forked from OSchip/llvm-project
980 lines
33 KiB
C++
980 lines
33 KiB
C++
//===- Scalarizer.cpp - Scalarize vector operations -----------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass converts vector operations into scalar operations, in order
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// to expose optimization opportunities on the individual scalar operations.
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// It is mainly intended for targets that do not have vector units, but it
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// may also be useful for revectorizing code to different vector widths.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Scalar/Scalarizer.h"
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#include "llvm/ADT/PostOrderIterator.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Twine.h"
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#include "llvm/Analysis/VectorUtils.h"
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#include "llvm/IR/Argument.h"
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#include "llvm/IR/BasicBlock.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Dominators.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/InstVisitor.h"
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#include "llvm/IR/InstrTypes.h"
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#include "llvm/IR/Instruction.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/Type.h"
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#include "llvm/IR/Value.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include <cassert>
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#include <cstdint>
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#include <iterator>
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#include <map>
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#include <utility>
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using namespace llvm;
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#define DEBUG_TYPE "scalarizer"
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static cl::opt<bool> ScalarizeVariableInsertExtract(
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"scalarize-variable-insert-extract", cl::init(true), cl::Hidden,
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cl::desc("Allow the scalarizer pass to scalarize "
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"insertelement/extractelement with variable index"));
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// This is disabled by default because having separate loads and stores
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// makes it more likely that the -combiner-alias-analysis limits will be
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// reached.
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static cl::opt<bool>
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ScalarizeLoadStore("scalarize-load-store", cl::init(false), cl::Hidden,
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cl::desc("Allow the scalarizer pass to scalarize loads and store"));
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namespace {
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// Used to store the scattered form of a vector.
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using ValueVector = SmallVector<Value *, 8>;
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// Used to map a vector Value to its scattered form. We use std::map
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// because we want iterators to persist across insertion and because the
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// values are relatively large.
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using ScatterMap = std::map<Value *, ValueVector>;
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// Lists Instructions that have been replaced with scalar implementations,
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// along with a pointer to their scattered forms.
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using GatherList = SmallVector<std::pair<Instruction *, ValueVector *>, 16>;
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// Provides a very limited vector-like interface for lazily accessing one
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// component of a scattered vector or vector pointer.
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class Scatterer {
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public:
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Scatterer() = default;
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// Scatter V into Size components. If new instructions are needed,
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// insert them before BBI in BB. If Cache is nonnull, use it to cache
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// the results.
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Scatterer(BasicBlock *bb, BasicBlock::iterator bbi, Value *v,
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ValueVector *cachePtr = nullptr);
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// Return component I, creating a new Value for it if necessary.
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Value *operator[](unsigned I);
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// Return the number of components.
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unsigned size() const { return Size; }
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private:
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BasicBlock *BB;
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BasicBlock::iterator BBI;
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Value *V;
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ValueVector *CachePtr;
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PointerType *PtrTy;
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ValueVector Tmp;
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unsigned Size;
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};
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// FCmpSpliiter(FCI)(Builder, X, Y, Name) uses Builder to create an FCmp
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// called Name that compares X and Y in the same way as FCI.
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struct FCmpSplitter {
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FCmpSplitter(FCmpInst &fci) : FCI(fci) {}
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Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1,
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const Twine &Name) const {
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return Builder.CreateFCmp(FCI.getPredicate(), Op0, Op1, Name);
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}
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FCmpInst &FCI;
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};
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// ICmpSpliiter(ICI)(Builder, X, Y, Name) uses Builder to create an ICmp
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// called Name that compares X and Y in the same way as ICI.
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struct ICmpSplitter {
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ICmpSplitter(ICmpInst &ici) : ICI(ici) {}
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Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1,
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const Twine &Name) const {
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return Builder.CreateICmp(ICI.getPredicate(), Op0, Op1, Name);
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}
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ICmpInst &ICI;
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};
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// UnarySpliiter(UO)(Builder, X, Name) uses Builder to create
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// a unary operator like UO called Name with operand X.
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struct UnarySplitter {
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UnarySplitter(UnaryOperator &uo) : UO(uo) {}
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Value *operator()(IRBuilder<> &Builder, Value *Op, const Twine &Name) const {
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return Builder.CreateUnOp(UO.getOpcode(), Op, Name);
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}
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UnaryOperator &UO;
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};
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// BinarySpliiter(BO)(Builder, X, Y, Name) uses Builder to create
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// a binary operator like BO called Name with operands X and Y.
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struct BinarySplitter {
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BinarySplitter(BinaryOperator &bo) : BO(bo) {}
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Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1,
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const Twine &Name) const {
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return Builder.CreateBinOp(BO.getOpcode(), Op0, Op1, Name);
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}
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BinaryOperator &BO;
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};
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// Information about a load or store that we're scalarizing.
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struct VectorLayout {
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VectorLayout() = default;
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// Return the alignment of element I.
