[llvm] r268446 - PM: Port LoopSimplifyCFG to the new pass manager
Justin Bogner via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 17 11:01:40 PDT 2016
Davide Italiano <davide at freebsd.org> writes:
> On Tue, May 3, 2016 at 2:47 PM, Justin Bogner via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>> Author: bogner
>> Date: Tue May 3 16:47:32 2016
>> New Revision: 268446
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=268446&view=rev
>> Log:
>> PM: Port LoopSimplifyCFG to the new pass manager
>>
>> Added:
>> llvm/trunk/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h
>> Modified:
>> llvm/trunk/include/llvm/InitializePasses.h
>> llvm/trunk/lib/Passes/PassBuilder.cpp
>> llvm/trunk/lib/Passes/PassRegistry.def
>> llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
>> llvm/trunk/lib/Transforms/Scalar/Scalar.cpp
>> llvm/trunk/test/Transforms/LoopSimplifyCFG/merge-header.ll
>>
>> Modified: llvm/trunk/include/llvm/InitializePasses.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=268446&r1=268445&r2=268446&view=diff
>> ==============================================================================
>> --- llvm/trunk/include/llvm/InitializePasses.h (original)
>> +++ llvm/trunk/include/llvm/InitializePasses.h Tue May 3 16:47:32 2016
>> @@ -180,7 +180,7 @@ void initializeLoopInterchangePass(PassR
>> void initializeLoopInstSimplifyPass(PassRegistry&);
>> void initializeLoopRotatePass(PassRegistry&);
>> void initializeLoopSimplifyPass(PassRegistry&);
>> -void initializeLoopSimplifyCFGPass(PassRegistry&);
>> +void initializeLoopSimplifyCFGLegacyPassPass(PassRegistry&);
>> void initializeLoopStrengthReducePass(PassRegistry&);
>> void initializeGlobalMergePass(PassRegistry&);
>> void initializeLoopRerollPass(PassRegistry&);
>>
>> Added: llvm/trunk/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h?rev=268446&view=auto
>> ==============================================================================
>> --- llvm/trunk/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h (added)
>> +++ llvm/trunk/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h Tue May 3 16:47:32 2016
>> @@ -0,0 +1,32 @@
>> +//===- LoopSimplifyCFG.cpp - Loop CFG Simplification Pass -------*- C++ -*-===//
>> +//
>> +// The LLVM Compiler Infrastructure
>> +//
>> +// This file is distributed under the University of Illinois Open Source
>> +// License. See LICENSE.TXT for details.
>> +//
>> +//===----------------------------------------------------------------------===//
>> +//
>> +// This file implements the Loop SimplifyCFG Pass. This pass is responsible for
>> +// basic loop CFG cleanup, primarily to assist other loop passes. If you
>> +// encounter a noncanonical CFG construct that causes another loop pass to
>> +// perform suboptimally, this is the place to fix it up.
>> +//
>> +//===----------------------------------------------------------------------===//
>> +
>> +#ifndef LLVM_TRANSFORMS_SCALAR_LOOPSIMPLIFYCFG_H
>> +#define LLVM_TRANSFORMS_SCALAR_LOOPSIMPLIFYCFG_H
>> +
>> +#include "llvm/Analysis/LoopInfo.h"
>> +#include "llvm/IR/PassManager.h"
>> +
>> +namespace llvm {
>> +
>> +/// Performs basic CFG simplifications to assist other loop passes.
>> +class LoopSimplifyCFGPass : public PassInfoMixin<LoopSimplifyCFGPass> {
>> +public:
>> + PreservedAnalyses run(Loop &L, AnalysisManager<Loop> &AM);
>> +};
>> +} // end namespace llvm
>> +
>> +#endif // LLVM_TRANSFORMS_SCALAR_LOOPSIMPLIFYCFG_H
>>
>> Modified: llvm/trunk/lib/Passes/PassBuilder.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassBuilder.cpp?rev=268446&r1=268445&r2=268446&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Passes/PassBuilder.cpp (original)
>> +++ llvm/trunk/lib/Passes/PassBuilder.cpp Tue May 3 16:47:32 2016
>> @@ -57,6 +57,7 @@
>> #include "llvm/Transforms/Scalar/ADCE.h"
>> #include "llvm/Transforms/Scalar/DCE.h"
>> #include "llvm/Transforms/Scalar/EarlyCSE.h"
>> +#include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
>> #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
>> #include "llvm/Transforms/Scalar/GVN.h"
>> #include "llvm/Transforms/Scalar/Reassociate.h"
>>
>> Modified: llvm/trunk/lib/Passes/PassRegistry.def
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassRegistry.def?rev=268446&r1=268445&r2=268446&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Passes/PassRegistry.def (original)
>> +++ llvm/trunk/lib/Passes/PassRegistry.def Tue May 3 16:47:32 2016
>> @@ -136,4 +136,5 @@ LOOP_ANALYSIS("no-op-loop", NoOpLoopAnal
>> LOOP_PASS("invalidate<all>", InvalidateAllAnalysesPass())
>> LOOP_PASS("no-op-loop", NoOpLoopPass())
