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Diffstat (limited to 'contrib/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp | 661 |
1 files changed, 661 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp b/contrib/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp new file mode 100644 index 000000000000..202b94b19c4c --- /dev/null +++ b/contrib/llvm/lib/Transforms/Instrumentation/IndirectCallPromotion.cpp @@ -0,0 +1,661 @@ +//===-- IndirectCallPromotion.cpp - Promote indirect calls to direct calls ===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the transformation that promotes indirect calls to +// conditional direct calls when the indirect-call value profile metadata is +// available. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/ADT/Triple.h" +#include "llvm/Analysis/CFG.h" +#include "llvm/Analysis/IndirectCallPromotionAnalysis.h" +#include "llvm/Analysis/IndirectCallSiteVisitor.h" +#include "llvm/IR/CallSite.h" +#include "llvm/IR/DiagnosticInfo.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/InstIterator.h" +#include "llvm/IR/InstVisitor.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/MDBuilder.h" +#include "llvm/IR/Module.h" +#include "llvm/Pass.h" +#include "llvm/ProfileData/InstrProfReader.h" +#include "llvm/Support/Debug.h" +#include "llvm/Transforms/Instrumentation.h" +#include "llvm/Transforms/PGOInstrumentation.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include <string> +#include <utility> +#include <vector> + +using namespace llvm; + +#define DEBUG_TYPE "pgo-icall-prom" + +STATISTIC(NumOfPGOICallPromotion, "Number of indirect call promotions."); +STATISTIC(NumOfPGOICallsites, "Number of indirect call candidate sites."); + +// Command line option to disable indirect-call promotion with the default as +// false. This is for debug purpose. +static cl::opt<bool> DisableICP("disable-icp", cl::init(false), cl::Hidden, + cl::desc("Disable indirect call promotion")); + +// Set the cutoff value for the promotion. If the value is other than 0, we +// stop the transformation once the total number of promotions equals the cutoff +// value. +// For debug use only. +static cl::opt<unsigned> + ICPCutOff("icp-cutoff", cl::init(0), cl::Hidden, cl::ZeroOrMore, + cl::desc("Max number of promotions for this compilaiton")); + +// If ICPCSSkip is non zero, the first ICPCSSkip callsites will be skipped. +// For debug use only. +static cl::opt<unsigned> + ICPCSSkip("icp-csskip", cl::init(0), cl::Hidden, cl::ZeroOrMore, + cl::desc("Skip Callsite up to this number for this compilaiton")); + +// Set if the pass is called in LTO optimization. The difference for LTO mode +// is the pass won't prefix the source module name to the internal linkage +// symbols. +static cl::opt<bool> ICPLTOMode("icp-lto", cl::init(false), cl::Hidden, + cl::desc("Run indirect-call promotion in LTO " + "mode")); + +// If the option is set to true, only call instructions will be considered for +// transformation -- invoke instructions will be ignored. +static cl::opt<bool> + ICPCallOnly("icp-call-only", cl::init(false), cl::Hidden, + cl::desc("Run indirect-call promotion for call instructions " + "only")); + +// If the option is set to true, only invoke instructions will be considered for +// transformation -- call instructions will be ignored. +static cl::opt<bool> ICPInvokeOnly("icp-invoke-only", cl::init(false), + cl::Hidden, + cl::desc("Run