| //===- Inliner.cpp - Code common to all inliners --------------------------===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| // | |
| // This file implements the mechanics required to implement inlining without | |
| // missing any calls and updating the call graph. The decisions of which calls | |
| // are profitable to inline are implemented elsewhere. | |
| // | |
| //===----------------------------------------------------------------------===// | |
| #include "llvm/Transforms/IPO/Inliner.h" | |
| #include "llvm/ADT/DenseMap.h" | |
| #include "llvm/ADT/PriorityWorklist.h" | |
| #include "llvm/ADT/STLExtras.h" | |
| #include "llvm/ADT/ScopeExit.h" | |
| #include "llvm/ADT/SetVector.h" | |
| #include "llvm/ADT/SmallPtrSet.h" | |
| #include "llvm/ADT/SmallVector.h" | |
| #include "llvm/ADT/Statistic.h" | |
| #include "llvm/ADT/StringExtras.h" | |
| #include "llvm/ADT/StringRef.h" | |
| #include "llvm/Analysis/AssumptionCache.h" | |
| #include "llvm/Analysis/BasicAliasAnalysis.h" | |
| #include "llvm/Analysis/BlockFrequencyInfo.h" | |
| #include "llvm/Analysis/CGSCCPassManager.h" | |
| #include "llvm/Analysis/CallGraph.h" | |
| #include "llvm/Analysis/InlineAdvisor.h" | |
| #include "llvm/Analysis/InlineCost.h" | |
| #include "llvm/Analysis/LazyCallGraph.h" | |
| #include "llvm/Analysis/OptimizationRemarkEmitter.h" | |
| #include "llvm/Analysis/ProfileSummaryInfo.h" | |
| #include "llvm/Analysis/ReplayInlineAdvisor.h" | |
| #include "llvm/Analysis/TargetLibraryInfo.h" | |
| #include "llvm/Analysis/Utils/ImportedFunctionsInliningStatistics.h" | |
| #include "llvm/IR/Attributes.h" | |
| #include "llvm/IR/BasicBlock.h" | |
| #include "llvm/IR/DebugLoc.h" | |
| #include "llvm/IR/DerivedTypes.h" | |
| #include "llvm/IR/DiagnosticInfo.h" | |
| #include "llvm/IR/Function.h" | |
| #include "llvm/IR/InstIterator.h" | |
| #include "llvm/IR/Instruction.h" | |
| #include "llvm/IR/Instructions.h" | |
| #include "llvm/IR/IntrinsicInst.h" | |
| #include "llvm/IR/Metadata.h" | |
| #include "llvm/IR/Module.h" | |
| #include "llvm/IR/PassManager.h" | |
| #include "llvm/IR/User.h" | |
| #include "llvm/IR/Value.h" | |
| #include "llvm/Pass.h" | |
| #include "llvm/Support/Casting.h" | |
| #include "llvm/Support/CommandLine.h" | |
| #include "llvm/Support/Debug.h" | |
| #include "llvm/Support/raw_ostream.h" | |
| #include "llvm/Transforms/Utils/CallPromotionUtils.h" | |
| #include "llvm/Transforms/Utils/Cloning.h" | |
| #include "llvm/Transforms/Utils/Local.h" | |
| #include "llvm/Transforms/Utils/ModuleUtils.h" | |
| #include <algorithm> | |
| #include <cassert> | |
| #include <functional> | |
| #include <utility> | |
| #include <vector> | |
| using namespace llvm; | |
| #define DEBUG_TYPE "inline" | |
| STATISTIC(NumInlined, "Number of functions inlined"); | |
| STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined"); | |
| STATISTIC(NumDeleted, "Number of functions deleted because all callers found"); | |
| STATISTIC(NumMergedAllocas, "Number of allocas merged together"); | |
| /// Flag to disable manual alloca merging. | |
| /// | |
| /// Merging of allocas was originally done as a stack-size saving technique | |
| /// prior to LLVM's code generator having support for stack coloring based on | |
| /// lifetime markers. It is now in the process of being removed. To experiment | |
| /// with disabling it and relying fully on lifetime marker based stack | |
| /// coloring, you can pass this flag to LLVM. | |
| static cl::opt<bool> | |
| DisableInlinedAllocaMerging("disable-inlined-alloca-merging", | |
| cl::init(false), cl::Hidden); | |
| static cl::opt<int> IntraSCCCostMultiplier( | |
| "intra-scc-cost-multiplier", cl::init(2), cl::Hidden, | |
| cl::desc( | |
| "Cost multiplier to multiply onto inlined call sites where the " | |
| "new call was previously an intra-SCC call (not relevant when the " | |
| "original call was already intra-SCC). This can accumulate over " | |
| "multiple inlinings (e.g. if a call site already had a cost " | |
| "multiplier and one of its inlined calls was also subject to " | |
| "this, the inlined call would have the original multiplier " | |
| "multiplied by intra-scc-cost-multiplier). This is to prevent tons of " | |
| "inlining through a child SCC which can cause terrible compile times")); | |
| /// A flag for test, so we can print the content of the advisor when running it | |
| /// as part of the default (e.g. -O3) pipeline. | |
| static cl::opt<bool> KeepAdvisorForPrinting("keep-inline-advisor-for-printing", | |
| cl::init(false), cl::Hidden); | |
| /// Allows printing the contents of the advisor after each SCC inliner pass. | |
| static cl::opt<bool> | |
| EnablePostSCCAdvisorPrinting("enable-scc-inline-advisor-printing", | |
| cl::init(false), cl::Hidden); | |
| namespace llvm { | |
| extern cl::opt<InlinerFunctionImportStatsOpts> InlinerFunctionImportStats; | |
| } | |
| static cl::opt<std::string> CGSCCInlineReplayFile( | |
| "cgscc-inline-replay", cl::init(""), cl::value_desc("filename"), | |
| cl::desc( | |
| "Optimization remarks file containing inline remarks to be replayed " | |
| "by cgscc inlining."), | |
| cl::Hidden); | |
| static cl::opt<ReplayInlinerSettings::Scope> CGSCCInlineReplayScope( | |
| "cgscc-inline-replay-scope", | |
| cl::init(ReplayInlinerSettings::Scope::Function), | |
| cl::values(clEnumValN(ReplayInlinerSettings::Scope::Function, "Function", | |
| "Replay on functions that have remarks associated " | |
| "with them (default)"), | |
| clEnumValN(ReplayInlinerSettings::Scope::Module, "Module", | |
| "Replay on the entire module")), | |
| cl::desc("Whether inline replay should be applied to the entire " | |
| "Module or just the Functions (default) that are present as " | |
| "callers in remarks during cgscc inlining."), | |
| cl::Hidden); | |
| static cl::opt<ReplayInlinerSettings::Fallback> CGSCCInlineReplayFallback( | |
| "cgscc-inline-replay-fallback", | |
| cl::init(ReplayInlinerSettings::Fallback::Original), | |
| cl::values( | |
| clEnumValN( | |
| ReplayInlinerSettings::Fallback::Original, "Original", | |
| "All decisions not in replay send to original advisor (default)"), | |
| clEnumValN(ReplayInlinerSettings::Fallback::AlwaysInline, | |
| "AlwaysInline", "All decisions not in replay are inlined"), | |
| clEnumValN(ReplayInlinerSettings::Fallback::NeverInline, "NeverInline", | |
| "All decisions not in replay are not inlined")), | |
| cl::desc( | |
