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 TargetTransformInfo; 22 class TargetLibraryInfo; 23 24 /// Helper class to create VPRecipies from IR instructions. 25 class VPRecipeBuilder { 26 /// The loop that we evaluate. 27 Loop *OrigLoop; 28 29 /// Target Library Info. 30 const TargetLibraryInfo *TLI; 31 32 /// The legality analysis. 33 LoopVectorizationLegality *Legal; 34 35 /// The profitablity analysis. 36 LoopVectorizationCostModel &CM; 37 38 VPBuilder &Builder; 39 40 /// When we if-convert we need to create edge masks. We have to cache values 41 /// so that we don't end up with exponential recursion/IR. Note that 42 /// if-conversion currently takes place during VPlan-construction, so these 43 /// caches are only used at that stage. 44 using EdgeMaskCacheTy = 45 DenseMap<std::pair<BasicBlock *, BasicBlock *>, VPValue *>; 46 using BlockMaskCacheTy = DenseMap<BasicBlock *, VPValue *>; 47 EdgeMaskCacheTy EdgeMaskCache; 48 BlockMaskCacheTy BlockMaskCache; 49 50 public: 51 /// A helper function that computes the predicate of the block BB, assuming 52 /// that the header block of the loop is set to True. It returns the *entry* 53 /// mask for the block BB. 54 VPValue *createBlockInMask(BasicBlock *BB, VPlanPtr &Plan); 55 56 /// A helper function that computes the predicate of the edge between SRC 57 /// and DST. 58 VPValue *createEdgeMask(BasicBlock *Src, BasicBlock *Dst, VPlanPtr &Plan); 59 60 /// Check if \I belongs to an Interleave Group within the given VF \p Range, 61 /// \return true in the first returned value if so and false otherwise. 62 /// Build a new VPInterleaveGroup Recipe if \I is the primary member of an IG 63 /// for \p Range.Start, and provide it as the second returned value. 64 /// Note that if \I is an adjunct member of an IG for \p Range.Start, the 65 /// \return value is <true, nullptr>, as it is handled by another recipe. 66 /// \p Range.End may be decreased to ensure same decision from \p Range.Start 67 /// to \p Range.End. 68 VPInterleaveRecipe *tryToInterleaveMemory(Instruction *I, VFRange &Range, 69 VPlanPtr &Plan); 70 71 /// Check if \I is a memory instruction to be widened for \p Range.Start and 72 /// potentially masked. Such instructions are handled by a recipe that takes 73 /// an additional VPInstruction for the mask. 74 VPWidenMemoryInstructionRecipe * 75 tryToWidenMemory(Instruction *I, VFRange &Range, VPlanPtr &Plan); 76 77 /// Check if an induction recipe should be constructed for \I within the given 78 /// VF \p Range. If so build and return it. If not, return null. \p Range.End 79 /// may be decreased to ensure same decision from \p Range.Start to 80 /// \p Range.End. 81 VPWidenIntOrFpInductionRecipe *tryToOptimizeInduction(Instruction *I, 82 VFRange &Range); 83 84 /// Handle non-loop phi nodes. Currently all such phi nodes are turned into 85 /// a sequence of select instructions as the vectorizer currently performs 86 /// full if-conversion. 87 VPBlendRecipe *tryToBlend(Instruction *I, VPlanPtr &Plan); 88 89 /// Check if \p I can be widened within the given VF \p Range. If \p I can be 90 /// widened for \p Range.Start, check if the last recipe of \p VPBB can be 91 /// extended to include \p I or else build a new VPWidenRecipe for it and 92 /// append it to \p VPBB. Return true if \p I can be widened for Range.Start, 93 /// false otherwise. Range.End may be decreased to ensure same decision from 94 /// \p Range.Start to \p Range.End. 95 bool tryToWiden(Instruction *I, VPBasicBlock *VPBB, VFRange &Range); 96 97 /// Create a replicating region for instruction \p I that requires 98 /// predication. \p PredRecipe is a VPReplicateRecipe holding \p I. 99 VPRegionBlock *createReplicateRegion(Instruction *I, VPRecipeBase *PredRecipe, 100 VPlanPtr &Plan); 101 102 public: 103 VPRecipeBuilder(Loop *OrigLoop, const TargetLibraryInfo *TLI, 104 LoopVectorizationLegality *Legal, 105 LoopVectorizationCostModel &CM, VPBuilder &Builder) 106 : OrigLoop(OrigLoop), TLI(TLI), Legal(Legal), CM(CM), Builder(Builder) {} 107 108 /// Check if a recipe can be create for \p I withing the given VF \p Range. 109 /// If a recipe can be created, it adds it to \p VPBB. 110 bool tryToCreateRecipe(Instruction *Instr, VFRange &Range, VPlanPtr &Plan, 111 VPBasicBlock *VPBB); 112 113 /// Build a VPReplicationRecipe for \p I and enclose it within a Region if it 114 /// is predicated. \return \p VPBB augmented with this new recipe if \p I is 115 /// not predicated, otherwise \return a new VPBasicBlock that succeeds the new 116 /// Region. Update the packing decision of predicated instructions if they 117 /// feed \p I. Range.End may be decreased to ensure same recipe behavior from 118 /// \p Range.Start to \p Range.End. 119 VPBasicBlock *handleReplication( 120 Instruction *I, VFRange &Range, VPBasicBlock *VPBB, 121 DenseMap<Instruction *, VPReplicateRecipe *> &PredInst2Recipe, 122 VPlanPtr &Plan); 123 }; 124 } // end namespace llvm 125 126 #endif // LLVM_TRANSFORMS_VECTORIZE_VPRECIPEBUILDER_H 127