indirect-call promotion for " + "invoke instruction only")); + +// Dump the function level IR if the transformation happened in this +// function. For debug use only. +static cl::opt<bool> + ICPDUMPAFTER("icp-dumpafter", cl::init(false), cl::Hidden, + cl::desc("Dump IR after transformation happens")); + +namespace { +class PGOIndirectCallPromotionLegacyPass : public ModulePass { +public: + static char ID; + + PGOIndirectCallPromotionLegacyPass(bool InLTO = false) + : ModulePass(ID), InLTO(InLTO) { + initializePGOIndirectCallPromotionLegacyPassPass( + *PassRegistry::getPassRegistry()); + } + + const char *getPassName() const override { + return "PGOIndirectCallPromotion"; + } + +private: + bool runOnModule(Module &M) override; + + // If this pass is called in LTO. We need to special handling the PGOFuncName + // for the static variables due to LTO's internalization. + bool InLTO; +}; +} // end anonymous namespace + +char PGOIndirectCallPromotionLegacyPass::ID = 0; +INITIALIZE_PASS(PGOIndirectCallPromotionLegacyPass, "pgo-icall-prom", + "Use PGO instrumentation profile to promote indirect calls to " + "direct calls.", + false, false) + +ModulePass *llvm::createPGOIndirectCallPromotionLegacyPass(bool InLTO) { + return new PGOIndirectCallPromotionLegacyPass(InLTO); +} + +namespace { +// The class for main data structure to promote indirect calls to conditional +// direct calls. +class ICallPromotionFunc { +private: + Function &F; + Module *M; + + // Symtab that maps indirect call profile values to function names and + // defines. + InstrProfSymtab *Symtab; + + enum TargetStatus { + OK, // Should be able to promote. + NotAvailableInModule, // Cannot find the target in current module. + ReturnTypeMismatch, // Return type mismatch b/w target and indirect-call. + NumArgsMismatch, // Number of arguments does not match. + ArgTypeMismatch // Type mismatch in the arguments (cannot bitcast). + }; + + // Test if we can legally promote this direct-call of Target. + TargetStatus isPromotionLegal(Instruction *Inst, uint64_t Target, + Function *&F); + + // A struct that records the direct target and it's call count. + struct PromotionCandidate { + Function *TargetFunction; + uint64_t Count; + PromotionCandidate(Function *F, uint64_t C) : TargetFunction(F), Count(C) {} + }; + + // Check if the indirect-call call site should be promoted. Return the number + // of promotions. Inst is the candidate indirect call, ValueDataRef + // contains the array of value profile data for profiled targets, + // TotalCount is the total profiled count of call executions, and + // NumCandidates is the number of candidate entries in ValueDataRef. + std::vector<PromotionCandidate> getPromotionCandidatesForCallSite( + Instruction *Inst, const ArrayRef<InstrProfValueData> &ValueDataRef, + uint64_t TotalCount, uint32_t NumCandidates); + + // Main function that transforms Inst (either a indirect-call instruction, or + // an invoke instruction , to a conditional call to F. This is like: + // if (Inst.CalledValue == F) + // F(...); + // else + // Inst(...); + // end + // TotalCount is the profile count value that the instruction executes. + // Count is the profile count value that F is the target function. + // These two values are being used to update the branch weight. + void promote(Instruction *Inst, Function *F, uint64_t Count, + uint64_t TotalCount); + + // Promote a list of