| "How cgscc inline replay treats sites that don't come from the replay. " | |
| "Original: defers to original advisor, AlwaysInline: inline all sites " | |
| "not in replay, NeverInline: inline no sites not in replay"), | |
| cl::Hidden); | |
| static cl::opt<CallSiteFormat::Format> CGSCCInlineReplayFormat( | |
| "cgscc-inline-replay-format", | |
| cl::init(CallSiteFormat::Format::LineColumnDiscriminator), | |
| cl::values( | |
| clEnumValN(CallSiteFormat::Format::Line, "Line", "<Line Number>"), | |
| clEnumValN(CallSiteFormat::Format::LineColumn, "LineColumn", | |
| "<Line Number>:<Column Number>"), | |
| clEnumValN(CallSiteFormat::Format::LineDiscriminator, | |
| "LineDiscriminator", "<Line Number>.<Discriminator>"), | |
| clEnumValN(CallSiteFormat::Format::LineColumnDiscriminator, | |
| "LineColumnDiscriminator", | |
| "<Line Number>:<Column Number>.<Discriminator> (default)")), | |
| cl::desc("How cgscc inline replay file is formatted"), cl::Hidden); | |
| LegacyInlinerBase::LegacyInlinerBase(char &ID) : CallGraphSCCPass(ID) {} | |
| LegacyInlinerBase::LegacyInlinerBase(char &ID, bool InsertLifetime) | |
| : CallGraphSCCPass(ID), InsertLifetime(InsertLifetime) {} | |
| /// For this class, we declare that we require and preserve the call graph. | |
| /// If the derived class implements this method, it should | |
| /// always explicitly call the implementation here. | |
| void LegacyInlinerBase::getAnalysisUsage(AnalysisUsage &AU) const { | |
| AU.addRequired<AssumptionCacheTracker>(); | |
| AU.addRequired<ProfileSummaryInfoWrapperPass>(); | |
| AU.addRequired<TargetLibraryInfoWrapperPass>(); | |
| getAAResultsAnalysisUsage(AU); | |
| CallGraphSCCPass::getAnalysisUsage(AU); | |
| } | |
| using InlinedArrayAllocasTy = DenseMap<ArrayType *, std::vector<AllocaInst *>>; | |
| /// Look at all of the allocas that we inlined through this call site. If we | |
| /// have already inlined other allocas through other calls into this function, | |
| /// then we know that they have disjoint lifetimes and that we can merge them. | |
| /// | |
| /// There are many heuristics possible for merging these allocas, and the | |
| /// different options have different tradeoffs. One thing that we *really* | |
| /// don't want to hurt is SRoA: once inlining happens, often allocas are no | |
| /// longer address taken and so they can be promoted. | |
| /// | |
| /// Our "solution" for that is to only merge allocas whose outermost type is an | |
| /// array type. These are usually not promoted because someone is using a | |
| /// variable index into them. These are also often the most important ones to | |
| /// merge. | |
| /// | |
| /// A better solution would be to have real memory lifetime markers in the IR | |
| /// and not have the inliner do any merging of allocas at all. This would | |
| /// allow the backend to do proper stack slot coloring of all allocas that | |
| /// *actually make it to the backend*, which is really what we want. | |
| /// | |
| /// Because we don't have this information, we do this simple and useful hack. | |
| static void mergeInlinedArrayAllocas(Function *Caller, InlineFunctionInfo &IFI, | |
| InlinedArrayAllocasTy &InlinedArrayAllocas, | |
| int InlineHistory) { | |
| SmallPtrSet<AllocaInst *, 16> UsedAllocas; | |
| // When processing our SCC, check to see if the call site was inlined from | |
| // some other call site. For example, if we're processing "A" in this code: | |
| // A() { B() } | |
| // B() { x = alloca ... C() } | |
| // C() { y = alloca ... } | |
| // Assume that C was not inlined into B initially, and so we're processing A | |
| // and decide to inline B into A. Doing this makes an alloca available for | |
| // reuse and makes a callsite (C) available for inlining. When we process | |
| // the C call site we don't want to do any alloca merging between X and Y | |
| // because their scopes are not disjoint. We could make this smarter by | |
| // keeping track of the inline history for each alloca in the | |
| // InlinedArrayAllocas but this isn't likely to be a significant win. | |
| if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. | |
| return; | |
| // Loop over all the allocas we have so far and see if they can be merged with | |
| // a previously inlined alloca. If not, remember that we had it. | |
| for (unsigned AllocaNo = 0, E = IFI.StaticAllocas.size(); AllocaNo != E; | |
| ++AllocaNo) { | |
| AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; | |
| // Don't bother trying to merge array allocations (they will usually be | |
| // canonicalized to be an allocation *of* an array), or allocations whose | |
| // type is not itself an array (because we're afraid of pessimizing SRoA). | |
| ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); | |
| if (!ATy || AI->isArrayAllocation()) | |
| continue; | |
| // Get the list of all available allocas for this array type. | |
| std::vector<AllocaInst *> &AllocasForType = InlinedArrayAllocas[ATy]; | |
| // Loop over the allocas in AllocasForType to see if we can reuse one. Note | |
| // that we have to be careful not to reuse the same "available" alloca for | |
| // multiple different allocas that we just inlined, we use the 'UsedAllocas' | |
| // set to keep track of which "available" allocas are being used by this | |
| // function. Also, AllocasForType can be empty of course! | |
| bool MergedAwayAlloca = false; | |
| for (AllocaInst *AvailableAlloca : AllocasForType) { | |
| Align Align1 = AI->getAlign(); | |
| Align Align2 = AvailableAlloca->getAlign(); | |
| // The available alloca has to be in the right function, not in some other | |
| // function in this SCC. | |
| if (AvailableAlloca->getParent() != AI->getParent()) | |
| continue; | |
| // If the inlined function already uses this alloca then we can't reuse | |
| // it. | |
| if (!UsedAllocas.insert(AvailableAlloca).second) | |
| continue; | |
| // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare | |
| // success! | |
| LLVM_DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI | |
| << "\n\t\tINTO: " << *AvailableAlloca << '\n'); | |
| // Move affected dbg.declare calls immediately after the new alloca to | |
| // avoid the situation when a dbg.declare precedes its alloca. | |
| if (auto *L = LocalAsMetadata::getIfExists(AI)) | |
| if (auto *MDV = MetadataAsValue::getIfExists(AI->getContext(), L)) | |
| for (User *U : MDV->users()) | |
| if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U)) | |
