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Diffstat (limited to 'llvm/lib/Transforms/Utils/InlineFunction.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/InlineFunction.cpp | 2417 |
1 files changed, 2417 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp new file mode 100644 index 000000000000..a7f0f7ac5d61 --- /dev/null +++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp @@ -0,0 +1,2417 @@ +//===- InlineFunction.cpp - Code to perform function inlining -------------===// +// +// 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 inlining of a function into a call site, resolving +// parameters and the return value as appropriate. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/None.h" +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SetVector.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/iterator_range.h" +#include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/Analysis/AssumptionCache.h" +#include "llvm/Analysis/BlockFrequencyInfo.h" +#include "llvm/Analysis/CallGraph.h" +#include "llvm/Analysis/CaptureTracking.h" +#include "llvm/Analysis/EHPersonalities.h" +#include "llvm/Analysis/InstructionSimplify.h" +#include "llvm/Analysis/ProfileSummaryInfo.h" +#include "llvm/Transforms/Utils/Local.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/Analysis/VectorUtils.h" +#include "llvm/IR/Argument.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/CFG.h" +#include "llvm/IR/CallSite.h" +#include "llvm/IR/Constant.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DIBuilder.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfoMetadata.h" +#include "llvm/IR/DebugLoc.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/InstrTypes.h" +#include "llvm/IR/Instruction.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/MDBuilder.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/User.h" +#include "llvm/IR/Value.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Transforms/Utils/Cloning.h" +#include "llvm/Transforms/Utils/ValueMapper.h" +#include <algorithm> +#include <cassert> +#include <cstdint> +#include <iterator> +#include <limits> +#include <string> +#include <utility> +#include <vector> + +using namespace llvm; +using ProfileCount = Function::ProfileCount; + +static cl::opt<bool> +EnableNoAliasConversion("enable-noalias-to-md-conversion", cl::init(true), + cl::Hidden, + cl::desc("Convert noalias attributes to metadata during inlining.")); + +static cl::opt<bool> +PreserveAlignmentAssumptions("preserve-alignment-assumptions-during-inlining", + cl::init(true), cl::Hidden, + cl::desc("Convert align attributes to assumptions during inlining.")); + +llvm::InlineResult llvm::InlineFunction(CallBase *CB, InlineFunctionInfo &IFI, + AAResults *CalleeAAR, + bool InsertLifetime) { + return InlineFunction(CallSite(CB), IFI, CalleeAAR, InsertLifetime); +} + +namespace { + + /// A class for recording information about inlining a landing pad. + class LandingPadInliningInfo { + /// Destination of the invoke's unwind. + BasicBlock *OuterResumeDest; + + /// Destination for the callee's resume. + BasicBlock *InnerResumeDest = nullptr; + + /// LandingPadInst associated with the invoke. + LandingPadInst *CallerLPad = nullptr; + + /// PHI for EH values from landingpad insts. + PHINode *InnerEHValuesPHI = nullptr; + + SmallVector<Value*, 8> UnwindDestPHIValues; + + public: + LandingPadInliningInfo(InvokeInst *II) + : OuterResumeDest(II->getUnwindDest()) { + // If there are PHI nodes in the unwind destination block, we need to keep + // track of which values came into them from the invoke before removing + // the edge from this block. + BasicBlock *InvokeBB = II->getParent(); + BasicBlock::iterator I = OuterResumeDest->begin(); + for (; isa<PHINode>(I); ++I) { + // Save the value to use for this edge. + PHINode *PHI = cast<PHINode>(I); + UnwindDestPHIValues.push_back(PHI->getIncomingValueForBlock(InvokeBB)); + } + + CallerLPad = cast<LandingPadInst>(I); + } + + /// The outer unwind destination is the target of + /// unwind edges introduced for calls within the inlined function. + BasicBlock *getOuterResumeDest() const { + return OuterResumeDest; + } + + BasicBlock *getInnerResumeDest(); + + LandingPadInst *getLandingPadInst() const { return CallerLPad; } + + /// Forward the 'resume' instruction to the caller's landing pad block. + /// When the landing pad block has only one predecessor, this is + /// a simple branch. When there is more than one predecessor, we need to + /// split the landing pad block after the landingpad instruction and jump + /// to there. + void forwardResume(ResumeInst *RI, + SmallPtrSetImpl<LandingPadInst*> &InlinedLPads); + + /// Add incoming-PHI values to the unwind destination block for the given + /// basic block, using the values for the original invoke's source block. + void addIncomingPHIValuesFor(BasicBlock *BB) const { + addIncomingPHIValuesForInto(BB, OuterResumeDest); + } + + void addIncomingPHIValuesForInto(BasicBlock *src, BasicBlock *dest) const { + BasicBlock::iterator I = dest->begin(); + for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) { + PHINode *phi = cast<PHINode>(I); + phi->addIncoming(UnwindDestPHIValues[i], src); + } + } + }; + +} // end anonymous namespace + +/// Get or create a target for the branch from ResumeInsts. +BasicBlock *LandingPadInliningInfo::getInnerResumeDest() { + if (InnerResumeDest) return InnerResumeDest; + + // Split the landing pad. + BasicBlock::iterator SplitPoint = ++CallerLPad->getIterator(); + InnerResumeDest = + OuterResumeDest->splitBasicBlock(SplitPoint, + OuterResumeDest->getName() + ".body"); + + // The number of incoming edges we expect to the inner landing pad. + const unsigned PHICapacity = 2; + + // Create corresponding new PHIs for all the PHIs in the outer landing pad. + Instruction *InsertPoint = &InnerResumeDest->front(); + BasicBlock::iterator I = OuterResumeDest->begin(); + for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) { + PHINode *OuterPHI = cast<PHINode>(I); + PHINode *InnerPHI = PHINode::Create(OuterPHI->getType(), PHICapacity, + OuterPHI->getName() + ".lpad-body", + InsertPoint); + OuterPHI->replaceAllUsesWith(InnerPHI); + InnerPHI->addIncoming(OuterPHI, OuterResumeDest); + } + + // Create a PHI for the exception values. + InnerEHValuesPHI = PHINode::Create(CallerLPad->getType(), PHICapacity, + "eh.lpad-body", InsertPoint); + CallerLPad->replaceAllUsesWith(InnerEHValuesPHI); + InnerEHValuesPHI->addIncoming(CallerLPad, OuterResumeDest); + + // All done. + return InnerResumeDest; +} + +/// Forward the 'resume' instruction to the caller's landing pad block. +/// When the landing pad block has only one predecessor, this is a simple +/// branch. When there is more than one predecessor, we need to split the +/// landing pad block after the landingpad instruction and jump to there. +void LandingPadInliningInfo::forwardResume( + ResumeInst *RI, SmallPtrSetImpl<LandingPadInst *> &InlinedLPads) { + BasicBlock *Dest = getInnerResumeDest(); + BasicBlock *Src = RI->getParent(); + + BranchInst::Create(Dest, Src); + + // Update the PHIs in the destination. They were inserted in an order which + // makes this work. + addIncomingPHIValuesForInto(Src, Dest); + + InnerEHValuesPHI->addIncoming(RI->getOperand(0), Src); + RI->eraseFromParent(); +} + +/// Helper for getUnwindDestToken/getUnwindDestTokenHelper. +static Value *getParentPad(Value *EHPad) { + if (auto *FPI = dyn_cast<FuncletPadInst>(EHPad)) + return FPI->getParentPad(); + return cast<CatchSwitchInst>(EHPad)->getParentPad(); +} + +using UnwindDestMemoTy = DenseMap<Instruction *, Value *>; + +/// Helper for getUnwindDestToken that does the descendant-ward part of +/// the search. +static Value *getUnwindDestTokenHelper(Instruction *EHPad, + UnwindDestMemoTy &MemoMap) { + SmallVector<Instruction *, 8> Worklist(1, EHPad); + + while (!Worklist.empty()) { + Instruction *CurrentPad = Worklist.pop_back_val(); + // We only put pads on the worklist that aren't in the MemoMap. When + // we find an unwind dest for a pad we may update its ancestors, but + // the queue only ever contains uncles/great-uncles/etc. of CurrentPad, + // so they should never get updated while queued on the worklist. + assert(!MemoMap.count(CurrentPad)); + Value *UnwindDestToken = nullptr; + if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(CurrentPad)) { + if (CatchSwitch->hasUnwindDest()) { + UnwindDestToken = CatchSwitch->getUnwindDest()->getFirstNonPHI(); + } else { + // Catchswitch doesn't have a 'nounwind' variant, and one might be + // annotated as "unwinds to caller" when really it's nounwind (see + // e.g. SimplifyCFGOpt::SimplifyUnreachable), so we can't infer the + // parent's unwind dest from this. We can check its catchpads' + // descendants, since they might include a cleanuppad with an + // "unwinds to caller" cleanupret, which can be trusted. + for (auto HI = CatchSwitch->handler_begin(), + HE = CatchSwitch->handler_end(); + HI != HE && !UnwindDestToken; ++HI) { + BasicBlock *HandlerBlock = *HI; + auto *CatchPad = cast<CatchPadInst>(HandlerBlock->getFirstNonPHI()); + for (User *Child : CatchPad->users()) { + // Intentionally ignore invokes here -- since the catchswitch is + // marked "unwind to caller", it would be a verifier error if it + // contained an invoke which unwinds out of it, so any invoke we'd + // encounter must unwind to some child of the catch. + if (!isa<CleanupPadInst>(Child) && !isa<CatchSwitchInst>(Child)) + continue; + + Instruction *ChildPad = cast<Instruction>(Child); + auto Memo = MemoMap.find(ChildPad); + if (Memo == MemoMap.end()) { + // Haven't figured out this child pad yet; queue it. + Worklist.push_back(ChildPad); + continue; + } + // We've already checked this child, but might have found that + // it offers no proof either way. + Value *ChildUnwindDestToken = Memo->second; + if (!ChildUnwindDestToken) + continue; + // We already know the child's unwind dest, which can either + // be ConstantTokenNone to indicate unwind to caller, or can + // be another child of the catchpad. Only the former indicates + // the unwind dest of the catchswitch. + if (isa<ConstantTokenNone>(ChildUnwindDestToken)) { + UnwindDestToken = ChildUnwindDestToken; + break; + } + assert(getParentPad(ChildUnwindDestToken) == CatchPad); + } + } + } + } else { + auto *CleanupPad = cast<CleanupPadInst>(CurrentPad); + for (User *U : CleanupPad->users()) { + if (auto *CleanupRet = dyn_cast<CleanupReturnInst>(U)) { + if (BasicBlock *RetUnwindDest = CleanupRet->getUnwindDest()) + UnwindDestToken = RetUnwindDest->getFirstNonPHI(); + else + UnwindDestToken = ConstantTokenNone::get(CleanupPad->getContext()); + break; + } + Value *ChildUnwindDestToken; + if (auto *Invoke = dyn_cast<InvokeInst>(U)) { + ChildUnwindDestToken = Invoke->getUnwindDest()->getFirstNonPHI(); + } else if (isa<CleanupPadInst>(U) || isa<CatchSwitchInst>(U)) { + Instruction *ChildPad = cast<Instruction>(U); + auto Memo = MemoMap.find(ChildPad); + if (Memo == MemoMap.end()) { + // Haven't resolved this child yet; queue it and keep searching. + Worklist.push_back(ChildPad); + continue; + } + // We've checked this child, but still need to ignore it if it + // had no proof either way. + ChildUnwindDestToken = Memo->second; + if (!ChildUnwindDestToken) + continue; + } else { + // Not a relevant user of the cleanuppad + continue; + } + // In a well-formed program, the child/invoke must either unwind to + // an(other) child of the cleanup, or exit the cleanup. In the + // first case, continue searching. + if (isa<Instruction>(ChildUnwindDestToken) && + getParentPad(ChildUnwindDestToken) == CleanupPad) + continue; + UnwindDestToken = ChildUnwindDestToken; + break; + } + } + // If we haven't found an unwind dest for CurrentPad, we may have queued its + // children, so move on to the next in the worklist. + if (!UnwindDestToken) + continue; + + // Now we know that CurrentPad unwinds to UnwindDestToken. It also exits + // any ancestors of CurrentPad up to but not including UnwindDestToken's + // parent pad. Record this in the memo map, and check to see if the + // original EHPad being queried is one of the ones exited. + Value *UnwindParent; + if (auto *UnwindPad = dyn_cast<Instruction>(UnwindDestToken)) + UnwindParent = getParentPad(UnwindPad); + else + UnwindParent = nullptr; + bool ExitedOriginalPad = false; + for (Instruction *ExitedPad = CurrentPad; + ExitedPad && ExitedPad != UnwindParent; + ExitedPad = dyn_cast<Instruction>(getParentPad(ExitedPad))) { + // Skip over catchpads since they just follow their catchswitches. + if (isa<CatchPadInst>(ExitedPad)) + continue; + MemoMap[ExitedPad] = UnwindDestToken; + ExitedOriginalPad |= (ExitedPad == EHPad); + } + + if (ExitedOriginalPad) + return UnwindDestToken; + + // Continue the search. + } + + // No definitive information is contained within this funclet. + return nullptr; +} + +/// Given an EH pad, find where it unwinds. If it unwinds to an EH pad, +/// return that pad instruction. If it unwinds to caller, return +/// ConstantTokenNone. If it does not have a definitive unwind destination, +/// return nullptr. +/// +/// This routine gets invoked for calls in funclets in inlinees when inlining +/// an invoke. Since many funclets don't have calls inside them, it's queried +/// on-demand rather than building a map of pads to unwind dests up front. +/// Determining a funclet's unwind dest may require recursively searching its +/// descendants, and also ancestors and cousins if the descendants don't provide +/// an answer. Since most funclets will have their unwind dest immediately +/// available as the unwind dest of a catchswitch or cleanupret, this routine +/// searches top-down from the given pad and then up. To avoid worst-case +/// quadratic run-time given that approach, it uses a memo map to avoid +/// re-processing funclet trees. The callers that rewrite the IR as they go +/// take advantage of this, for correctness, by checking/forcing rewritten +/// pads' entries to match the original callee view. +static Value *getUnwindDestToken(Instruction *EHPad, + UnwindDestMemoTy &MemoMap) { + // Catchpads unwind to the same place as their catchswitch; + // redirct any queries on catchpads so the code below can + // deal with just catchswitches and cleanuppads. + if (auto *CPI = dyn_cast<CatchPadInst>(EHPad)) + EHPad = CPI->getCatchSwitch(); + + // Check if we've already determined the unwind dest for this pad. + auto Memo = MemoMap.find(EHPad); + if (Memo != MemoMap.end()) + return Memo->second; + + // Search EHPad and, if necessary, its descendants. + Value *UnwindDestToken = getUnwindDestTokenHelper(EHPad, MemoMap); + assert((UnwindDestToken == nullptr) != (MemoMap.count(EHPad) != 0)); + if (UnwindDestToken) + return UnwindDestToken; + + // No information is available for this EHPad from itself or any of its + // descendants. An unwind all the way out to a pad in the caller would + // need also to agree with the unwind dest of the parent funclet, so + // search up the chain to try to find a funclet with information. Put + // null entries in the memo map to avoid re-processing as we go up. + MemoMap[EHPad] = nullptr; +#ifndef NDEBUG + SmallPtrSet<Instruction *, 4> TempMemos; + TempMemos.insert(EHPad); +#endif + Instruction *LastUselessPad = EHPad; + Value *AncestorToken; + for (AncestorToken = getParentPad(EHPad); + auto *AncestorPad = dyn_cast<Instruction>(AncestorToken); + AncestorToken = getParentPad(AncestorToken)) { + // Skip over catchpads since they just follow their catchswitches. + if (isa<CatchPadInst>(AncestorPad)) + continue; + // If the MemoMap had an entry mapping AncestorPad to nullptr, since we + // haven't yet called getUnwindDestTokenHelper for AncestorPad in this + // call to getUnwindDestToken, that would mean that AncestorPad had no + // information in itself, its descendants, or its ancestors. If that + // were the case, then we should also have recorded the lack of information + // for the descendant that we're coming from. So assert that we don't + // find a null entry in the MemoMap for AncestorPad. + assert(!MemoMap.count(AncestorPad) || MemoMap[AncestorPad]); + auto AncestorMemo = MemoMap.find(AncestorPad); + if (AncestorMemo == MemoMap.end()) { + UnwindDestToken = getUnwindDestTokenHelper(AncestorPad, MemoMap); + } else { + UnwindDestToken = AncestorMemo->second; + } + if (UnwindDestToken) + break; + LastUselessPad = AncestorPad; + MemoMap[LastUselessPad] = nullptr; +#ifndef NDEBUG + TempMemos.insert(LastUselessPad); +#endif + } + + // We know that getUnwindDestTokenHelper was called on LastUselessPad and + // returned nullptr (and likewise for EHPad and any of its ancestors up to + // LastUselessPad), so LastUselessPad has no information from below. Since + // getUnwindDestTokenHelper must investigate all downward paths through + // no-information nodes to prove that a node has no information like this, + // and since any time it finds information it records it in the MemoMap for + // not just the immediately-containing funclet but also any ancestors also + // exited, it must be the case that, walking downward from LastUselessPad, + // visiting just those nodes which have not been mapped to an unwind dest + // by getUnwindDestTokenHelper (the nullptr TempMemos notwithstanding, since + // they are just used to keep getUnwindDestTokenHelper from repeating work), + // any node visited must have been exhaustively searched with no information + // for it found. + SmallVector<Instruction *, 8> Worklist(1, LastUselessPad); + while (!Worklist.empty()) { + Instruction *UselessPad = Worklist.pop_back_val(); + auto Memo = MemoMap.find(UselessPad); + if (Memo != MemoMap.end() && Memo->second) { + // Here the name 'UselessPad' is a bit of a misnomer, because we've found + // that it is a funclet that does have information about unwinding to + // a particular destination; its parent was a useless pad. + // Since its parent has no information, the unwind edge must not escape + // the parent, and must target a sibling of this pad. This local unwind + // gives us no information about EHPad. Leave it and the subtree rooted + // at it alone. + assert(getParentPad(Memo->second) == getParentPad(UselessPad)); + continue; + } + // We know we don't have information for UselesPad. If it has an entry in + // the MemoMap (mapping it to nullptr), it must be one of the TempMemos + // added on this invocation of getUnwindDestToken; if a previous invocation + // recorded nullptr, it would have had to prove that the ancestors of + // UselessPad, which include LastUselessPad, had no information, and that + // in turn would have required proving that the descendants of + // LastUselesPad, which include EHPad, have no information about + // LastUselessPad, which would imply that EHPad was mapped to nullptr in + // the MemoMap on that invocation, which isn't the case if we got here. + assert(!MemoMap.count(UselessPad) || TempMemos.count(UselessPad)); + // Assert as we enumerate users that 'UselessPad' doesn't have any unwind + // information that we'd be contradicting by making a map entry for it + // (which is something that getUnwindDestTokenHelper must have proved for + // us to get here). Just assert on is direct users here; the checks in + // this downward walk at its descendants will verify that they don't have + // any unwind edges that exit 'UselessPad' either (i.e. they either have no + // unwind edges or unwind to a sibling). + MemoMap[UselessPad] = UnwindDestToken; + if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(UselessPad)) { + assert(CatchSwitch->getUnwindDest() == nullptr && "Expected useless pad"); + for (BasicBlock *HandlerBlock : CatchSwitch->handlers()) { + auto *CatchPad = HandlerBlock->getFirstNonPHI(); + for (User *U : CatchPad->users()) { + assert( + (!isa<InvokeInst>(U) || + (getParentPad( + cast<InvokeInst>(U)->getUnwindDest()->getFirstNonPHI()) == + CatchPad)) && + "Expected useless pad"); + if (isa<CatchSwitchInst>(U) || isa<CleanupPadInst>(U)) + Worklist.push_back(cast<Instruction>(U)); + } + } + } else { + assert(isa<CleanupPadInst>(UselessPad)); + for (User *U : UselessPad->users()) { + assert(!isa<CleanupReturnInst>(U) && "Expected useless pad"); + assert((!isa<InvokeInst>(U) || + (getParentPad( + cast<InvokeInst>(U)->getUnwindDest()->getFirstNonPHI()) == + UselessPad)) && + "Expected useless pad"); + if (isa<CatchSwitchInst>(U) || isa<CleanupPadInst>(U)) + Worklist.push_back(cast<Instruction>(U)); + } + } + } + + return UnwindDestToken; +} + +/// When we inline a basic block into an invoke, +/// we have to turn all of the calls that can throw into invokes. +/// This function analyze BB to see if there are any calls, and if so, +/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI +/// nodes in that block with the values specified in InvokeDestPHIValues. +static BasicBlock *HandleCallsInBlockInlinedThroughInvoke( + BasicBlock *BB, BasicBlock *UnwindEdge, + UnwindDestMemoTy *FuncletUnwindMap = nullptr) { + for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) { + Instruction *I = &*BBI++; + + // We only need to check for function calls: inlined invoke + // instructions require no special handling. + CallInst *CI = dyn_cast<CallInst>(I); + + if (!CI || CI->doesNotThrow() || isa<InlineAsm>(CI->getCalledValue())) + continue; + + // We do not need to (and in fact, cannot) convert possibly throwing calls + // to @llvm.experimental_deoptimize (resp. @llvm.experimental.guard) into + // invokes. The caller's "segment" of the deoptimization continuation + // attached to the newly inlined @llvm.experimental_deoptimize + // (resp. @llvm.experimental.guard) call should contain the exception + // handling logic, if any. + if (auto *F = CI->getCalledFunction()) + if (F->getIntrinsicID() == Intrinsic::experimental_deoptimize || + F->getIntrinsicID() == Intrinsic::experimental_guard) + continue; + + if (auto FuncletBundle = CI->getOperandBundle(LLVMContext::OB_funclet)) { + // This call is nested inside a funclet. If that funclet has an unwind + // destination within the inlinee, then unwinding out of this call would + // be UB. Rewriting this call to an invoke which targets the inlined + // invoke's unwind dest would give the call's parent funclet multiple + // unwind destinations, which is something that subsequent EH table + // generation can't handle and that the veirifer rejects. So when we + // see such a call, leave it as a call. + auto *FuncletPad = cast<Instruction>(FuncletBundle->Inputs[0]); + Value *UnwindDestToken = + getUnwindDestToken(FuncletPad, *FuncletUnwindMap); + if (UnwindDestToken && !isa<ConstantTokenNone>(UnwindDestToken)) + continue; +#ifndef NDEBUG + Instruction *MemoKey; + if (auto *CatchPad = dyn_cast<CatchPadInst>(FuncletPad)) + MemoKey = CatchPad->getCatchSwitch(); + else + MemoKey = FuncletPad; + assert(FuncletUnwindMap->count(MemoKey) && + (*FuncletUnwindMap)[MemoKey] == UnwindDestToken && + "must get memoized to avoid confusing later searches"); +#endif // NDEBUG + } + + changeToInvokeAndSplitBasicBlock(CI, UnwindEdge); + return BB; + } + return nullptr; +} + +/// If we inlined an invoke site, we need to convert calls +/// in the body of the inlined function into invokes. +/// +/// II is the invoke instruction being inlined. FirstNewBlock is the first +/// block of the inlined code (the last block is the end of the function), +/// and InlineCodeInfo is information about the code that got inlined. +static void HandleInlinedLandingPad(InvokeInst *II, BasicBlock *FirstNewBlock, + ClonedCodeInfo &InlinedCodeInfo) { + BasicBlock *InvokeDest = II->getUnwindDest(); + + Function *Caller = FirstNewBlock->getParent(); + + // The inlined code is currently at the end of the function, scan from the + // start of the inlined code to its end, checking for stuff we need to + // rewrite. + LandingPadInliningInfo Invoke(II); + + // Get all of the inlined landing pad instructions. + SmallPtrSet<LandingPadInst*, 16> InlinedLPads; + for (Function::iterator I = FirstNewBlock->getIterator(), E = Caller->end(); + I != E; ++I) + if (InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) + InlinedLPads.insert(II->getLandingPadInst()); + + // Append the clauses from the outer landing pad instruction into the inlined + // landing pad instructions. + LandingPadInst *OuterLPad = Invoke.getLandingPadInst(); + for (LandingPadInst *InlinedLPad : InlinedLPads) { + unsigned OuterNum = OuterLPad->getNumClauses(); + InlinedLPad->reserveClauses(OuterNum); + for (unsigned OuterIdx = 0; OuterIdx != OuterNum; ++OuterIdx) + InlinedLPad->addClause(OuterLPad->getClause(OuterIdx)); + if (OuterLPad->isCleanup()) + InlinedLPad->setCleanup(true); + } + + for (Function::iterator BB = FirstNewBlock->getIterator(), E = Caller->end(); + BB != E; ++BB) { + if (InlinedCodeInfo.ContainsCalls) + if (BasicBlock *NewBB = HandleCallsInBlockInlinedThroughInvoke( + &*BB, Invoke.getOuterResumeDest())) + // Update any PHI nodes in the exceptional block to indicate that there + // is now a new entry in them. + Invoke.addIncomingPHIValuesFor(NewBB); + + // Forward any resumes that are remaining here. + if (ResumeInst *RI = dyn_cast<ResumeInst>(BB->getTerminator())) + Invoke.forwardResume(RI, InlinedLPads); + } + + // Now that everything is happy, we have one final detail. The PHI nodes in + // the exception destination block still have entries due to the original + // invoke instruction. Eliminate these entries (which might even delete the + // PHI node) now. + InvokeDest->removePredecessor(II->getParent()); +} + +/// If we inlined an invoke site, we need to convert calls +/// in the body of the inlined function into invokes. +/// +/// II is the invoke instruction being inlined. FirstNewBlock is the first +/// block of the inlined code (the last block is the end of the function), +/// and InlineCodeInfo is information about the code that got inlined. +static void HandleInlinedEHPad(InvokeInst *II, BasicBlock *FirstNewBlock, + ClonedCodeInfo &InlinedCodeInfo) { + BasicBlock *UnwindDest = II->getUnwindDest(); + Function *Caller = FirstNewBlock->getParent(); + + assert(UnwindDest->getFirstNonPHI()->isEHPad() && "unexpected BasicBlock!"); + + // If there are PHI nodes in the unwind destination block, we need to keep + // track of which values came into them from the invoke before removing the + // edge from this block. + SmallVector<Value *, 8> UnwindDestPHIValues; + BasicBlock *InvokeBB = II->getParent(); + for (Instruction &I : *UnwindDest) { + // Save the value to use for this edge. + PHINode *PHI = dyn_cast<PHINode>(&I); + if (!PHI) + break; + UnwindDestPHIValues.push_back(PHI->getIncomingValueForBlock(InvokeBB)); + } + + // Add incoming-PHI values to the unwind destination block for the given basic + // block, using the values for the original invoke's source block. + auto UpdatePHINodes = [&](BasicBlock *Src) { + BasicBlock::iterator I = UnwindDest->begin(); + for (Value *V : UnwindDestPHIValues) { + PHINode *PHI = cast<PHINode>(I); + PHI->addIncoming(V, Src); + ++I; + } + }; + + // This connects all the instructions which 'unwind to caller' to the invoke + // destination. + UnwindDestMemoTy FuncletUnwindMap; + for (Function::iterator BB = FirstNewBlock->getIterator(), E = Caller->end(); + BB != E; ++BB) { + if (auto *CRI = dyn_cast<CleanupReturnInst>(BB->getTerminator())) { + if (CRI->unwindsToCaller()) { + auto *CleanupPad = CRI->getCleanupPad(); + CleanupReturnInst::Create(CleanupPad, UnwindDest, CRI); + CRI->eraseFromParent(); + UpdatePHINodes(&*BB); + // Finding a cleanupret with an unwind destination would confuse + // subsequent calls to getUnwindDestToken, so map the cleanuppad + // to short-circuit any such calls and recognize this as an "unwind + // to caller" cleanup. + assert(!FuncletUnwindMap.count(CleanupPad) || + isa<ConstantTokenNone>(FuncletUnwindMap[CleanupPad])); + FuncletUnwindMap[CleanupPad] = + ConstantTokenNone::get(Caller->getContext()); + } + } + + Instruction *I = BB->getFirstNonPHI(); + if (!I->isEHPad()) + continue; + + Instruction *Replacement = nullptr; + if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(I)) { + if (CatchSwitch->unwindsToCaller()) { + Value *UnwindDestToken; + if (auto *ParentPad = + dyn_cast<Instruction>(CatchSwitch->getParentPad())) { + // This catchswitch is nested inside another funclet. If that + // funclet has an unwind destination within the inlinee, then + // unwinding out of this catchswitch would be UB. Rewriting this + // catchswitch to unwind to the inlined invoke's unwind dest would + // give the parent funclet multiple unwind destinations, which is + // something that subsequent EH table generation can't handle and + // that the veirifer rejects. So when we see such a call, leave it + // as "unwind to caller". + UnwindDestToken = getUnwindDestToken(ParentPad, FuncletUnwindMap); + if (UnwindDestToken && !isa<ConstantTokenNone>(UnwindDestToken)) + continue; + } else { + // This catchswitch has no parent to inherit constraints from, and + // none of its descendants can have an unwind edge that exits it and + // targets another funclet in the inlinee. It may or may not have a + // descendant that definitively has an unwind to caller. In either + // case, we'll have to assume that any unwinds out of it may need to + // be routed to the caller, so treat it as though it has a definitive + // unwind to caller. + UnwindDestToken = ConstantTokenNone::get(Caller->getContext()); + } + auto *NewCatchSwitch = CatchSwitchInst::Create( + CatchSwitch->getParentPad(), UnwindDest, + CatchSwitch->getNumHandlers(), CatchSwitch->getName(), + CatchSwitch); + for (BasicBlock *PadBB : CatchSwitch->handlers()) + NewCatchSwitch->addHandler(PadBB); + // Propagate info for the old catchswitch over to the new one in + // the unwind map. This also serves to short-circuit any subsequent + // checks for the unwind dest of this catchswitch, which would get + // confused if they found the outer handler in the callee. + FuncletUnwindMap[NewCatchSwitch] = UnwindDestToken; + Replacement = NewCatchSwitch; + } + } else if (!isa<FuncletPadInst>(I)) { + llvm_unreachable("unexpected EHPad!"); + } + + if (Replacement) { + Replacement->takeName(I); + I->replaceAllUsesWith(Replacement); + I->eraseFromParent(); + UpdatePHINodes(&*BB); + } + } + + if (InlinedCodeInfo.ContainsCalls) + for (Function::iterator BB = FirstNewBlock->getIterator(), + E = Caller->end(); + BB != E; ++BB) + if (BasicBlock *NewBB = HandleCallsInBlockInlinedThroughInvoke( + &*BB, UnwindDest, &FuncletUnwindMap)) + // Update any PHI nodes in the exceptional block to indicate that there + // is now a new entry in them. + UpdatePHINodes(NewBB); + + // Now that everything is happy, we have one final detail. The PHI nodes in + // the exception destination block still have entries due to the original + // invoke instruction. Eliminate these entries (which might even delete the + // PHI node) now. + UnwindDest->removePredecessor(InvokeBB); +} + +/// When inlining a call site that has !llvm.mem.parallel_loop_access or +/// llvm.access.group metadata, that metadata should be propagated to all +/// memory-accessing cloned instructions. +static void PropagateParallelLoopAccessMetadata(CallSite CS, + ValueToValueMapTy &VMap) { + MDNode *M = + CS.getInstruction()->getMetadata(LLVMContext::MD_mem_parallel_loop_access); + MDNode *CallAccessGroup = + CS.getInstruction()->getMetadata(LLVMContext::MD_access_group); + if (!M && !CallAccessGroup) + return; + + for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end(); + VMI != VMIE; ++VMI) { + if (!VMI->second) + continue; + + Instruction *NI = dyn_cast<Instruction>(VMI->second); + if (!NI) + continue; + + if (M) { + if (MDNode *PM = + NI->getMetadata(LLVMContext::MD_mem_parallel_loop_access)) { + M = MDNode::concatenate(PM, M); + NI->setMetadata(LLVMContext::MD_mem_parallel_loop_access, M); + } else if (NI->mayReadOrWriteMemory()) { + NI->setMetadata(LLVMContext::MD_mem_parallel_loop_access, M); + } + } + + if (NI->mayReadOrWriteMemory()) { + MDNode *UnitedAccGroups = uniteAccessGroups( + NI->getMetadata(LLVMContext::MD_access_group), CallAccessGroup); + NI->setMetadata(LLVMContext::MD_access_group, UnitedAccGroups); + } + } +} + +/// When inlining a function that contains noalias scope metadata, +/// this metadata needs to be cloned so that the inlined blocks +/// have different "unique scopes" at every call site. Were this not done, then +/// aliasing scopes from a function inlined into a caller multiple times could +/// not be differentiated (and this would lead to miscompiles because the +/// non-aliasing property communicated by the metadata could have +/// call-site-specific control dependencies). +static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) { + const