targets for one indirect-call callsite. Return + // the number of promotions. + uint32_t tryToPromote(Instruction *Inst, + const std::vector<PromotionCandidate> &Candidates, + uint64_t &TotalCount); + + static const char *StatusToString(const TargetStatus S) { + switch (S) { + case OK: + return "OK to promote"; + case NotAvailableInModule: + return "Cannot find the target"; + case ReturnTypeMismatch: + return "Return type mismatch"; + case NumArgsMismatch: + return "The number of arguments mismatch"; + case ArgTypeMismatch: + return "Argument Type mismatch"; + } + llvm_unreachable("Should not reach here"); + } + + // Noncopyable + ICallPromotionFunc(const ICallPromotionFunc &other) = delete; + ICallPromotionFunc &operator=(const ICallPromotionFunc &other) = delete; + +public: + ICallPromotionFunc(Function &Func, Module *Modu, InstrProfSymtab *Symtab) + : F(Func), M(Modu), Symtab(Symtab) { + } + bool processFunction(); +}; +} // end anonymous namespace + +ICallPromotionFunc::TargetStatus +ICallPromotionFunc::isPromotionLegal(Instruction *Inst, uint64_t Target, + Function *&TargetFunction) { + Function *DirectCallee = Symtab->getFunction(Target); + if (DirectCallee == nullptr) + return NotAvailableInModule; + // Check the return type. + Type *CallRetType = Inst->getType(); + if (!CallRetType->isVoidTy()) { + Type *FuncRetType = DirectCallee->getReturnType(); + if (FuncRetType != CallRetType && + !CastInst::isBitCastable(FuncRetType, CallRetType)) + return ReturnTypeMismatch; + } + + // Check if the arguments are compatible with the parameters + FunctionType *DirectCalleeType = DirectCallee->getFunctionType(); + unsigned ParamNum = DirectCalleeType->getFunctionNumParams(); + CallSite CS(Inst); + unsigned ArgNum = CS.arg_size(); + + if (ParamNum != ArgNum && !DirectCalleeType->isVarArg()) + return NumArgsMismatch; + + for (unsigned I = 0; I < ParamNum; ++I) { + Type *PTy = DirectCalleeType->getFunctionParamType(I); + Type *ATy = CS.getArgument(I)->getType(); + if (PTy == ATy) + continue; + if (!CastInst::castIsValid(Instruction::BitCast, CS.getArgument(I), PTy)) + return ArgTypeMismatch; + } + + DEBUG(dbgs() << " #" << NumOfPGOICallPromotion << " Promote the icall to " + << Symtab->getFuncName(Target) << "\n"); + TargetFunction = DirectCallee; + return OK; +} + +// Indirect-call promotion heuristic. The direct targets are sorted based on +// the count. Stop at the first target that is not promoted. +std::vector<ICallPromotionFunc::PromotionCandidate> +ICallPromotionFunc::getPromotionCandidatesForCallSite( + Instruction *Inst, const ArrayRef<InstrProfValueData> &ValueDataRef, + uint64_t TotalCount, uint32_t NumCandidates) { + std::vector<PromotionCandidate> Ret; + + DEBUG(dbgs() << " \nWork on callsite #" << NumOfPGOICallsites << *Inst + << " Num_targets: " << ValueDataRef.size() + << " Num_candidates: " << NumCandidates << "\n"); + NumOfPGOICallsites++; + if (ICPCSSkip != 0 && NumOfPGOICallsites <= ICPCSSkip) { + DEBUG(dbgs() << " Skip: User options.\n"); + return Ret; + } + + for (uint32_t I = 0; I < NumCandidates; I++) { + uint64_t Count = ValueDataRef[I].Count; + assert(Count <= TotalCount); + uint64_t Target = ValueDataRef[I].Value; + DEBUG(dbgs() << " Candidate " << I << " Count=" << Count + << " Target_func: " << Target << "\n"); + + if (ICPInvokeOnly && dyn_cast<CallInst>(Inst)) { + DEBUG(dbgs() << " Not promote: User options.