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Align getElemAlign(unsigned I) {
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return commonAlignment(VecAlign, I * ElemSize);
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}
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// The type of the vector.
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VectorType *VecTy = nullptr;
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// The type of each element.
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Type *ElemTy = nullptr;
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// The alignment of the vector.
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Align VecAlign;
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// The size of each element.
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uint64_t ElemSize = 0;
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};
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class ScalarizerVisitor : public InstVisitor<ScalarizerVisitor, bool> {
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public:
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ScalarizerVisitor(unsigned ParallelLoopAccessMDKind, DominatorTree *DT)
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: ParallelLoopAccessMDKind(ParallelLoopAccessMDKind), DT(DT) {
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}
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bool visit(Function &F);
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// InstVisitor methods. They return true if the instruction was scalarized,
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// false if nothing changed.
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bool visitInstruction(Instruction &I) { return false; }
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bool visitSelectInst(SelectInst &SI);
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bool visitICmpInst(ICmpInst &ICI);
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bool visitFCmpInst(FCmpInst &FCI);
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bool visitUnaryOperator(UnaryOperator &UO);
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bool visitBinaryOperator(BinaryOperator &BO);
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bool visitGetElementPtrInst(GetElementPtrInst &GEPI);
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bool visitCastInst(CastInst &CI);
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bool visitBitCastInst(BitCastInst &BCI);
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bool visitInsertElementInst(InsertElementInst &IEI);
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bool visitExtractElementInst(ExtractElementInst &EEI);
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bool visitShuffleVectorInst(ShuffleVectorInst &SVI);
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bool visitPHINode(PHINode &PHI);
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bool visitLoadInst(LoadInst &LI);
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bool visitStoreInst(StoreInst &SI);
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bool visitCallInst(CallInst &ICI);
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private:
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Scatterer scatter(Instruction *Point, Value *V);
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void gather(Instruction *Op, const ValueVector &CV);
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bool canTransferMetadata(unsigned Kind);
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void transferMetadataAndIRFlags(Instruction *Op, const ValueVector &CV);
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Optional<VectorLayout> getVectorLayout(Type *Ty, Align Alignment,
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const DataLayout &DL);
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bool finish();
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template<typename T> bool splitUnary(Instruction &, const T &);
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template<typename T> bool splitBinary(Instruction &, const T &);
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bool splitCall(CallInst &CI);
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ScatterMap Scattered;
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GatherList Gathered;
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SmallVector<WeakTrackingVH, 32> PotentiallyDeadInstrs;
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unsigned ParallelLoopAccessMDKind;
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DominatorTree *DT;
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};
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class ScalarizerLegacyPass : public FunctionPass {
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public:
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static char ID;
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ScalarizerLegacyPass() : FunctionPass(ID) {
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initializeScalarizerLegacyPassPass(*PassRegistry::getPassRegistry());
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}
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bool runOnFunction(Function &F) override;
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void getAnalysisUsage(AnalysisUsage& AU) const override {
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AU.addRequired<DominatorTreeWrapperPass>();
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AU.addPreserved<DominatorTreeWrapperPass>();
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}
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};
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} // end anonymous namespace
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char ScalarizerLegacyPass::ID = 0;
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INITIALIZE_PASS_BEGIN(ScalarizerLegacyPass, "scalarizer",
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"Scalarize vector operations", false, false)
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INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
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INITIALIZE_PASS_END(ScalarizerLegacyPass, "scalarizer",
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"Scalarize vector operations", false, false)
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Scatterer::Scatterer(BasicBlock *bb, BasicBlock::iterator bbi, Value *v,
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ValueVector *cachePtr)
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: BB(bb), BBI(bbi), V(v), CachePtr(cachePtr) {
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Type *Ty = V->getType();
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PtrTy = dyn_cast<PointerType>(Ty);
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if (PtrTy)
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Ty = PtrTy->getElementType();
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Size = cast<FixedVectorType>(Ty)->getNumElements();
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if (!CachePtr)
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Tmp.resize(Size, nullptr);
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else if (CachePtr->empty())
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CachePtr->resize(Size, nullptr);
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else
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assert(Size == CachePtr->size() && "Inconsistent vector sizes");
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}
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// Return component I, creating a new Value for it if necessary.
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Value *Scatterer::operator[](unsigned I) {
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ValueVector &CV = (CachePtr ? *CachePtr : Tmp);
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// Try to reuse a previous value.
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if (CV[I])
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return CV[I];
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IRBuilder<> Builder(BB, BBI);
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if (PtrTy) {
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Type *ElTy = cast<VectorType>(PtrTy->getElementType())->getElementType();
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if (!CV[0]) {
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Type *NewPtrTy = PointerType::get(ElTy, PtrTy->getAddressSpace());
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CV[0] = Builder.CreateBitCast(V, NewPtrTy, V->getName() + ".i0");
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}
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if (I != 0)
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CV[I] = Builder.CreateConstGEP1_32(ElTy, CV[0], I,
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V->getName() + ".i" + Twine(I));
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} else {
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// Search through a chain of InsertElementInsts looking for element I.
