUNCTION__)); |
| 4410 | |
| 4411 | InductionDescriptor II = Legal->getInductionVars().lookup(P); |
| 4412 | const DataLayout &DL = OrigLoop->getHeader()->getModule()->getDataLayout(); |
| 4413 | |
| 4414 | // FIXME: The newly created binary instructions should contain nsw/nuw flags, |
| 4415 | // which can be found from the original scalar operations. |
| 4416 | switch (II.getKind()) { |
| 4417 | case InductionDescriptor::IK_NoInduction: |
| 4418 | llvm_unreachable("Unknown induction")::llvm::llvm_unreachable_internal("Unknown induction", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4418); |
| 4419 | case InductionDescriptor::IK_IntInduction: |
| 4420 | case InductionDescriptor::IK_FpInduction: |
| 4421 | llvm_unreachable("Integer/fp induction is handled elsewhere.")::llvm::llvm_unreachable_internal("Integer/fp induction is handled elsewhere." , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4421); |
| 4422 | case InductionDescriptor::IK_PtrInduction: { |
| 4423 | // Handle the pointer induction variable case. |
| 4424 | assert(P->getType()->isPointerTy() && "Unexpected type.")((P->getType()->isPointerTy() && "Unexpected type." ) ? static_cast<void> (0) : __assert_fail ("P->getType()->isPointerTy() && \"Unexpected type.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4424, __PRETTY_FUNCTION__)); |
| 4425 | |
| 4426 | if (Cost->isScalarAfterVectorization(P, VF)) { |
| 4427 | // This is the normalized GEP that starts counting at zero. |
| 4428 | Value *PtrInd = |
| 4429 | Builder.CreateSExtOrTrunc(Induction, II.getStep()->getType()); |
| 4430 | // Determine the number of scalars we need to generate for each unroll |
| 4431 | // iteration. If the instruction is uniform, we only need to generate the |
| 4432 | // first lane. Otherwise, we generate all VF values. |
| 4433 | unsigned Lanes = |
| 4434 | Cost->isUniformAfterVectorization(P, VF) ? 1 : VF.getKnownMinValue(); |
| 4435 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4436 | for (unsigned Lane = 0; Lane < Lanes; ++Lane) { |
| 4437 | Constant *Idx = ConstantInt::get(PtrInd->getType(), |
| 4438 | Lane + Part * VF.getKnownMinValue()); |
| 4439 | Value *GlobalIdx = Builder.CreateAdd(PtrInd, Idx); |
| 4440 | Value *SclrGep = |
| 4441 | emitTransformedIndex(Builder, GlobalIdx, PSE.getSE(), DL, II); |
| 4442 | SclrGep->setName("next.gep"); |
| 4443 | VectorLoopValueMap.setScalarValue(P, {Part, Lane}, SclrGep); |
| 4444 | } |
| 4445 | } |
| 4446 | return; |
| 4447 | } |
| 4448 | assert(isa<SCEVConstant>(II.getStep()) &&((isa<SCEVConstant>(II.getStep()) && "Induction step not a SCEV constant!" ) ? static_cast<void> (0) : __assert_fail ("isa<SCEVConstant>(II.getStep()) && \"Induction step not a SCEV constant!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4449, __PRETTY_FUNCTION__)) |
| 4449 | "Induction step not a SCEV constant!")((isa<SCEVConstant>(II.getStep()) && "Induction step not a SCEV constant!" ) ? static_cast<void> (0) : __assert_fail ("isa<SCEVConstant>(II.getStep()) && \"Induction step not a SCEV constant!\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4449, __PRETTY_FUNCTION__)); |
| 4450 | Type *PhiType = II.getStep()->getType(); |
| 4451 | |
| 4452 | // Build a pointer phi |
| 4453 | Value *ScalarStartValue = II.getStartValue(); |
| 4454 | Type *ScStValueType = ScalarStartValue->getType(); |
| 4455 | PHINode *NewPointerPhi = |
| 4456 | PHINode::Create(ScStValueType, 2, "pointer.phi", Induction); |
| 4457 | NewPointerPhi->addIncoming(ScalarStartValue, LoopVectorPreHeader); |
| 4458 | |
| 4459 | // A pointer induction, performed by using a gep |
| 4460 | BasicBlock *LoopLatch = LI->getLoopFor(LoopVectorBody)->getLoopLatch(); |
| 4461 | Instruction *InductionLoc = LoopLatch->getTerminator(); |
| 4462 | const SCEV *ScalarStep = II.getStep(); |
| 4463 | SCEVExpander Exp(*PSE.getSE(), DL, "induction"); |
| 4464 | Value *ScalarStepValue = |
| 4465 | Exp.expandCodeFor(ScalarStep, PhiType, InductionLoc); |
| 4466 | Value *InductionGEP = GetElementPtrInst::Create( |
| 4467 | ScStValueType->getPointerElementType(), NewPointerPhi, |
| 4468 | Builder.CreateMul( |
| 4469 | ScalarStepValue, |
| 4470 | ConstantInt::get(PhiType, VF.getKnownMinValue() * UF)), |
| 4471 | "ptr.ind", InductionLoc); |
| 4472 | NewPointerPhi->addIncoming(InductionGEP, LoopLatch); |
| 4473 | |
| 4474 | // Create UF many actual address geps that use the pointer |
| 4475 | // phi as base and a vectorized version of the step value |
| 4476 | // (<step*0, ..., step*N>) as offset. |
| 4477 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4478 | SmallVector<Constant *, 8> Indices; |
| 4479 | // Create a vector of consecutive numbers from zero to VF. |
| 4480 | for (unsigned i = 0; i < VF.getKnownMinValue(); ++i) |
| 4481 | Indices.push_back( |
| 4482 | ConstantInt::get(PhiType, i + Part * VF.getKnownMinValue())); |
| 4483 | Constant *StartOffset = ConstantVector::get(Indices); |
| 4484 | |
| 4485 | Value *GEP = Builder.CreateGEP( |
| 4486 | ScStValueType->getPointerElementType(), NewPointerPhi, |
| 4487 | Builder.CreateMul( |
| 4488 | StartOffset, |
| 4489 | Builder.CreateVectorSplat(VF.getKnownMinValue(), ScalarStepValue), |
| 4490 | "vector.gep")); |
| 4491 | VectorLoopValueMap.setVectorValue(P, Part, GEP); |
| 4492 | } |
| 4493 | } |
| 4494 | } |
| 4495 | } |
| 4496 | |
| 4497 | /// A helper function for checking whether an integer division-related |
| 4498 | /// instruction may divide by zero (in which case it must be predicated if |
| 4499 | /// executed conditionally in the scalar code). |
| 4500 | /// TODO: It may be worthwhile to generalize and check isKnownNonZero(). |
| 4501 | /// Non-zero divisors that are non compile-time constants will not be |
| 4502 | /// converted into multiplication, so we will still end up scalarizing |
| 4503 | /// the division, but can do so w/o predication. |
| 4504 | static bool mayDivideByZero(Instruction &I) { |
| 4505 | assert((I.getOpcode() == Instruction::UDiv ||(((I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction ::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction") ? static_cast<void> (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4509, __PRETTY_FUNCTION__)) |
| 4506 | I.getOpcode() == Instruction::SDiv ||(((I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction ::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction") ? static_cast<void> (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4509, __PRETTY_FUNCTION__)) |
| 4507 | I.getOpcode() == Instruction::URem ||(((I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction ::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction") ? static_cast<void> (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4509, __PRETTY_FUNCTION__)) |
| 4508 | I.getOpcode() == Instruction::SRem) &&(((I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction ::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction") ? static_cast<void> (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4509, __PRETTY_FUNCTION__)) |
| 4509 | "Unexpected instruction")(((I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction ::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && "Unexpected instruction") ? static_cast<void> (0) : __assert_fail ("(I.getOpcode() == Instruction::UDiv || I.getOpcode() == Instruction::SDiv || I.getOpcode() == Instruction::URem || I.getOpcode() == Instruction::SRem) && \"Unexpected instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4509, __PRETTY_FUNCTION__)); |
| 4510 | Value *Divisor = I.getOperand(1); |
| 4511 | auto *CInt = dyn_cast<ConstantInt>(Divisor); |
| 4512 | return !CInt || CInt->isZero(); |
