1 //===- VPRecipeBuilder.h - Helper class to build recipes --------*- C++ -*-===// 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 #ifndef LLVM_TRANSFORMS_VECTORIZE_VPRECIPEBUILDER_H 10 #define LLVM_TRANSFORMS_VECTORIZE_VPRECIPEBUILDER_H 11 12 #include "LoopVectorizationPlanner.h" 13 #include "VPlan.h" 14 #include "llvm/ADT/DenseMap.h" 15 #include "llvm/IR/IRBuilder.h" 16 17 namespace llvm { 18 19 class LoopVectorizationLegality; 20 class LoopVectorizationCostModel; 21 class TargetLibraryInfo; 22 23 /// Helper class to create VPRecipies from IR instructions. 24 class VPRecipeBuilder { 25 /// The loop that we evaluate. 26 Loop *OrigLoop; 27 28 /// Target Library Info. 29 const TargetLibraryInfo *TLI; 30 31 /// The legality analysis. 32 LoopVectorizationLegality *Legal; 33 34 /// The profitablity analysis. 35 LoopVectorizationCostModel &CM; 36 37 PredicatedScalarEvolution &PSE; 38 39 VPBuilder &Builder; 40 41 /// When we if-convert we need to create edge masks. We have to cache values 42 /// so that we don't end up with exponential recursion/IR. Note that 43 /// if-conversion currently takes place during VPlan-construction, so these 44 /// caches are only used at that stage. 45 using EdgeMaskCacheTy = 46 DenseMap<std::pair<BasicBlock *, BasicBlock *>, VPValue *>; 47 using BlockMaskCacheTy = DenseMap<BasicBlock *, VPValue *>; 48 EdgeMaskCacheTy EdgeMaskCache; 49 BlockMaskCacheTy BlockMaskCache; 50 51 // VPlan-VPlan transformations support: Hold a mapping from ingredients to 52 // their recipe. To save on memory, only do so for selected ingredients, 53 // marked by having a nullptr entry in this map. 54 DenseMap<Instruction *, VPRecipeBase *> Ingredient2Recipe; 55 56 /// Check if \p I can be widened at the start of \p Range and possibly 57 /// decrease the range such that the returned value holds for the entire \p 58 /// Range. The function should not be called for memory instructions or calls. 59 bool shouldWiden(Instruction *I, VFRange &Range) const; 60 61 /// Check if the load or store instruction \p I should widened for \p 62 /// Range.Start and potentially masked. Such instructions are handled by a 63 /// recipe that takes an additional VPInstruction for the mask. 64 VPWidenMemoryInstructionRecipe * 65 tryToWidenMemory(Instruction *I, VFRange &Range, VPlanPtr &Plan); 66 67 /// Check if an induction recipe should be constructed for \I. If so build and 68 /// return it. If not, return null. 69 VPWidenIntOrFpInductionRecipe *tryToOptimizeInductionPHI(PHINode *Phi) const; 70 71 /// Optimize the special case where the operand of \p I is a constant integer 72 /// induction variable. 73 VPWidenIntOrFpInductionRecipe * 74 tryToOptimizeInductionTruncate(TruncInst *I, VFRange &Range) const; 75 76 /// Handle non-loop phi nodes. Currently all such phi nodes are turned into 77 /// a sequence of select instructions as the vectorizer currently performs 78 /// full if-conversion. 79 VPBlendRecipe *tryToBlend(PHINode *Phi, VPlanPtr &Plan); 80 81 /// Handle call instructions. If \p CI can be widened for \p Range.Start, 82 /// return a new VPWidenCallRecipe. Range.End may be decreased to ensure same 83 /// decision from \p Range.Start to \p Range.End. 84 VPWidenCallRecipe *tryToWidenCall(CallInst *CI, VFRange &Range, 85 VPlan &Plan) const; 86 87 /// Check if \p I has an opcode that can be widened and return a VPWidenRecipe 88 /// if it can. The function should only be called if the cost-model indicates 89 /// that widening should be performed. 90 VPWidenRecipe *tryToWiden(Instruction *I, VPlan &Plan) const; 91 92 public: 93 VPRecipeBuilder(Loop *OrigLoop, const TargetLibraryInfo *TLI, 94 LoopVectorizationLegality *Legal, 95 LoopVectorizationCostModel &CM, 96 PredicatedScalarEvolution &PSE, VPBuilder &Builder) 97 : OrigLoop(OrigLoop), TLI(TLI), Legal(Legal), CM(CM), PSE(PSE), 98 Builder(Builder) {} 99 100 /// Check if a recipe can be create for \p I withing the given VF \p Range. 101 /// If a recipe can be created, return it. Otherwise return nullptr. 102 VPRecipeBase *tryToCreateWidenRecipe(Instruction *Instr, VFRange &Range, 103 VPlanPtr &Plan); 104 105 /// Set the recipe created for given ingredient. This operation is a no-op for 106 /// ingredients that were not marked using a nullptr entry in the map. 107 void setRecipe(Instruction *I, VPRecipeBase *R) { 108 if (!Ingredient2Recipe.count(I)) 109 return; 110 assert(Ingredient2Recipe[I] == nullptr && 111 "Recipe already set for ingredient"); 112 Ingredient2Recipe[I] = R; 113 } 114 115 /// A helper function that computes the predicate of the block BB, assuming 116 /// that the header block of the loop is set to True. It returns the *entry* 117 /// mask for the block BB. 118 VPValue *createBlockInMask(BasicBlock *BB, VPlanPtr &Plan); 119 120 /// A helper function that computes the predicate of the edge between SRC 121 /// and DST. 122 VPValue *createEdgeMask(BasicBlock *Src, BasicBlock *Dst, VPlanPtr &Plan); 123 124 /// Mark given ingredient for recording its recipe once one is created for 125 /// it. 126 void recordRecipeOf(Instruction *I) { 127 assert((!Ingredient2Recipe.count(I) || Ingredient2Recipe[I] == nullptr) && 128 "Recipe already set for ingredient"); 129 Ingredient2Recipe[I] = nullptr; 130 } 131 132 /// Return the recipe created for given ingredient. 133 VPRecipeBase *getRecipe(Instruction *I) { 134 assert(Ingredient2Recipe.count(I) && 135 "Recording this ingredients recipe was not requested"); 136 assert(Ingredient2Recipe[I] != nullptr && 137 "Ingredient doesn't have a recipe"); 138 return Ingredient2Recipe[I]; 139 } 140 141 /// Create a replicating region for instruction \p I that requires 142 /// predication. \p PredRecipe is a VPReplicateRecipe holding \p I. 143 VPRegionBlock *createReplicateRegion(Instruction *I, VPRecipeBase *PredRecipe, 144 VPlanPtr &Plan); 145 146 /// Build a VPReplicationRecipe for \p I and enclose it within a Region if it 147 /// is predicated. \return \p VPBB augmented with this new recipe if \p I is 148 /// not predicated, otherwise \return a new VPBasicBlock that succeeds the new 149 /// Region. Update the packing decision of predicated instructions if they 150 /// feed \p I. Range.End may be decreased to ensure same recipe behavior from 151 /// \p Range.Start to \p Range.End. 152 VPBasicBlock *handleReplication( 153 Instruction *I, VFRange &Range, VPBasicBlock *VPBB, 154 DenseMap<Instruction *, VPReplicateRecipe *> &PredInst2Recipe, 155 VPlanPtr &Plan); 156 }; 157 } // end namespace llvm 158 159 #endif // LLVM_TRANSFORMS_VECTORIZE_VPRECIPEBUILDER_H 160