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// Record other elements in the cache. The new V is still suitable
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// for all uncached indices.
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while (true) {
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InsertElementInst *Insert = dyn_cast<InsertElementInst>(V);
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if (!Insert)
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break;
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ConstantInt *Idx = dyn_cast<ConstantInt>(Insert->getOperand(2));
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if (!Idx)
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break;
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unsigned J = Idx->getZExtValue();
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V = Insert->getOperand(0);
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if (I == J) {
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CV[J] = Insert->getOperand(1);
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return CV[J];
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} else if (!CV[J]) {
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// Only cache the first entry we find for each index we're not actively
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// searching for. This prevents us from going too far up the chain and
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// caching incorrect entries.
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CV[J] = Insert->getOperand(1);
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}
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}
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CV[I] = Builder.CreateExtractElement(V, Builder.getInt32(I),
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V->getName() + ".i" + Twine(I));
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}
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return CV[I];
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}
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bool ScalarizerLegacyPass::runOnFunction(Function &F) {
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if (skipFunction(F))
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return false;
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Module &M = *F.getParent();
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unsigned ParallelLoopAccessMDKind =
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M.getContext().getMDKindID("llvm.mem.parallel_loop_access");
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DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
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ScalarizerVisitor Impl(ParallelLoopAccessMDKind, DT);
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return Impl.visit(F);
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}
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FunctionPass *llvm::createScalarizerPass() {
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return new ScalarizerLegacyPass();
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}
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bool ScalarizerVisitor::visit(Function &F) {
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assert(Gathered.empty() && Scattered.empty());
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// To ensure we replace gathered components correctly we need to do an ordered
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// traversal of the basic blocks in the function.
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ReversePostOrderTraversal<BasicBlock *> RPOT(&F.getEntryBlock());
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for (BasicBlock *BB : RPOT) {
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for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;) {
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Instruction *I = &*II;
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bool Done = InstVisitor::visit(I);
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++II;
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if (Done && I->getType()->isVoidTy())
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I->eraseFromParent();
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}
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}
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return finish();
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}
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// Return a scattered form of V that can be accessed by Point. V must be a
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// vector or a pointer to a vector.
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Scatterer ScalarizerVisitor::scatter(Instruction *Point, Value *V) {
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if (Argument *VArg = dyn_cast<Argument>(V)) {
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// Put the scattered form of arguments in the entry block,
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// so that it can be used everywhere.
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Function *F = VArg->getParent();
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BasicBlock *BB = &F->getEntryBlock();
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return Scatterer(BB, BB->begin(), V, &Scattered[V]);
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}
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if (Instruction *VOp = dyn_cast<Instruction>(V)) {
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// When scalarizing PHI nodes we might try to examine/rewrite InsertElement
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// nodes in predecessors. If those predecessors are unreachable from entry,
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// then the IR in those blocks could have unexpected properties resulting in
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// infinite loops in Scatterer::operator[]. By simply treating values
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// originating from instructions in unreachable blocks as undef we do not
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// need to analyse them further.
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if (!DT->isReachableFromEntry(VOp->getParent()))
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return Scatterer(Point->getParent(), Point->getIterator(),
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UndefValue::get(V->getType()));
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// Put the scattered form of an instruction directly after the
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// instruction.
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BasicBlock *BB = VOp->getParent();
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return Scatterer(BB, std::next(BasicBlock::iterator(VOp)),
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V, &Scattered[V]);
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}
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// In the fallback case, just put the scattered before Point and
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// keep the result local to Point.
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return Scatterer(Point->getParent(), Point->getIterator(), V);
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}
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// Replace Op with the gathered form of the components in CV. Defer the
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// deletion of Op and creation of the gathered form to the end of the pass,
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// so that we can avoid creating the gathered form if all uses of Op are
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// replaced with uses of CV.
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void ScalarizerVisitor::gather(Instruction *Op, const ValueVector &CV) {
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transferMetadataAndIRFlags(Op, CV);
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// If we already have a scattered form of Op (created from ExtractElements
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// of Op itself), replace them with the new form.
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ValueVector &SV = Scattered[Op];
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if (!SV.empty()) {
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for (unsigned I = 0, E = SV.size(); I != E; ++I) {
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Value *V = SV[I];
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if (V == nullptr || SV[I] == CV[I])
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continue;
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Instruction *Old = cast<Instruction>(V);
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if (isa<Instruction>(CV[I]))
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CV[I]->takeName(Old);
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Old->replaceAllUsesWith(CV[I]);
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PotentiallyDeadInstrs.emplace_back(Old);
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}
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}
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SV = CV;
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Gathered.push_back(GatherList::value_type(Op, &SV));
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}
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// Return true if it is safe to transfer the given metadata tag from
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// vector to scalar instructions.