| DDI->moveBefore(AvailableAlloca->getNextNode()); | |
| AI->replaceAllUsesWith(AvailableAlloca); | |
| if (Align1 > Align2) | |
| AvailableAlloca->setAlignment(AI->getAlign()); | |
| AI->eraseFromParent(); | |
| MergedAwayAlloca = true; | |
| ++NumMergedAllocas; | |
| IFI.StaticAllocas[AllocaNo] = nullptr; | |
| break; | |
| } | |
| // If we already nuked the alloca, we're done with it. | |
| if (MergedAwayAlloca) | |
| continue; | |
| // If we were unable to merge away the alloca either because there are no | |
| // allocas of the right type available or because we reused them all | |
| // already, remember that this alloca came from an inlined function and mark | |
| // it used so we don't reuse it for other allocas from this inline | |
| // operation. | |
| AllocasForType.push_back(AI); | |
| UsedAllocas.insert(AI); | |
| } | |
| } | |
| /// If it is possible to inline the specified call site, | |
| /// do so and update the CallGraph for this operation. | |
| /// | |
| /// This function also does some basic book-keeping to update the IR. The | |
| /// InlinedArrayAllocas map keeps track of any allocas that are already | |
| /// available from other functions inlined into the caller. If we are able to | |
| /// inline this call site we attempt to reuse already available allocas or add | |
| /// any new allocas to the set if not possible. | |
| static InlineResult inlineCallIfPossible( | |
| CallBase &CB, InlineFunctionInfo &IFI, | |
| InlinedArrayAllocasTy &InlinedArrayAllocas, int InlineHistory, | |
| bool InsertLifetime, function_ref<AAResults &(Function &)> &AARGetter, | |
| ImportedFunctionsInliningStatistics &ImportedFunctionsStats) { | |
| Function *Callee = CB.getCalledFunction(); | |
| Function *Caller = CB.getCaller(); | |
| AAResults &AAR = AARGetter(*Callee); | |
| // Try to inline the function. Get the list of static allocas that were | |
| // inlined. | |
| InlineResult IR = | |
| InlineFunction(CB, IFI, | |
| /*MergeAttributes=*/true, &AAR, InsertLifetime); | |
| if (!IR.isSuccess()) | |
| return IR; | |
| if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No) | |
| ImportedFunctionsStats.recordInline(*Caller, *Callee); | |
| if (!DisableInlinedAllocaMerging) | |
| mergeInlinedArrayAllocas(Caller, IFI, InlinedArrayAllocas, InlineHistory); | |
| return IR; // success | |
| } | |
| /// Return true if the specified inline history ID | |
| /// indicates an inline history that includes the specified function. | |
| static bool inlineHistoryIncludes( | |
| Function *F, int InlineHistoryID, | |
| const SmallVectorImpl<std::pair<Function *, int>> &InlineHistory) { | |
| while (InlineHistoryID != -1) { | |
| assert(unsigned(InlineHistoryID) < InlineHistory.size() && | |
| "Invalid inline history ID"); | |
| if (InlineHistory[InlineHistoryID].first == F) | |
| return true; | |
| InlineHistoryID = InlineHistory[InlineHistoryID].second; | |
| } | |
| return false; | |
| } | |
| bool LegacyInlinerBase::doInitialization(CallGraph &CG) { | |
| if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No) | |
| ImportedFunctionsStats.setModuleInfo(CG.getModule()); | |
| return false; // No changes to CallGraph. | |
| } | |
| bool LegacyInlinerBase::runOnSCC(CallGraphSCC &SCC) { | |
| if (skipSCC(SCC)) | |
| return false; | |
| return inlineCalls(SCC); | |
| } | |
| static bool | |
| inlineCallsImpl(CallGraphSCC &SCC, CallGraph &CG, | |
| std::function<AssumptionCache &(Function &)> GetAssumptionCache, | |
| ProfileSummaryInfo *PSI, | |
| std::function<const TargetLibraryInfo &(Function &)> GetTLI, | |
| bool InsertLifetime, | |
| function_ref<InlineCost(CallBase &CB)> GetInlineCost, | |
| function_ref<AAResults &(Function &)> AARGetter, | |
| ImportedFunctionsInliningStatistics &ImportedFunctionsStats) { | |
| SmallPtrSet<Function *, 8> SCCFunctions; | |
| LLVM_DEBUG(dbgs() << "Inliner visiting SCC:"); | |
| for (CallGraphNode *Node : SCC) { | |
| Function *F = Node->getFunction(); | |
| if (F) | |
| SCCFunctions.insert(F); | |
| LLVM_DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); | |
| } | |
| // Scan through and identify all call sites ahead of time so that we only | |
| // inline call sites in the original functions, not call sites that result | |
| // from inlining other functions. | |
| SmallVector<std::pair<CallBase *, int>, 16> CallSites; | |
| // When inlining a callee produces new call sites, we want to keep track of | |
| // the fact that they were inlined from the callee. This allows us to avoid | |
| // infinite inlining in some obscure cases. To represent this, we use an | |
| // index into the InlineHistory vector. | |
| SmallVector<std::pair<Function *, int>, 8> InlineHistory; | |
| for (CallGraphNode *Node : SCC) { | |
| Function *F = Node->getFunction(); | |
| if (!F || F->isDeclaration()) | |
| continue; | |
| OptimizationRemarkEmitter ORE(F); | |
| for (BasicBlock &BB : *F) | |
| for (Instruction &I : BB) { | |
| auto *CB = dyn_cast<CallBase>(&I); | |
| // If this isn't a call, or it is a call to an intrinsic, it can | |
| // never be inlined. | |
| if (!CB || isa<IntrinsicInst>(I)) | |
| continue; | |
| // If this is a direct call to an external function, we can never inline | |
| // it. If it is an indirect call, inlining may resolve it to be a | |
| // direct call, so we keep it. | |
| if (Function *Callee = CB->getCalledFunction()) | |
| if (Callee->isDeclaration()) { | |
| using namespace ore; | |
| setInlineRemark(*CB, "unavailable definition"); | |
| ORE.emit([&]() { | |
| return OptimizationRemarkMissed(DEBUG_TYPE, "NoDefinition", &I) | |
| << NV("Callee", Callee) << " will not be inlined into " | |
| << NV("Caller", CB->getCaller()) | |
| << " because its definition is unavailable" | |
| << setIsVerbose(); | |
| }); | |
| continue; | |
| } | |
| CallSites.push_back(std::make_pair(CB, -1)); | |
| } | |
| } | |
| LLVM_DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); | |
| // If there are no calls in this function, exit early. | |
| if (CallSites.empty()) | |
| return false; | |
| // Now that we have all of the call sites, move the ones to functions in the | |
| // current SCC to the end of the list. | |
| unsigned FirstCallInSCC = CallSites.size(); | |
| for (unsigned I = 0; I < FirstCallInSCC; ++I) | |
| if (Function *F = CallSites[I].first->getCalledFunction()) | |
| if (SCCFunctions.count(F)) | |
| std::swap(CallSites[I--], CallSites[--FirstCallInSCC]); | |
