[PATCH] D20146: [PM] Port DSE to the new pass manager.
Justin Bogner via llvm-commits
llvm-commits at lists.llvm.org
Fri May 13 16:14:46 PDT 2016
Jake VanAdrighem <jvanadrighem at gmail.com> writes:
> JakeVanAdrighem updated this revision to Diff 56994.
> JakeVanAdrighem added a comment.
>
> Not sure if the amount of change here is 'ugly' but I've addressed all
> the responses.
Since all of the state is explicitly passed around now anyway, we might
as well turn the methods of DSEPass into free functions. This will allow
us to get rid of the private namespace and avoid the awkward friend-ing
of the legacy pass as well, which will make the API much clearer.
>
> Repository:
> rL LLVM
>
> http://reviews.llvm.org/D20146
>
> Files:
> include/llvm/InitializePasses.h
> include/llvm/Transforms/Scalar/DeadStoreElimination.h
> lib/Passes/PassBuilder.cpp
> lib/Passes/PassRegistry.def
> lib/Transforms/Scalar/DeadStoreElimination.cpp
> lib/Transforms/Scalar/Scalar.cpp
> test/Transforms/DeadStoreElimination/simple.ll
>
> Index: test/Transforms/DeadStoreElimination/simple.ll
> ===================================================================
> --- test/Transforms/DeadStoreElimination/simple.ll
> +++ test/Transforms/DeadStoreElimination/simple.ll
> @@ -1,4 +1,5 @@
> ; RUN: opt < %s -basicaa -dse -S | FileCheck %s
> +; RUN: opt < %s -aa-pipeline=basic-aa -passes=dse -S | FileCheck %s
> target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
>
> declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
> Index: lib/Transforms/Scalar/Scalar.cpp
> ===================================================================
> --- lib/Transforms/Scalar/Scalar.cpp
> +++ lib/Transforms/Scalar/Scalar.cpp
> @@ -40,7 +40,7 @@
> initializeDCELegacyPassPass(Registry);
> initializeDeadInstEliminationPass(Registry);
> initializeScalarizerPass(Registry);
> - initializeDSEPass(Registry);
> + initializeDSELegacyPassPass(Registry);
> initializeGVNLegacyPassPass(Registry);
> initializeEarlyCSELegacyPassPass(Registry);
> initializeFlattenCFGPassPass(Registry);
> Index: lib/Transforms/Scalar/DeadStoreElimination.cpp
> ===================================================================
> --- lib/Transforms/Scalar/DeadStoreElimination.cpp
> +++ lib/Transforms/Scalar/DeadStoreElimination.cpp
> @@ -15,7 +15,7 @@
> //
> //===----------------------------------------------------------------------===//
>
> -#include "llvm/Transforms/Scalar.h"
> +#include "llvm/Transforms/Scalar/DeadStoreElimination.h"
> #include "llvm/ADT/STLExtras.h"
> #include "llvm/ADT/SetVector.h"
> #include "llvm/ADT/Statistic.h"
> @@ -36,8 +36,10 @@
> #include "llvm/Pass.h"
> #include "llvm/Support/Debug.h"
> #include "llvm/Support/raw_ostream.h"
> +#include "llvm/Transforms/Scalar.h"
> #include "llvm/Transforms/Utils/Local.h"
> using namespace llvm;
> +using namespace llvm::dse;
>
> #define DEBUG_TYPE "dse"
>
> @@ -45,69 +47,6 @@
> STATISTIC(NumFastStores, "Number of stores deleted");
> STATISTIC(NumFastOther , "Number of other instrs removed");
>
> -namespace {
> - struct DSE : public FunctionPass {
> - AliasAnalysis *AA;
> - MemoryDependenceResults *MD;
> - DominatorTree *DT;
> - const TargetLibraryInfo *TLI;
> -
> - static char ID; // Pass identification, replacement for typeid
> - DSE() : FunctionPass(ID), AA(nullptr), MD(nullptr), DT(nullptr) {
> - initializeDSEPass(*PassRegistry::getPassRegistry());
> - }
> -
> - bool runOnFunction(Function &F) override {
> - if (skipFunction(F))
> - return false;
> -
> - AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
> - MD = &getAnalysis<MemoryDependenceWrapperPass>().getMemDep();
> - DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
> - TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
> -
> - bool Changed = false;
> - for (BasicBlock &I : F)
> - // Only check non-dead blocks. Dead blocks may have strange pointer
> - // cycles that will confuse alias analysis.