| 4513 | } |
| 4514 | |
| 4515 | void InnerLoopVectorizer::widenInstruction(Instruction &I, VPUser &User, |
| 4516 | VPTransformState &State) { |
| 4517 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4517, __PRETTY_FUNCTION__)); |
| 4518 | switch (I.getOpcode()) { |
| 4519 | case Instruction::Call: |
| 4520 | case Instruction::Br: |
| 4521 | case Instruction::PHI: |
| 4522 | case Instruction::GetElementPtr: |
| 4523 | case Instruction::Select: |
| 4524 | llvm_unreachable("This instruction is handled by a different recipe.")::llvm::llvm_unreachable_internal("This instruction is handled by a different recipe." , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4524); |
| 4525 | case Instruction::UDiv: |
| 4526 | case Instruction::SDiv: |
| 4527 | case Instruction::SRem: |
| 4528 | case Instruction::URem: |
| 4529 | case Instruction::Add: |
| 4530 | case Instruction::FAdd: |
| 4531 | case Instruction::Sub: |
| 4532 | case Instruction::FSub: |
| 4533 | case Instruction::FNeg: |
| 4534 | case Instruction::Mul: |
| 4535 | case Instruction::FMul: |
| 4536 | case Instruction::FDiv: |
| 4537 | case Instruction::FRem: |
| 4538 | case Instruction::Shl: |
| 4539 | case Instruction::LShr: |
| 4540 | case Instruction::AShr: |
| 4541 | case Instruction::And: |
| 4542 | case Instruction::Or: |
| 4543 | case Instruction::Xor: { |
| 4544 | // Just widen unops and binops. |
| 4545 | setDebugLocFromInst(Builder, &I); |
| 4546 | |
| 4547 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4548 | SmallVector<Value *, 2> Ops; |
| 4549 | for (VPValue *VPOp : User.operands()) |
| 4550 | Ops.push_back(State.get(VPOp, Part)); |
| 4551 | |
| 4552 | Value *V = Builder.CreateNAryOp(I.getOpcode(), Ops); |
| 4553 | |
| 4554 | if (auto *VecOp = dyn_cast<Instruction>(V)) |
| 4555 | VecOp->copyIRFlags(&I); |
| 4556 | |
| 4557 | // Use this vector value for all users of the original instruction. |
| 4558 | VectorLoopValueMap.setVectorValue(&I, Part, V); |
| 4559 | addMetadata(V, &I); |
| 4560 | } |
| 4561 | |
| 4562 | break; |
| 4563 | } |
| 4564 | case Instruction::ICmp: |
| 4565 | case Instruction::FCmp: { |
| 4566 | // Widen compares. Generate vector compares. |
| 4567 | bool FCmp = (I.getOpcode() == Instruction::FCmp); |
| 4568 | auto *Cmp = cast<CmpInst>(&I); |
| 4569 | setDebugLocFromInst(Builder, Cmp); |
| 4570 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4571 | Value *A = State.get(User.getOperand(0), Part); |
| 4572 | Value *B = State.get(User.getOperand(1), Part); |
| 4573 | Value *C = nullptr; |
| 4574 | if (FCmp) { |
| 4575 | // Propagate fast math flags. |
| 4576 | IRBuilder<>::FastMathFlagGuard FMFG(Builder); |
| 4577 | Builder.setFastMathFlags(Cmp->getFastMathFlags()); |
| 4578 | C = Builder.CreateFCmp(Cmp->getPredicate(), A, B); |
| 4579 | } else { |
| 4580 | C = Builder.CreateICmp(Cmp->getPredicate(), A, B); |
| 4581 | } |
| 4582 | VectorLoopValueMap.setVectorValue(&I, Part, C); |
| 4583 | addMetadata(C, &I); |
| 4584 | } |
| 4585 | |
| 4586 | break; |
| 4587 | } |
| 4588 | |
| 4589 | case Instruction::ZExt: |
| 4590 | case Instruction::SExt: |
| 4591 | case Instruction::FPToUI: |
| 4592 | case Instruction::FPToSI: |
| 4593 | case Instruction::FPExt: |
| 4594 | case Instruction::PtrToInt: |
| 4595 | case Instruction::IntToPtr: |
| 4596 | case Instruction::SIToFP: |
| 4597 | case Instruction::UIToFP: |
| 4598 | case Instruction::Trunc: |
| 4599 | case Instruction::FPTrunc: |
| 4600 | case Instruction::BitCast: { |
| 4601 | auto *CI = cast<CastInst>(&I); |
| 4602 | setDebugLocFromInst(Builder, CI); |
| 4603 | |
| 4604 | /// Vectorize casts. |
| 4605 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4605, __PRETTY_FUNCTION__)); |
| 4606 | Type *DestTy = |
| 4607 | (VF.isScalar()) ? CI->getType() : VectorType::get(CI->getType(), VF); |
| 4608 | |
| 4609 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4610 | Value *A = State.get(User.getOperand(0), Part); |
| 4611 | Value *Cast = Builder.CreateCast(CI->getOpcode(), A, DestTy); |
| 4612 | VectorLoopValueMap.setVectorValue(&I, Part, Cast); |
| 4613 | addMetadata(Cast, &I); |
| 4614 | } |
| 4615 | break; |
| 4616 | } |
| 4617 | default: |
| 4618 | // This instruction is not vectorized by simple widening. |
| 4619 | LLVM_DEBUG(dbgs() << "LV: Found an unhandled instruction: " << I)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found an unhandled instruction: " << I; } } while (false); |
| 4620 | llvm_unreachable("Unhandled instruction!")::llvm::llvm_unreachable_internal("Unhandled instruction!", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4620); |
| 4621 | } // end of switch. |
| 4622 | } |
| 4623 | |
| 4624 | void InnerLoopVectorizer::widenCallInstruction(CallInst &I, VPValue *Def, |
| 4625 | VPUser &ArgOperands, |
| 4626 | VPTransformState &State) { |
| 4627 | assert(!isa<DbgInfoIntrinsic>(I) &&((!isa<DbgInfoIntrinsic>(I) && "DbgInfoIntrinsic should have been dropped during VPlan construction" ) ? static_cast<void> (0) : __assert_fail ("!isa<DbgInfoIntrinsic>(I) && \"DbgInfoIntrinsic should have been dropped during VPlan construction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4628, __PRETTY_FUNCTION__)) |
| 4628 | "DbgInfoIntrinsic should have been dropped during VPlan construction")((!isa<DbgInfoIntrinsic>(I) && "DbgInfoIntrinsic should have been dropped during VPlan construction" ) ? static_cast<void> (0) : __assert_fail ("!isa<DbgInfoIntrinsic>(I) && \"DbgInfoIntrinsic should have been dropped during VPlan construction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4628, __PRETTY_FUNCTION__)); |
| 4629 | setDebugLocFromInst(Builder, &I); |
| 4630 | |
| 4631 | Module *M = I.getParent()->getParent()->getParent(); |
| 4632 | auto *CI = cast<CallInst>(&I); |
| 4633 | |
| 4634 | SmallVector<Type *, 4> Tys; |
| 4635 | for (Value *ArgOperand : CI->arg_operands()) |
| 4636 | Tys.push_back(ToVectorTy(ArgOperand->getType(), VF.getKnownMinValue())); |
| 4637 | |
| 4638 | Intrinsic::ID ID = getVectorIntrinsicIDForCall(CI, TLI); |
| 4639 | |
| 4640 | // The flag shows whether we use Intrinsic or a usual Call for vectorized |
| 4641 | // version of the instruction. |
| 4642 | // Is it beneficial to perform intrinsic call compared to lib call? |
| 4643 | bool NeedToScalarize = false; |
| 4644 | unsigned CallCost = Cost->getVectorCallCost(CI, VF, NeedToScalarize); |
| 4645 | bool UseVectorIntrinsic = |
| 4646 | ID && Cost->getVectorIntrinsicCost(CI, VF) <= CallCost; |
| 4647 | assert((UseVectorIntrinsic || !NeedToScalarize) &&(((UseVectorIntrinsic || !NeedToScalarize) && "Instruction should be scalarized elsewhere." ) ? static_cast<void> (0) : __assert_fail ("(UseVectorIntrinsic || !NeedToScalarize) && \"Instruction should be scalarized elsewhere.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4648, __PRETTY_FUNCTION__)) |
| 4648 | "Instruction should be scalarized elsewhere.")(((UseVectorIntrinsic || !NeedToScalarize) && "Instruction should be scalarized elsewhere." ) ? static_cast<void> (0) : __assert_fail ("(UseVectorIntrinsic || !NeedToScalarize) && \"Instruction should be scalarized elsewhere.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4648, __PRETTY_FUNCTION__)); |
| 4649 | |
| 4650 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4651 | SmallVector<Value *, 4> Args; |
| 4652 | for (auto &I : enumerate(ArgOperands.operands())) { |
| 4653 | // Some intrinsics have a scalar argument - don't replace it with a |
| 4654 | // vector. |
| 4655 | Value *Arg; |
| 4656 | if (!UseVectorIntrinsic || !hasVectorInstrinsicScalarOpd(ID, I.index())) |
| 4657 | Arg = State.get(I.value(), Part); |
| 4658 | else |