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bool ScalarizerVisitor::canTransferMetadata(unsigned Tag) {
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return (Tag == LLVMContext::MD_tbaa
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|| Tag == LLVMContext::MD_fpmath
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|| Tag == LLVMContext::MD_tbaa_struct
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|| Tag == LLVMContext::MD_invariant_load
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|| Tag == LLVMContext::MD_alias_scope
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|| Tag == LLVMContext::MD_noalias
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|| Tag == ParallelLoopAccessMDKind
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|| Tag == LLVMContext::MD_access_group);
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}
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// Transfer metadata from Op to the instructions in CV if it is known
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// to be safe to do so.
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void ScalarizerVisitor::transferMetadataAndIRFlags(Instruction *Op,
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const ValueVector &CV) {
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SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
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Op->getAllMetadataOtherThanDebugLoc(MDs);
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for (unsigned I = 0, E = CV.size(); I != E; ++I) {
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if (Instruction *New = dyn_cast<Instruction>(CV[I])) {
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for (const auto &MD : MDs)
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if (canTransferMetadata(MD.first))
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New->setMetadata(MD.first, MD.second);
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New->copyIRFlags(Op);
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if (Op->getDebugLoc() && !New->getDebugLoc())
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New->setDebugLoc(Op->getDebugLoc());
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}
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}
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}
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// Try to fill in Layout from Ty, returning true on success. Alignment is
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// the alignment of the vector, or None if the ABI default should be used.
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Optional<VectorLayout>
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ScalarizerVisitor::getVectorLayout(Type *Ty, Align Alignment,
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const DataLayout &DL) {
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VectorLayout Layout;
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// Make sure we're dealing with a vector.
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Layout.VecTy = dyn_cast<VectorType>(Ty);
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if (!Layout.VecTy)
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return None;
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// Check that we're dealing with full-byte elements.
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Layout.ElemTy = Layout.VecTy->getElementType();
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if (!DL.typeSizeEqualsStoreSize(Layout.ElemTy))
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return None;
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Layout.VecAlign = Alignment;
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Layout.ElemSize = DL.getTypeStoreSize(Layout.ElemTy);
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return Layout;
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}
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// Scalarize one-operand instruction I, using Split(Builder, X, Name)
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// to create an instruction like I with operand X and name Name.
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template<typename Splitter>
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bool ScalarizerVisitor::splitUnary(Instruction &I, const Splitter &Split) {
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VectorType *VT = dyn_cast<VectorType>(I.getType());
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if (!VT)
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return false;
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unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
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IRBuilder<> Builder(&I);
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Scatterer Op = scatter(&I, I.getOperand(0));
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assert(Op.size() == NumElems && "Mismatched unary operation");
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ValueVector Res;
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Res.resize(NumElems);
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for (unsigned Elem = 0; Elem < NumElems; ++Elem)
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Res[Elem] = Split(Builder, Op[Elem], I.getName() + ".i" + Twine(Elem));
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gather(&I, Res);
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return true;
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}
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// Scalarize two-operand instruction I, using Split(Builder, X, Y, Name)
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// to create an instruction like I with operands X and Y and name Name.
|
|
template<typename Splitter>
|
|
bool ScalarizerVisitor::splitBinary(Instruction &I, const Splitter &Split) {
|
|
VectorType *VT = dyn_cast<VectorType>(I.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&I);
|
|
Scatterer VOp0 = scatter(&I, I.getOperand(0));
|
|
Scatterer VOp1 = scatter(&I, I.getOperand(1));
|
|
assert(VOp0.size() == NumElems && "Mismatched binary operation");
|
|
assert(VOp1.size() == NumElems && "Mismatched binary operation");
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
for (unsigned Elem = 0; Elem < NumElems; ++Elem) {
|
|
Value *Op0 = VOp0[Elem];
|
|
Value *Op1 = VOp1[Elem];
|
|
Res[Elem] = Split(Builder, Op0, Op1, I.getName() + ".i" + Twine(Elem));
|
|
}
|
|
gather(&I, Res);
|
|
return true;
|
|
}
|
|
|
|
static bool isTriviallyScalariable(Intrinsic::ID ID) {
|
|
return isTriviallyVectorizable(ID);
|
|
}
|
|
|
|
// All of the current scalarizable intrinsics only have one mangled type.
|
|
static Function *getScalarIntrinsicDeclaration(Module *M,
|
|
Intrinsic::ID ID,
|
|
ArrayRef<Type*> Tys) {
|
|
return Intrinsic::getDeclaration(M, ID, Tys);
|
|
}
|
|
|
|
/// If a call to a vector typed intrinsic function, split into a scalar call per
|
|
/// element if possible for the intrinsic.