\n"); + break; + } + if (ICPCallOnly && dyn_cast<InvokeInst>(Inst)) { + DEBUG(dbgs() << " Not promote: User option.\n"); + break; + } + if (ICPCutOff != 0 && NumOfPGOICallPromotion >= ICPCutOff) { + DEBUG(dbgs() << " Not promote: Cutoff reached.\n"); + break; + } + Function *TargetFunction = nullptr; + TargetStatus Status = isPromotionLegal(Inst, Target, TargetFunction); + if (Status != OK) { + StringRef TargetFuncName = Symtab->getFuncName(Target); + const char *Reason = StatusToString(Status); + DEBUG(dbgs() << " Not promote: " << Reason << "\n"); + emitOptimizationRemarkMissed( + F.getContext(), "pgo-icall-prom", F, Inst->getDebugLoc(), + Twine("Cannot promote indirect call to ") + + (TargetFuncName.empty() ? Twine(Target) : Twine(TargetFuncName)) + + Twine(" with count of ") + Twine(Count) + ": " + Reason); + break; + } + Ret.push_back(PromotionCandidate(TargetFunction, Count)); + TotalCount -= Count; + } + return Ret; +} + +// Create a diamond structure for If_Then_Else. Also update the profile +// count. Do the fix-up for the invoke instruction. +static void createIfThenElse(Instruction *Inst, Function *DirectCallee, + uint64_t Count, uint64_t TotalCount, + BasicBlock **DirectCallBB, + BasicBlock **IndirectCallBB, + BasicBlock **MergeBB) { + CallSite CS(Inst); + Value *OrigCallee = CS.getCalledValue(); + + IRBuilder<> BBBuilder(Inst); + LLVMContext &Ctx = Inst->getContext(); + Value *BCI1 = + BBBuilder.CreateBitCast(OrigCallee, Type::getInt8PtrTy(Ctx), ""); + Value *BCI2 = + BBBuilder.CreateBitCast(DirectCallee, Type::getInt8PtrTy(Ctx), ""); + Value *PtrCmp = BBBuilder.CreateICmpEQ(BCI1, BCI2, ""); + + uint64_t ElseCount = TotalCount - Count; + uint64_t MaxCount = (Count >= ElseCount ? Count : ElseCount); + uint64_t Scale = calculateCountScale(MaxCount); + MDBuilder MDB(Inst->getContext()); + MDNode *BranchWeights = MDB.createBranchWeights( + scaleBranchCount(Count, Scale), scaleBranchCount(ElseCount, Scale)); + TerminatorInst *ThenTerm, *ElseTerm; + SplitBlockAndInsertIfThenElse(PtrCmp, Inst, &ThenTerm, &ElseTerm, + BranchWeights); + *DirectCallBB = ThenTerm->getParent(); + (*DirectCallBB)->setName("if.true.direct_targ"); + *IndirectCallBB = ElseTerm->getParent(); + (*IndirectCallBB)->setName("if.false.orig_indirect"); + *MergeBB = Inst->getParent(); + (*MergeBB)->setName("if.end.icp"); + + // Special handing of Invoke instructions. + InvokeInst *II = dyn_cast<InvokeInst>(Inst); + if (!II) + return; + + // We don't need branch instructions for invoke. + ThenTerm->eraseFromParent(); + ElseTerm->eraseFromParent(); + + // Add jump from Merge BB to the NormalDest. This is needed for the newly + // created direct invoke stmt -- as its NormalDst will be fixed up to MergeBB. + BranchInst::Create(II->getNormalDest(), *MergeBB); +} + +// Find the PHI in BB that have the CallResult as the operand. +static bool getCallRetPHINode(BasicBlock *BB, Instruction *Inst) { + BasicBlock *From = Inst->getParent(); + for (auto &I : *BB) { + PHINode *PHI = dyn_cast<PHINode>(&I); + if (!PHI) + continue; + int IX = PHI->getBasicBlockIndex(From); + if (IX == -1) + continue; + Value *V = PHI->getIncomingValue(IX); + if (dyn_cast<Instruction>(V) == Inst) + return true; + } + return false; +} + +// This method fixes up PHI nodes in BB where BB is the UnwindDest of an +// invoke instruction. In BB, there may be PHIs with incoming block being +// OrigBB (the MergeBB after if-then-else