| 4659 | Arg = State.get(I.value(), {0, 0}); |
| 4660 | Args.push_back(Arg); |
| 4661 | } |
| 4662 | |
| 4663 | Function *VectorF; |
| 4664 | if (UseVectorIntrinsic) { |
| 4665 | // Use vector version of the intrinsic. |
| 4666 | Type *TysForDecl[] = {CI->getType()}; |
| 4667 | if (VF.isVector()) { |
| 4668 | assert(!VF.isScalable() && "VF is assumed to be non scalable.")((!VF.isScalable() && "VF is assumed to be non scalable." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"VF is assumed to be non scalable.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4668, __PRETTY_FUNCTION__)); |
| 4669 | TysForDecl[0] = VectorType::get(CI->getType()->getScalarType(), VF); |
| 4670 | } |
| 4671 | VectorF = Intrinsic::getDeclaration(M, ID, TysForDecl); |
| 4672 | assert(VectorF && "Can't retrieve vector intrinsic.")((VectorF && "Can't retrieve vector intrinsic.") ? static_cast <void> (0) : __assert_fail ("VectorF && \"Can't retrieve vector intrinsic.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4672, __PRETTY_FUNCTION__)); |
| 4673 | } else { |
| 4674 | // Use vector version of the function call. |
| 4675 | const VFShape Shape = VFShape::get(*CI, VF, false /*HasGlobalPred*/); |
| 4676 | #ifndef NDEBUG |
| 4677 | assert(VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr &&((VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && "Can't create vector function.") ? static_cast<void> ( 0) : __assert_fail ("VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && \"Can't create vector function.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4678, __PRETTY_FUNCTION__)) |
| 4678 | "Can't create vector function.")((VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && "Can't create vector function.") ? static_cast<void> ( 0) : __assert_fail ("VFDatabase(*CI).getVectorizedFunction(Shape) != nullptr && \"Can't create vector function.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4678, __PRETTY_FUNCTION__)); |
| 4679 | #endif |
| 4680 | VectorF = VFDatabase(*CI).getVectorizedFunction(Shape); |
| 4681 | } |
| 4682 | SmallVector<OperandBundleDef, 1> OpBundles; |
| 4683 | CI->getOperandBundlesAsDefs(OpBundles); |
| 4684 | CallInst *V = Builder.CreateCall(VectorF, Args, OpBundles); |
| 4685 | |
| 4686 | if (isa<FPMathOperator>(V)) |
| 4687 | V->copyFastMathFlags(CI); |
| 4688 | |
| 4689 | State.set(Def, &I, V, Part); |
| 4690 | addMetadata(V, &I); |
| 4691 | } |
| 4692 | } |
| 4693 | |
| 4694 | void InnerLoopVectorizer::widenSelectInstruction(SelectInst &I, VPValue *VPDef, |
| 4695 | VPUser &Operands, |
| 4696 | bool InvariantCond, |
| 4697 | VPTransformState &State) { |
| 4698 | setDebugLocFromInst(Builder, &I); |
| 4699 | |
| 4700 | // The condition can be loop invariant but still defined inside the |
| 4701 | // loop. This means that we can't just use the original 'cond' value. |
| 4702 | // We have to take the 'vectorized' value and pick the first lane. |
| 4703 | // Instcombine will make this a no-op. |
| 4704 | auto *InvarCond = |
| 4705 | InvariantCond ? State.get(Operands.getOperand(0), {0, 0}) : nullptr; |
| 4706 | |
| 4707 | for (unsigned Part = 0; Part < UF; ++Part) { |
| 4708 | Value *Cond = |
| 4709 | InvarCond ? InvarCond : State.get(Operands.getOperand(0), Part); |
| 4710 | Value *Op0 = State.get(Operands.getOperand(1), Part); |
| 4711 | Value *Op1 = State.get(Operands.getOperand(2), Part); |
| 4712 | Value *Sel = Builder.CreateSelect(Cond, Op0, Op1); |
| 4713 | State.set(VPDef, &I, Sel, Part); |
| 4714 | addMetadata(Sel, &I); |
| 4715 | } |
| 4716 | } |
| 4717 | |
| 4718 | void LoopVectorizationCostModel::collectLoopScalars(ElementCount VF) { |
| 4719 | // We should not collect Scalars more than once per VF. Right now, this |
| 4720 | // function is called from collectUniformsAndScalars(), which already does |
| 4721 | // this check. Collecting Scalars for VF=1 does not make any sense. |
| 4722 | assert(VF.isVector() && Scalars.find(VF) == Scalars.end() &&((VF.isVector() && Scalars.find(VF) == Scalars.end() && "This function should not be visited twice for the same VF") ? static_cast<void> (0) : __assert_fail ("VF.isVector() && Scalars.find(VF) == Scalars.end() && \"This function should not be visited twice for the same VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4723, __PRETTY_FUNCTION__)) |
| 4723 | "This function should not be visited twice for the same VF")((VF.isVector() && Scalars.find(VF) == Scalars.end() && "This function should not be visited twice for the same VF") ? static_cast<void> (0) : __assert_fail ("VF.isVector() && Scalars.find(VF) == Scalars.end() && \"This function should not be visited twice for the same VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4723, __PRETTY_FUNCTION__)); |
| 4724 | |
| 4725 | SmallSetVector<Instruction *, 8> Worklist; |
| 4726 | |
| 4727 | // These sets are used to seed the analysis with pointers used by memory |
| 4728 | // accesses that will remain scalar. |
| 4729 | SmallSetVector<Instruction *, 8> ScalarPtrs; |
| 4730 | SmallPtrSet<Instruction *, 8> PossibleNonScalarPtrs; |
| 4731 | auto *Latch = TheLoop->getLoopLatch(); |
| 4732 | |
| 4733 | // A helper that returns true if the use of Ptr by MemAccess will be scalar. |
| 4734 | // The pointer operands of loads and stores will be scalar as long as the |
| 4735 | // memory access is not a gather or scatter operation. The value operand of a |
| 4736 | // store will remain scalar if the store is scalarized. |
| 4737 | auto isScalarUse = [&](Instruction *MemAccess, Value *Ptr) { |
| 4738 | InstWidening WideningDecision = getWideningDecision(MemAccess, VF); |
| 4739 | assert(WideningDecision != CM_Unknown &&((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4740, __PRETTY_FUNCTION__)) |
| 4740 | "Widening decision should be ready at this moment")((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4740, __PRETTY_FUNCTION__)); |
| 4741 | if (auto *Store = dyn_cast<StoreInst>(MemAccess)) |
| 4742 | if (Ptr == Store->getValueOperand()) |
| 4743 | return WideningDecision == CM_Scalarize; |
| 4744 | assert(Ptr == getLoadStorePointerOperand(MemAccess) &&((Ptr == getLoadStorePointerOperand(MemAccess) && "Ptr is neither a value or pointer operand" ) ? static_cast<void> (0) : __assert_fail ("Ptr == getLoadStorePointerOperand(MemAccess) && \"Ptr is neither a value or pointer operand\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4745, __PRETTY_FUNCTION__)) |
| 4745 | "Ptr is neither a value or pointer operand")((Ptr == getLoadStorePointerOperand(MemAccess) && "Ptr is neither a value or pointer operand" ) ? static_cast<void> (0) : __assert_fail ("Ptr == getLoadStorePointerOperand(MemAccess) && \"Ptr is neither a value or pointer operand\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4745, __PRETTY_FUNCTION__)); |
| 4746 | return WideningDecision != CM_GatherScatter; |
| 4747 | }; |
| 4748 | |
| 4749 | // A helper that returns true if the given value is a bitcast or |
| 4750 | // getelementptr instruction contained in the loop. |
| 4751 | auto isLoopVaryingBitCastOrGEP = [&](Value *V) { |
| 4752 | return ((isa<BitCastInst>(V) && V->getType()->isPointerTy()) || |
| 4753 | isa<GetElementPtrInst>(V)) && |
| 4754 | !TheLoop->isLoopInvariant(V); |
| 4755 | }; |
| 4756 | |
| 4757 | auto isScalarPtrInduction = [&](Instruction *MemAccess, Value *Ptr) { |
| 4758 | if (!isa<PHINode>(Ptr) || |
| 4759 | !Legal->getInductionVars().count(cast<PHINode>(Ptr))) |
| 4760 | return false; |
| 4761 | auto &Induction = Legal->getInductionVars()[cast<PHINode>(Ptr)]; |
| 4762 | if (Induction.getKind() != InductionDescriptor::IK_PtrInduction) |
| 4763 | return false; |