> - if (DT->isReachableFromEntry(&I))
> - Changed |= runOnBasicBlock(I);
> -
> - AA = nullptr; MD = nullptr; DT = nullptr;
> - return Changed;
> - }
> -
> - bool runOnBasicBlock(BasicBlock &BB);
> - bool MemoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI);
> - bool HandleFree(CallInst *F);
> - bool handleEndBlock(BasicBlock &BB);
> - void RemoveAccessedObjects(const MemoryLocation &LoadedLoc,
> - SmallSetVector<Value *, 16> &DeadStackObjects,
> - const DataLayout &DL);
> -
> - void getAnalysisUsage(AnalysisUsage &AU) const override {
> - AU.setPreservesCFG();
> - AU.addRequired<DominatorTreeWrapperPass>();
> - AU.addRequired<AAResultsWrapperPass>();
> - AU.addRequired<MemoryDependenceWrapperPass>();
> - AU.addRequired<TargetLibraryInfoWrapperPass>();
> - AU.addPreserved<DominatorTreeWrapperPass>();
> - AU.addPreserved<GlobalsAAWrapperPass>();
> - AU.addPreserved<MemoryDependenceWrapperPass>();
> - }
> - };
> -}
> -
> -char DSE::ID = 0;
> -INITIALIZE_PASS_BEGIN(DSE, "dse", "Dead Store Elimination", false, false)
> -INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
> -INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
> -INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
> -INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)
> -INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
> -INITIALIZE_PASS_END(DSE, "dse", "Dead Store Elimination", false, false)
> -
> -FunctionPass *llvm::createDeadStoreEliminationPass() { return new DSE(); }
>
> //===----------------------------------------------------------------------===//
> // Helper functions
> @@ -507,7 +446,9 @@
> // DSE Pass
> //===----------------------------------------------------------------------===//
>
> -bool DSE::runOnBasicBlock(BasicBlock &BB) {
> +bool DSEPass::runOnBasicBlock(BasicBlock &BB, AliasAnalysis *AA,
> + MemoryDependenceResults *MD, DominatorTree *DT,
> + const TargetLibraryInfo *TLI) {
> const DataLayout &DL = BB.getModule()->getDataLayout();
> bool MadeChange = false;
>
> @@ -517,7 +458,7 @@
>
> // Handle 'free' calls specially.
> if (CallInst *F = isFreeCall(Inst, TLI)) {
> - MadeChange |= HandleFree(F);
> + MadeChange |= HandleFree(F, AA, MD, DT, TLI);
> continue;
> }
>
> @@ -547,7 +488,7 @@
> if (LoadInst *DepLoad = dyn_cast<LoadInst>(SI->getValueOperand())) {
> if (SI->getPointerOperand() == DepLoad->getPointerOperand() &&
> isRemovable(SI) &&
> - MemoryIsNotModifiedBetween(DepLoad, SI)) {
> + MemoryIsNotModifiedBetween(DepLoad, SI, AA)) {
>
> DEBUG(dbgs() << "DSE: Remove Store Of Load from same pointer:\n "
> << "LOAD: " << *DepLoad << "\n STORE: " << *SI << '\n');
> @@ -566,7 +507,7 @@
> GetUnderlyingObject(SI->getPointerOperand(), DL));
>
> if (UnderlyingPointer && isCallocLikeFn(UnderlyingPointer, TLI) &&
> - MemoryIsNotModifiedBetween(UnderlyingPointer, SI)) {
> + MemoryIsNotModifiedBetween(UnderlyingPointer, SI, AA)) {
> DEBUG(dbgs()
> << "DSE: Remove null store to the calloc'ed object:\n DEAD: "
> << *Inst << "\n OBJECT: " << *UnderlyingPointer << '\n');
> @@ -698,7 +639,7 @@
> // If this block ends in a return, unwind, or unreachable, all allocas are
> // dead at its end, which means stores to them are also dead.