|
|
bool ScalarizerVisitor::splitCall(CallInst &CI) {
|
|
VectorType *VT = dyn_cast<VectorType>(CI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
Function *F = CI.getCalledFunction();
|
|
if (!F)
|
|
return false;
|
|
|
|
Intrinsic::ID ID = F->getIntrinsicID();
|
|
if (ID == Intrinsic::not_intrinsic || !isTriviallyScalariable(ID))
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
unsigned NumArgs = CI.getNumArgOperands();
|
|
|
|
ValueVector ScalarOperands(NumArgs);
|
|
SmallVector<Scatterer, 8> Scattered(NumArgs);
|
|
|
|
Scattered.resize(NumArgs);
|
|
|
|
SmallVector<llvm::Type *, 3> Tys;
|
|
Tys.push_back(VT->getScalarType());
|
|
|
|
// Assumes that any vector type has the same number of elements as the return
|
|
// vector type, which is true for all current intrinsics.
|
|
for (unsigned I = 0; I != NumArgs; ++I) {
|
|
Value *OpI = CI.getOperand(I);
|
|
if (OpI->getType()->isVectorTy()) {
|
|
Scattered[I] = scatter(&CI, OpI);
|
|
assert(Scattered[I].size() == NumElems && "mismatched call operands");
|
|
} else {
|
|
ScalarOperands[I] = OpI;
|
|
if (hasVectorInstrinsicOverloadedScalarOpd(ID, I))
|
|
Tys.push_back(OpI->getType());
|
|
}
|
|
}
|
|
|
|
ValueVector Res(NumElems);
|
|
ValueVector ScalarCallOps(NumArgs);
|
|
|
|
Function *NewIntrin = getScalarIntrinsicDeclaration(F->getParent(), ID, Tys);
|
|
IRBuilder<> Builder(&CI);
|
|
|
|
// Perform actual scalarization, taking care to preserve any scalar operands.
|
|
for (unsigned Elem = 0; Elem < NumElems; ++Elem) {
|
|
ScalarCallOps.clear();
|
|
|
|
for (unsigned J = 0; J != NumArgs; ++J) {
|
|
if (hasVectorInstrinsicScalarOpd(ID, J))
|
|
ScalarCallOps.push_back(ScalarOperands[J]);
|
|
else
|
|
ScalarCallOps.push_back(Scattered[J][Elem]);
|
|
}
|
|
|
|
Res[Elem] = Builder.CreateCall(NewIntrin, ScalarCallOps,
|
|
CI.getName() + ".i" + Twine(Elem));
|
|
}
|
|
|
|
gather(&CI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitSelectInst(SelectInst &SI) {
|
|
VectorType *VT = dyn_cast<VectorType>(SI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&SI);
|
|
Scatterer VOp1 = scatter(&SI, SI.getOperand(1));
|
|
Scatterer VOp2 = scatter(&SI, SI.getOperand(2));
|
|
assert(VOp1.size() == NumElems && "Mismatched select");
|
|
assert(VOp2.size() == NumElems && "Mismatched select");
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
|
|
if (SI.getOperand(0)->getType()->isVectorTy()) {
|
|
Scatterer VOp0 = scatter(&SI, SI.getOperand(0));
|
|
assert(VOp0.size() == NumElems && "Mismatched select");
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
Value *Op0 = VOp0[I];
|
|
Value *Op1 = VOp1[I];
|
|
Value *Op2 = VOp2[I];
|
|
Res[I] = Builder.CreateSelect(Op0, Op1, Op2,
|
|
SI.getName() + ".i" + Twine(I));
|
|
}
|
|
} else {
|
|
Value *Op0 = SI.getOperand(0);
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
Value *Op1 = VOp1[I];
|
|
Value *Op2 = VOp2[I];
|
|
Res[I] = Builder.CreateSelect(Op0, Op1, Op2,
|
|
SI.getName() + ".i" + Twine(I));
|
|
}
|
|
}
|
|
gather(&SI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitICmpInst(ICmpInst &ICI) {
|
|
return splitBinary(ICI, ICmpSplitter(ICI));
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitFCmpInst(FCmpInst &FCI) {
|
|
return splitBinary(FCI, FCmpSplitter(FCI));
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitUnaryOperator(UnaryOperator &UO) {
|
|
return splitUnary(UO, UnarySplitter(UO));
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitBinaryOperator(BinaryOperator &BO) {
|
|
return splitBinary(BO, BinarySplitter(BO));
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitGetElementPtrInst(GetElementPtrInst &GEPI) {
|
|
VectorType *VT = dyn_cast<VectorType>(GEPI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
IRBuilder<> Builder(&GEPI);
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
unsigned NumIndices = GEPI.getNumIndices();
|
|
|
|
// The base pointer might be scalar even if it's a vector GEP. In those cases,
|
|
// splat the pointer into a vector value, and scatter that vector.