| InlinedArrayAllocasTy InlinedArrayAllocas; | |
| InlineFunctionInfo InlineInfo(&CG, GetAssumptionCache, PSI); | |
| // Now that we have all of the call sites, loop over them and inline them if | |
| // it looks profitable to do so. | |
| bool Changed = false; | |
| bool LocalChange; | |
| do { | |
| LocalChange = false; | |
| // Iterate over the outer loop because inlining functions can cause indirect | |
| // calls to become direct calls. | |
| // CallSites may be modified inside so ranged for loop can not be used. | |
| for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { | |
| auto &P = CallSites[CSi]; | |
| CallBase &CB = *P.first; | |
| const int InlineHistoryID = P.second; | |
| Function *Caller = CB.getCaller(); | |
| Function *Callee = CB.getCalledFunction(); | |
| // We can only inline direct calls to non-declarations. | |
| if (!Callee || Callee->isDeclaration()) | |
| continue; | |
| bool IsTriviallyDead = isInstructionTriviallyDead(&CB, &GetTLI(*Caller)); | |
| if (!IsTriviallyDead) { | |
| // If this call site was obtained by inlining another function, verify | |
| // that the include path for the function did not include the callee | |
| // itself. If so, we'd be recursively inlining the same function, | |
| // which would provide the same callsites, which would cause us to | |
| // infinitely inline. | |
| if (InlineHistoryID != -1 && | |
| inlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) { | |
| setInlineRemark(CB, "recursive"); | |
| continue; | |
| } | |
| } | |
| // FIXME for new PM: because of the old PM we currently generate ORE and | |
| // in turn BFI on demand. With the new PM, the ORE dependency should | |
| // just become a regular analysis dependency. | |
| OptimizationRemarkEmitter ORE(Caller); | |
| auto OIC = shouldInline(CB, GetInlineCost, ORE); | |
| // If the policy determines that we should inline this function, | |
| // delete the call instead. | |
| if (!OIC) | |
| continue; | |
| // If this call site is dead and it is to a readonly function, we should | |
| // just delete the call instead of trying to inline it, regardless of | |
| // size. This happens because IPSCCP propagates the result out of the | |
| // call and then we're left with the dead call. | |
| if (IsTriviallyDead) { | |
| LLVM_DEBUG(dbgs() << " -> Deleting dead call: " << CB << "\n"); | |
| // Update the call graph by deleting the edge from Callee to Caller. | |
| setInlineRemark(CB, "trivially dead"); | |
| CG[Caller]->removeCallEdgeFor(CB); | |
| CB.eraseFromParent(); | |
| ++NumCallsDeleted; | |
| } else { | |
| // Get DebugLoc to report. CB will be invalid after Inliner. | |
| DebugLoc DLoc = CB.getDebugLoc(); | |
| BasicBlock *Block = CB.getParent(); | |
| // Attempt to inline the function. | |
| using namespace ore; | |
| InlineResult IR = inlineCallIfPossible( | |
| CB, InlineInfo, InlinedArrayAllocas, InlineHistoryID, | |
| InsertLifetime, AARGetter, ImportedFunctionsStats); | |
| if (!IR.isSuccess()) { | |
| setInlineRemark(CB, std::string(IR.getFailureReason()) + "; " + | |
| inlineCostStr(*OIC)); | |
| ORE.emit([&]() { | |
| return OptimizationRemarkMissed(DEBUG_TYPE, "NotInlined", DLoc, | |
| Block) | |
| << NV("Callee", Callee) << " will not be inlined into " | |
| << NV("Caller", Caller) << ": " | |
| << NV("Reason", IR.getFailureReason()); | |
| }); | |
| continue; | |
| } | |
| ++NumInlined; | |
| emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC); | |
| // If inlining this function gave us any new call sites, throw them | |
| // onto our worklist to process. They are useful inline candidates. | |
| if (!InlineInfo.InlinedCalls.empty()) { | |
| // Create a new inline history entry for this, so that we remember | |
| // that these new callsites came about due to inlining Callee. | |
| int NewHistoryID = InlineHistory.size(); | |
| InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); | |
| #ifndef NDEBUG | |
| // Make sure no dupplicates in the inline candidates. This could | |
| // happen when a callsite is simpilfied to reusing the return value | |
| // of another callsite during function cloning, thus the other | |
| // callsite will be reconsidered here. | |
| DenseSet<CallBase *> DbgCallSites; | |
| for (auto &II : CallSites) | |
| DbgCallSites.insert(II.first); | |
| #endif | |
| for (Value *Ptr : InlineInfo.InlinedCalls) { | |
| #ifndef NDEBUG | |
| assert(DbgCallSites.count(dyn_cast<CallBase>(Ptr)) == 0); | |
| #endif | |
| CallSites.push_back( | |
| std::make_pair(dyn_cast<CallBase>(Ptr), NewHistoryID)); | |
| } | |
| } | |
| } | |
| // If we inlined or deleted the last possible call site to the function, | |
| // delete the function body now. | |
| if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && | |
| // TODO: Can remove if in SCC now. | |
| !SCCFunctions.count(Callee) && | |
| // The function may be apparently dead, but if there are indirect | |
| // callgraph references to the node, we cannot delete it yet, this | |
| // could invalidate the CGSCC iterator. | |
| CG[Callee]->getNumReferences() == 0) { | |
| LLVM_DEBUG(dbgs() << " -> Deleting dead function: " | |
| << Callee->getName() << "\n"); | |
| CallGraphNode *CalleeNode = CG[Callee]; | |
| // Remove any call graph edges from the callee to its callees. | |
| CalleeNode->removeAllCalledFunctions(); | |
| // Removing the node for callee from the call graph and delete it. | |
| delete CG.removeFunctionFromModule(CalleeNode); | |
| ++NumDeleted; | |
| } | |
| // Remove this call site from the list. If possible, use | |
| // swap/pop_back for efficiency, but do not use it if doing so would | |
| // move a call site to a function in this SCC before the | |
| // 'FirstCallInSCC' barrier. | |
| if (SCC.isSingular()) { | |
| CallSites[CSi] = CallSites.back(); | |
| CallSites.pop_back(); | |
| } else { | |
| CallSites.erase(CallSites.begin() + CSi); | |
| } | |
| --CSi; | |
| Changed = true; | |
| LocalChange = true; | |
| } | |
| } while (LocalChange); | |
| return Changed; | |
| } | |
| bool LegacyInlinerBase::inlineCalls(CallGraphSCC &SCC) { | |
| CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); | |
| ACT = &getAnalysis<AssumptionCacheTracker>(); | |
| PSI = &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI(); | |
| GetTLI = [&](Function &F) -> const TargetLibraryInfo & { | |
| return getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F); | |
| }; | |
| auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & { | |
| return ACT->getAssumptionCache(F); | |
| }; | |
| return inlineCallsImpl( | |
| SCC, CG, GetAssumptionCache, PSI, GetTLI, InsertLifetime, | |
| [&](CallBase &CB) { return getInlineCost(CB); }, LegacyAARGetter(*this), | |
| ImportedFunctionsStats); | |
| } | |
| /// Remove now-dead linkonce functions at the end of | |
| /// processing to avoid breaking the SCC traversal. | |
| bool LegacyInlinerBase::doFinalization(CallGraph &CG) { | |
| if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No) | |
| ImportedFunctionsStats.dump(InlinerFunctionImportStats == | |
| InlinerFunctionImportStatsOpts::Verbose); | |
| return removeDeadFunctions(CG); | |
| } | |
| /// Remove dead functions that are not included in DNR (Do Not Remove) list. | |
| bool LegacyInlinerBase::removeDeadFunctions(CallGraph &CG, | |
| bool AlwaysInlineOnly) { | |
| SmallVector<CallGraphNode *, 16> FunctionsToRemove; | |
| SmallVector<Function *, 16> DeadFunctionsInComdats; | |
| auto RemoveCGN = [&](CallGraphNode *CGN) { | |
| // Remove any call graph edges from the function to its callees. | |
| CGN->removeAllCalledFunctions(); | |
| // Remove any edges from the external node to the function's call graph | |
| // node. These edges might have been made irrelegant due to | |
| // optimization of the program. | |
| CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); | |
| // Removing the node for callee from the call graph and delete it. | |
| FunctionsToRemove.push_back(CGN); | |
| }; | |
| // Scan for all of the functions, looking for ones that should now be removed | |
| // from the program. Insert the dead ones in the FunctionsToRemove set. | |
| for (const auto &I : CG) { | |
| CallGraphNode *CGN = I.second.get(); | |
| Function *F = CGN->getFunction(); | |
| if (!F || F->isDeclaration()) | |
| continue; | |
| // Handle the case when this function is called and we only want to care | |
| // about always-inline functions. This is a bit of a hack to share code | |
| // between here and the InlineAlways pass. | |
| if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline)) | |
| continue; | |
| // If the only remaining users of the function are dead constants, remove | |
| // them. | |
| F->removeDeadConstantUsers(); | |
| if (!F->isDefTriviallyDead()) | |
| continue; | |
| // It is unsafe to drop a function with discardable linkage from a COMDAT | |
| // without also dropping the other members of the COMDAT. | |
| // The inliner doesn't visit non-function entities which are in COMDAT | |
| // groups so it is unsafe to do so *unless* the linkage is local. | |
| if (!F->hasLocalLinkage()) { | |
| if (F->hasComdat()) { | |
| DeadFunctionsInComdats.push_back(F); | |
| continue; | |
| } | |
| } | |
| RemoveCGN(CGN); | |
| } | |
| if (!DeadFunctionsInComdats.empty()) { | |
| // Filter out the functions whose comdats remain alive. | |
| filterDeadComdatFunctions(DeadFunctionsInComdats); | |
| // Remove the rest. | |
| for (Function *F : DeadFunctionsInComdats) | |
| RemoveCGN(CG[F]); | |
| } | |
| if (FunctionsToRemove.empty()) | |
| return false; | |
| // Now that we know which functions to delete, do so. We didn't want to do | |
| // this inline, because that would invalidate our CallGraph::iterator | |
| // objects. :( | |
| // | |
| // Note that it doesn't matter that we are iterating over a non-stable order | |
| // here to do this, it doesn't matter which order the functions are deleted | |
| // in. | |
| array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end()); | |
| FunctionsToRemove.erase( | |
| std::unique(FunctionsToRemove.begin(), FunctionsToRemove.end()), | |
| FunctionsToRemove.end()); | |
| for (CallGraphNode *CGN : FunctionsToRemove) { | |
| delete CG.removeFunctionFromModule(CGN); | |
| ++NumDeleted; | |
| } | |
| return true; | |
| } | |
| InlineAdvisor & | |
| InlinerPass::getAdvisor(const ModuleAnalysisManagerCGSCCProxy::Result &MAM, | |
| FunctionAnalysisManager &FAM, Module &M) { | |
| if (OwnedAdvisor) | |
| return *OwnedAdvisor; | |
| auto *IAA = MAM.getCachedResult<InlineAdvisorAnalysis>(M); | |
| if (!IAA) { | |
| // It should still be possible to run the inliner as a stand-alone SCC pass, | |
| // for test scenarios. In that case, we default to the | |
| // DefaultInlineAdvisor, which doesn't need to keep state between SCC pass | |
| // runs. It also uses just the default InlineParams. | |
| // In this case, we need to use the provided FAM, which is valid for the | |
| // duration of the inliner pass, and thus the lifetime of the owned advisor. | |
| // The one we would get from the MAM can be invalidated as a result of the | |
| // inliner's activity. | |
| OwnedAdvisor = std::make_unique<DefaultInlineAdvisor>( | |
| M, FAM, getInlineParams(), | |
| InlineContext{LTOPhase, InlinePass::CGSCCInliner}); | |
| if (!CGSCCInlineReplayFile.empty()) | |
| OwnedAdvisor = getReplayInlineAdvisor( | |
| M, FAM, M.getContext(), std::move(OwnedAdvisor), | |
| ReplayInlinerSettings{CGSCCInlineReplayFile, | |
| CGSCCInlineReplayScope, | |
| CGSCCInlineReplayFallback, | |
| {CGSCCInlineReplayFormat}}, | |
| /*EmitRemarks=*/true, | |
| InlineContext{LTOPhase, | |
| InlinePass::ReplayCGSCCInliner}); | |
| return *OwnedAdvisor; | |
| } | |
| assert(IAA->getAdvisor() && | |
| "Expected a present InlineAdvisorAnalysis also have an " | |
| "InlineAdvisor initialized"); | |
| return *IAA->getAdvisor(); | |
| } | |
| PreservedAnalyses InlinerPass::run(LazyCallGraph::SCC &InitialC, | |
| CGSCCAnalysisManager &AM, LazyCallGraph &CG, | |
| CGSCCUpdateResult &UR) { | |
| const auto &MAMProxy = | |
| AM.getResult<ModuleAnalysisManagerCGSCCProxy>(InitialC, CG); | |
| bool Changed = false; | |
| assert(InitialC.size() > 0 && "Cannot handle an empty SCC!"); | |
| Module &M = *InitialC.begin()->getFunction().getParent(); | |
| ProfileSummaryInfo *PSI = MAMProxy.getCachedResult<ProfileSummaryAnalysis>(M); | |
| FunctionAnalysisManager &FAM = | |
| AM.getResult<FunctionAnalysisManagerCGSCCProxy>(InitialC, CG) | |
| .getManager(); | |
| InlineAdvisor &Advisor = getAdvisor(MAMProxy, FAM, M); | |
| Advisor.onPassEntry(&InitialC); | |
| auto AdvisorOnExit = make_scope_exit([&] { Advisor.onPassExit(&InitialC); }); | |
| // We use a single common worklist for calls across the entire SCC. We | |
| // process these in-order and append new calls introduced during inlining to | |
| // the end. The PriorityInlineOrder is optional here, in which the smaller | |