> if (BB.getTerminator()->getNumSuccessors() == 0)
> - MadeChange |= handleEndBlock(BB);
> + MadeChange |= handleEndBlock(BB, AA, MD, TLI);
>
> return MadeChange;
> }
> @@ -707,8 +648,9 @@
> /// modified between the first and the second instruction.
> /// Precondition: Second instruction must be dominated by the first
> /// instruction.
> -bool DSE::MemoryIsNotModifiedBetween(Instruction *FirstI,
> - Instruction *SecondI) {
> +bool DSEPass::MemoryIsNotModifiedBetween(Instruction *FirstI,
> + Instruction *SecondI,
> + AliasAnalysis *AA) {
> SmallVector<BasicBlock *, 16> WorkList;
> SmallPtrSet<BasicBlock *, 8> Visited;
> BasicBlock::iterator FirstBBI(FirstI);
> @@ -779,7 +721,9 @@
>
> /// HandleFree - Handle frees of entire structures whose dependency is a store
> /// to a field of that structure.
> -bool DSE::HandleFree(CallInst *F) {
> +bool DSEPass::HandleFree(CallInst *F, AliasAnalysis *AA,
> + MemoryDependenceResults *MD, DominatorTree *DT,
> + const TargetLibraryInfo *TLI) {
> bool MadeChange = false;
>
> MemoryLocation Loc = MemoryLocation(F->getOperand(0));
> @@ -834,7 +778,9 @@
> /// ...
> /// store i32 1, i32* %A
> /// ret void
> -bool DSE::handleEndBlock(BasicBlock &BB) {
> +bool DSEPass::handleEndBlock(BasicBlock &BB, AliasAnalysis *AA,
> + MemoryDependenceResults *MD,
> + const TargetLibraryInfo *TLI) {
> bool MadeChange = false;
>
> // Keep track of all of the stack objects that are dead at the end of the
> @@ -967,7 +913,7 @@
>
> // Remove any allocas from the DeadPointer set that are loaded, as this
> // makes any stores above the access live.
> - RemoveAccessedObjects(LoadedLoc, DeadStackObjects, DL);
> + RemoveAccessedObjects(LoadedLoc, DeadStackObjects, DL, AA, TLI);
>
> // If all of the allocas were clobbered by the access then we're not going
> // to find anything else to process.
> @@ -981,9 +927,10 @@
> /// RemoveAccessedObjects - Check to see if the specified location may alias any
> /// of the stack objects in the DeadStackObjects set. If so, they become live
> /// because the location is being loaded.
> -void DSE::RemoveAccessedObjects(const MemoryLocation &LoadedLoc,
> - SmallSetVector<Value *, 16> &DeadStackObjects,
> - const DataLayout &DL) {
> +void DSEPass::RemoveAccessedObjects(
> + const MemoryLocation &LoadedLoc,
> + SmallSetVector<Value *, 16> &DeadStackObjects, const DataLayout &DL,
> + AliasAnalysis *AA, const TargetLibraryInfo *TLI) {
> const Value *UnderlyingPointer = GetUnderlyingObject(LoadedLoc.Ptr, DL);
>
> // A constant can't be in the dead pointer set.
> @@ -1004,3 +951,79 @@
> return !AA->isNoAlias(StackLoc, LoadedLoc);
> });
> }
> +
> +PreservedAnalyses DSEPass::run(Function &F, FunctionAnalysisManager &AM) {
> + return runImpl(F, AM.getResult<AAManager>(F),
> + AM.getResult<MemoryDependenceAnalysis>(F),
> + AM.getResult<DominatorTreeAnalysis>(F),
> + AM.getResult<TargetLibraryAnalysis>(F));
> +}
> +
> +PreservedAnalyses DSEPass::runImpl(Function &F, AliasAnalysis &RunAA,
> + MemoryDependenceResults &RunMemDep,
> + DominatorTree &RunDT,
> + TargetLibraryInfo &RunTLI) {
> +
> + bool Changed = false;
> + for (BasicBlock &I : F)
> + // Only check non-dead blocks. Dead blocks may have strange pointer
> + // cycles that will confuse alias analysis.
