From e77eb6a23d69bfb175a0bfef5a081269ca8d120c Mon Sep 17 00:00:00 2001 From: Serge Pavlov Date: Fri, 13 Jan 2017 06:09:54 +0000 Subject: [PATCH] Track validity of pass results Running tests with expensive checks enabled exhibits some problems with verification of pass results. First, the pass verification may require results of analysis that are not available. For instance, verification of loop info requires results of dominator tree analysis. A pass may be marked as conserving loop info but does not need to be dependent on DominatorTreePass. When a pass manager tries to verify that loop info is valid, it needs dominator tree, but corresponding analysis may be already destroyed as no user of it remained. Another case is a pass that is skipped. For instance, entities with linkage available_externally do not need code generation and such passes are skipped for them. In this case result verification must also be skipped. To solve these problems this change introduces a special flag to the Pass structure to mark passes that have valid results. If this flag is reset, verifications dependent on the pass result are skipped. Differential Revision: https://reviews.llvm.org/D27190 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291882 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Pass.h | 36 ++++++++++++++++---- include/llvm/PassAnalysisSupport.h | 5 +++ lib/Analysis/CallGraphSCCPass.cpp | 1 + lib/Analysis/LoopInfo.cpp | 6 ++-- lib/Analysis/LoopPass.cpp | 1 + lib/CodeGen/MachineDominators.cpp | 2 +- lib/CodeGen/MachineFunctionPass.cpp | 4 ++- lib/IR/LegacyPassManager.cpp | 18 ++++++++-- lib/IR/Pass.cpp | 7 ++-- test/CodeGen/Generic/externally_available.ll | 2 +- test/CodeGen/Mips/mul.ll | 2 +- 11 files changed, 67 insertions(+), 17 deletions(-) diff --git a/include/llvm/Pass.h b/include/llvm/Pass.h index e9c8ca3072c..105da67cbb3 100644 --- a/include/llvm/Pass.h +++ b/include/llvm/Pass.h @@ -29,6 +29,7 @@ #ifndef LLVM_PASS_H #define LLVM_PASS_H +#include #include namespace llvm { @@ -82,17 +83,40 @@ class Pass { AnalysisResolver *Resolver; // Used to resolve analysis const void *PassID; PassKind Kind; + bool Executed; + void operator=(const Pass&) = delete; Pass(const Pass &) = delete; public: explicit Pass(PassKind K, char &pid) - : Resolver(nullptr), PassID(&pid), Kind(K) { } + : Resolver(nullptr), PassID(&pid), Kind(K), Executed(false) { } virtual ~Pass(); - PassKind getPassKind() const { return Kind; } + /// Returns true if the pass has already executed. + /// + /// For an analysis pass it means the result is available. If the function + /// returns false, the pass was not run, was skipped or freed. + /// + bool isExecuted() const { return Executed; } + + /// Marks the pass as executed or not. + /// + /// A pass should be marked as executed, if its 'runOn*' method successfully + /// finished. When the pass is not needed anymore, it is marked as + /// 'non-executed', it takes place in \c freePass. It also occurs when the + /// pass is skipped for some reason. + /// + /// The flag should be set prior to call to 'runOn*' method. If it decides + /// that the pass should be skipped, it will reset the flag. + /// + void setExecuted(bool x) { + assert(x || !getAsImmutablePass()); // Immutable pass cannot be invalidated. + Executed = x; + } + /// getPassName - Return a nice clean name for a pass. This usually /// implemented in terms of the name that is registered by one of the /// Registration templates, but can be overloaded directly. @@ -279,8 +303,7 @@ public: /// bool runOnModule(Module &) override { return false; } - explicit ImmutablePass(char &pid) - : ModulePass(pid) {} + explicit ImmutablePass(char &pid) : ModulePass(pid) { setExecuted(true); } // Force out-of-line virtual method. ~ImmutablePass() override; @@ -316,8 +339,9 @@ public: protected: /// Optional passes call this function to check whether the pass should be /// skipped. This is the case when Attribute::OptimizeNone is set or when - /// optimization bisect is over the limit. - bool skipFunction(const Function &F) const; + /// optimization bisect is over the limit. It also resets flag Executed on + /// the pass. + bool skipFunction(const Function &F); }; diff --git a/include/llvm/PassAnalysisSupport.h b/include/llvm/PassAnalysisSupport.h index abd99293805..d7091fc4fe4 100644 --- a/include/llvm/PassAnalysisSupport.h +++ b/include/llvm/PassAnalysisSupport.h @@ -206,6 +206,9 @@ AnalysisType *Pass::getAnalysisIfAvailable() const { Pass *ResultPass = Resolver->getAnalysisIfAvailable(PI, true); if (!ResultPass) return nullptr; + if (!ResultPass->isExecuted()) + return nullptr; + // Because the AnalysisType may not be a subclass of pass (for // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially // adjust the return pointer (because the class may multiply inherit, once @@ -234,6 +237,8 @@ AnalysisType &Pass::getAnalysisID(AnalysisID PI) const { assert (ResultPass && "getAnalysis*() called on an analysis that was not " "'required' by pass!"); + assert(ResultPass->isExecuted() && + "getAnalysis*() called on an analysis that was freed"); // Because the AnalysisType may not be a subclass of pass (for // AnalysisGroups), we use getAdjustedAnalysisPointer here to potentially diff --git a/lib/Analysis/CallGraphSCCPass.cpp b/lib/Analysis/CallGraphSCCPass.cpp index 9cef7814415..290fd34cff5 100644 --- a/lib/Analysis/CallGraphSCCPass.cpp +++ b/lib/Analysis/CallGraphSCCPass.cpp @@ -414,6 +414,7 @@ bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, initializeAnalysisImpl(P); // Actually run this pass on the current SCC. + P->setExecuted(true); Changed |= RunPassOnSCC(P, CurSCC, CG, CallGraphUpToDate, DevirtualizedCall); diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp index f449ce94d57..1b5d6e5d1b7 100644 --- a/lib/Analysis/LoopInfo.cpp +++ b/lib/Analysis/LoopInfo.cpp @@ -722,8 +722,10 @@ void LoopInfoWrapperPass::verifyAnalysis() const { // checking by default, LoopPass has been taught to call verifyLoop manually // during loop pass sequences. if (VerifyLoopInfo) { - auto &DT = getAnalysis().getDomTree(); - LI.verify(DT); + if (auto *Analysis = getAnalysisIfAvailable()) { + auto &DT = Analysis->getDomTree(); + LI.verify(DT); + } } } diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp index 3f4a0794215..d3e697e5c61 100644 --- a/lib/Analysis/LoopPass.cpp +++ b/lib/Analysis/LoopPass.cpp @@ -198,6 +198,7 @@ bool LPPassManager::runOnFunction(Function &F) { PassManagerPrettyStackEntry X(P, *CurrentLoop->getHeader()); TimeRegion PassTimer(getPassTimer(P)); + P->setExecuted(true); Changed |= P->runOnLoop(CurrentLoop, *this); } LoopWasDeleted = CurrentLoop->isInvalid(); diff --git a/lib/CodeGen/MachineDominators.cpp b/lib/CodeGen/MachineDominators.cpp index 303a6a9263b..a548480044e 100644 --- a/lib/CodeGen/MachineDominators.cpp +++ b/lib/CodeGen/MachineDominators.cpp @@ -69,7 +69,7 @@ void MachineDominatorTree::releaseMemory() { } void MachineDominatorTree::verifyAnalysis() const { - if (VerifyMachineDomInfo) + if (VerifyMachineDomInfo && isExecuted()) verifyDomTree(); } diff --git a/lib/CodeGen/MachineFunctionPass.cpp b/lib/CodeGen/MachineFunctionPass.cpp index 2265676ff8b..a7ece36a1e5 100644 --- a/lib/CodeGen/MachineFunctionPass.cpp +++ b/lib/CodeGen/MachineFunctionPass.cpp @@ -38,8 +38,10 @@ Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O, bool MachineFunctionPass::runOnFunction(Function &F) { // Do not codegen any 'available_externally' functions at all, they have // definitions outside the translation unit. - if (F.hasAvailableExternallyLinkage()) + if (F.hasAvailableExternallyLinkage()) { + setExecuted(false); return false; + } MachineModuleInfo &MMI = getAnalysis(); MachineFunction &MF = MMI.getMachineFunction(F); diff --git a/lib/IR/LegacyPassManager.cpp b/lib/IR/LegacyPassManager.cpp index 628a67bd639..0b2c40b742a 100644 --- a/lib/IR/LegacyPassManager.cpp +++ b/lib/IR/LegacyPassManager.cpp @@ -955,6 +955,9 @@ void PMDataManager::freePass(Pass *P, StringRef Msg, AvailableAnalysis.erase(Pos); } } + + if (!P->getAsImmutablePass()) + P->setExecuted(false); } /// Add pass P into the PassVector. Update @@ -1293,6 +1296,7 @@ bool BBPassManager::runOnFunction(Function &F) { PassManagerPrettyStackEntry X(BP, *I); TimeRegion PassTimer(getPassTimer(BP)); + BP->setExecuted(true); LocalChanged |= BP->runOnBasicBlock(*I); } @@ -1459,7 +1463,9 @@ bool FunctionPassManagerImpl::run(Function &F) { initializeAllAnalysisInfo(); for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) { - Changed |= getContainedManager(Index)->runOnFunction(F); + FPPassManager *P = getContainedManager(Index); + P->setExecuted(true); + Changed |= P->runOnFunction(F); F.getContext().yield(); } @@ -1510,6 +1516,7 @@ bool FPPassManager::runOnFunction(Function &F) { PassManagerPrettyStackEntry X(FP, F); TimeRegion PassTimer(getPassTimer(FP)); + FP->setExecuted(true); LocalChanged |= FP->runOnFunction(F); } @@ -1530,8 +1537,10 @@ bool FPPassManager::runOnFunction(Function &F) { bool FPPassManager::runOnModule(Module &M) { bool Changed = false; - for (Function &F : M) + for (Function &F : M) { + setExecuted(true); Changed |= runOnFunction(F); + } return Changed; } @@ -1587,6 +1596,7 @@ MPPassManager::runOnModule(Module &M) { PassManagerPrettyStackEntry X(MP, M); TimeRegion PassTimer(getPassTimer(MP)); + MP->setExecuted(true); LocalChanged |= MP->runOnModule(M); } @@ -1690,7 +1700,9 @@ bool PassManagerImpl::run(Module &M) { initializeAllAnalysisInfo(); for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) { - Changed |= getContainedManager(Index)->runOnModule(M); + MPPassManager *P = getContainedManager(Index); + P->setExecuted(true); + Changed |= P->runOnModule(M); M.getContext().yield(); } diff --git a/lib/IR/Pass.cpp b/lib/IR/Pass.cpp index a42945ef3ff..6e22c1d4641 100644 --- a/lib/IR/Pass.cpp +++ b/lib/IR/Pass.cpp @@ -146,13 +146,16 @@ PassManagerType FunctionPass::getPotentialPassManagerType() const { return PMT_FunctionPassManager; } -bool FunctionPass::skipFunction(const Function &F) const { - if (!F.getContext().getOptBisect().shouldRunPass(this, F)) +bool FunctionPass::skipFunction(const Function &F) { + if (!F.getContext().getOptBisect().shouldRunPass(this, F)) { + setExecuted(false); return true; + } if (F.hasFnAttribute(Attribute::OptimizeNone)) { DEBUG(dbgs() << "Skipping pass '" << getPassName() << "' on function " << F.getName() << "\n"); + setExecuted(false); return true; } return false; diff --git a/test/CodeGen/Generic/externally_available.ll b/test/CodeGen/Generic/externally_available.ll index 7976cc97188..2376bc73992 100644 --- a/test/CodeGen/Generic/externally_available.ll +++ b/test/CodeGen/Generic/externally_available.ll @@ -1,4 +1,4 @@ -; RUN: llc < %s | not grep test_ +; RUN: llc -verify-machine-dom-info < %s | not grep test_ ; test_function should not be emitted to the .s file. define available_externally i32 @test_function() { diff --git a/test/CodeGen/Mips/mul.ll b/test/CodeGen/Mips/mul.ll index 9e053fc2e7d..fa147b08ff2 100644 --- a/test/CodeGen/Mips/mul.ll +++ b/test/CodeGen/Mips/mul.ll @@ -1,4 +1,4 @@ -; RUN: llc -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16 +; RUN: llc -march=mipsel -mattr=mips16 -relocation-model=pic -O3 -verify-loop-info < %s | FileCheck %s -check-prefix=16 @iiii = global i32 5, align 4 @jjjj = global i32 -6, align 4 -- 2.40.0