| 4764 | return isScalarUse(MemAccess, Ptr); |
| 4765 | }; |
| 4766 | |
| 4767 | // A helper that evaluates a memory access's use of a pointer. If the |
| 4768 | // pointer is actually the pointer induction of a loop, it is being |
| 4769 | // inserted into Worklist. If the use will be a scalar use, and the |
| 4770 | // pointer is only used by memory accesses, we place the pointer in |
| 4771 | // ScalarPtrs. Otherwise, the pointer is placed in PossibleNonScalarPtrs. |
| 4772 | auto evaluatePtrUse = [&](Instruction *MemAccess, Value *Ptr) { |
| 4773 | if (isScalarPtrInduction(MemAccess, Ptr)) { |
| 4774 | Worklist.insert(cast<Instruction>(Ptr)); |
| 4775 | Instruction *Update = cast<Instruction>( |
| 4776 | cast<PHINode>(Ptr)->getIncomingValueForBlock(Latch)); |
| 4777 | Worklist.insert(Update); |
| 4778 | LLVM_DEBUG(dbgs() << "LV: Found new scalar instruction: " << *Ptrdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: " << *Ptr << "\n"; } } while (false) |
| 4779 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: " << *Ptr << "\n"; } } while (false); |
| 4780 | LLVM_DEBUG(dbgs() << "LV: Found new scalar instruction: " << *Updatedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: " << *Update << "\n"; } } while (false) |
| 4781 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found new scalar instruction: " << *Update << "\n"; } } while (false); |
| 4782 | return; |
| 4783 | } |
| 4784 | // We only care about bitcast and getelementptr instructions contained in |
| 4785 | // the loop. |
| 4786 | if (!isLoopVaryingBitCastOrGEP(Ptr)) |
| 4787 | return; |
| 4788 | |
| 4789 | // If the pointer has already been identified as scalar (e.g., if it was |
| 4790 | // also identified as uniform), there's nothing to do. |
| 4791 | auto *I = cast<Instruction>(Ptr); |
| 4792 | if (Worklist.count(I)) |
| 4793 | return; |
| 4794 | |
| 4795 | // If the use of the pointer will be a scalar use, and all users of the |
| 4796 | // pointer are memory accesses, place the pointer in ScalarPtrs. Otherwise, |
| 4797 | // place the pointer in PossibleNonScalarPtrs. |
| 4798 | if (isScalarUse(MemAccess, Ptr) && llvm::all_of(I->users(), [&](User *U) { |
| 4799 | return isa<LoadInst>(U) || isa<StoreInst>(U); |
| 4800 | })) |
| 4801 | ScalarPtrs.insert(I); |
| 4802 | else |
| 4803 | PossibleNonScalarPtrs.insert(I); |
| 4804 | }; |
| 4805 | |
| 4806 | // We seed the scalars analysis with three classes of instructions: (1) |
| 4807 | // instructions marked uniform-after-vectorization and (2) bitcast, |
| 4808 | // getelementptr and (pointer) phi instructions used by memory accesses |
| 4809 | // requiring a scalar use. |
| 4810 | // |
| 4811 | // (1) Add to the worklist all instructions that have been identified as |
| 4812 | // uniform-after-vectorization. |
| 4813 | Worklist.insert(Uniforms[VF].begin(), Uniforms[VF].end()); |
| 4814 | |
| 4815 | // (2) Add to the worklist all bitcast and getelementptr instructions used by |
| 4816 | // memory accesses requiring a scalar use. The pointer operands of loads and |
| 4817 | // stores will be scalar as long as the memory accesses is not a gather or |
| 4818 | // scatter operation. The value operand of a store will remain scalar if the |
| 4819 | // store is scalarized. |
| 4820 | for (auto *BB : TheLoop->blocks()) |
| 4821 | for (auto &I : *BB) { |
| 4822 | if (auto *Load = dyn_cast<LoadInst>(&I)) { |
| 4823 | evaluatePtrUse(Load, Load->getPointerOperand()); |
| 4824 | } else if (auto *Store = dyn_cast<StoreInst>(&I)) { |
| 4825 | evaluatePtrUse(Store, Store->getPointerOperand()); |
| 4826 | evaluatePtrUse(Store, Store->getValueOperand()); |
| 4827 | } |
| 4828 | } |
| 4829 | for (auto *I : ScalarPtrs) |
| 4830 | if (!PossibleNonScalarPtrs.count(I)) { |
| 4831 | LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: " << *I << "\n"; } } while (false); |
| 4832 | Worklist.insert(I); |
| 4833 | } |
| 4834 | |
| 4835 | // Insert the forced scalars. |
| 4836 | // FIXME: Currently widenPHIInstruction() often creates a dead vector |
| 4837 | // induction variable when the PHI user is scalarized. |
| 4838 | auto ForcedScalar = ForcedScalars.find(VF); |
| 4839 | if (ForcedScalar != ForcedScalars.end()) |
| 4840 | for (auto *I : ForcedScalar->second) |
| 4841 | Worklist.insert(I); |
| 4842 | |
| 4843 | // Expand the worklist by looking through any bitcasts and getelementptr |
| 4844 | // instructions we've already identified as scalar. This is similar to the |
| 4845 | // expansion step in collectLoopUniforms(); however, here we're only |
| 4846 | // expanding to include additional bitcasts and getelementptr instructions. |
| 4847 | unsigned Idx = 0; |
| 4848 | while (Idx != Worklist.size()) { |
| 4849 | Instruction *Dst = Worklist[Idx++]; |
| 4850 | if (!isLoopVaryingBitCastOrGEP(Dst->getOperand(0))) |
| 4851 | continue; |
| 4852 | auto *Src = cast<Instruction>(Dst->getOperand(0)); |
| 4853 | if (llvm::all_of(Src->users(), [&](User *U) -> bool { |
| 4854 | auto *J = cast<Instruction>(U); |
| 4855 | return !TheLoop->contains(J) || Worklist.count(J) || |
| 4856 | ((isa<LoadInst>(J) || isa<StoreInst>(J)) && |
| 4857 | isScalarUse(J, Src)); |
| 4858 | })) { |
| 4859 | Worklist.insert(Src); |
| 4860 | LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *Src << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: " << *Src << "\n"; } } while (false); |
| 4861 | } |
| 4862 | } |
| 4863 | |
| 4864 | // An induction variable will remain scalar if all users of the induction |
| 4865 | // variable and induction variable update remain scalar. |
| 4866 | for (auto &Induction : Legal->getInductionVars()) { |
| 4867 | auto *Ind = Induction.first; |
| 4868 | auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch)); |
| 4869 | |
| 4870 | // If tail-folding is applied, the primary induction variable will be used |
| 4871 | // to feed a vector compare. |
| 4872 | if (Ind == Legal->getPrimaryInduction() && foldTailByMasking()) |
| 4873 | continue; |
| 4874 | |
| 4875 | // Determine if all users of the induction variable are scalar after |
| 4876 | // vectorization. |
| 4877 | auto ScalarInd = llvm::all_of(Ind->users(), [&](User *U) -> bool { |
| 4878 | auto *I = cast<Instruction>(U); |
| 4879 | return I == IndUpdate || !TheLoop->contains(I) || Worklist.count(I); |
| 4880 | }); |
| 4881 | if (!ScalarInd) |
| 4882 | continue; |
| 4883 | |
| 4884 | // Determine if all users of the induction variable update instruction are |
| 4885 | // scalar after vectorization. |
| 4886 | auto ScalarIndUpdate = |
| 4887 | llvm::all_of(IndUpdate->users(), [&](User *U) -> bool { |
| 4888 | auto *I = cast<Instruction>(U); |
| 4889 | return I == Ind || !TheLoop->contains(I) || Worklist.count(I); |
| 4890 | }); |
| 4891 | if (!ScalarIndUpdate) |
| 4892 | continue; |
| 4893 | |
| 4894 | // The induction variable and its update instruction will remain scalar. |
| 4895 | Worklist.insert(Ind); |
| 4896 | Worklist.insert(IndUpdate); |
| 4897 | LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *Ind << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: " << *Ind << "\n"; } } while (false); |
| 4898 | LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *IndUpdatedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: " << *IndUpdate << "\n"; } } while (false) |
| 4899 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found scalar instruction: " << *IndUpdate << "\n"; } } while (false); |
| 4900 | } |
| 4901 | |
| 4902 | Scalars[VF].insert(Worklist.begin(), Worklist.end()); |
| 4903 | } |
| 4904 | |
| 4905 | bool LoopVectorizationCostModel::isScalarWithPredication(Instruction *I, |
| 4906 | ElementCount VF) { |