splitting). After moving the invoke +// instructions to its own BB, OrigBB is no longer the predecessor block of BB. +// Instead two new predecessors are added: IndirectCallBB and DirectCallBB, +// so the PHI node's incoming BBs need to be fixed up accordingly. +static void fixupPHINodeForUnwind(Instruction *Inst, BasicBlock *BB, + BasicBlock *OrigBB, + BasicBlock *IndirectCallBB, + BasicBlock *DirectCallBB) { + for (auto &I : *BB) { + PHINode *PHI = dyn_cast<PHINode>(&I); + if (!PHI) + continue; + int IX = PHI->getBasicBlockIndex(OrigBB); + if (IX == -1) + continue; + Value *V = PHI->getIncomingValue(IX); + PHI->addIncoming(V, IndirectCallBB); + PHI->setIncomingBlock(IX, DirectCallBB); + } +} + +// This method fixes up PHI nodes in BB where BB is the NormalDest of an +// invoke instruction. In BB, there may be PHIs with incoming block being +// OrigBB (the MergeBB after if-then-else splitting). After moving the invoke +// instructions to its own BB, a new incoming edge will be added to the original +// NormalDstBB from the IndirectCallBB. +static void fixupPHINodeForNormalDest(Instruction *Inst, BasicBlock *BB, + BasicBlock *OrigBB, + BasicBlock *IndirectCallBB, + Instruction *NewInst) { + for (auto &I : *BB) { + PHINode *PHI = dyn_cast<PHINode>(&I); + if (!PHI) + continue; + int IX = PHI->getBasicBlockIndex(OrigBB); + if (IX == -1) + continue; + Value *V = PHI->getIncomingValue(IX); + if (dyn_cast<Instruction>(V) == Inst) { + PHI->setIncomingBlock(IX, IndirectCallBB); + PHI->addIncoming(NewInst, OrigBB); + continue; + } + PHI->addIncoming(V, IndirectCallBB); + } +} + +// Add a bitcast instruction to the direct-call return value if needed. +static Instruction *insertCallRetCast(const Instruction *Inst, + Instruction *DirectCallInst, + Function *DirectCallee) { + if (Inst->getType()->isVoidTy()) + return DirectCallInst; + + Type *CallRetType = Inst->getType(); + Type *FuncRetType = DirectCallee->getReturnType(); + if (FuncRetType == CallRetType) + return DirectCallInst; + + BasicBlock *InsertionBB; + if (CallInst *CI = dyn_cast<CallInst>(DirectCallInst)) + InsertionBB = CI->getParent(); + else + InsertionBB = (dyn_cast<InvokeInst>(DirectCallInst))->getNormalDest(); + + return (new BitCastInst(DirectCallInst, CallRetType, "", + InsertionBB->getTerminator())); +} + +// Create a DirectCall instruction in the DirectCallBB. +// Parameter Inst is the indirect-call (invoke) instruction. +// DirectCallee is the decl of the direct-call (invoke) target. +// DirecallBB is the BB that the direct-call (invoke) instruction is inserted. +// MergeBB is the bottom BB of the if-then-else-diamond after the +// transformation. For invoke instruction, the edges from DirectCallBB and +// IndirectCallBB to MergeBB are removed before this call (during +// createIfThenElse). +static Instruction *createDirectCallInst(const Instruction *Inst, + Function *DirectCallee, + BasicBlock *DirectCallBB, + BasicBlock *MergeBB) { + Instruction *NewInst = Inst->clone(); + if (CallInst *CI = dyn_cast<CallInst>(NewInst)) { + CI->setCalledFunction(DirectCallee); + CI->mutateFunctionType(DirectCallee->getFunctionType()); + } else { + // Must be an invoke instruction. Direct invoke's normal destination is + // fixed up to MergeBB. MergeBB is the place where return cast is inserted. + // Also since IndirectCallBB does not have an edge to MergeBB, there is no + // need to insert new PHIs into