| //===- 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 << ")"; |
| } |