| 4907 | assert(!VF.isScalable() && "scalable vectors not yet supported.")((!VF.isScalable() && "scalable vectors not yet supported." ) ? static_cast<void> (0) : __assert_fail ("!VF.isScalable() && \"scalable vectors not yet supported.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4907, __PRETTY_FUNCTION__)); |
| 4908 | if (!blockNeedsPredication(I->getParent())) |
| 4909 | return false; |
| 4910 | switch(I->getOpcode()) { |
| 4911 | default: |
| 4912 | break; |
| 4913 | case Instruction::Load: |
| 4914 | case Instruction::Store: { |
| 4915 | if (!Legal->isMaskRequired(I)) |
| 4916 | return false; |
| 4917 | auto *Ptr = getLoadStorePointerOperand(I); |
| 4918 | auto *Ty = getMemInstValueType(I); |
| 4919 | // We have already decided how to vectorize this instruction, get that |
| 4920 | // result. |
| 4921 | if (VF.isVector()) { |
| 4922 | InstWidening WideningDecision = getWideningDecision(I, VF); |
| 4923 | assert(WideningDecision != CM_Unknown &&((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4924, __PRETTY_FUNCTION__)) |
| 4924 | "Widening decision should be ready at this moment")((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4924, __PRETTY_FUNCTION__)); |
| 4925 | return WideningDecision == CM_Scalarize; |
| 4926 | } |
| 4927 | const Align Alignment = getLoadStoreAlignment(I); |
| 4928 | return isa<LoadInst>(I) ? !(isLegalMaskedLoad(Ty, Ptr, Alignment) || |
| 4929 | isLegalMaskedGather(Ty, Alignment)) |
| 4930 | : !(isLegalMaskedStore(Ty, Ptr, Alignment) || |
| 4931 | isLegalMaskedScatter(Ty, Alignment)); |
| 4932 | } |
| 4933 | case Instruction::UDiv: |
| 4934 | case Instruction::SDiv: |
| 4935 | case Instruction::SRem: |
| 4936 | case Instruction::URem: |
| 4937 | return mayDivideByZero(*I); |
| 4938 | } |
| 4939 | return false; |
| 4940 | } |
| 4941 | |
| 4942 | bool LoopVectorizationCostModel::interleavedAccessCanBeWidened( |
| 4943 | Instruction *I, ElementCount VF) { |
| 4944 | assert(isAccessInterleaved(I) && "Expecting interleaved access.")((isAccessInterleaved(I) && "Expecting interleaved access." ) ? static_cast<void> (0) : __assert_fail ("isAccessInterleaved(I) && \"Expecting interleaved access.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4944, __PRETTY_FUNCTION__)); |
| 4945 | assert(getWideningDecision(I, VF) == CM_Unknown &&((getWideningDecision(I, VF) == CM_Unknown && "Decision should not be set yet." ) ? static_cast<void> (0) : __assert_fail ("getWideningDecision(I, VF) == CM_Unknown && \"Decision should not be set yet.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4946, __PRETTY_FUNCTION__)) |
| 4946 | "Decision should not be set yet.")((getWideningDecision(I, VF) == CM_Unknown && "Decision should not be set yet." ) ? static_cast<void> (0) : __assert_fail ("getWideningDecision(I, VF) == CM_Unknown && \"Decision should not be set yet.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4946, __PRETTY_FUNCTION__)); |
| 4947 | auto *Group = getInterleavedAccessGroup(I); |
| 4948 | assert(Group && "Must have a group.")((Group && "Must have a group.") ? static_cast<void > (0) : __assert_fail ("Group && \"Must have a group.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4948, __PRETTY_FUNCTION__)); |
| 4949 | |
| 4950 | // If the instruction's allocated size doesn't equal it's type size, it |
| 4951 | // requires padding and will be scalarized. |
| 4952 | auto &DL = I->getModule()->getDataLayout(); |
| 4953 | auto *ScalarTy = getMemInstValueType(I); |
| 4954 | if (hasIrregularType(ScalarTy, DL, VF)) |
| 4955 | return false; |
| 4956 | |
| 4957 | // Check if masking is required. |
| 4958 | // A Group may need masking for one of two reasons: it resides in a block that |
| 4959 | // needs predication, or it was decided to use masking to deal with gaps. |
| 4960 | bool PredicatedAccessRequiresMasking = |
| 4961 | Legal->blockNeedsPredication(I->getParent()) && Legal->isMaskRequired(I); |
| 4962 | bool AccessWithGapsRequiresMasking = |
| 4963 | Group->requiresScalarEpilogue() && !isScalarEpilogueAllowed(); |
| 4964 | if (!PredicatedAccessRequiresMasking && !AccessWithGapsRequiresMasking) |
| 4965 | return true; |
| 4966 | |
| 4967 | // If masked interleaving is required, we expect that the user/target had |
| 4968 | // enabled it, because otherwise it either wouldn't have been created or |
| 4969 | // it should have been invalidated by the CostModel. |
| 4970 | assert(useMaskedInterleavedAccesses(TTI) &&((useMaskedInterleavedAccesses(TTI) && "Masked interleave-groups for predicated accesses are not enabled." ) ? static_cast<void> (0) : __assert_fail ("useMaskedInterleavedAccesses(TTI) && \"Masked interleave-groups for predicated accesses are not enabled.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4971, __PRETTY_FUNCTION__)) |
| 4971 | "Masked interleave-groups for predicated accesses are not enabled.")((useMaskedInterleavedAccesses(TTI) && "Masked interleave-groups for predicated accesses are not enabled." ) ? static_cast<void> (0) : __assert_fail ("useMaskedInterleavedAccesses(TTI) && \"Masked interleave-groups for predicated accesses are not enabled.\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4971, __PRETTY_FUNCTION__)); |
| 4972 | |
| 4973 | auto *Ty = getMemInstValueType(I); |
| 4974 | const Align Alignment = getLoadStoreAlignment(I); |
| 4975 | return isa<LoadInst>(I) ? TTI.isLegalMaskedLoad(Ty, Alignment) |
| 4976 | : TTI.isLegalMaskedStore(Ty, Alignment); |
| 4977 | } |
| 4978 | |
| 4979 | bool LoopVectorizationCostModel::memoryInstructionCanBeWidened( |
| 4980 | Instruction *I, ElementCount VF) { |
| 4981 | // Get and ensure we have a valid memory instruction. |
| 4982 | LoadInst *LI = dyn_cast<LoadInst>(I); |
| 4983 | StoreInst *SI = dyn_cast<StoreInst>(I); |
| 4984 | assert((LI || SI) && "Invalid memory instruction")(((LI || SI) && "Invalid memory instruction") ? static_cast <void> (0) : __assert_fail ("(LI || SI) && \"Invalid memory instruction\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 4984, __PRETTY_FUNCTION__)); |
| 4985 | |
| 4986 | auto *Ptr = getLoadStorePointerOperand(I); |
| 4987 | |
| 4988 | // In order to be widened, the pointer should be consecutive, first of all. |
| 4989 | if (!Legal->isConsecutivePtr(Ptr)) |
| 4990 | return false; |
| 4991 | |
| 4992 | // If the instruction is a store located in a predicated block, it will be |
| 4993 | // scalarized. |
| 4994 | if (isScalarWithPredication(I)) |
| 4995 | return false; |
| 4996 | |
| 4997 | // If the instruction's allocated size doesn't equal it's type size, it |
| 4998 | // requires padding and will be scalarized. |
| 4999 | auto &DL = I->getModule()->getDataLayout(); |
| 5000 | auto *ScalarTy = LI ? LI->getType() : SI->getValueOperand()->getType(); |
| 5001 | if (hasIrregularType(ScalarTy, DL, VF)) |
| 5002 | return false; |
| 5003 | |
| 5004 | return true; |
| 5005 | } |
| 5006 | |
| 5007 | void LoopVectorizationCostModel::collectLoopUniforms(ElementCount VF) { |
| 5008 | // We should not collect Uniforms more than once per VF. Right now, |
| 5009 | // this function is called from collectUniformsAndScalars(), which |
| 5010 | // already does this check. Collecting Uniforms for VF=1 does not make any |
| 5011 | // sense. |
| 5012 | |
| 5013 | assert(VF.isVector() && Uniforms.find(VF) == Uniforms.end() &&((VF.isVector() && Uniforms.find(VF) == Uniforms.end( ) && "This function should not be visited twice for the same VF" ) ? static_cast<void> (0) : __assert_fail ("VF.isVector() && Uniforms.find(VF) == Uniforms.end() && \"This function should not be visited twice for the same VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5014, __PRETTY_FUNCTION__)) |