>> LOOP_PASS("print", PrintLoopPass(dbgs()))
>> +LOOP_PASS("simplify-cfg", LoopSimplifyCFGPass())
>> #undef LOOP_PASS
>>
>> Modified: llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp?rev=268446&r1=268445&r2=268446&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp Tue May 3 16:47:32 2016
>> @@ -14,7 +14,7 @@
>> //
>> //===----------------------------------------------------------------------===//
>>
>> -#include "llvm/Transforms/Scalar.h"
>> +#include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
>> #include "llvm/ADT/SmallVector.h"
>> #include "llvm/ADT/Statistic.h"
>> #include "llvm/Analysis/AliasAnalysis.h"
>> @@ -24,47 +24,23 @@
>> #include "llvm/Analysis/GlobalsModRef.h"
>> #include "llvm/Analysis/LoopInfo.h"
>> #include "llvm/Analysis/LoopPass.h"
>> +#include "llvm/Analysis/LoopPassManager.h"
>> #include "llvm/Analysis/ScalarEvolution.h"
>> #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
>> #include "llvm/Analysis/TargetTransformInfo.h"
>> #include "llvm/IR/Dominators.h"
>> +#include "llvm/Transforms/Scalar.h"
>> #include "llvm/Transforms/Utils/Local.h"
>> #include "llvm/Transforms/Utils/LoopUtils.h"
>> using namespace llvm;
>>
>> #define DEBUG_TYPE "loop-simplifycfg"
>>
>> -namespace {
>> -class LoopSimplifyCFG : public LoopPass {
>> -public:
>> - static char ID; // Pass ID, replacement for typeid
>> - LoopSimplifyCFG() : LoopPass(ID) {
>> - initializeLoopSimplifyCFGPass(*PassRegistry::getPassRegistry());
>> - }
>> -
>> - bool runOnLoop(Loop *L, LPPassManager &) override;
>> -
>> - void getAnalysisUsage(AnalysisUsage &AU) const override {
>> - AU.addPreserved<DependenceAnalysis>();
>> - getLoopAnalysisUsage(AU);
>> - }
>> -};
>> -}
>> -
>> -char LoopSimplifyCFG::ID = 0;
>> -INITIALIZE_PASS_BEGIN(LoopSimplifyCFG, "loop-simplifycfg", "Simplify loop CFG",
>> - false, false)
>> -INITIALIZE_PASS_DEPENDENCY(LoopPass)
>> -INITIALIZE_PASS_END(LoopSimplifyCFG, "loop-simplifycfg", "Simplify loop CFG",
>> - false, false)
>> -
>> -Pass *llvm::createLoopSimplifyCFGPass() { return new LoopSimplifyCFG(); }
>> -
>> -static bool simplifyLoopCFG(Loop *L, DominatorTree *DT, LoopInfo *LI) {
>> +static bool simplifyLoopCFG(Loop &L, DominatorTree &DT, LoopInfo &LI) {
>> bool Changed = false;
>> // Copy blocks into a temporary array to avoid iterator invalidation issues
>> // as we remove them.
>> - SmallVector<WeakVH, 16> Blocks(L->blocks());
>> + SmallVector<WeakVH, 16> Blocks(L.blocks());
>>
>> for (auto &Block : Blocks) {
>> // Attempt to merge blocks in the trivial case. Don't modify blocks which
>> @@ -74,27 +50,64 @@ static bool simplifyLoopCFG(Loop *L, Dom
>> continue;
>>
>> BasicBlock *Pred = Succ->getSinglePredecessor();
>> - if (!Pred || !Pred->getSingleSuccessor() || LI->getLoopFor(Pred) != L)
>> + if (!Pred || !Pred->getSingleSuccessor() || LI.getLoopFor(Pred) != &L)
>> continue;
>>
>> // Pred is going to disappear, so we need to update the loop info.
>> - if (L->getHeader() == Pred)
>> - L->moveToHeader(Succ);
>> - LI->removeBlock(Pred);
>> - MergeBasicBlockIntoOnlyPred(Succ, DT);
>> + if (L.getHeader() == Pred)
>> + L.moveToHeader(Succ);
>> + LI.removeBlock(Pred);
>> + MergeBasicBlockIntoOnlyPred(Succ, &DT);
>> Changed = true;
>> }
>>
>> return Changed;
>> }
>>
>> -/// runOnLoop - Perform basic CFG simplifications to assist other loop passes.
>> -/// For now, this only attempts to merge blocks in the trivial case.
>> -bool LoopSimplifyCFG::runOnLoop(Loop *L, LPPassManager &) {
>> - if (skipLoop(L))
>> - return false;
>> -
>> - DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
>> - LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
>> - return simplifyLoopCFG(L, DT, LI);
>> +PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, AnalysisManager<Loop> &AM) {
>> + auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
>> + Function *F = L.getHeader()->getParent();
>> +
>> + auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
>> + auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
>> + assert((LI && DT) && "Analyses for LoopSimplifyCFG not available");
>> +
>
> Is there a particular reason why this uses getCachedResult() +
> assert() instead of getResult() ?
Simply put, getResult() isn't allowed here. Try to change it and check
the compile errors ;)
This is one of those cases where writing "auto &" hurt clarity.
getManager returns const&, and getResult isn't const so it can't be
called. We've discussed that it might be better to add more API for
these "required to have already been calculated" results, since this
kind of assert is a bit fragile.
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