> + if (RunDT.isReachableFromEntry(&I))
> + Changed |= runOnBasicBlock(I, &RunAA, &RunMemDep, &RunDT, &RunTLI);
> +
> + return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
> +}
> +
> +/// A legacy pass for the legacy pass manager that wraps the \c DSE pass.
> +///
> +/// This is in the llvm namespace purely to allow it to be a friend of the \c
> +/// DSE pass.
> +class llvm::dse::DSELegacyPass : public FunctionPass {
> + /// The DSE Implementation
> + DSEPass Impl;
> +
> +public:
> + DSELegacyPass() : FunctionPass(ID) {
> + initializeDSELegacyPassPass(*PassRegistry::getPassRegistry());
> + }
> +
> + bool runOnFunction(Function &F) override {
> + if (skipFunction(F))
> + return false;
> +
> + auto PA =
> + Impl.runImpl(F, getAnalysis<AAResultsWrapperPass>().getAAResults(),
> + getAnalysis<MemoryDependenceWrapperPass>().getMemDep(),
> + getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
> + getAnalysis<TargetLibraryInfoWrapperPass>().getTLI());
> + return !PA.areAllPreserved();
> + }
> +
> + void getAnalysisUsage(AnalysisUsage &AU) const override {
> + AU.setPreservesCFG();
> + AU.addRequired<DominatorTreeWrapperPass>();
> + AU.addRequired<AAResultsWrapperPass>();
> + AU.addRequired<MemoryDependenceWrapperPass>();
> + AU.addRequired<TargetLibraryInfoWrapperPass>();
> + AU.addPreserved<DominatorTreeWrapperPass>();
> + AU.addPreserved<GlobalsAAWrapperPass>();
> + AU.addPreserved<MemoryDependenceWrapperPass>();
> + }
> +
> + static char ID; // Pass identification, replacement for typeid
> +};
> +
> +char DSELegacyPass::ID = 0;
> +INITIALIZE_PASS_BEGIN(DSELegacyPass, "dse", "Dead Store Elimination", false,
> + false)
> +INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
> +INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
> +INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
> +INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)
> +INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
> +INITIALIZE_PASS_END(DSELegacyPass, "dse", "Dead Store Elimination", false,
> + false)
> +
> +FunctionPass *llvm::createDeadStoreEliminationPass() {
> + return new DSELegacyPass();
> +}
> Index: lib/Passes/PassRegistry.def
> ===================================================================
> --- lib/Passes/PassRegistry.def
> +++ lib/Passes/PassRegistry.def
> @@ -109,6 +109,7 @@
> FUNCTION_PASS("aa-eval", AAEvaluator())
> FUNCTION_PASS("adce", ADCEPass())
> FUNCTION_PASS("dce", DCEPass())
> +FUNCTION_PASS("dse", DSEPass())
> FUNCTION_PASS("early-cse", EarlyCSEPass())
> FUNCTION_PASS("instcombine", InstCombinePass())
> FUNCTION_PASS("invalidate<all>", InvalidateAllAnalysesPass())
> Index: lib/Passes/PassBuilder.cpp
> ===================================================================
> --- lib/Passes/PassBuilder.cpp
> +++ lib/Passes/PassBuilder.cpp
> @@ -63,6 +63,7 @@
> #include "llvm/Transforms/PGOInstrumentation.h"
> #include "llvm/Transforms/Scalar/ADCE.h"
> #include "llvm/Transforms/Scalar/DCE.h"
> +#include "llvm/Transforms/Scalar/DeadStoreElimination.h"
> #include "llvm/Transforms/Scalar/EarlyCSE.h"
> #include "llvm/Transforms/Scalar/GVN.h"
> #include "llvm/Transforms/Scalar/LoopRotation.h"
> Index: include/llvm/Transforms/Scalar/DeadStoreElimination.h
> ===================================================================
> --- /dev/null
> +++ include/llvm/Transforms/Scalar/DeadStoreElimination.h
> @@ -0,0 +1,71 @@
> +//===- DeadStoreElimination.h - Fast Dead Store Elimination -------------===//
> +//
> +// The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +//
> +// This file implements a trivial dead store elimination that only considers
> +// basic-block local redundant stores.