| 5014 | "This function should not be visited twice for the same VF")((VF.isVector() && Uniforms.find(VF) == Uniforms.end( ) && "This function should not be visited twice for the same VF" ) ? static_cast<void> (0) : __assert_fail ("VF.isVector() && Uniforms.find(VF) == Uniforms.end() && \"This function should not be visited twice for the same VF\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5014, __PRETTY_FUNCTION__)); |
| 5015 | |
| 5016 | // Visit the list of Uniforms. If we'll not find any uniform value, we'll |
| 5017 | // not analyze again. Uniforms.count(VF) will return 1. |
| 5018 | Uniforms[VF].clear(); |
| 5019 | |
| 5020 | // We now know that the loop is vectorizable! |
| 5021 | // Collect instructions inside the loop that will remain uniform after |
| 5022 | // vectorization. |
| 5023 | |
| 5024 | // Global values, params and instructions outside of current loop are out of |
| 5025 | // scope. |
| 5026 | auto isOutOfScope = [&](Value *V) -> bool { |
| 5027 | Instruction *I = dyn_cast<Instruction>(V); |
| 5028 | return (!I || !TheLoop->contains(I)); |
| 5029 | }; |
| 5030 | |
| 5031 | SetVector<Instruction *> Worklist; |
| 5032 | BasicBlock *Latch = TheLoop->getLoopLatch(); |
| 5033 | |
| 5034 | // Instructions that are scalar with predication must not be considered |
| 5035 | // uniform after vectorization, because that would create an erroneous |
| 5036 | // replicating region where only a single instance out of VF should be formed. |
| 5037 | // TODO: optimize such seldom cases if found important, see PR40816. |
| 5038 | auto addToWorklistIfAllowed = [&](Instruction *I) -> void { |
| 5039 | if (isOutOfScope(I)) { |
| 5040 | LLVM_DEBUG(dbgs() << "LV: Found not uniform due to scope: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found not uniform due to scope: " << *I << "\n"; } } while (false) |
| 5041 | << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found not uniform due to scope: " << *I << "\n"; } } while (false); |
| 5042 | return; |
| 5043 | } |
| 5044 | if (isScalarWithPredication(I, VF)) { |
| 5045 | LLVM_DEBUG(dbgs() << "LV: Found not uniform being ScalarWithPredication: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found not uniform being ScalarWithPredication: " << *I << "\n"; } } while (false) |
| 5046 | << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found not uniform being ScalarWithPredication: " << *I << "\n"; } } while (false); |
| 5047 | return; |
| 5048 | } |
| 5049 | LLVM_DEBUG(dbgs() << "LV: Found uniform instruction: " << *I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found uniform instruction: " << *I << "\n"; } } while (false); |
| 5050 | Worklist.insert(I); |
| 5051 | }; |
| 5052 | |
| 5053 | // Start with the conditional branch. If the branch condition is an |
| 5054 | // instruction contained in the loop that is only used by the branch, it is |
| 5055 | // uniform. |
| 5056 | auto *Cmp = dyn_cast<Instruction>(Latch->getTerminator()->getOperand(0)); |
| 5057 | if (Cmp && TheLoop->contains(Cmp) && Cmp->hasOneUse()) |
| 5058 | addToWorklistIfAllowed(Cmp); |
| 5059 | |
| 5060 | // Holds consecutive and consecutive-like pointers. Consecutive-like pointers |
| 5061 | // are pointers that are treated like consecutive pointers during |
| 5062 | // vectorization. The pointer operands of interleaved accesses are an |
| 5063 | // example. |
| 5064 | SmallSetVector<Value *, 8> ConsecutiveLikePtrs; |
| 5065 | |
| 5066 | // Holds pointer operands of instructions that are possibly non-uniform. |
| 5067 | SmallPtrSet<Value *, 8> PossibleNonUniformPtrs; |
| 5068 | |
| 5069 | auto isUniformDecision = [&](Instruction *I, ElementCount VF) { |
| 5070 | InstWidening WideningDecision = getWideningDecision(I, VF); |
| 5071 | assert(WideningDecision != CM_Unknown &&((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5072, __PRETTY_FUNCTION__)) |
| 5072 | "Widening decision should be ready at this moment")((WideningDecision != CM_Unknown && "Widening decision should be ready at this moment" ) ? static_cast<void> (0) : __assert_fail ("WideningDecision != CM_Unknown && \"Widening decision should be ready at this moment\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5072, __PRETTY_FUNCTION__)); |
| 5073 | |
| 5074 | // The address of a uniform mem op is itself uniform. We exclude stores |
| 5075 | // here as there's an assumption in the current code that all uses of |
| 5076 | // uniform instructions are uniform and, as noted below, uniform stores are |
| 5077 | // still handled via replication (i.e. aren't uniform after vectorization). |
| 5078 | if (isa<LoadInst>(I) && Legal->isUniformMemOp(*I)) { |
| 5079 | assert(WideningDecision == CM_Scalarize)((WideningDecision == CM_Scalarize) ? static_cast<void> (0) : __assert_fail ("WideningDecision == CM_Scalarize", "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5079, __PRETTY_FUNCTION__)); |
| 5080 | return true; |
| 5081 | } |
| 5082 | |
| 5083 | return (WideningDecision == CM_Widen || |
| 5084 | WideningDecision == CM_Widen_Reverse || |
| 5085 | WideningDecision == CM_Interleave); |
| 5086 | }; |
| 5087 | |
| 5088 | |
| 5089 | // Returns true if Ptr is the pointer operand of a memory access instruction |
| 5090 | // I, and I is known to not require scalarization. |
| 5091 | auto isVectorizedMemAccessUse = [&](Instruction *I, Value *Ptr) -> bool { |
| 5092 | return getLoadStorePointerOperand(I) == Ptr && isUniformDecision(I, VF); |
| 5093 | }; |
| 5094 | |
| 5095 | // Iterate over the instructions in the loop, and collect all |
| 5096 | // consecutive-like pointer operands in ConsecutiveLikePtrs. If it's possible |
| 5097 | // that a consecutive-like pointer operand will be scalarized, we collect it |
| 5098 | // in PossibleNonUniformPtrs instead. We use two sets here because a single |
| 5099 | // getelementptr instruction can be used by both vectorized and scalarized |
| 5100 | // memory instructions. For example, if a loop loads and stores from the same |
| 5101 | // location, but the store is conditional, the store will be scalarized, and |
| 5102 | // the getelementptr won't remain uniform. |
| 5103 | for (auto *BB : TheLoop->blocks()) |
| 5104 | for (auto &I : *BB) { |
| 5105 | // If there's no pointer operand, there's nothing to do. |
| 5106 | auto *Ptr = getLoadStorePointerOperand(&I); |
| 5107 | if (!Ptr) |
| 5108 | continue; |
| 5109 | |
| 5110 | // For now, avoid walking use lists in other functions. |
| 5111 | // TODO: Rewrite this algorithm from uses up. |
| 5112 | if (!isa<Instruction>(Ptr) && !isa<Argument>(Ptr)) |
| 5113 | continue; |
| 5114 | |
| 5115 | // A uniform memory op is itself uniform. We exclude stores here as we |
| 5116 | // haven't yet added dedicated logic in the CLONE path and rely on |
| 5117 | // REPLICATE + DSE for correctness. |
| 5118 | if (isa<LoadInst>(I) && Legal->isUniformMemOp(I)) |
| 5119 | addToWorklistIfAllowed(&I); |
| 5120 | |
| 5121 | // True if all users of Ptr are memory accesses that have Ptr as their |
| 5122 | // pointer operand. |
| 5123 | auto UsersAreMemAccesses = |
| 5124 | llvm::all_of(Ptr->users(), [&](User *U) -> bool { |
| 5125 | return getLoadStorePointerOperand(U) == Ptr; |
| 5126 | }); |
| 5127 | |
| 5128 | // Ensure the memory instruction will not be scalarized or used by |
| 5129 | // gather/scatter, making its pointer operand non-uniform. If the pointer |
| 5130 | // operand is used by any instruction other than a memory access, we |
| 5131 | // conservatively assume the pointer operand may be non-uniform. |
| 5132 | if (!UsersAreMemAccesses || !isUniformDecision(&I, VF)) |