Function *CalledFunc = CS.getCalledFunction(); + SetVector<const MDNode *> MD; + + // Note: We could only clone the metadata if it is already used in the + // caller. I'm omitting that check here because it might confuse + // inter-procedural alias analysis passes. We can revisit this if it becomes + // an efficiency or overhead problem. + + for (const BasicBlock &I : *CalledFunc) + for (const Instruction &J : I) { + if (const MDNode *M = J.getMetadata(LLVMContext::MD_alias_scope)) + MD.insert(M); + if (const MDNode *M = J.getMetadata(LLVMContext::MD_noalias)) + MD.insert(M); + } + + if (MD.empty()) + return; + + // Walk the existing metadata, adding the complete (perhaps cyclic) chain to + // the set. + SmallVector<const Metadata *, 16> Queue(MD.begin(), MD.end()); + while (!Queue.empty()) { + const MDNode *M = cast<MDNode>(Queue.pop_back_val()); + for (unsigned i = 0, ie = M->getNumOperands(); i != ie; ++i) + if (const MDNode *M1 = dyn_cast<MDNode>(M->getOperand(i))) + if (MD.insert(M1)) + Queue.push_back(M1); + } + + // Now we have a complete set of all metadata in the chains used to specify + // the noalias scopes and the lists of those scopes. + SmallVector<TempMDTuple, 16> DummyNodes; + DenseMap<const MDNode *, TrackingMDNodeRef> MDMap; + for (const MDNode *I : MD) { + DummyNodes.push_back(MDTuple::getTemporary(CalledFunc->getContext(), None)); + MDMap[I].reset(DummyNodes.back().get()); + } + + // Create new metadata nodes to replace the dummy nodes, replacing old + // metadata references with either a dummy node or an already-created new + // node. + for (const MDNode *I : MD) { + SmallVector<Metadata *, 4> NewOps; + for (unsigned i = 0, ie = I->getNumOperands(); i != ie; ++i) { + const Metadata *V = I->getOperand(i); + if (const MDNode *M = dyn_cast<MDNode>(V)) + NewOps.push_back(MDMap[M]); + else + NewOps.push_back(const_cast<Metadata *>(V)); + } + + MDNode *NewM = MDNode::get(CalledFunc->getContext(), NewOps); + MDTuple *TempM = cast<MDTuple>(MDMap[I]); + assert(TempM->isTemporary() && "Expected temporary node"); + + TempM->replaceAllUsesWith(NewM); + } + + // Now replace the metadata in the new inlined instructions with the + // repacements from the map. + for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end(); + VMI != VMIE; ++VMI) { + if (!VMI->second) + continue; + + Instruction *NI = dyn_cast<Instruction>(VMI->second); + if (!NI) + continue; + + if (MDNode *M = NI->getMetadata(LLVMContext::MD_alias_scope)) { + MDNode *NewMD = MDMap[M]; + // If the call site also had alias scope metadata (a list of scopes to + // which instructions inside it might belong), propagate those scopes to + // the inlined instructions. + if (MDNode *CSM = + CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope)) + NewMD = MDNode::concatenate(NewMD, CSM); + NI->setMetadata(LLVMContext::MD_alias_scope, NewMD); + } else if (NI->mayReadOrWriteMemory()) { + if (MDNode *M = + CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope)) + NI->setMetadata(LLVMContext::MD_alias_scope, M); + } + + if (MDNode *M = NI->getMetadata(LLVMContext::MD_noalias)) { + MDNode *NewMD = MDMap[M]; + // If the call site also had noalias metadata (a list of scopes with + // which instructions inside it don't alias), propagate those scopes to + // the inlined instructions. + if (MDNode *CSM = + CS.getInstruction()->getMetadata(LLVMContext::MD_noalias)) + NewMD = MDNode::concatenate(NewMD, CSM); + NI->setMetadata(LLVMContext::MD_noalias, NewMD); + } else if (NI->mayReadOrWriteMemory()) { + if (MDNode *M = CS.getInstruction()->getMetadata(LLVMContext::MD_noalias)) + NI->setMetadata(LLVMContext::MD_noalias, M); + } + } +} + +/// If the inlined function has noalias arguments, +/// then add new alias scopes for each noalias argument, tag the mapped noalias +/// parameters with noalias metadata specifying the new scope, and tag all +/// non-derived loads, stores and memory intrinsics with the new alias scopes. +static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap, + const DataLayout &DL, AAResults *CalleeAAR) { + if (!EnableNoAliasConversion) + return; + + const Function *CalledFunc = CS.getCalledFunction(); + SmallVector<const Argument *, 4> NoAliasArgs; + + for (const Argument &Arg : CalledFunc->args()) + if (Arg.hasNoAliasAttr() && !Arg.use_empty()) + NoAliasArgs.push_back(&Arg); + + if (NoAliasArgs.empty()) + return; + + // To do a good job, if a noalias variable is captured, we need to know if + // the capture point dominates the particular use we're considering. + DominatorTree DT; + DT.recalculate(const_cast<Function&>(*CalledFunc)); + + // noalias indicates that pointer values based on the argument do not alias + // pointer values which are not based on it. So we add a new "scope" for each + // noalias function argument. Accesses using pointers based on that argument + // become part of that alias scope, accesses using pointers not based on that + // argument are tagged as noalias with that scope. + + DenseMap<const Argument *, MDNode *> NewScopes; + MDBuilder MDB(CalledFunc->getContext()); + + // Create a new scope domain for this function. + MDNode *NewDomain = + MDB.createAnonymousAliasScopeDomain(CalledFunc->getName()); + for (unsigned i = 0, e = NoAliasArgs.size(); i != e; ++i) { + const Argument *A = NoAliasArgs[i]; + + std::string Name = CalledFunc->getName(); + if (A->hasName()) { + Name += ": %"; + Name += A->getName(); + } else { + Name += ": argument "; + Name += utostr(i); + } + + // Note: We always create a new anonymous root here. This is true regardless + // of the linkage of the callee because the aliasing "scope" is not just a + // property of the callee, but also all control dependencies in the caller. + MDNode *NewScope = MDB.createAnonymousAliasScope(NewDomain, Name); + NewScopes.insert(std::make_pair(A, NewScope)); + } + + // Iterate over all new instructions in the map; for all memory-access + // instructions, add the alias scope metadata. + for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end(); + VMI != VMIE; ++VMI) { + if (const Instruction *I = dyn_cast<Instruction>(VMI->first)) { + if (!VMI->second) + continue; + + Instruction *NI = dyn_cast<Instruction>(VMI->second); + if (!NI) + continue; + + bool IsArgMemOnlyCall = false, IsFuncCall = false; + SmallVector<const Value *, 2> PtrArgs; + + if (const LoadInst *LI = dyn_cast<LoadInst>(I)) + PtrArgs.push_back(LI->getPointerOperand()); + else if (const StoreInst *SI = dyn_cast<StoreInst>(I)) + PtrArgs.push_back(SI->getPointerOperand()); + else if (const VAArgInst *VAAI = dyn_cast<VAArgInst>(I)) + PtrArgs.push_back(VAAI->getPointerOperand()); + else if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I)) + PtrArgs.push_back(CXI->getPointerOperand()); + else if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) + PtrArgs.push_back(RMWI->getPointerOperand()); + else if (const auto *Call = dyn_cast<CallBase>(I)) { + // If we know that the call does not access memory, then we'll still + // know that about the inlined clone of this call site, and we don't + // need to add metadata. + if (Call->doesNotAccessMemory()) + continue; + + IsFuncCall = true; + if (CalleeAAR) { + FunctionModRefBehavior MRB = CalleeAAR->getModRefBehavior(Call); + if (MRB == FMRB_OnlyAccessesArgumentPointees || + MRB == FMRB_OnlyReadsArgumentPointees) + IsArgMemOnlyCall = true; + } + + for (Value *Arg : Call->args()) { + // We need to check the underlying objects of all arguments, not just + // the pointer arguments, because we might be passing pointers as + // integers, etc. + // However, if we know that the call only accesses pointer arguments, + // then we only need to check the pointer arguments. + if (IsArgMemOnlyCall && !Arg->getType()->isPointerTy()) + continue; + + PtrArgs.push_back(Arg); + } + } + + // If we found no pointers, then this instruction is not suitable for + // pairing with an instruction to receive aliasing metadata. + // However, if this is a call, this we might just alias with none of the + // noalias arguments. + if (PtrArgs.empty() && !IsFuncCall) + continue; + + // It is possible that there is only one underlying object, but you + // need to go through several PHIs to see it, and thus could be + // repeated in the Objects list. + SmallPtrSet<const Value *, 4> ObjSet; + SmallVector<Metadata *, 4> Scopes, NoAliases; + + SmallSetVector<const Argument *, 4> NAPtrArgs; + for (const Value *V : PtrArgs) { + SmallVector<const Value *, 4> Objects; + GetUnderlyingObjects(V, Objects, DL, /* LI = */ nullptr); + + for (const Value *O : Objects) + ObjSet.insert(O); + } + + // Figure out if we're derived from anything that is not a noalias + // argument. + bool CanDeriveViaCapture = false, UsesAliasingPtr = false; + for (const Value *V : ObjSet) { + // Is this value a constant that cannot be derived from any pointer + // value (we need to exclude constant expressions, for example, that + // are formed from arithmetic on global symbols). + bool IsNonPtrConst = isa<ConstantInt>(V) || isa<ConstantFP>(V) || + isa<ConstantPointerNull>(V) || + isa<ConstantDataVector>(V) || isa<UndefValue>(V); + if (IsNonPtrConst) + continue; + + // If this is anything other than a noalias argument, then we cannot + // completely describe the aliasing properties using alias.scope + // metadata (and, thus, won't add any). + if (const Argument *A = dyn_cast<Argument>(V)) { + if (!A->hasNoAliasAttr()) + UsesAliasingPtr = true; + } else { + UsesAliasingPtr = true; + } + + // If this is not some identified function-local object (which cannot + // directly alias a noalias argument), or some other argument (which, + // by definition, also cannot alias a noalias argument), then we could + // alias a noalias argument that has been captured). + if (!isa<Argument>(V) && + !isIdentifiedFunctionLocal(const_cast<Value*>(V))) + CanDeriveViaCapture = true; + } + + // A function call can always get captured noalias pointers (via other + // parameters, globals, etc.). + if (IsFuncCall && !IsArgMemOnlyCall) + CanDeriveViaCapture = true; + + // First, we want to figure out all of the sets with which we definitely + // don't alias. Iterate over all noalias set, and add those for which: + // 1. The noalias argument is not in the set of objects from which we + // definitely derive. + // 2. The noalias argument has not yet been captured. + // An arbitrary function that might load pointers could see captured + // noalias arguments via other noalias arguments or globals, and so we + // must always check for prior capture. + for (const Argument *A : NoAliasArgs) { + if (!ObjSet.count(A) && (!CanDeriveViaCapture || + // It might be tempting to skip the + // PointerMayBeCapturedBefore check if + // A->hasNoCaptureAttr() is true, but this is + // incorrect because nocapture only guarantees + // that no copies outlive the function, not + // that the value cannot be locally captured. + !PointerMayBeCapturedBefore(A, + /* ReturnCaptures */ false, + /* StoreCaptures */ false, I, &DT))) + NoAliases.push_back(NewScopes[A]); + } + + if (!NoAliases.empty()) + NI->setMetadata(LLVMContext::MD_noalias, + MDNode::concatenate( + NI->getMetadata(LLVMContext::MD_noalias), + MDNode::get(CalledFunc->getContext(), NoAliases))); + + // Next, we want to figure out all of the sets to which we might belong. + // We might belong to a set if the noalias argument is in the set of + // underlying objects. If there is some non-noalias argument in our list + // of underlying objects, then we cannot add a scope because the fact + // that some access does not alias with any set of our noalias arguments + // cannot itself guarantee that it does not alias with this access + // (because there is some pointer of unknown origin involved and the + // other access might also depend on this pointer). We also cannot add + // scopes to arbitrary functions unless we know they don't access any + // non-parameter pointer-values. + bool CanAddScopes = !UsesAliasingPtr; + if (CanAddScopes && IsFuncCall) + CanAddScopes = IsArgMemOnlyCall; + + if (CanAddScopes) + for (const Argument *A : NoAliasArgs) { + if (ObjSet.count(A)) + Scopes.push_back(NewScopes[A]); + } + + if (!Scopes.empty()) + NI->setMetadata( + LLVMContext::MD_alias_scope, + MDNode::concatenate(NI->getMetadata(LLVMContext::MD_alias_scope), + MDNode::get(CalledFunc->getContext(), Scopes))); + } + } +} + +/// If the inlined function has non-byval align arguments, then +/// add @llvm.assume-based alignment assumptions to preserve this information. +static void AddAlignmentAssumptions(CallSite CS, InlineFunctionInfo &IFI) { + if (!PreserveAlignmentAssumptions || !IFI.GetAssumptionCache) + return; + + AssumptionCache *AC = &(*IFI.GetAssumptionCache)(*CS.getCaller()); + auto &DL = CS.getCaller()->getParent()->getDataLayout(); + + // To avoid inserting redundant assumptions, we should check for assumptions + // already in the caller. To do this, we might need a DT of the caller. + DominatorTree DT; + bool DTCalculated = false; + + Function *CalledFunc = CS.getCalledFunction(); + for (Argument &Arg : CalledFunc->args()) { + unsigned Align = Arg.getType()->isPointerTy() ? Arg.getParamAlignment() : 0; + if (Align && !Arg.hasByValOrInAllocaAttr() && !Arg.hasNUses(0)) { + if (!DTCalculated) { + DT.recalculate(*CS.getCaller()); + DTCalculated = true; + } + + // If we can already prove the asserted alignment in the context of the + // caller, then don't bother inserting the assumption. + Value *ArgVal = CS.getArgument(Arg.getArgNo()); + if (getKnownAlignment(ArgVal, DL, CS.getInstruction(), AC, &DT) >= Align) + continue; + + CallInst *NewAsmp = IRBuilder<>(CS.getInstruction()) + .CreateAlignmentAssumption(DL, ArgVal, Align); + AC->registerAssumption(NewAsmp); + } + } +} + +/// Once we have cloned code over from a callee into the caller, +/// update the specified callgraph to reflect the changes we made. +/// Note that it's possible that not all code was copied over, so only +/// some edges of the callgraph may remain. +static void UpdateCallGraphAfterInlining(CallSite CS, + Function::iterator FirstNewBlock, + ValueToValueMapTy &VMap, + InlineFunctionInfo &IFI) { + CallGraph &CG = *IFI.CG; + const Function *Caller = CS.getCaller(); + const Function *Callee = CS.getCalledFunction(); + CallGraphNode *CalleeNode = CG[Callee]; + CallGraphNode *CallerNode = CG[Caller]; + + // Since we inlined some uninlined call sites in the callee into the caller, + // add edges from the caller to all of the callees of the callee. + CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end(); + + // Consider the case where CalleeNode == CallerNode. + CallGraphNode::CalledFunctionsVector CallCache; + if (CalleeNode == CallerNode) { + CallCache.assign(I, E); + I = CallCache.begin(); + E = CallCache.end(); + } + + for (; I != E; ++I) { + const Value *OrigCall = I->first; + + ValueToValueMapTy::iterator VMI = VMap.find(OrigCall); + // Only copy the edge if the call was inlined! + if (VMI == VMap.end() || VMI->second == nullptr) + continue; + + // If the call was inlined, but then constant folded, there is no edge to + // add. Check for this case. + auto *NewCall = dyn_cast<CallBase>(VMI->second); + if (!NewCall) + continue; + + // We do not treat intrinsic calls like real function calls because we + // expect them to become inline code; do not add an edge for an intrinsic. + if (NewCall->getCalledFunction() && + NewCall->getCalledFunction()->isIntrinsic()) + continue; + + // Remember that this call site got inlined for the client of + // InlineFunction. + IFI.InlinedCalls.push_back(NewCall); + + // It's possible that inlining the callsite will cause it to go from an + // indirect to a direct call by resolving a function pointer. If this + // happens, set the callee of the new call site to a more precise + // destination. This can also happen if the call graph node of the caller + // was just unnecessarily imprecise. + if (!I->second->getFunction()) + if (Function *F = NewCall->getCalledFunction()) { + // Indirect call site resolved to direct call. + CallerNode->addCalledFunction(NewCall, CG[F]); + + continue; + } + + CallerNode->addCalledFunction(NewCall, I->second); + } + + // Update the call graph by deleting the edge from Callee to Caller. We must + // do this after the loop above in case Caller and Callee are the same. + CallerNode->removeCallEdgeFor(*cast<CallBase>(CS.getInstruction())); +} + +static void HandleByValArgumentInit(Value *Dst, Value *Src, Module *M, + BasicBlock *InsertBlock, + InlineFunctionInfo &IFI) { + Type *AggTy = cast<PointerType>(Src->getType())->getElementType(); + IRBuilder<> Builder(InsertBlock, InsertBlock->begin()); + + Value *Size = Builder.getInt64(M->getDataLayout().getTypeStoreSize(AggTy)); + + // Always generate a memcpy of alignment 1 here because we don't know + // the alignment of the src pointer. Other optimizations can infer + // better alignment. + Builder.CreateMemCpy(Dst, /*DstAlign*/1, Src, /*SrcAlign*/1, Size); +} + +/// When inlining a call site that has a byval argument, +/// we have to make the implicit memcpy explicit by adding it. +static Value *HandleByValArgument(Value *Arg, Instruction *TheCall, + const Function *CalledFunc, + InlineFunctionInfo &IFI, + unsigned ByValAlignment) { + PointerType *ArgTy = cast<PointerType>(Arg->getType()); + Type *AggTy = ArgTy->getElementType(); + + Function *Caller = TheCall->getFunction(); + const DataLayout &DL = Caller->getParent()->getDataLayout(); + + // If the called function is readonly, then it could not mutate the caller's + // copy of the byval'd memory. In this case, it is safe to elide the copy and + // temporary. + if (CalledFunc->onlyReadsMemory()) { + // If the byval argument has a specified alignment that is greater than the + // passed in pointer, then we either have to round up the input pointer or + // give up on this transformation. + if (ByValAlignment <= 1) // 0 = unspecified, 1 = no particular alignment. + return Arg; + + AssumptionCache *AC = + IFI.GetAssumptionCache ? &(*IFI.GetAssumptionCache)(*Caller) : nullptr; + + // If the pointer is already known to be sufficiently aligned, or if we can + // round it up to a larger alignment, then we don't need a temporary. + if (getOrEnforceKnownAlignment(Arg, ByValAlignment, DL, TheCall, AC) >= + ByValAlignment) + return Arg; + + // Otherwise, we have to make a memcpy to get a safe alignment. This is bad + // for code quality, but rarely happens and is required for correctness. + } + + // Create the alloca. If we have DataLayout, use nice alignment. + unsigned Align = DL.getPrefTypeAlignment(AggTy); + + // If the byval had an alignment specified, we *must* use at least that + // alignment, as it is required by the byval argument (and uses of the + // pointer inside the callee). + Align = std::max(Align, ByValAlignment); + + Value *NewAlloca = new AllocaInst(AggTy, DL.getAllocaAddrSpace(), + nullptr, Align, Arg->getName(), + &*Caller->begin()->begin()); + IFI.StaticAllocas.push_back(cast<AllocaInst>(NewAlloca)); + + // Uses of the argument in the function should use our new alloca + // instead. + return NewAlloca; +} + +// Check whether this Value is used by a lifetime intrinsic. +static bool isUsedByLifetimeMarker(Value *V) { + for (User *U : V->users()) + if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) + if (II->isLifetimeStartOrEnd()) + return true; + return false; +} + +// Check whether the given alloca already has +// lifetime.start or lifetime.end intrinsics. +static bool hasLifetimeMarkers(AllocaInst *AI) { + Type *Ty = AI->getType(); + Type *Int8PtrTy = Type::getInt8PtrTy(Ty->getContext(), + Ty->getPointerAddressSpace()); + if (Ty == Int8PtrTy) + return isUsedByLifetimeMarker(AI); + + // Do a scan to find all the casts to i8*. + for (User *U : AI->users()) { + if (U->getType() != Int8PtrTy) continue; + if (U->stripPointerCasts() != AI) continue; + if (isUsedByLifetimeMarker(U)) + return true; + } + return false; +} + +/// Return the result of AI->isStaticAlloca() if AI were moved to the entry +/// block. Allocas used in inalloca calls and allocas of dynamic array size +/// cannot be static. +static bool allocaWouldBeStaticInEntry(const AllocaInst *AI ) { + return isa<Constant>(AI->getArraySize()) && !AI->isUsedWithInAlloca(); +} + +/// Returns a DebugLoc for a new DILocation which is a clone of \p OrigDL +/// inlined at \p InlinedAt. \p IANodes is an inlined-at cache. +static DebugLoc inlineDebugLoc(DebugLoc OrigDL, DILocation *InlinedAt, + LLVMContext &Ctx, + DenseMap<const MDNode *, MDNode *> &IANodes) { + auto IA = DebugLoc::appendInlinedAt(OrigDL, InlinedAt, Ctx, IANodes); + return DebugLoc::get(OrigDL.getLine(), OrigDL.getCol(), OrigDL.getScope(), + IA); +} + +/// Returns the LoopID for a loop which has has been cloned from another +/// function for inlining with the new inlined-at start and end locs. +static MDNode *inlineLoopID(const MDNode *OrigLoopId, DILocation *InlinedAt, + LLVMContext &Ctx, + DenseMap<const MDNode *, MDNode *> &IANodes) { + assert(OrigLoopId && OrigLoopId->getNumOperands() > 0 && + "Loop ID needs at least one operand"); + assert(OrigLoopId && OrigLoopId->getOperand(0).get() == OrigLoopId && + "Loop ID should refer to itself"); + + // Save space for the self-referential LoopID. + SmallVector<Metadata *, 4> MDs = {nullptr}; + + for (unsigned i = 1; i < OrigLoopId->getNumOperands(); ++i) { + Metadata *MD = OrigLoopId->getOperand(i); + // Update the DILocations to encode the inlined-at metadata. + if (DILocation *DL = dyn_cast<DILocation>(MD)) + MDs.push_back(inlineDebugLoc(DL, InlinedAt, Ctx, IANodes)); + else + MDs.push_back(MD); + } + + MDNode *NewLoopID = MDNode::getDistinct(Ctx, MDs); + // Insert the self-referential LoopID. + NewLoopID->replaceOperandWith(0, NewLoopID); + return NewLoopID; +} + +/// Update inlined instructions' line numbers to +/// to encode location