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//===- VPRecipeBuilder.h - Helper class to build recipes --------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "LoopVectorizationPlanner.h"
#include "VPlan.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/IR/IRBuilder.h"
namespace llvm {
class LoopVectorizationLegality;
class LoopVectorizationCostModel;
class TargetLibraryInfo;
using VPRecipeOrVPValueTy = PointerUnion<VPRecipeBase *, VPValue *>;
/// Helper class to create VPRecipies from IR instructions.
class VPRecipeBuilder {
/// The loop that we evaluate.
Loop *OrigLoop;
/// Target Library Info.
const TargetLibraryInfo *TLI;
/// The legality analysis.
LoopVectorizationLegality *Legal;
/// The profitablity analysis.
LoopVectorizationCostModel &CM;
PredicatedScalarEvolution &PSE;
VPBuilder &Builder;
/// When we if-convert we need to create edge masks. We have to cache values
/// so that we don't end up with exponential recursion/IR. Note that
/// if-conversion currently takes place during VPlan-construction, so these
/// caches are only used at that stage.
using EdgeMaskCacheTy =
DenseMap<std::pair<BasicBlock *, BasicBlock *>, VPValue *>;
using BlockMaskCacheTy = DenseMap<BasicBlock *, VPValue *>;
EdgeMaskCacheTy EdgeMaskCache;
BlockMaskCacheTy BlockMaskCache;
// VPlan-VPlan transformations support: Hold a mapping from ingredients to
// their recipe. To save on memory, only do so for selected ingredients,
// marked by having a nullptr entry in this map.
DenseMap<Instruction *, VPRecipeBase *> Ingredient2Recipe;
/// Check if \p I can be widened at the start of \p Range and possibly
/// decrease the range such that the returned value holds for the entire \p
/// Range. The function should not be called for memory instructions or calls.
bool shouldWiden(Instruction *I, VFRange &Range) const;
/// Check if the load or store instruction \p I should widened for \p
/// Range.Start and potentially masked. Such instructions are handled by a
/// recipe that takes an additional VPInstruction for the mask.
VPRecipeBase *tryToWidenMemory(Instruction *I, ArrayRef<VPValue *> Operands,
VFRange &Range, VPlanPtr &Plan);
/// Check if an induction recipe should be constructed for \I. If so build and
/// return it. If not, return null.
VPWidenIntOrFpInductionRecipe *
tryToOptimizeInductionPHI(PHINode *Phi, ArrayRef<VPValue *> Operands) const;
/// Optimize the special case where the operand of \p I is a constant integer
/// induction variable.
VPWidenIntOrFpInductionRecipe *
tryToOptimizeInductionTruncate(TruncInst *I, ArrayRef<VPValue *> Operands,
VFRange &Range, VPlan &Plan) const;
/// Handle non-loop phi nodes. Return a VPValue, if all incoming values match
/// or a new VPBlendRecipe otherwise. Currently all such phi nodes are turned
/// into a sequence of select instructions as the vectorizer currently
/// performs full if-conversion.
VPRecipeOrVPValueTy tryToBlend(PHINode *Phi, ArrayRef<VPValue *> Operands,
VPlanPtr &Plan);
/// Handle call instructions. If \p CI can be widened for \p Range.Start,
/// return a new VPWidenCallRecipe. Range.End may be decreased to ensure same
/// decision from \p Range.Start to \p Range.End.
VPWidenCallRecipe *tryToWidenCall(CallInst *CI, ArrayRef<VPValue *> Operands,
VFRange &Range) const;
/// Check if \p I has an opcode that can be widened and return a VPWidenRecipe
/// if it can. The function should only be called if the cost-model indicates
/// that widening should be performed.
VPWidenRecipe *tryToWiden(Instruction *I, ArrayRef<VPValue *> Operands) const;
/// Return a VPRecipeOrValueTy with VPRecipeBase * being set. This can be used to force the use as VPRecipeBase* for recipe sub-types that also inherit from VPValue.
VPRecipeOrVPValueTy toVPRecipeResult(VPRecipeBase *R) const { return R; }
VPRecipeBuilder(Loop *OrigLoop, const TargetLibraryInfo *TLI,
LoopVectorizationLegality *Legal,
LoopVectorizationCostModel &CM,
PredicatedScalarEvolution &PSE, VPBuilder &Builder)
: OrigLoop(OrigLoop), TLI(TLI), Legal(Legal), CM(CM), PSE(PSE),
Builder(Builder) {}
/// Check if an existing VPValue can be used for \p Instr or a recipe can be
/// create for \p I withing the given VF \p Range. If an existing VPValue can
/// be used or if a recipe can be created, return it. Otherwise return a
/// VPRecipeOrVPValueTy with nullptr.
VPRecipeOrVPValueTy tryToCreateWidenRecipe(Instruction *Instr,
ArrayRef<VPValue *> Operands,
VFRange &Range, VPlanPtr &Plan);
/// Set the recipe created for given ingredient. This operation is a no-op for
/// ingredients that were not marked using a nullptr entry in the map.
void setRecipe(Instruction *I, VPRecipeBase *R) {
if (!Ingredient2Recipe.count(I))
assert(Ingredient2Recipe[I] == nullptr &&
"Recipe already set for ingredient");
Ingredient2Recipe[I] = R;
/// A helper function that computes the predicate of the block BB, assuming
/// that the header block of the loop is set to True. It returns the *entry*
/// mask for the block BB.
VPValue *createBlockInMask(BasicBlock *BB, VPlanPtr &Plan);
/// A helper function that computes the predicate of the edge between SRC
/// and DST.
VPValue *createEdgeMask(BasicBlock *Src, BasicBlock *Dst, VPlanPtr &Plan);
/// Mark given ingredient for recording its recipe once one is created for
/// it.
void recordRecipeOf(Instruction *I) {
assert((!Ingredient2Recipe.count(I) || Ingredient2Recipe[I] == nullptr) &&
"Recipe already set for ingredient");
Ingredient2Recipe[I] = nullptr;
/// Return the recipe created for given ingredient.
VPRecipeBase *getRecipe(Instruction *I) {
assert(Ingredient2Recipe.count(I) &&
"Recording this ingredients recipe was not requested");
assert(Ingredient2Recipe[I] != nullptr &&
"Ingredient doesn't have a recipe");
return Ingredient2Recipe[I];
/// Create a replicating region for instruction \p I that requires
/// predication. \p PredRecipe is a VPReplicateRecipe holding \p I.
VPRegionBlock *createReplicateRegion(Instruction *I, VPRecipeBase *PredRecipe,
VPlanPtr &Plan);
/// Build a VPReplicationRecipe for \p I and enclose it within a Region if it
/// is predicated. \return \p VPBB augmented with this new recipe if \p I is
/// not predicated, otherwise \return a new VPBasicBlock that succeeds the new
/// Region. Update the packing decision of predicated instructions if they
/// feed \p I. Range.End may be decreased to ensure same recipe behavior from
/// \p Range.Start to \p Range.End.
VPBasicBlock *handleReplication(
Instruction *I, VFRange &Range, VPBasicBlock *VPBB,
VPlanPtr &Plan);
} // end namespace llvm