> +//
> +// FIXME: This should eventually be extended to be a post-dominator tree
> +// traversal. Doing so would be pretty trivial.
> +//
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_TRANSFORMS_SCALAR_DSE_H
> +#define LLVM_TRANSFORMS_SCALAR_DSE_H
> +
> +#include "llvm/ADT/SetVector.h"
> +#include "llvm/Analysis/AliasAnalysis.h"
> +#include "llvm/Analysis/MemoryDependenceAnalysis.h"
> +#include "llvm/Analysis/TargetLibraryInfo.h"
> +#include "llvm/IR/Dominators.h"
> +#include "llvm/IR/Function.h"
> +#include "llvm/IR/PassManager.h"
> +
> +namespace llvm {
> +
> +/// A private "module" namespace for types and utilities used by DSE. These
> +/// are implementation details and should not be used by clients.
> +namespace dse {
> +class DSELegacyPass;
> +}
> +
> +/// This class implements a trivial dead store elimination. We consider
> +/// only the redundant stores that are local to a single Basic Block.
> +class DSEPass : public PassInfoMixin<DSEPass> {
> +public:
> + DSEPass() {}
> +
> + /// \brief Run the pass over the function.
> + PreservedAnalyses run(Function &F, AnalysisManager<Function> &FAM);
> +
> +private:
> + friend class dse::DSELegacyPass;
> +
> + /// Helper used by both the public run method and by the legacy pass.
> + PreservedAnalyses runImpl(Function &F, AliasAnalysis &RunAA,
> + MemoryDependenceResults &RunMemDep,
> + DominatorTree &RunDT, TargetLibraryInfo &RunTLI);
> +
> + bool runOnBasicBlock(BasicBlock &BB, AliasAnalysis *AA,
> + MemoryDependenceResults *MD, DominatorTree *DT,
> + const TargetLibraryInfo *TLI);
> + bool MemoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI,
> + AliasAnalysis *AA);
> + bool HandleFree(CallInst *F, AliasAnalysis *AA, MemoryDependenceResults *MD,
> + DominatorTree *DT, const TargetLibraryInfo *TLI);
> + bool handleEndBlock(BasicBlock &BB, AliasAnalysis *AA,
> + MemoryDependenceResults *MD,
> + const TargetLibraryInfo *TLI);
> + void RemoveAccessedObjects(const MemoryLocation &LoadedLoc,
> + SmallSetVector<Value *, 16> &DeadStackObjects,
> + const DataLayout &DL, AliasAnalysis *AA,
> + const TargetLibraryInfo *TLI);
> +};
> +}
> +
> +#endif // LLVM_TRANSFORMS_SCALAR_DSE_H
> Index: include/llvm/InitializePasses.h
> ===================================================================
> --- include/llvm/InitializePasses.h
> +++ include/llvm/InitializePasses.h
> @@ -105,7 +105,7 @@
> void initializeDAEPass(PassRegistry&);
> void initializeDAHPass(PassRegistry&);
> void initializeDCELegacyPassPass(PassRegistry&);
> -void initializeDSEPass(PassRegistry&);
> +void initializeDSELegacyPassPass(PassRegistry&);
> void initializeDeadInstEliminationPass(PassRegistry&);
> void initializeDeadMachineInstructionElimPass(PassRegistry&);
> void initializeDelinearizationPass(PassRegistry &);
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