where these instructions are inlined. +static void fixupLineNumbers(Function *Fn, Function::iterator FI, + Instruction *TheCall, bool CalleeHasDebugInfo) { + const DebugLoc &TheCallDL = TheCall->getDebugLoc(); + if (!TheCallDL) + return; + + auto &Ctx = Fn->getContext(); + DILocation *InlinedAtNode = TheCallDL; + + // Create a unique call site, not to be confused with any other call from the + // same location. + InlinedAtNode = DILocation::getDistinct( + Ctx, InlinedAtNode->getLine(), InlinedAtNode->getColumn(), + InlinedAtNode->getScope(), InlinedAtNode->getInlinedAt()); + + // Cache the inlined-at nodes as they're built so they are reused, without + // this every instruction's inlined-at chain would become distinct from each + // other. + DenseMap<const MDNode *, MDNode *> IANodes; + + for (; FI != Fn->end(); ++FI) { + for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); + BI != BE; ++BI) { + // Loop metadata needs to be updated so that the start and end locs + // reference inlined-at locations. + if (MDNode *LoopID = BI->getMetadata(LLVMContext::MD_loop)) { + MDNode *NewLoopID = + inlineLoopID(LoopID, InlinedAtNode, BI->getContext(), IANodes); + BI->setMetadata(LLVMContext::MD_loop, NewLoopID); + } + + if (DebugLoc DL = BI->getDebugLoc()) { + DebugLoc IDL = + inlineDebugLoc(DL, InlinedAtNode, BI->getContext(), IANodes); + BI->setDebugLoc(IDL); + continue; + } + + if (CalleeHasDebugInfo) + continue; + + // If the inlined instruction has no line number, make it look as if it + // originates from the call location. This is important for + // ((__always_inline__, __nodebug__)) functions which must use caller + // location for all instructions in their function body. + + // Don't update static allocas, as they may get moved later. + if (auto *AI = dyn_cast<AllocaInst>(BI)) + if (allocaWouldBeStaticInEntry(AI)) + continue; + + BI->setDebugLoc(TheCallDL); + } + } +} + +/// Update the block frequencies of the caller after a callee has been inlined. +/// +/// Each block cloned into the caller has its block frequency scaled by the +/// ratio of CallSiteFreq/CalleeEntryFreq. This ensures that the cloned copy of +/// callee's entry block gets the same frequency as the callsite block and the +/// relative frequencies of all cloned blocks remain the same after cloning. +static void updateCallerBFI(BasicBlock *CallSiteBlock, + const ValueToValueMapTy &VMap, + BlockFrequencyInfo *CallerBFI, + BlockFrequencyInfo *CalleeBFI, + const BasicBlock &CalleeEntryBlock) { + SmallPtrSet<BasicBlock *, 16> ClonedBBs; + for (auto const &Entry : VMap) { + if (!isa<BasicBlock>(Entry.first) || !Entry.second) + continue; + auto *OrigBB = cast<BasicBlock>(Entry.first); + auto *ClonedBB = cast<BasicBlock>(Entry.second); + uint64_t Freq = CalleeBFI->getBlockFreq(OrigBB).getFrequency(); + if (!ClonedBBs.insert(ClonedBB).second) { + // Multiple blocks in the callee might get mapped to one cloned block in + // the caller since we prune the callee as we clone it. When that happens, + // we want to use the maximum among the original blocks' frequencies. + uint64_t NewFreq = CallerBFI->getBlockFreq(ClonedBB).getFrequency(); + if (NewFreq > Freq) + Freq = NewFreq; + } + CallerBFI->setBlockFreq(ClonedBB, Freq); + } + BasicBlock *EntryClone = cast<BasicBlock>(VMap.lookup(&CalleeEntryBlock)); + CallerBFI->setBlockFreqAndScale( + EntryClone, CallerBFI->getBlockFreq(CallSiteBlock).getFrequency(), + ClonedBBs); +} + +/// Update the branch metadata for cloned call instructions. +static void updateCallProfile(Function *Callee, const ValueToValueMapTy &VMap, + const ProfileCount &CalleeEntryCount, + const Instruction *TheCall, + ProfileSummaryInfo *PSI, + BlockFrequencyInfo *CallerBFI) { + if (!CalleeEntryCount.hasValue() || CalleeEntryCount.isSynthetic() || + CalleeEntryCount.getCount() < 1) + return; + auto CallSiteCount = PSI ? PSI->getProfileCount(TheCall, CallerBFI) : None; + int64_t CallCount = + std::min(CallSiteCount.hasValue() ? CallSiteCount.getValue() : 0, + CalleeEntryCount.getCount()); + updateProfileCallee(Callee, -CallCount, &VMap); +} + +void llvm::updateProfileCallee( + Function *Callee, int64_t entryDelta, + const ValueMap<const Value *, WeakTrackingVH> *VMap) { + auto CalleeCount = Callee->getEntryCount(); + if (!CalleeCount.hasValue()) + return; + + uint64_t priorEntryCount = CalleeCount.getCount(); + uint64_t newEntryCount; + + // Since CallSiteCount is an estimate, it could exceed the original callee + // count and has to be set to 0 so guard against underflow. + if (entryDelta < 0 && static_cast<uint64_t>(-entryDelta) > priorEntryCount) + newEntryCount = 0; + else + newEntryCount = priorEntryCount + entryDelta; + + Callee->setEntryCount(newEntryCount); + + // During inlining ? + if (VMap) { + uint64_t cloneEntryCount = priorEntryCount - newEntryCount; + for (auto const &Entry : *VMap) + if (isa<CallInst>(Entry.first)) + if (auto *CI = dyn_cast_or_null<CallInst>(Entry.second)) + CI->updateProfWeight(cloneEntryCount, priorEntryCount); + } + for (BasicBlock &BB : *Callee) + // No need to update the callsite if it is pruned during inlining. + if (!VMap || VMap->count(&BB)) + for (Instruction &I : BB) + if (CallInst *CI = dyn_cast<CallInst>(&I)) + CI->updateProfWeight(newEntryCount, priorEntryCount); +} + +/// This function inlines the called function into the basic block of the +/// caller. This returns false if it is not possible to inline this call. +/// The program is still in a well defined state if this occurs though. +/// +/// Note that this only does one level of inlining. For example, if the +/// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now +/// exists in the instruction stream. Similarly this will inline a recursive +/// function by one level. +llvm::InlineResult llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI, + AAResults *CalleeAAR, + bool InsertLifetime, + Function *ForwardVarArgsTo) { + Instruction *TheCall = CS.getInstruction(); + assert(TheCall->getParent() && TheCall->getFunction() + && "Instruction not in function!"); + + // FIXME: we don't inline callbr yet. + if (isa<CallBrInst>(TheCall)) + return false; + + // If IFI has any state in it, zap it before we fill it in. + IFI.reset(); + + Function *CalledFunc = CS.getCalledFunction(); + if (!CalledFunc || // Can't inline external function or indirect + CalledFunc->isDeclaration()) // call! + return "external or indirect"; + + // The inliner does not know how to inline through calls with operand bundles + // in general ... + if (CS.hasOperandBundles()) { + for (int i = 0, e = CS.getNumOperandBundles(); i != e; ++i) { + uint32_t Tag = CS.getOperandBundleAt(i).getTagID(); + // ... but it knows how to inline through "deopt" operand bundles ... + if (Tag == LLVMContext::OB_deopt) + continue; + // ... and "funclet" operand bundles. + if (Tag == LLVMContext::OB_funclet) + continue; + + return "unsupported operand bundle"; + } + } + + // If the call to the callee cannot throw, set the 'nounwind' flag on any + // calls that we inline. + bool MarkNoUnwind = CS.doesNotThrow(); + + BasicBlock *OrigBB = TheCall->getParent(); + Function *Caller = OrigBB->getParent(); + + // GC poses two hazards to inlining, which only occur when the callee has GC: + // 1. If the caller has no GC, then the callee's GC must be propagated to the + // caller. + // 2. If the caller has a differing GC, it is invalid to inline. + if (CalledFunc->hasGC()) { + if (!Caller->hasGC()) + Caller->setGC(CalledFunc->getGC()); + else if (CalledFunc->getGC() != Caller->getGC()) + return "incompatible GC"; + } + + // Get the personality function from the callee if it contains a landing pad. + Constant *CalledPersonality = + CalledFunc->hasPersonalityFn() + ? CalledFunc->getPersonalityFn()->stripPointerCasts() + : nullptr; + + // Find the personality function used by the landing pads of the caller. If it + // exists, then check to see that it matches the personality function used in + // the callee. + Constant *CallerPersonality = + Caller->hasPersonalityFn() + ? Caller->getPersonalityFn()->stripPointerCasts() + : nullptr; + if (CalledPersonality) { + if (!CallerPersonality) + Caller->setPersonalityFn(CalledPersonality); + // If the personality functions match, then we can perform the + // inlining. Otherwise, we can't inline. + // TODO: This isn't 100% true. Some personality functions are proper + // supersets of others and can be used in place of the other. + else if (CalledPersonality != CallerPersonality) + return "incompatible personality"; + } + + // We need to figure out which funclet the callsite was in so that we may + // properly nest the callee. + Instruction *CallSiteEHPad = nullptr; + if (CallerPersonality) { + EHPersonality Personality = classifyEHPersonality(CallerPersonality); + if (isScopedEHPersonality(Personality)) { + Optional<OperandBundleUse> ParentFunclet = + CS.getOperandBundle(LLVMContext::OB_funclet); + if (ParentFunclet) + CallSiteEHPad = cast<FuncletPadInst>(ParentFunclet->Inputs.front()); + + // OK, the inlining site is legal. What about the target function? + + if (CallSiteEHPad) { + if (Personality == EHPersonality::MSVC_CXX) { + // The MSVC personality cannot tolerate catches getting inlined into + // cleanup funclets. + if (isa<CleanupPadInst>(CallSiteEHPad)) { + // Ok, the call site is within a cleanuppad. Let's check the callee + // for catchpads. + for (const BasicBlock &CalledBB : *CalledFunc) { + if (isa<CatchSwitchInst>(CalledBB.getFirstNonPHI())) + return "catch in cleanup funclet"; + } + } + } else if (isAsynchronousEHPersonality(Personality)) { + // SEH is even less tolerant, there may not be any sort of exceptional + // funclet in the callee. + for (const BasicBlock &CalledBB : *CalledFunc) { + if (CalledBB.isEHPad()) + return "SEH in cleanup funclet"; + } + } + } + } + } + + // Determine if we are dealing with a call in an EHPad which does not unwind + // to caller. + bool EHPadForCallUnwindsLocally = false; + if (CallSiteEHPad && CS.isCall()) { + UnwindDestMemoTy FuncletUnwindMap; + Value *CallSiteUnwindDestToken = + getUnwindDestToken(CallSiteEHPad, FuncletUnwindMap); + + EHPadForCallUnwindsLocally = + CallSiteUnwindDestToken && + !isa<ConstantTokenNone>(CallSiteUnwindDestToken); + } + + // Get an iterator to the last basic block in the function, which will have + // the new function inlined after it. + Function::iterator LastBlock = --Caller->end(); + + // Make sure to capture all of the return instructions from the cloned + // function. + SmallVector<ReturnInst*, 8> Returns; + ClonedCodeInfo InlinedFunctionInfo; + Function::iterator FirstNewBlock; + + { // Scope to destroy VMap after cloning. + ValueToValueMapTy VMap; + // Keep a list of pair (dst, src) to emit byval initializations. + SmallVector<std::pair<Value*, Value*>, 4> ByValInit; + + auto &DL = Caller->getParent()->getDataLayout(); + + // Calculate the vector of arguments to pass into the function