MergeBB. + InvokeInst *II = dyn_cast<InvokeInst>(NewInst); + assert(II); + II->setCalledFunction(DirectCallee); + II->mutateFunctionType(DirectCallee->getFunctionType()); + II->setNormalDest(MergeBB); + } + + DirectCallBB->getInstList().insert(DirectCallBB->getFirstInsertionPt(), + NewInst); + + // Clear the value profile data. + NewInst->setMetadata(LLVMContext::MD_prof, 0); + CallSite NewCS(NewInst); + FunctionType *DirectCalleeType = DirectCallee->getFunctionType(); + unsigned ParamNum = DirectCalleeType->getFunctionNumParams(); + for (unsigned I = 0; I < ParamNum; ++I) { + Type *ATy = NewCS.getArgument(I)->getType(); + Type *PTy = DirectCalleeType->getParamType(I); + if (ATy != PTy) { + BitCastInst *BI = new BitCastInst(NewCS.getArgument(I), PTy, "", NewInst); + NewCS.setArgument(I, BI); + } + } + + return insertCallRetCast(Inst, NewInst, DirectCallee); +} + +// Create a PHI to unify the return values of calls. +static void insertCallRetPHI(Instruction *Inst, Instruction *CallResult, + Function *DirectCallee) { + if (Inst->getType()->isVoidTy()) + return; + + BasicBlock *RetValBB = CallResult->getParent(); + + BasicBlock *PHIBB; + if (InvokeInst *II = dyn_cast<InvokeInst>(CallResult)) + RetValBB = II->getNormalDest(); + + PHIBB = RetValBB->getSingleSuccessor(); + if (getCallRetPHINode(PHIBB, Inst)) + return; + + PHINode *CallRetPHI = PHINode::Create(Inst->getType(), 0); + PHIBB->getInstList().push_front(CallRetPHI); + Inst->replaceAllUsesWith(CallRetPHI); + CallRetPHI->addIncoming(Inst, Inst->getParent()); + CallRetPHI->addIncoming(CallResult, RetValBB); +} + +// This function does the actual indirect-call promotion transformation: +// For an indirect-call like: +// Ret = (*Foo)(Args); +// It transforms to: +// if (Foo == DirectCallee) +// Ret1 = DirectCallee(Args); +// else +// Ret2 = (*Foo)(Args); +// Ret = phi(Ret1, Ret2); +// It adds type casts for the args do not match the parameters and the return +// value. Branch weights metadata also updated. +void ICallPromotionFunc::promote(Instruction *Inst, Function *DirectCallee, + uint64_t Count, uint64_t TotalCount) { + assert(DirectCallee != nullptr); + BasicBlock *BB = Inst->getParent(); + // Just to suppress the non-debug build warning. + (void)BB; + DEBUG(dbgs() << "\n\n== Basic Block Before ==\n"); + DEBUG(dbgs() << *BB << "\n"); + + BasicBlock *DirectCallBB, *IndirectCallBB, *MergeBB; + createIfThenElse(Inst, DirectCallee, Count, TotalCount, &DirectCallBB, + &IndirectCallBB, &MergeBB); + + Instruction *NewInst = + createDirectCallInst(Inst, DirectCallee, DirectCallBB, MergeBB); + + // Move Inst from MergeBB to IndirectCallBB. + Inst->removeFromParent(); + IndirectCallBB->getInstList().insert(IndirectCallBB->getFirstInsertionPt(), + Inst); + + if (InvokeInst *II = dyn_cast<InvokeInst>(Inst)) { + // At this point, the original indirect invoke instruction has the original + // UnwindDest and NormalDest. For the direct invoke instruction, the + // NormalDest points to MergeBB, and MergeBB jumps to the original + // NormalDest. MergeBB might have a new bitcast instruction for the return + // value. The PHIs are with the original NormalDest. Since we now have two + // incoming edges to NormalDest and UnwindDest, we have to do some fixups. + // + // UnwindDest will not use the return value. So pass nullptr here. + fixupPHINodeForUnwind(Inst, II->getUnwindDest(), MergeBB, IndirectCallBB, + DirectCallBB); + // We