|
|
Value *Op0 = GEPI.getOperand(0);
|
|
if (!Op0->getType()->isVectorTy())
|
|
Op0 = Builder.CreateVectorSplat(NumElems, Op0);
|
|
Scatterer Base = scatter(&GEPI, Op0);
|
|
|
|
SmallVector<Scatterer, 8> Ops;
|
|
Ops.resize(NumIndices);
|
|
for (unsigned I = 0; I < NumIndices; ++I) {
|
|
Value *Op = GEPI.getOperand(I + 1);
|
|
|
|
// The indices might be scalars even if it's a vector GEP. In those cases,
|
|
// splat the scalar into a vector value, and scatter that vector.
|
|
if (!Op->getType()->isVectorTy())
|
|
Op = Builder.CreateVectorSplat(NumElems, Op);
|
|
|
|
Ops[I] = scatter(&GEPI, Op);
|
|
}
|
|
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
SmallVector<Value *, 8> Indices;
|
|
Indices.resize(NumIndices);
|
|
for (unsigned J = 0; J < NumIndices; ++J)
|
|
Indices[J] = Ops[J][I];
|
|
Res[I] = Builder.CreateGEP(GEPI.getSourceElementType(), Base[I], Indices,
|
|
GEPI.getName() + ".i" + Twine(I));
|
|
if (GEPI.isInBounds())
|
|
if (GetElementPtrInst *NewGEPI = dyn_cast<GetElementPtrInst>(Res[I]))
|
|
NewGEPI->setIsInBounds();
|
|
}
|
|
gather(&GEPI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitCastInst(CastInst &CI) {
|
|
VectorType *VT = dyn_cast<VectorType>(CI.getDestTy());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&CI);
|
|
Scatterer Op0 = scatter(&CI, CI.getOperand(0));
|
|
assert(Op0.size() == NumElems && "Mismatched cast");
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
for (unsigned I = 0; I < NumElems; ++I)
|
|
Res[I] = Builder.CreateCast(CI.getOpcode(), Op0[I], VT->getElementType(),
|
|
CI.getName() + ".i" + Twine(I));
|
|
gather(&CI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitBitCastInst(BitCastInst &BCI) {
|
|
VectorType *DstVT = dyn_cast<VectorType>(BCI.getDestTy());
|
|
VectorType *SrcVT = dyn_cast<VectorType>(BCI.getSrcTy());
|
|
if (!DstVT || !SrcVT)
|
|
return false;
|
|
|
|
unsigned DstNumElems = cast<FixedVectorType>(DstVT)->getNumElements();
|
|
unsigned SrcNumElems = cast<FixedVectorType>(SrcVT)->getNumElements();
|
|
IRBuilder<> Builder(&BCI);
|
|
Scatterer Op0 = scatter(&BCI, BCI.getOperand(0));
|
|
ValueVector Res;
|
|
Res.resize(DstNumElems);
|
|
|
|
if (DstNumElems == SrcNumElems) {
|
|
for (unsigned I = 0; I < DstNumElems; ++I)
|
|
Res[I] = Builder.CreateBitCast(Op0[I], DstVT->getElementType(),
|
|
BCI.getName() + ".i" + Twine(I));
|
|
} else if (DstNumElems > SrcNumElems) {
|
|
// <M x t1> -> <N*M x t2>. Convert each t1 to <N x t2> and copy the
|
|
// individual elements to the destination.
|
|
unsigned FanOut = DstNumElems / SrcNumElems;
|
|
auto *MidTy = FixedVectorType::get(DstVT->getElementType(), FanOut);
|
|
unsigned ResI = 0;
|
|
for (unsigned Op0I = 0; Op0I < SrcNumElems; ++Op0I) {
|
|
Value *V = Op0[Op0I];
|
|
Instruction *VI;
|
|
// Look through any existing bitcasts before converting to <N x t2>.
|
|
// In the best case, the resulting conversion might be a no-op.
|
|
while ((VI = dyn_cast<Instruction>(V)) &&
|
|
VI->getOpcode() == Instruction::BitCast)
|
|
V = VI->getOperand(0);
|
|
V = Builder.CreateBitCast(V, MidTy, V->getName() + ".cast");
|
|
Scatterer Mid = scatter(&BCI, V);
|
|
for (unsigned MidI = 0; MidI < FanOut; ++MidI)
|
|
Res[ResI++] = Mid[MidI];
|
|
}
|
|
} else {
|
|
// <N*M x t1> -> <M x t2>. Convert each group of <N x t1> into a t2.