| // callee would have a higher priority to inline. | |
| // | |
| // Note that this particular order of processing is actually critical to | |
| // avoid very bad behaviors. Consider *highly connected* call graphs where | |
| // each function contains a small amount of code and a couple of calls to | |
| // other functions. Because the LLVM inliner is fundamentally a bottom-up | |
| // inliner, it can handle gracefully the fact that these all appear to be | |
| // reasonable inlining candidates as it will flatten things until they become | |
| // too big to inline, and then move on and flatten another batch. | |
| // | |
| // However, when processing call edges *within* an SCC we cannot rely on this | |
| // bottom-up behavior. As a consequence, with heavily connected *SCCs* of | |
| // functions we can end up incrementally inlining N calls into each of | |
| // N functions because each incremental inlining decision looks good and we | |
| // don't have a topological ordering to prevent explosions. | |
| // | |
| // To compensate for this, we don't process transitive edges made immediate | |
| // by inlining until we've done one pass of inlining across the entire SCC. | |
| // Large, highly connected SCCs still lead to some amount of code bloat in | |
| // this model, but it is uniformly spread across all the functions in the SCC | |
| // and eventually they all become too large to inline, rather than | |
| // incrementally maknig a single function grow in a super linear fashion. | |
| SmallVector<std::pair<CallBase *, int>, 16> Calls; | |
| // Populate the initial list of calls in this SCC. | |
| for (auto &N : InitialC) { | |
| auto &ORE = | |
| FAM.getResult<OptimizationRemarkEmitterAnalysis>(N.getFunction()); | |
| // We want to generally process call sites top-down in order for | |
| // simplifications stemming from replacing the call with the returned value | |
| // after inlining to be visible to subsequent inlining decisions. | |
| // FIXME: Using instructions sequence is a really bad way to do this. | |
| // Instead we should do an actual RPO walk of the function body. | |
| for (Instruction &I : instructions(N.getFunction())) | |
| if (auto *CB = dyn_cast<CallBase>(&I)) | |
| if (Function *Callee = CB->getCalledFunction()) { | |
| if (!Callee->isDeclaration()) | |
| Calls.push_back({CB, -1}); | |
| else if (!isa<IntrinsicInst>(I)) { | |
| using namespace ore; | |
| setInlineRemark(*CB, "unavailable definition"); | |
| ORE.emit([&]() { | |
| return OptimizationRemarkMissed(DEBUG_TYPE, "NoDefinition", &I) | |
| << NV("Callee", Callee) << " will not be inlined into " | |
| << NV("Caller", CB->getCaller()) | |
| << " because its definition is unavailable" | |
| << setIsVerbose(); | |
| }); | |
| } | |
| } | |
| } | |
| if (Calls.empty()) | |
| return PreservedAnalyses::all(); | |
| // Capture updatable variable for the current SCC. | |
| auto *C = &InitialC; | |
| // When inlining a callee produces new call sites, we want to keep track of | |
| // the fact that they were inlined from the callee. This allows us to avoid | |
| // infinite inlining in some obscure cases. To represent this, we use an | |
| // index into the InlineHistory vector. | |
| SmallVector<std::pair<Function *, int>, 16> InlineHistory; | |
| // Track a set vector of inlined callees so that we can augment the caller | |
| // with all of their edges in the call graph before pruning out the ones that | |
| // got simplified away. | |
| SmallSetVector<Function *, 4> InlinedCallees; | |
| // Track the dead functions to delete once finished with inlining calls. We | |
| // defer deleting these to make it easier to handle the call graph updates. | |
| SmallVector<Function *, 4> DeadFunctions; | |
| // Track potentially dead non-local functions with comdats to see if they can | |
| // be deleted as a batch after inlining. | |
| SmallVector<Function *, 4> DeadFunctionsInComdats; | |
| // Loop forward over all of the calls. Note that we cannot cache the size as | |
| // inlining can introduce new calls that need to be processed. | |
| for (int I = 0; I < (int)Calls.size(); ++I) { | |
| // We expect the calls to typically be batched with sequences of calls that | |
| // have the same caller, so we first set up some shared infrastructure for | |
| // this caller. We also do any pruning we can at this layer on the caller | |
| // alone. | |
| Function &F = *Calls[I].first->getCaller(); | |
| LazyCallGraph::Node &N = *CG.lookup(F); | |
| if (CG.lookupSCC(N) != C) | |
| continue; | |
| LLVM_DEBUG(dbgs() << "Inlining calls in: " << F.getName() << "\n" | |
| << " Function size: " << F.getInstructionCount() | |
| << "\n"); | |
| auto GetAssumptionCache = [&](Function &F) -> AssumptionCache & { | |
| return FAM.getResult<AssumptionAnalysis>(F); | |
| }; | |
| // Now process as many calls as we have within this caller in the sequence. | |
| // We bail out as soon as the caller has to change so we can update the | |
| // call graph and prepare the context of that new caller. | |
| bool DidInline = false; | |
| for (; I < (int)Calls.size() && Calls[I].first->getCaller() == &F; ++I) { | |
| auto &P = Calls[I]; | |
| CallBase *CB = P.first; | |
| const int InlineHistoryID = P.second; | |
| Function &Callee = *CB->getCalledFunction(); | |
| if (InlineHistoryID != -1 && | |
| inlineHistoryIncludes(&Callee, InlineHistoryID, InlineHistory)) { | |
| LLVM_DEBUG(dbgs() << "Skipping inlining due to history: " | |
| << F.getName() << " -> " << Callee.getName() << "\n"); | |
| setInlineRemark(*CB, "recursive"); | |
| continue; | |
| } | |
| // Check if this inlining may repeat breaking an SCC apart that has | |
| // already been split once before. In that case, inlining here may | |
| // trigger infinite inlining, much like is prevented within the inliner | |
| // itself by the InlineHistory above, but spread across CGSCC iterations | |
| // and thus hidden from the full inline history. | |
| LazyCallGraph::SCC *CalleeSCC = CG.lookupSCC(*CG.lookup(Callee)); | |
| if (CalleeSCC == C && UR.InlinedInternalEdges.count({&N, C})) { | |
| LLVM_DEBUG(dbgs() << "Skipping inlining internal SCC edge from a node " | |
| "previously split out of this SCC by inlining: " | |
| << F.getName() << " -> " << Callee.getName() << "\n"); | |
| setInlineRemark(*CB, "recursive SCC split"); | |
| continue; | |
| } | |
| std::unique_ptr<InlineAdvice> Advice = | |
| Advisor.getAdvice(*CB, OnlyMandatory); | |
