| //===- AssumptionCache.cpp - Cache finding @llvm.assume calls -------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains a pass that keeps track of @llvm.assume intrinsics in |
| // the functions of a module. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/AssumptionCache.h" |
| #include "llvm/IR/CallSite.h" |
| #include "llvm/IR/Dominators.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/IntrinsicInst.h" |
| #include "llvm/IR/PassManager.h" |
| #include "llvm/IR/PatternMatch.h" |
| #include "llvm/Support/Debug.h" |
| using namespace llvm; |
| using namespace llvm::PatternMatch; |
| |
| void AssumptionCache::scanFunction() { |
| assert(!Scanned && "Tried to scan the function twice!"); |
| assert(AssumeHandles.empty() && "Already have assumes when scanning!"); |
| |
| // Go through all instructions in all blocks, add all calls to @llvm.assume |
| // to this cache. |
| for (BasicBlock &B : F) |
| for (Instruction &II : B) |
| if (match(&II, m_Intrinsic<Intrinsic::assume>())) |
| AssumeHandles.push_back(&II); |
| |
| // Mark the scan as complete. |
| Scanned = true; |
| } |
| |
| void AssumptionCache::registerAssumption(CallInst *CI) { |
| assert(match(CI, m_Intrinsic<Intrinsic::assume>()) && |
| "Registered call does not call @llvm.assume"); |
| |
| // If we haven't scanned the function yet, just drop this assumption. It will |
| // be found when we scan later. |
| if (!Scanned) |
| return; |
| |
| AssumeHandles.push_back(CI); |
| |
| #ifndef NDEBUG |
| assert(CI->getParent() && |
| "Cannot register @llvm.assume call not in a basic block"); |
| assert(&F == CI->getParent()->getParent() && |
| "Cannot register @llvm.assume call not in this function"); |
| |
| // We expect the number of assumptions to be small, so in an asserts build |
| // check that we don't accumulate duplicates and that all assumptions point |
| // to the same function. |
| SmallPtrSet<Value *, 16> AssumptionSet; |
| for (auto &VH : AssumeHandles) { |
| if (!VH) |
| continue; |
| |
| assert(&F == cast<Instruction>(VH)->getParent()->getParent() && |
| "Cached assumption not inside this function!"); |
| assert(match(cast<CallInst>(VH), m_Intrinsic<Intrinsic::assume>()) && |
| "Cached something other than a call to @llvm.assume!"); |
| assert(AssumptionSet.insert(VH).second && |
| "Cache contains multiple copies of a call!"); |
| } |
| #endif |
| } |
| |
| char AssumptionAnalysis::PassID; |
| |
| PreservedAnalyses AssumptionPrinterPass::run(Function &F, |
| AnalysisManager<Function> *AM) { |
| AssumptionCache &AC = AM->getResult<AssumptionAnalysis>(F); |
| |
| OS << "Cached assumptions for function: " << F.getName() << "\n"; |
| for (auto &VH : AC.assumptions()) |
| if (VH) |
| OS << " " << *cast<CallInst>(VH)->getArgOperand(0) << "\n"; |
| |
| return PreservedAnalyses::all(); |
| } |
| |
| void AssumptionCacheTracker::FunctionCallbackVH::deleted() { |
| auto I = ACT->AssumptionCaches.find_as(cast<Function>(getValPtr())); |
| if (I != ACT->AssumptionCaches.end()) |
| ACT->AssumptionCaches.erase(I); |
| // 'this' now dangles! |
| } |
| |
| AssumptionCache &AssumptionCacheTracker::getAssumptionCache(Function &F) { |
| // We probe the function map twice to try and avoid creating a value handle |
| // around the function in common cases. This makes insertion a bit slower, |
| // but if we have to insert we're going to scan the whole function so that |
| // shouldn't matter. |
| auto I = AssumptionCaches.find_as(&F); |
| if (I != AssumptionCaches.end()) |
| return *I->second; |
| |
| // Ok, build a new cache by scanning the function, insert it and the value |
| // handle into our map, and return the newly populated cache. |
| auto IP = AssumptionCaches.insert(std::make_pair( |
| FunctionCallbackVH(&F, this), llvm::make_unique<AssumptionCache>(F))); |
| assert(IP.second && "Scanning function already in the map?"); |
| return *IP.first->second; |
| } |
| |
| void AssumptionCacheTracker::verifyAnalysis() const { |
| #ifndef NDEBUG |
| SmallPtrSet<const CallInst *, 4> AssumptionSet; |
| for (const auto &I : AssumptionCaches) { |
| for (auto &VH : I.second->assumptions()) |
| if (VH) |
| AssumptionSet.insert(cast<CallInst>(VH)); |
| |
| for (const BasicBlock &B : cast<Function>(*I.first)) |
| for (const Instruction &II : B) |
| if (match(&II, m_Intrinsic<Intrinsic::assume>())) |
| assert(AssumptionSet.count(cast<CallInst>(&II)) && |
| "Assumption in scanned function not in cache"); |
| } |
| #endif |
| } |
| |
| AssumptionCacheTracker::AssumptionCacheTracker() : ImmutablePass(ID) { |
| initializeAssumptionCacheTrackerPass(*PassRegistry::getPassRegistry()); |
| } |
| |
| AssumptionCacheTracker::~AssumptionCacheTracker() {} |
| |
| INITIALIZE_PASS(AssumptionCacheTracker, "assumption-cache-tracker", |
| "Assumption Cache Tracker", false, true) |
| char AssumptionCacheTracker::ID = 0; |