| 5133 | PossibleNonUniformPtrs.insert(Ptr); |
| 5134 | |
| 5135 | // If the memory instruction will be vectorized and its pointer operand |
| 5136 | // is consecutive-like, or interleaving - the pointer operand should |
| 5137 | // remain uniform. |
| 5138 | else |
| 5139 | ConsecutiveLikePtrs.insert(Ptr); |
| 5140 | } |
| 5141 | |
| 5142 | // Add to the Worklist all consecutive and consecutive-like pointers that |
| 5143 | // aren't also identified as possibly non-uniform. |
| 5144 | for (auto *V : ConsecutiveLikePtrs) |
| 5145 | if (!PossibleNonUniformPtrs.count(V)) |
| 5146 | if (auto *I = dyn_cast<Instruction>(V)) |
| 5147 | addToWorklistIfAllowed(I); |
| 5148 | |
| 5149 | // Expand Worklist in topological order: whenever a new instruction |
| 5150 | // is added , its users should be already inside Worklist. It ensures |
| 5151 | // a uniform instruction will only be used by uniform instructions. |
| 5152 | unsigned idx = 0; |
| 5153 | while (idx != Worklist.size()) { |
| 5154 | Instruction *I = Worklist[idx++]; |
| 5155 | |
| 5156 | for (auto OV : I->operand_values()) { |
| 5157 | // isOutOfScope operands cannot be uniform instructions. |
| 5158 | if (isOutOfScope(OV)) |
| 5159 | continue; |
| 5160 | // First order recurrence Phi's should typically be considered |
| 5161 | // non-uniform. |
| 5162 | auto *OP = dyn_cast<PHINode>(OV); |
| 5163 | if (OP && Legal->isFirstOrderRecurrence(OP)) |
| 5164 | continue; |
| 5165 | // If all the users of the operand are uniform, then add the |
| 5166 | // operand into the uniform worklist. |
| 5167 | auto *OI = cast<Instruction>(OV); |
| 5168 | if (llvm::all_of(OI->users(), [&](User *U) -> bool { |
| 5169 | auto *J = cast<Instruction>(U); |
| 5170 | return Worklist.count(J) || isVectorizedMemAccessUse(J, OI); |
| 5171 | })) |
| 5172 | addToWorklistIfAllowed(OI); |
| 5173 | } |
| 5174 | } |
| 5175 | |
| 5176 | // For an instruction to be added into Worklist above, all its users inside |
| 5177 | // the loop should also be in Worklist. However, this condition cannot be |
| 5178 | // true for phi nodes that form a cyclic dependence. We must process phi |
| 5179 | // nodes separately. An induction variable will remain uniform if all users |
| 5180 | // of the induction variable and induction variable update remain uniform. |
| 5181 | // The code below handles both pointer and non-pointer induction variables. |
| 5182 | for (auto &Induction : Legal->getInductionVars()) { |
| 5183 | auto *Ind = Induction.first; |
| 5184 | auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch)); |
| 5185 | |
| 5186 | // Determine if all users of the induction variable are uniform after |
| 5187 | // vectorization. |
| 5188 | auto UniformInd = llvm::all_of(Ind->users(), [&](User *U) -> bool { |
| 5189 | auto *I = cast<Instruction>(U); |
| 5190 | return I == IndUpdate || !TheLoop->contains(I) || Worklist.count(I) || |
| 5191 | isVectorizedMemAccessUse(I, Ind); |
| 5192 | }); |
| 5193 | if (!UniformInd) |
| 5194 | continue; |
| 5195 | |
| 5196 | // Determine if all users of the induction variable update instruction are |
| 5197 | // uniform after vectorization. |
| 5198 | auto UniformIndUpdate = |
| 5199 | llvm::all_of(IndUpdate->users(), [&](User *U) -> bool { |
| 5200 | auto *I = cast<Instruction>(U); |
| 5201 | return I == Ind || !TheLoop->contains(I) || Worklist.count(I) || |
| 5202 | isVectorizedMemAccessUse(I, IndUpdate); |
| 5203 | }); |
| 5204 | if (!UniformIndUpdate) |
| 5205 | continue; |
| 5206 | |
| 5207 | // The induction variable and its update instruction will remain uniform. |
| 5208 | addToWorklistIfAllowed(Ind); |
| 5209 | addToWorklistIfAllowed(IndUpdate); |
| 5210 | } |
| 5211 | |
| 5212 | Uniforms[VF].insert(Worklist.begin(), Worklist.end()); |
| 5213 | } |
| 5214 | |
| 5215 | bool LoopVectorizationCostModel::runtimeChecksRequired() { |
| 5216 | LLVM_DEBUG(dbgs() << "LV: Performing code size checks.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Performing code size checks.\n" ; } } while (false); |
| 5217 | |
| 5218 | if (Legal->getRuntimePointerChecking()->Need) { |
| 5219 | reportVectorizationFailure("Runtime ptr check is required with -Os/-Oz", |
| 5220 | "runtime pointer checks needed. Enable vectorization of this " |
| 5221 | "loop with '#pragma clang loop vectorize(enable)' when " |
| 5222 | "compiling with -Os/-Oz", |
| 5223 | "CantVersionLoopWithOptForSize", ORE, TheLoop); |
| 5224 | return true; |
| 5225 | } |
| 5226 | |
| 5227 | if (!PSE.getUnionPredicate().getPredicates().empty()) { |
| 5228 | reportVectorizationFailure("Runtime SCEV check is required with -Os/-Oz", |
| 5229 | "runtime SCEV checks needed. Enable vectorization of this " |
| 5230 | "loop with '#pragma clang loop vectorize(enable)' when " |
| 5231 | "compiling with -Os/-Oz", |
| 5232 | "CantVersionLoopWithOptForSize", ORE, TheLoop); |
| 5233 | return true; |
| 5234 | } |
| 5235 | |
| 5236 | // FIXME: Avoid specializing for stride==1 instead of bailing out. |
| 5237 | if (!Legal->getLAI()->getSymbolicStrides().empty()) { |
| 5238 | reportVectorizationFailure("Runtime stride check for small trip count", |
| 5239 | "runtime stride == 1 checks needed. Enable vectorization of " |
| 5240 | "this loop without such check by compiling with -Os/-Oz", |
| 5241 | "CantVersionLoopWithOptForSize", ORE, TheLoop); |
| 5242 | return true; |
| 5243 | } |
| 5244 | |
| 5245 | return false; |
| 5246 | } |
| 5247 | |
| 5248 | Optional<ElementCount> |
| 5249 | LoopVectorizationCostModel::computeMaxVF(ElementCount UserVF, unsigned UserIC) { |
| 5250 | if (Legal->getRuntimePointerChecking()->Need && TTI.hasBranchDivergence()) { |
| 5251 | // TODO: It may by useful to do since it's still likely to be dynamically |
| 5252 | // uniform if the target can skip. |
| 5253 | reportVectorizationFailure( |
| 5254 | "Not inserting runtime ptr check for divergent target", |
| 5255 | "runtime pointer checks needed. Not enabled for divergent target", |
| 5256 | "CantVersionLoopWithDivergentTarget", ORE, TheLoop); |
| 5257 | return None; |
| 5258 | } |
| 5259 | |
| 5260 | unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop); |
| 5261 | LLVM_DEBUG(dbgs() << "LV: Found trip count: " << TC << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Found trip count: " << TC << '\n'; } } while (false); |
| 5262 | if (TC == 1) { |
| 5263 | reportVectorizationFailure("Single iteration (non) loop", |
| 5264 | "loop trip count is one, irrelevant for vectorization", |
| 5265 | "SingleIterationLoop", ORE, TheLoop); |
| 5266 | return None; |
| 5267 | } |
| 5268 | |
| 5269 | switch (ScalarEpilogueStatus) { |
| 5270 | case CM_ScalarEpilogueAllowed: |
| 5271 | return UserVF ? UserVF : computeFeasibleMaxVF(TC); |
| 5272 | case CM_ScalarEpilogueNotNeededUsePredicate: |
| 5273 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n" << "LV: Not allowing scalar epilogue, creating predicated " << "vector loop.\n"; } } while (false) |
| 5274 | dbgs() << "LV: vector predicate hint/switch found.\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n" << "LV: Not allowing scalar epilogue, creating predicated " << "vector loop.\n"; } } while (false) |
| 5275 | << "LV: Not allowing scalar epilogue, creating predicated "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n" << "LV: Not allowing scalar epilogue, creating predicated " << "vector loop.\n"; } } while (false) |
| 5276 | << "vector loop.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: vector predicate hint/switch found.\n" << "LV: Not allowing scalar epilogue, creating predicated " << "vector loop.\n"; } } while (false); |
| 5277 | break; |
| 5278 | case CM_ScalarEpilogueNotAllowedLowTripLoop: |