don't need to update the operand from NormalDest for DirectCallBB. + // Pass nullptr here. + fixupPHINodeForNormalDest(Inst, II->getNormalDest(), MergeBB, + IndirectCallBB, NewInst); + } + + insertCallRetPHI(Inst, NewInst, DirectCallee); + + DEBUG(dbgs() << "\n== Basic Blocks After ==\n"); + DEBUG(dbgs() << *BB << *DirectCallBB << *IndirectCallBB << *MergeBB << "\n"); + + emitOptimizationRemark( + F.getContext(), "pgo-icall-prom", F, Inst->getDebugLoc(), + Twine("Promote indirect call to ") + DirectCallee->getName() + + " with count " + Twine(Count) + " out of " + Twine(TotalCount)); +} + +// Promote indirect-call to conditional direct-call for one callsite. +uint32_t ICallPromotionFunc::tryToPromote( + Instruction *Inst, const std::vector<PromotionCandidate> &Candidates, + uint64_t &TotalCount) { + uint32_t NumPromoted = 0; + + for (auto &C : Candidates) { + uint64_t Count = C.Count; + promote(Inst, C.TargetFunction, Count, TotalCount); + assert(TotalCount >= Count); + TotalCount -= Count; + NumOfPGOICallPromotion++; + NumPromoted++; + } + return NumPromoted; +} + +// Traverse all the indirect-call callsite and get the value profile +// annotation to perform indirect-call promotion. +bool ICallPromotionFunc::processFunction() { + bool Changed = false; + ICallPromotionAnalysis ICallAnalysis; + for (auto &I : findIndirectCallSites(F)) { + uint32_t NumVals, NumCandidates; + uint64_t TotalCount; + auto ICallProfDataRef = ICallAnalysis.getPromotionCandidatesForInstruction( + I, NumVals, TotalCount, NumCandidates); + if (!NumCandidates) + continue; + auto PromotionCandidates = getPromotionCandidatesForCallSite( + I, ICallProfDataRef, TotalCount, NumCandidates); + uint32_t NumPromoted = tryToPromote(I, PromotionCandidates, TotalCount); + if (NumPromoted == 0) + continue; + + Changed = true; + // Adjust the MD.prof metadata. First delete the old one. + I->setMetadata(LLVMContext::MD_prof, 0); + // If all promoted, we don't need the MD.prof metadata. + if (TotalCount == 0 || NumPromoted == NumVals) + continue; + // Otherwise we need update with the un-promoted records back. + annotateValueSite(*M, *I, ICallProfDataRef.slice(NumPromoted), TotalCount, + IPVK_IndirectCallTarget, NumCandidates); + } + return Changed; +} + +// A wrapper function that does the actual work. +static bool promoteIndirectCalls(Module &M, bool InLTO) { + if (DisableICP) + return false; + InstrProfSymtab Symtab; + Symtab.create(M, InLTO); + bool Changed = false; + for (auto &F : M) { + if (F.isDeclaration()) + continue; + if (F.hasFnAttribute(Attribute::OptimizeNone)) + continue; + ICallPromotionFunc ICallPromotion(F, &M, &Symtab); + bool FuncChanged = ICallPromotion.processFunction(); + if (ICPDUMPAFTER && FuncChanged) { + DEBUG(dbgs() << "\n== IR Dump After =="; F.print(dbgs())); + DEBUG(dbgs() << "\n"); + } + Changed |= FuncChanged; + if (ICPCutOff != 0 && NumOfPGOICallPromotion >= ICPCutOff) { + DEBUG(dbgs() << " Stop: Cutoff reached.\n"); + break; + } + } + return Changed; +} + +bool PGOIndirectCallPromotionLegacyPass::runOnModule(Module &M) { + // Command-line option has the priority for InLTO. + return promoteIndirectCalls(M, InLTO | ICPLTOMode); +} + +PreservedAnalyses PGOIndirectCallPromotion::run(Module &M, AnalysisManager<Module> &AM) { + if (!promoteIndirectCalls(M, InLTO | ICPLTOMode)) + return PreservedAnalyses::all(); + + return PreservedAnalyses::none(); +} |