|
|
unsigned FanIn = SrcNumElems / DstNumElems;
|
|
auto *MidTy = FixedVectorType::get(SrcVT->getElementType(), FanIn);
|
|
unsigned Op0I = 0;
|
|
for (unsigned ResI = 0; ResI < DstNumElems; ++ResI) {
|
|
Value *V = PoisonValue::get(MidTy);
|
|
for (unsigned MidI = 0; MidI < FanIn; ++MidI)
|
|
V = Builder.CreateInsertElement(V, Op0[Op0I++], Builder.getInt32(MidI),
|
|
BCI.getName() + ".i" + Twine(ResI)
|
|
+ ".upto" + Twine(MidI));
|
|
Res[ResI] = Builder.CreateBitCast(V, DstVT->getElementType(),
|
|
BCI.getName() + ".i" + Twine(ResI));
|
|
}
|
|
}
|
|
gather(&BCI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitInsertElementInst(InsertElementInst &IEI) {
|
|
VectorType *VT = dyn_cast<VectorType>(IEI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&IEI);
|
|
Scatterer Op0 = scatter(&IEI, IEI.getOperand(0));
|
|
Value *NewElt = IEI.getOperand(1);
|
|
Value *InsIdx = IEI.getOperand(2);
|
|
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
|
|
if (auto *CI = dyn_cast<ConstantInt>(InsIdx)) {
|
|
for (unsigned I = 0; I < NumElems; ++I)
|
|
Res[I] = CI->getValue().getZExtValue() == I ? NewElt : Op0[I];
|
|
} else {
|
|
if (!ScalarizeVariableInsertExtract)
|
|
return false;
|
|
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
Value *ShouldReplace =
|
|
Builder.CreateICmpEQ(InsIdx, ConstantInt::get(InsIdx->getType(), I),
|
|
InsIdx->getName() + ".is." + Twine(I));
|
|
Value *OldElt = Op0[I];
|
|
Res[I] = Builder.CreateSelect(ShouldReplace, NewElt, OldElt,
|
|
IEI.getName() + ".i" + Twine(I));
|
|
}
|
|
}
|
|
|
|
gather(&IEI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitExtractElementInst(ExtractElementInst &EEI) {
|
|
VectorType *VT = dyn_cast<VectorType>(EEI.getOperand(0)->getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumSrcElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&EEI);
|
|
Scatterer Op0 = scatter(&EEI, EEI.getOperand(0));
|
|
Value *ExtIdx = EEI.getOperand(1);
|
|
|
|
if (auto *CI = dyn_cast<ConstantInt>(ExtIdx)) {
|
|
Value *Res = Op0[CI->getValue().getZExtValue()];
|
|
gather(&EEI, {Res});
|
|
return true;
|
|
}
|
|
|
|
if (!ScalarizeVariableInsertExtract)
|
|
return false;
|
|
|
|
Value *Res = UndefValue::get(VT->getElementType());
|
|
for (unsigned I = 0; I < NumSrcElems; ++I) {
|
|
Value *ShouldExtract =
|
|
Builder.CreateICmpEQ(ExtIdx, ConstantInt::get(ExtIdx->getType(), I),
|
|
ExtIdx->getName() + ".is." + Twine(I));
|
|
Value *Elt = Op0[I];
|
|
Res = Builder.CreateSelect(ShouldExtract, Elt, Res,
|
|
EEI.getName() + ".upto" + Twine(I));
|
|
}
|
|
gather(&EEI, {Res});
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
|
|
VectorType *VT = dyn_cast<VectorType>(SVI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
Scatterer Op0 = scatter(&SVI, SVI.getOperand(0));
|
|
Scatterer Op1 = scatter(&SVI, SVI.getOperand(1));
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
int Selector = SVI.getMaskValue(I);
|
|
if (Selector < 0)
|
|
Res[I] = UndefValue::get(VT->getElementType());
|
|
else if (unsigned(Selector) < Op0.size())
|
|
Res[I] = Op0[Selector];
|
|
else
|
|
Res[I] = Op1[Selector - Op0.size()];
|
|
}
|
|
gather(&SVI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitPHINode(PHINode &PHI) {
|
|
VectorType *VT = dyn_cast<VectorType>(PHI.getType());
|
|
if (!VT)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(VT)->getNumElements();
|
|
IRBuilder<> Builder(&PHI);
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
|
|
unsigned NumOps = PHI.getNumOperands();
|
|
for (unsigned I = 0; I < NumElems; ++I)
|
|
Res[I] = Builder.CreatePHI(VT->getElementType(), NumOps,
|
|
PHI.getName() + ".i" + Twine(I));
|
|
|
|
for (unsigned I = 0; I < NumOps; ++I) {
|
|
Scatterer Op = scatter(&PHI, PHI.getIncomingValue(I));
|
|
BasicBlock *IncomingBlock = PHI.getIncomingBlock(I);
|
|
for (unsigned J = 0; J < NumElems; ++J)