| 5279 | // fallthrough as a special case of OptForSize |
| 5280 | case CM_ScalarEpilogueNotAllowedOptSize: |
| 5281 | if (ScalarEpilogueStatus == CM_ScalarEpilogueNotAllowedOptSize) |
| 5282 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n" ; } } while (false) |
| 5283 | dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to -Os/-Oz.\n" ; } } while (false); |
| 5284 | else |
| 5285 | LLVM_DEBUG(dbgs() << "LV: Not allowing scalar epilogue due to low trip "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to low trip " << "count.\n"; } } while (false) |
| 5286 | << "count.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Not allowing scalar epilogue due to low trip " << "count.\n"; } } while (false); |
| 5287 | |
| 5288 | // Bail if runtime checks are required, which are not good when optimising |
| 5289 | // for size. |
| 5290 | if (runtimeChecksRequired()) |
| 5291 | return None; |
| 5292 | break; |
| 5293 | } |
| 5294 | |
| 5295 | // Now try the tail folding |
| 5296 | |
| 5297 | // Invalidate interleave groups that require an epilogue if we can't mask |
| 5298 | // the interleave-group. |
| 5299 | if (!useMaskedInterleavedAccesses(TTI)) { |
| 5300 | assert(WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() &&((WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && "No decisions should have been taken at this point" ) ? static_cast<void> (0) : __assert_fail ("WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && \"No decisions should have been taken at this point\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5301, __PRETTY_FUNCTION__)) |
| 5301 | "No decisions should have been taken at this point")((WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && "No decisions should have been taken at this point" ) ? static_cast<void> (0) : __assert_fail ("WideningDecisions.empty() && Uniforms.empty() && Scalars.empty() && \"No decisions should have been taken at this point\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5301, __PRETTY_FUNCTION__)); |
| 5302 | // Note: There is no need to invalidate any cost modeling decisions here, as |
| 5303 | // non where taken so far. |
| 5304 | InterleaveInfo.invalidateGroupsRequiringScalarEpilogue(); |
| 5305 | } |
| 5306 | |
| 5307 | ElementCount MaxVF = UserVF ? UserVF : computeFeasibleMaxVF(TC); |
| 5308 | assert(!MaxVF.isScalable() &&((!MaxVF.isScalable() && "Scalable vectors do not yet support tail folding" ) ? static_cast<void> (0) : __assert_fail ("!MaxVF.isScalable() && \"Scalable vectors do not yet support tail folding\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5309, __PRETTY_FUNCTION__)) |
| 5309 | "Scalable vectors do not yet support tail folding")((!MaxVF.isScalable() && "Scalable vectors do not yet support tail folding" ) ? static_cast<void> (0) : __assert_fail ("!MaxVF.isScalable() && \"Scalable vectors do not yet support tail folding\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5309, __PRETTY_FUNCTION__)); |
| 5310 | assert((UserVF.isNonZero() || isPowerOf2_32(MaxVF.getFixedValue())) &&(((UserVF.isNonZero() || isPowerOf2_32(MaxVF.getFixedValue()) ) && "MaxVF must be a power of 2") ? static_cast<void > (0) : __assert_fail ("(UserVF.isNonZero() || isPowerOf2_32(MaxVF.getFixedValue())) && \"MaxVF must be a power of 2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5311, __PRETTY_FUNCTION__)) |
| 5311 | "MaxVF must be a power of 2")(((UserVF.isNonZero() || isPowerOf2_32(MaxVF.getFixedValue()) ) && "MaxVF must be a power of 2") ? static_cast<void > (0) : __assert_fail ("(UserVF.isNonZero() || isPowerOf2_32(MaxVF.getFixedValue())) && \"MaxVF must be a power of 2\"" , "/build/llvm-toolchain-snapshot-12~++20201124111112+7b5254223ac/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp" , 5311, __PRETTY_FUNCTION__)); |
| 5312 | unsigned MaxVFtimesIC = |
| 5313 | UserIC ? MaxVF.getFixedValue() * UserIC : MaxVF.getFixedValue(); |
| 5314 | if (TC > 0 && TC % MaxVFtimesIC == 0) { |
| 5315 | // Accept MaxVF if we do not have a tail. |
| 5316 | LLVM_DEBUG(dbgs() << "LV: No tail will remain for any chosen VF.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: No tail will remain for any chosen VF.\n" ; } } while (false); |
| 5317 | return MaxVF; |
| 5318 | } |
| 5319 | |
| 5320 | // If we don't know the precise trip count, or if the trip count that we |
| 5321 | // found modulo the vectorization factor is not zero, try to fold the tail |
| 5322 | // by masking. |
| 5323 | // FIXME: look for a smaller MaxVF that does divide TC rather than masking. |
| 5324 | if (Legal->prepareToFoldTailByMasking()) { |
| 5325 | FoldTailByMasking = true; |
| 5326 | return MaxVF; |
| 5327 | } |
| 5328 | |
| 5329 | // If there was a tail-folding hint/switch, but we can't fold the tail by |
| 5330 | // masking, fallback to a vectorization with a scalar epilogue. |
| 5331 | if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate) { |
| 5332 | if (PreferPredicateOverEpilogue == PreferPredicateTy::PredicateOrDontVectorize) { |
| 5333 | LLVM_DEBUG(dbgs() << "LV: Can't fold tail by masking: don't vectorize\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Can't fold tail by masking: don't vectorize\n" ; } } while (false); |
| 5334 | return None; |
| 5335 | } |
| 5336 | LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking: vectorize with a "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a " "scalar epilogue instead.\n"; } } while (false) |
| 5337 | "scalar epilogue instead.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-vectorize")) { dbgs() << "LV: Cannot fold tail by masking: vectorize with a " "scalar epilogue instead.\n"; } } while (false); |
| 5338 | ScalarEpilogueStatus = CM_ScalarEpilogueAllowed; |
| 5339 | return MaxVF; |
| 5340 | } |
| 5341 | |
| 5342 | if (TC == 0) { |
| 5343 | reportVectorizationFailure( |
| 5344 | "Unable to calculate the loop count due to complex control flow", |
| 5345 | "unable to calculate the loop count due to complex control flow", |
| 5346 | "UnknownLoopCountComplexCFG", ORE, TheLoop); |
| 5347 | return None; |
| 5348 | } |
| 5349 | |
| 5350 | reportVectorizationFailure( |
| 5351 | "Cannot optimize for size and vectorize at the same time.", |
| 5352 | "cannot optimize for size and vectorize at the same time. " |
| 5353 | "Enable vectorization of this loop with '#pragma clang loop " |
| 5354 | "vectorize(enable)' when compiling with -Os/-Oz", |
| 5355 | "NoTailLoopWithOptForSize", ORE, TheLoop); |
| 5356 | return None; |
| 5357 | } |
| 5358 | |
| 5359 | ElementCount |
| 5360 | LoopVectorizationCostModel::computeFeasibleMaxVF(unsigned ConstTripCount) { |
| 5361 | MinBWs = computeMinimumValueSizes(TheLoop->getBlocks(), *DB, &TTI); |
| 5362 | unsigned SmallestType, WidestType; |
| 5363 | std::tie(SmallestType, WidestType) = getSmallestAndWidestTypes(); |
| 5364 | unsigned WidestRegister = TTI.getRegisterBitWidth(true); |
| 5365 | |
| 5366 | // Get the maximum safe dependence distance in bits computed by LAA. |
| 5367 | // It is computed by MaxVF * sizeOf(type) * 8, where type is taken from |
| 5368 | // the memory accesses that is most restrictive (involved in the smallest |
| 5369 | // dependence distance). |
| 5370 | unsigned MaxSafeRegisterWidth = Legal->getMaxSafeRegisterWidth(); |
| 5371 | |
| 5372 | WidestRegister = std::min(WidestRegister, MaxSafeRegisterWidth); |
| 5373 | |
| 5374 | // Ensure MaxVF is a power of 2; the dependence distance bound may not be. |
| 5375 | // Note that both WidestRegister and WidestType may not be a powers of 2. |
| 5376 | unsigned MaxVectorSize = PowerOf2Floor(WidestRegister / WidestType); |
| 5377 | |
| 5378 | LLVM_DEBU |