| // Check whether we want to inline this callsite. | |
| if (!Advice) | |
| continue; | |
| if (!Advice->isInliningRecommended()) { | |
| Advice->recordUnattemptedInlining(); | |
| continue; | |
| } | |
| int CBCostMult = | |
| getStringFnAttrAsInt( | |
| *CB, InlineConstants::FunctionInlineCostMultiplierAttributeName) | |
| .value_or(1); | |
| // Setup the data structure used to plumb customization into the | |
| // `InlineFunction` routine. | |
| InlineFunctionInfo IFI( | |
| /*cg=*/nullptr, GetAssumptionCache, PSI, | |
| &FAM.getResult<BlockFrequencyAnalysis>(*(CB->getCaller())), | |
| &FAM.getResult<BlockFrequencyAnalysis>(Callee)); | |
| InlineResult IR = | |
| InlineFunction(*CB, IFI, /*MergeAttributes=*/true, | |
| &FAM.getResult<AAManager>(*CB->getCaller())); | |
| if (!IR.isSuccess()) { | |
| Advice->recordUnsuccessfulInlining(IR); | |
| continue; | |
| } | |
| DidInline = true; | |
| InlinedCallees.insert(&Callee); | |
| ++NumInlined; | |
| LLVM_DEBUG(dbgs() << " Size after inlining: " | |
| << F.getInstructionCount() << "\n"); | |
| // Add any new callsites to defined functions to the worklist. | |
| if (!IFI.InlinedCallSites.empty()) { | |
| int NewHistoryID = InlineHistory.size(); | |
| InlineHistory.push_back({&Callee, InlineHistoryID}); | |
| for (CallBase *ICB : reverse(IFI.InlinedCallSites)) { | |
| Function *NewCallee = ICB->getCalledFunction(); | |
| assert(!(NewCallee && NewCallee->isIntrinsic()) && | |
| "Intrinsic calls should not be tracked."); | |
| if (!NewCallee) { | |
| // Try to promote an indirect (virtual) call without waiting for | |
| // the post-inline cleanup and the next DevirtSCCRepeatedPass | |
| // iteration because the next iteration may not happen and we may | |
| // miss inlining it. | |
| if (tryPromoteCall(*ICB)) | |
| NewCallee = ICB->getCalledFunction(); | |
| } | |
| if (NewCallee) { | |
| if (!NewCallee->isDeclaration()) { | |
| Calls.push_back({ICB, NewHistoryID}); | |
| // Continually inlining through an SCC can result in huge compile | |
| // times and bloated code since we arbitrarily stop at some point | |
| // when the inliner decides it's not profitable to inline anymore. | |
| // We attempt to mitigate this by making these calls exponentially | |
| // more expensive. | |
| // This doesn't apply to calls in the same SCC since if we do | |
| // inline through the SCC the function will end up being | |
| // self-recursive which the inliner bails out on, and inlining | |
| // within an SCC is necessary for performance. | |
| if (CalleeSCC != C && | |
| CalleeSCC == CG.lookupSCC(CG.get(*NewCallee))) { | |
| Attribute NewCBCostMult = Attribute::get( | |
| M.getContext(), | |
| InlineConstants::FunctionInlineCostMultiplierAttributeName, | |
| itostr(CBCostMult * IntraSCCCostMultiplier)); | |
| ICB->addFnAttr(NewCBCostMult); | |
| } | |
| } | |
| } | |
| } | |
| } | |
| // For local functions or discardable functions without comdats, check | |
| // whether this makes the callee trivially dead. In that case, we can drop | |
| // the body of the function eagerly which may reduce the number of callers | |
| // of other functions to one, changing inline cost thresholds. Non-local | |
| // discardable functions with comdats are checked later on. | |
| bool CalleeWasDeleted = false; | |
| if (Callee.isDiscardableIfUnused() && Callee.hasZeroLiveUses() && | |
| !CG.isLibFunction(Callee)) { | |
| if (Callee.hasLocalLinkage() || !Callee.hasComdat()) { | |
| Calls.erase( | |
| std::remove_if(Calls.begin() + I + 1, Calls.end(), | |
| [&](const std::pair<CallBase *, int> &Call) { | |
| return Call.first->getCaller() == &Callee; | |
| }), | |
| Calls.end()); | |
| // Clear the body and queue the function itself for deletion when we | |
| // finish inlining and call graph updates. | |
| // Note that after this point, it is an error to do anything other | |
| // than use the callee's address or delete it. | |
| Callee.dropAllReferences(); | |
| assert(!is_contained(DeadFunctions, &Callee) && | |
| "Cannot put cause a function to become dead twice!"); | |
| DeadFunctions.push_back(&Callee); | |
| CalleeWasDeleted = true; | |
| } else { | |
| DeadFunctionsInComdats.push_back(&Callee); | |
| } | |
| } | |
| if (CalleeWasDeleted) | |
| Advice->recordInliningWithCalleeDeleted(); | |
| else | |
| Advice->recordInlining(); | |
| } | |
| // Back the call index up by one to put us in a good position to go around | |
| // the outer loop. | |
| --I; | |
| if (!DidInline) | |
| continue; | |
| Changed = true; | |
| // At this point, since we have made changes we have at least removed | |
| // a call instruction. However, in the process we do some incremental | |
| // simplification of the surrounding code. This simplification can | |
| // essentially do all of the same things as a function pass and we can | |
| // re-use the exact same logic for updating the call graph to reflect the | |
| // change. | |
| // Inside the update, we also update the FunctionAnalysisManager in the | |
| // proxy for this particular SCC. We do this as the SCC may have changed and | |
| // as we're going to mutate this particular function we want to make sure | |
| // the proxy is in place to forward any invalidation events. | |
| LazyCallGraph::SCC *OldC = C; | |
| C = &updateCGAndAnalysisManagerForCGSCCPass(CG, *C, N, AM, UR, FAM); | |
| LLVM_DEBUG(dbgs() << "Updated inlining SCC: " << *C << "\n"); | |
| // If this causes an SCC to split apart into multiple smaller SCCs, there | |
| // is a subtle risk we need to prepare for. Other transformations may | |
| // expose an "infinite inlining" opportunity later, and because of the SCC | |
| // mutation, we will revisit this function and potentially re-inline. If we | |
| // do, and that re-inlining also has the potentially to mutate the SCC | |
| // structure, the infinite inlining problem can manifest through infinite | |
| // SCC splits and merges. To avoid this, we capture the originating caller | |
| // node and the SCC containing the call edge. This is a slight over | |
| // approximation of the possible inlining decisions that must be avoided, | |
| // but is relatively efficient to store. We use C != OldC to know when | |
| // a new SCC is generated and the original SCC may be generated via merge | |
| // in later iterations. | |
| // | |
| // It is also possible that even if no new SCC is generated | |
| // (i.e., C == OldC), the original SCC could be split and then merged | |