|
|
cast<PHINode>(Res[J])->addIncoming(Op[J], IncomingBlock);
|
|
}
|
|
gather(&PHI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitLoadInst(LoadInst &LI) {
|
|
if (!ScalarizeLoadStore)
|
|
return false;
|
|
if (!LI.isSimple())
|
|
return false;
|
|
|
|
Optional<VectorLayout> Layout = getVectorLayout(
|
|
LI.getType(), LI.getAlign(), LI.getModule()->getDataLayout());
|
|
if (!Layout)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(Layout->VecTy)->getNumElements();
|
|
IRBuilder<> Builder(&LI);
|
|
Scatterer Ptr = scatter(&LI, LI.getPointerOperand());
|
|
ValueVector Res;
|
|
Res.resize(NumElems);
|
|
|
|
for (unsigned I = 0; I < NumElems; ++I)
|
|
Res[I] = Builder.CreateAlignedLoad(Layout->VecTy->getElementType(), Ptr[I],
|
|
Align(Layout->getElemAlign(I)),
|
|
LI.getName() + ".i" + Twine(I));
|
|
gather(&LI, Res);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitStoreInst(StoreInst &SI) {
|
|
if (!ScalarizeLoadStore)
|
|
return false;
|
|
if (!SI.isSimple())
|
|
return false;
|
|
|
|
Value *FullValue = SI.getValueOperand();
|
|
Optional<VectorLayout> Layout = getVectorLayout(
|
|
FullValue->getType(), SI.getAlign(), SI.getModule()->getDataLayout());
|
|
if (!Layout)
|
|
return false;
|
|
|
|
unsigned NumElems = cast<FixedVectorType>(Layout->VecTy)->getNumElements();
|
|
IRBuilder<> Builder(&SI);
|
|
Scatterer VPtr = scatter(&SI, SI.getPointerOperand());
|
|
Scatterer VVal = scatter(&SI, FullValue);
|
|
|
|
ValueVector Stores;
|
|
Stores.resize(NumElems);
|
|
for (unsigned I = 0; I < NumElems; ++I) {
|
|
Value *Val = VVal[I];
|
|
Value *Ptr = VPtr[I];
|
|
Stores[I] = Builder.CreateAlignedStore(Val, Ptr, Layout->getElemAlign(I));
|
|
}
|
|
transferMetadataAndIRFlags(&SI, Stores);
|
|
return true;
|
|
}
|
|
|
|
bool ScalarizerVisitor::visitCallInst(CallInst &CI) {
|
|
return splitCall(CI);
|
|
}
|
|
|
|
// Delete the instructions that we scalarized. If a full vector result
|
|
// is still needed, recreate it using InsertElements.
|
|
bool ScalarizerVisitor::finish() {
|
|
// The presence of data in Gathered or Scattered indicates changes
|
|
// made to the Function.
|
|
if (Gathered.empty() && Scattered.empty())
|
|
return false;
|
|
for (const auto &GMI : Gathered) {
|
|
Instruction *Op = GMI.first;
|
|
ValueVector &CV = *GMI.second;
|
|
if (!Op->use_empty()) {
|
|
// The value is still needed, so recreate it using a series of
|
|
// InsertElements.
|
|
Value *Res = PoisonValue::get(Op->getType());
|
|
if (auto *Ty = dyn_cast<VectorType>(Op->getType())) {
|
|
BasicBlock *BB = Op->getParent();
|
|
unsigned Count = cast<FixedVectorType>(Ty)->getNumElements();
|
|
IRBuilder<> Builder(Op);
|
|
if (isa<PHINode>(Op))
|
|
Builder.SetInsertPoint(BB, BB->getFirstInsertionPt());
|
|
for (unsigned I = 0; I < Count; ++I)
|
|
Res = Builder.CreateInsertElement(Res, CV[I], Builder.getInt32(I),
|
|
Op->getName() + ".upto" + Twine(I));
|
|
Res->takeName(Op);
|
|
} else {
|
|
assert(CV.size() == 1 && Op->getType() == CV[0]->getType());
|
|
Res = CV[0];
|
|
if (Op == Res)
|
|
continue;
|
|
}
|
|
Op->replaceAllUsesWith(Res);
|
|
}
|
|
PotentiallyDeadInstrs.emplace_back(Op);
|
|
}
|
|
Gathered.clear();
|
|
Scattered.clear();
|
|
|
|
RecursivelyDeleteTriviallyDeadInstructionsPermissive(PotentiallyDeadInstrs);
|
|
|
|
return true;
|
|
}
|
|
|
|
PreservedAnalyses ScalarizerPass::run(Function &F, FunctionAnalysisManager &AM) {
|
|
Module &M = *F.getParent();
|
|
unsigned ParallelLoopAccessMDKind =
|
|
M.getContext().getMDKindID("llvm.mem.parallel_loop_access");
|
|
DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F);
|
|
ScalarizerVisitor Impl(ParallelLoopAccessMDKind, DT);
|
|
bool Changed = Impl.visit(F);
|
|
PreservedAnalyses PA;
|
|
PA.preserve<DominatorTreeAnalysis>();
|
|
return Changed ? PA : PreservedAnalyses::all();
|
|
}
|