| // into the same one as itself. and the original SCC will be added into | |
| // UR.CWorklist again, we want to catch such cases too. | |
| // | |
| // FIXME: This seems like a very heavyweight way of retaining the inline | |
| // history, we should look for a more efficient way of tracking it. | |
| if ((C != OldC || UR.CWorklist.count(OldC)) && | |
| llvm::any_of(InlinedCallees, [&](Function *Callee) { | |
| return CG.lookupSCC(*CG.lookup(*Callee)) == OldC; | |
| })) { | |
| LLVM_DEBUG(dbgs() << "Inlined an internal call edge and split an SCC, " | |
| "retaining this to avoid infinite inlining.\n"); | |
| UR.InlinedInternalEdges.insert({&N, OldC}); | |
| } | |
| InlinedCallees.clear(); | |
| // Invalidate analyses for this function now so that we don't have to | |
| // invalidate analyses for all functions in this SCC later. | |
| FAM.invalidate(F, PreservedAnalyses::none()); | |
| } | |
| // We must ensure that we only delete functions with comdats if every function | |
| // in the comdat is going to be deleted. | |
| if (!DeadFunctionsInComdats.empty()) { | |
| filterDeadComdatFunctions(DeadFunctionsInComdats); | |
| for (auto *Callee : DeadFunctionsInComdats) | |
| Callee->dropAllReferences(); | |
| DeadFunctions.append(DeadFunctionsInComdats); | |
| } | |
| // Now that we've finished inlining all of the calls across this SCC, delete | |
| // all of the trivially dead functions, updating the call graph and the CGSCC | |
| // pass manager in the process. | |
| // | |
| // Note that this walks a pointer set which has non-deterministic order but | |
| // that is OK as all we do is delete things and add pointers to unordered | |
| // sets. | |
| for (Function *DeadF : DeadFunctions) { | |
| // Get the necessary information out of the call graph and nuke the | |
| // function there. Also, clear out any cached analyses. | |
| auto &DeadC = *CG.lookupSCC(*CG.lookup(*DeadF)); | |
| FAM.clear(*DeadF, DeadF->getName()); | |
| AM.clear(DeadC, DeadC.getName()); | |
| auto &DeadRC = DeadC.getOuterRefSCC(); | |
| CG.removeDeadFunction(*DeadF); | |
| // Mark the relevant parts of the call graph as invalid so we don't visit | |
| // them. | |
| UR.InvalidatedSCCs.insert(&DeadC); | |
| UR.InvalidatedRefSCCs.insert(&DeadRC); | |
| // If the updated SCC was the one containing the deleted function, clear it. | |
| if (&DeadC == UR.UpdatedC) | |
| UR.UpdatedC = nullptr; | |
| // And delete the actual function from the module. | |
| M.getFunctionList().erase(DeadF); | |
| ++NumDeleted; | |
| } | |
| if (!Changed) | |
| return PreservedAnalyses::all(); | |
| PreservedAnalyses PA; | |
| // Even if we change the IR, we update the core CGSCC data structures and so | |
| // can preserve the proxy to the function analysis manager. | |
| PA.preserve<FunctionAnalysisManagerCGSCCProxy>(); | |
| // We have already invalidated all analyses on modified functions. | |
| PA.preserveSet<AllAnalysesOn<Function>>(); | |
| return PA; | |
| } | |
| ModuleInlinerWrapperPass::ModuleInlinerWrapperPass(InlineParams Params, | |
| bool MandatoryFirst, | |
| InlineContext IC, | |
| InliningAdvisorMode Mode, | |
| unsigned MaxDevirtIterations) | |
| : Params(Params), IC(IC), Mode(Mode), | |
| MaxDevirtIterations(MaxDevirtIterations) { | |
| // Run the inliner first. The theory is that we are walking bottom-up and so | |
| // the callees have already been fully optimized, and we want to inline them | |
| // into the callers so that our optimizations can reflect that. | |
| // For PreLinkThinLTO pass, we disable hot-caller heuristic for sample PGO | |
| // because it makes profile annotation in the backend inaccurate. | |
| if (MandatoryFirst) { | |
| PM.addPass(InlinerPass(/*OnlyMandatory*/ true)); | |
| if (EnablePostSCCAdvisorPrinting) | |
| PM.addPass(InlineAdvisorAnalysisPrinterPass(dbgs())); | |
| } | |
| PM.addPass(InlinerPass()); | |
| if (EnablePostSCCAdvisorPrinting) | |
| PM.addPass(InlineAdvisorAnalysisPrinterPass(dbgs())); | |
| } | |
| PreservedAnalyses ModuleInlinerWrapperPass::run(Module &M, | |
| ModuleAnalysisManager &MAM) { | |
| auto &IAA = MAM.getResult<InlineAdvisorAnalysis>(M); | |
| if (!IAA.tryCreate(Params, Mode, | |
| {CGSCCInlineReplayFile, | |
| CGSCCInlineReplayScope, | |
| CGSCCInlineReplayFallback, | |
| {CGSCCInlineReplayFormat}}, | |
| IC)) { | |
| M.getContext().emitError( | |
| "Could not setup Inlining Advisor for the requested " | |
| "mode and/or options"); | |
| return PreservedAnalyses::all(); | |
| } | |
| // We wrap the CGSCC pipeline in a devirtualization repeater. This will try | |
| // to detect when we devirtualize indirect calls and iterate the SCC passes | |
| // in that case to try and catch knock-on inlining or function attrs | |
| // opportunities. Then we add it to the module pipeline by walking the SCCs | |
| // in postorder (or bottom-up). | |
| // If MaxDevirtIterations is 0, we just don't use the devirtualization | |
| // wrapper. | |
| if (MaxDevirtIterations == 0) | |
| MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(PM))); | |
| else | |
| MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor( | |
| createDevirtSCCRepeatedPass(std::move(PM), MaxDevirtIterations))); | |
| MPM.addPass(std::move(AfterCGMPM)); | |
| MPM.run(M, MAM); | |
| // Discard the InlineAdvisor, a subsequent inlining session should construct | |
| // its own. | |
| auto PA = PreservedAnalyses::all(); | |
| if (!KeepAdvisorForPrinting) | |
| PA.abandon<InlineAdvisorAnalysis>(); | |
| return PA; | |
| } | |
| void InlinerPass::printPipeline( | |
| raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) { | |
| static_cast<PassInfoMixin<InlinerPass> *>(this)->printPipeline( | |
| OS, MapClassName2PassName); | |
| if (OnlyMandatory) | |
| OS << "<only-mandatory>"; | |
| } | |
| void ModuleInlinerWrapperPass::printPipeline( | |
| raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) { | |
| // Print some info about passes added to the wrapper. This is however | |
| // incomplete as InlineAdvisorAnalysis part isn't included (which also depends | |
| // on Params and Mode). | |
| if (!MPM.isEmpty()) { | |
| MPM.printPipeline(OS, MapClassName2PassName); | |
| OS << ","; | |
| } | |
| OS << "cgscc("; | |
| if (MaxDevirtIterations != 0) | |
| OS << "devirt<" << MaxDevirtIterations << ">("; | |
| PM.printPipeline(OS, MapClassName2PassName); | |
| if (MaxDevirtIterations != 0) | |
| OS << ")"; | |
| OS << ")"; | |
| } |