cloner, which + // matches up the formal to the actual argument values. + CallSite::arg_iterator AI = CS.arg_begin(); + unsigned ArgNo = 0; + for (Function::arg_iterator I = CalledFunc->arg_begin(), + E = CalledFunc->arg_end(); I != E; ++I, ++AI, ++ArgNo) { + Value *ActualArg = *AI; + + // When byval arguments actually inlined, we need to make the copy implied + // by them explicit. However, we don't do this if the callee is readonly + // or readnone, because the copy would be unneeded: the callee doesn't + // modify the struct. + if (CS.isByValArgument(ArgNo)) { + ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI, + CalledFunc->getParamAlignment(ArgNo)); + if (ActualArg != *AI) + ByValInit.push_back(std::make_pair(ActualArg, (Value*) *AI)); + } + + VMap[&*I] = ActualArg; + } + + // Add alignment assumptions if necessary. We do this before the inlined + // instructions are actually cloned into the caller so that we can easily + // check what will be known at the start of the inlined code. + AddAlignmentAssumptions(CS, IFI); + + // We want the inliner to prune the code as it copies. We would LOVE to + // have no dead or constant instructions leftover after inlining occurs + // (which can happen, e.g., because an argument was constant), but we'll be + // happy with whatever the cloner can do. + CloneAndPruneFunctionInto(Caller, CalledFunc, VMap, + /*ModuleLevelChanges=*/false, Returns, ".i", + &InlinedFunctionInfo, TheCall); + // Remember the first block that is newly cloned over. + FirstNewBlock = LastBlock; ++FirstNewBlock; + + if (IFI.CallerBFI != nullptr && IFI.CalleeBFI != nullptr) + // Update the BFI of blocks cloned into the caller. + updateCallerBFI(OrigBB, VMap, IFI.CallerBFI, IFI.CalleeBFI, + CalledFunc->front()); + + updateCallProfile(CalledFunc, VMap, CalledFunc->getEntryCount(), TheCall, + IFI.PSI, IFI.CallerBFI); + + // Inject byval arguments initialization. + for (std::pair<Value*, Value*> &Init : ByValInit) + HandleByValArgumentInit(Init.first, Init.second, Caller->getParent(), + &*FirstNewBlock, IFI); + + Optional<OperandBundleUse> ParentDeopt = + CS.getOperandBundle(LLVMContext::OB_deopt); + if (ParentDeopt) { + SmallVector<OperandBundleDef, 2> OpDefs; + + for (auto &VH : InlinedFunctionInfo.OperandBundleCallSites) { + Instruction *I = dyn_cast_or_null<Instruction>(VH); + if (!I) continue; // instruction was DCE'd or RAUW'ed to undef + + OpDefs.clear(); + + CallSite ICS(I); + OpDefs.reserve(ICS.getNumOperandBundles()); + + for (unsigned i = 0, e = ICS.getNumOperandBundles(); i < e; ++i) { + auto ChildOB = ICS.getOperandBundleAt(i); + if (ChildOB.getTagID() != LLVMContext::OB_deopt) { + // If the inlined call has other operand bundles, let them be + OpDefs.emplace_back(ChildOB); + continue; + } + + // It may be useful to separate this logic (of handling operand + // bundles) out to a separate "policy" component if this gets crowded. + // Prepend the parent's deoptimization continuation to the newly + // inlined call's deoptimization continuation. + std::vector<Value *> MergedDeoptArgs; + MergedDeoptArgs.reserve(ParentDeopt->Inputs.size() + + ChildOB.Inputs.size()); + + MergedDeoptArgs.insert(MergedDeoptArgs.end(), + ParentDeopt->Inputs.begin(), + ParentDeopt->Inputs.end()); + MergedDeoptArgs.insert(MergedDeoptArgs.end(), ChildOB.Inputs.begin(), + ChildOB.Inputs.end()); + + OpDefs.emplace_back("deopt", std::move(MergedDeoptArgs)); + } + + Instruction *NewI = nullptr; + if (isa<CallInst>(I)) + NewI = CallInst::Create(cast<CallInst>(I), OpDefs, I); + else if (isa<CallBrInst>(I)) + NewI = CallBrInst::Create(cast<CallBrInst>(I), OpDefs, I); + else + NewI = InvokeInst::Create(cast<InvokeInst>(I), OpDefs, I); + + // Note: the RAUW does the appropriate fixup in VMap, so we need to do + // this even if the call returns void. + I->replaceAllUsesWith(NewI); + + VH = nullptr; + I->eraseFromParent(); + } + } + + // Update the callgraph if requested. + if (IFI.CG) + UpdateCallGraphAfterInlining(CS, FirstNewBlock, VMap, IFI); + + // For 'nodebug' functions, the associated DISubprogram is always null. + // Conservatively avoid propagating the callsite debug location to + // instructions inlined from a function whose DISubprogram is not null. + fixupLineNumbers(Caller, FirstNewBlock, TheCall, + CalledFunc->getSubprogram() != nullptr); + + // Clone existing noalias metadata if necessary. + CloneAliasScopeMetadata(CS, VMap); + + // Add noalias metadata if necessary. + AddAliasScopeMetadata(CS, VMap, DL, CalleeAAR); + + // Propagate llvm.mem.parallel_loop_access if necessary. + PropagateParallelLoopAccessMetadata(CS, VMap); + + // Register any cloned assumptions. + if (IFI.GetAssumptionCache) + for (BasicBlock &NewBlock : + make_range(FirstNewBlock->getIterator(), Caller->end())) + for (Instruction &I : NewBlock) { + if (auto *II = dyn_cast<IntrinsicInst>(&I)) + if (II->getIntrinsicID() == Intrinsic::assume) + (*IFI.GetAssumptionCache)(*Caller).registerAssumption(II); + } + } + + // If there are any alloca instructions in the block that used to be the entry + // block for the callee, move them to the entry block of the caller. First + // calculate which instruction they should be inserted before. We insert the + // instructions at the end of the current alloca list. + { + BasicBlock::iterator InsertPoint = Caller->begin()->begin(); + for (BasicBlock::iterator I = FirstNewBlock->begin(), + E = FirstNewBlock->end(); I != E; ) { + AllocaInst *AI = dyn_cast<AllocaInst>(I++); + if (!AI) continue; + + // If the alloca is now dead, remove it. This often occurs due to code + // specialization. + if (AI->use_empty()) { + AI->eraseFromParent(); + continue; + } + + if (!allocaWouldBeStaticInEntry(AI)) + continue; + + // Keep track of the static allocas that we inline into the caller. + IFI.StaticAllocas.push_back(AI); + + // Scan for the block of allocas that we can move over, and move them + // all at once. + while (isa<AllocaInst>(I) && + allocaWouldBeStaticInEntry(cast<AllocaInst>(I))) { + IFI.StaticAllocas.push_back(cast<AllocaInst>(I)); + ++I; + } + + // Transfer all of the allocas over in a block. Using splice means + // that the instructions aren't removed from the symbol table, then + // reinserted. + Caller->getEntryBlock().getInstList().splice( + InsertPoint, FirstNewBlock->getInstList(), AI->getIterator(), I); + } + // Move any dbg.declares describing the allocas into the entry basic block. + DIBuilder DIB(*Caller->getParent()); + for (auto &AI : IFI.StaticAllocas) + replaceDbgDeclareForAlloca(AI, AI, DIB, DIExpression::ApplyOffset, 0); + } + + SmallVector<Value*,4> VarArgsToForward; + SmallVector<AttributeSet, 4> VarArgsAttrs; + for (unsigned i = CalledFunc->getFunctionType()->getNumParams(); + i < CS.getNumArgOperands(); i++) { + VarArgsToForward.push_back(CS.getArgOperand(i)); + VarArgsAttrs.push_back(CS.getAttributes().getParamAttributes(i)); + } + + bool InlinedMustTailCalls = false, InlinedDeoptimizeCalls = false; + if (InlinedFunctionInfo.ContainsCalls) { + CallInst::TailCallKind CallSiteTailKind = CallInst::TCK_None; + if (CallInst *CI = dyn_cast<CallInst>(TheCall)) + CallSiteTailKind = CI->getTailCallKind(); + + // For inlining purposes, the "notail" marker is the same as no marker. + if (CallSiteTailKind == CallInst::TCK_NoTail) + CallSiteTailKind = CallInst::TCK_None; + + for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; + ++BB) { + for (auto II = BB->begin(); II != BB->end();) { + Instruction &I = *II++; + CallInst *CI = dyn_cast<CallInst>(&I); + if (!CI) + continue; + + // Forward varargs from inlined call site to calls to the + // ForwardVarArgsTo function, if requested, and to musttail calls. + if (!VarArgsToForward.empty() && + ((ForwardVarArgsTo && + CI->getCalledFunction() == ForwardVarArgsTo) || + CI->isMustTailCall())) { + // Collect attributes for non-vararg parameters. + AttributeList Attrs = CI->getAttributes(); + SmallVector<AttributeSet, 8> ArgAttrs; + if (!Attrs.isEmpty() || !VarArgsAttrs.empty()) { + for (unsigned ArgNo = 0; + ArgNo < CI->getFunctionType()->getNumParams(); ++ArgNo) + ArgAttrs.push_back(Attrs.getParamAttributes(ArgNo)); + } + + // Add VarArg attributes. + ArgAttrs.append(VarArgsAttrs.begin(), VarArgsAttrs.end()); + Attrs = AttributeList::get(CI->getContext(), Attrs.getFnAttributes(), + Attrs.getRetAttributes(), ArgAttrs); + // Add VarArgs to existing parameters. + SmallVector<Value *, 6> Params(CI->arg_operands()); + Params.append(VarArgsToForward.begin(), VarArgsToForward.end()); + CallInst *NewCI = CallInst::Create( + CI->getFunctionType(), CI->getCalledOperand(), Params, "", CI); + NewCI->setDebugLoc(CI->getDebugLoc()); + NewCI->setAttributes(Attrs); + NewCI->setCallingConv(CI->getCallingConv()); + CI->replaceAllUsesWith(NewCI); + CI->eraseFromParent(); + CI = NewCI; + } + + if (Function *F = CI->getCalledFunction()) + InlinedDeoptimizeCalls |= + F->getIntrinsicID() == Intrinsic::experimental_deoptimize; + + // We need to reduce the strength of any inlined tail calls. For + // musttail, we have to avoid introducing potential unbounded stack + // growth. For example, if functions 'f' and 'g' are mutually recursive + // with musttail, we can inline 'g' into 'f' so long as we preserve + // musttail on the cloned call to 'f'. If either the inlined call site + // or the cloned call site is *not* musttail, the program already has + // one frame of stack growth, so it's safe to remove musttail. Here is + // a table of example transformations: + // + // f -> musttail g -> musttail f ==> f -> musttail f + // f -> musttail g -> tail f ==> f -> tail f + // f -> g -> musttail f ==> f -> f + // f -> g -> tail f ==> f -> f + // + // Inlined notail calls should remain notail calls. + CallInst::TailCallKind ChildTCK = CI->getTailCallKind(); + if (ChildTCK != CallInst::TCK_NoTail) + ChildTCK = std::min(CallSiteTailKind, ChildTCK); + CI->setTailCallKind(ChildTCK); + InlinedMustTailCalls |= CI->isMustTailCall(); + + // Calls inlined through a 'nounwind' call site should be marked + // 'nounwind'. + if (MarkNoUnwind) + CI->setDoesNotThrow(); + } + } + } + + // Leave lifetime markers for the static alloca's, scoping them to the + // function we just inlined. + if (InsertLifetime && !IFI.StaticAllocas.empty()) { + IRBuilder<> builder(&FirstNewBlock->front()); + for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) { + AllocaInst *AI = IFI.StaticAllocas[ai]; + // Don't mark swifterror allocas. They can't have bitcast uses. + if (AI->isSwiftError()) + continue; + + // If the alloca is already scoped to something smaller than the whole + // function then there's no need to add redundant, less accurate markers. + if (hasLifetimeMarkers(AI)) + continue; + + // Try to determine the size of the allocation. + ConstantInt *AllocaSize = nullptr; + if (ConstantInt *AIArraySize = + dyn_cast<ConstantInt>(AI->getArraySize())) { + auto &DL = Caller->getParent()->getDataLayout(); + Type *AllocaType = AI->getAllocatedType(); + uint64_t AllocaTypeSize = DL.getTypeAllocSize(AllocaType); + uint64_t AllocaArraySize = AIArraySize->getLimitedValue(); + + // Don't add markers for zero-sized allocas. + if (AllocaArraySize == 0) + continue; + + // Check that array size doesn't saturate uint64_t and doesn't + // overflow when it's multiplied by type size. + if (AllocaArraySize != std::numeric_limits<uint64_t>::max() && + std::numeric_limits<uint64_t>::max() / AllocaArraySize >= + AllocaTypeSize) { + AllocaSize = ConstantInt::get(Type::getInt64Ty(AI->getContext()), + AllocaArraySize * AllocaTypeSize); + } + } + + builder.CreateLifetimeStart(AI, AllocaSize); + for (ReturnInst *RI : Returns) { + // Don't insert llvm.lifetime.end calls between a musttail or deoptimize + // call and a return. The return kills all local allocas. + if (InlinedMustTailCalls && + RI->getParent()->getTerminatingMustTailCall()) + continue; + if (InlinedDeoptimizeCalls && + RI->getParent()->getTerminatingDeoptimizeCall()) + continue; + IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize); + } + } + } + + // If the inlined code contained dynamic alloca instructions, wrap the inlined + // code with llvm.stacksave/llvm.stackrestore intrinsics. + if (InlinedFunctionInfo.ContainsDynamicAllocas) { + Module *M = Caller->getParent(); + // Get the two intrinsics we care about. + Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave); + Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore); + + // Insert the llvm.stacksave. + CallInst *SavedPtr = IRBuilder<>(&*FirstNewBlock, FirstNewBlock->begin()) + .CreateCall(StackSave, {}, "savedstack"); + + // Insert a call to llvm.stackrestore before any return instructions in the + // inlined function. + for (ReturnInst *RI : Returns) { + // Don't insert llvm.stackrestore calls between a musttail or deoptimize + // call and a return. The return will restore the stack pointer. + if (InlinedMustTailCalls && RI->getParent()->getTerminatingMustTailCall()) + continue; + if (InlinedDeoptimizeCalls && RI->getParent()->getTerminatingDeoptimizeCall()) + continue; + IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr); + } + } + + // If we are inlining for an invoke instruction, we must make sure to rewrite + // any call instructions into invoke instructions. This is sensitive to which + // funclet pads were top-level in the inlinee, so must be done before + // rewriting the "parent pad" links. + if (auto *II = dyn_cast<InvokeInst>(TheCall)) { + BasicBlock *UnwindDest = II->getUnwindDest(); + Instruction *FirstNonPHI = UnwindDest->getFirstNonPHI(); + if (isa<LandingPadInst>(FirstNonPHI)) { + HandleInlinedLandingPad(II, &*FirstNewBlock, InlinedFunctionInfo); + } else { + HandleInlinedEHPad(II, &*FirstNewBlock, InlinedFunctionInfo); + } + } + + // Update the lexical scopes of the new funclets and callsites. + // Anything that had 'none' as its parent is now nested inside the callsite's + // EHPad. + + if (CallSiteEHPad) { + for (Function::iterator BB = FirstNewBlock->getIterator(), + E = Caller->end(); + BB != E; ++BB) { + // Add bundle operands to any top-level call sites. + SmallVector<OperandBundleDef, 1> OpBundles; + for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E;) { + Instruction *I = &*BBI++; + CallSite CS(I); + if (!CS) + continue; + + // Skip call sites which are nounwind intrinsics. + auto *CalledFn = + dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts()); + if (CalledFn && CalledFn->isIntrinsic() && CS.doesNotThrow()) + continue; + + // Skip call sites which already have a "funclet" bundle. + if (CS.getOperandBundle(LLVMContext::OB_funclet)) + continue; + + CS.getOperandBundlesAsDefs(OpBundles); + OpBundles.emplace_back("funclet", CallSiteEHPad); + + Instruction *NewInst; + if (CS.isCall()) + NewInst = CallInst::Create(cast<CallInst>(I), OpBundles, I); + else if (CS.isCallBr()) + NewInst = CallBrInst::Create(cast<CallBrInst>(I), OpBundles, I); + else + NewInst = InvokeInst::Create(cast<InvokeInst>(I), OpBundles, I); + NewInst->takeName(I); + I->replaceAllUsesWith(NewInst); + I->eraseFromParent(); + + OpBundles.clear(); + } + + // It is problematic if the inlinee has a cleanupret which unwinds to + // caller and we inline it into a call site which doesn't unwind but into + // an EH pad that does. Such an edge must be dynamically unreachable. + // As such, we replace the cleanupret with unreachable. + if (auto *CleanupRet = dyn_cast<CleanupReturnInst>(BB->getTerminator())) + if (CleanupRet->unwindsToCaller() && EHPadForCallUnwindsLocally) + changeToUnreachable(CleanupRet, /*UseLLVMTrap=*/false); + + Instruction *I = BB->getFirstNonPHI(); + if (!I->isEHPad()) + continue; + + if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(I)) { + if (isa<ConstantTokenNone>(CatchSwitch->getParentPad())) + CatchSwitch->setParentPad(CallSiteEHPad); + } else { + auto *FPI = cast<FuncletPadInst>(I); + if (isa<ConstantTokenNone>(FPI->getParentPad())) + FPI->setParentPad(CallSiteEHPad); + } + } + } + + if (InlinedDeoptimizeCalls) { + // We need to at least remove the deoptimizing returns from the Return set, + // so that the control flow from those returns does not get merged into the + // caller (but terminate it instead). If the caller's return type does not + // match the callee's return type, we also need to change the return type of + // the intrinsic. + if (Caller->getReturnType() == TheCall->getType()) { + auto NewEnd = llvm::remove_if(Returns, [](ReturnInst *RI) { + return RI->getParent()->getTerminatingDeoptimizeCall() != nullptr; + }); + Returns.erase(NewEnd, Returns.end()); + } else { + SmallVector<ReturnInst *, 8> NormalReturns; + Function *NewDeoptIntrinsic = Intrinsic::getDeclaration( + Caller->getParent(), Intrinsic::experimental_deoptimize, + {Caller->getReturnType()}); + + for (ReturnInst *RI : Returns) { + CallInst *DeoptCall = RI->getParent()->getTerminatingDeoptimizeCall(); + if (!DeoptCall) { + NormalReturns.push_back(RI); + continue; + } + + // The calling convention on the deoptimize call itself may be bogus, + // since the code we're inlining may have undefined behavior (and may + // never actually execute at runtime); but all + // @llvm.experimental.deoptimize declarations have to have the same + // calling convention in a well-formed module. + auto CallingConv = DeoptCall->getCalledFunction()->getCallingConv(); + NewDeoptIntrinsic->setCallingConv(CallingConv); + auto *CurBB = RI->getParent(); + RI->eraseFromParent(); + + SmallVector<Value *, 4> CallArgs(DeoptCall->arg_begin(), + DeoptCall->arg_end()); + + SmallVector<OperandBundleDef, 1> OpBundles; + DeoptCall->getOperandBundlesAsDefs(OpBundles); + DeoptCall->eraseFromParent(); + assert(!OpBundles.empty() && + "Expected at least the deopt operand bundle"); + + IRBuilder<> Builder(CurBB); + CallInst *NewDeoptCall = + Builder.CreateCall(NewDeoptIntrinsic, CallArgs, OpBundles); + NewDeoptCall->setCallingConv(CallingConv); + if (NewDeoptCall->getType()->isVoidTy()) + Builder.CreateRetVoid(); + else + Builder.CreateRet(NewDeoptCall); + } + + // Leave behind the normal returns so we can merge control flow. + std::swap(Returns, NormalReturns); + } + } + + // Handle any inlined musttail call sites. In order for a new call site to be + // musttail, the source of the clone and the inlined call site must have been + // musttail. Therefore it's safe to return without merging control into the + // phi below. + if (InlinedMustTailCalls) { + // Check if we need to bitcast the result of any musttail calls. + Type *NewRetTy = Caller->getReturnType(); + bool NeedBitCast = !TheCall->use_empty() && TheCall->getType() != NewRetTy; + + // Handle the returns preceded by musttail calls separately. + SmallVector<ReturnInst *, 8> NormalReturns; + for (ReturnInst *RI : Returns) { + CallInst *ReturnedMustTail = + RI->getParent()->getTerminatingMustTailCall(); + if (!ReturnedMustTail) { + NormalReturns.push_back(RI); + continue; + } + if (!NeedBitCast) + continue; + + // Delete the old return and any preceding bitcast. + BasicBlock *CurBB = RI->getParent(); + auto *OldCast = dyn_cast_or_null<BitCastInst>(RI->getReturnValue()); + RI->eraseFromParent(); + if (OldCast) + OldCast->eraseFromParent(); + + // Insert a new bitcast and return with the right type. + IRBuilder<> Builder(CurBB); + Builder.CreateRet(Builder.CreateBitCast(ReturnedMustTail, NewRetTy)); + } + + // Leave behind the normal returns so we can merge control flow. + std::swap(Returns, NormalReturns); + } + + // Now that all of the transforms on the inlined code have taken place but + // before we splice the inlined code into the CFG and lose track of which + // blocks were actually inlined, collect the call sites. We only do this if + // call graph updates weren't requested, as those provide value handle based + // tracking of inlined call sites instead. + if (InlinedFunctionInfo.ContainsCalls && !IFI.CG) { + // Otherwise just collect the raw call sites that were inlined. + for (BasicBlock &NewBB : + make_range(FirstNewBlock->getIterator(), Caller->end())) + for (Instruction &I : NewBB) + if (auto CS = CallSite(&I)) + IFI.InlinedCallSites.push_back(CS); + } + + // If we cloned in _exactly one_ basic block, and if that block ends in a + // return instruction, we splice the body of the inlined callee directly into + // the calling basic block. + if (Returns.size() == 1 && std::distance(FirstNewBlock, Caller->end()) == 1) { + // Move all of the instructions right before the call. + OrigBB->getInstList().splice(TheCall->getIterator(), + FirstNewBlock->getInstList(), + FirstNewBlock->begin(), FirstNewBlock->end()); + // Remove the cloned basic block. + Caller->getBasicBlockList().pop_back(); + + // If the call site was an invoke instruction, add a branch to the normal + // destination. + if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { + BranchInst *NewBr = BranchInst::Create(II->getNormalDest(), TheCall); + NewBr->setDebugLoc(Returns[0]->getDebugLoc()); + } + + // If the return instruction returned a value, replace uses of the call with + // uses of the returned value. + if (!TheCall->use_empty()) { + ReturnInst *R = Returns[0]; + if (TheCall == R->getReturnValue()) + TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); + else + TheCall->replaceAllUsesWith(R->getReturnValue()); + } + // Since we are now done with the Call/Invoke, we can delete it. + TheCall->eraseFromParent(); + + // Since we are now done with the return instruction, delete it also. + Returns[0]->eraseFromParent(); + + // We are now done with the inlining. + return true; + } + + // Otherwise, we have the normal case, of more than one block to inline or + // multiple return sites. + + // We want to clone the entire callee function into the hole between the + // "starter" and "ender" blocks. How we accomplish this depends on whether + // this is an invoke instruction or a call instruction. + BasicBlock *AfterCallBB; + BranchInst *CreatedBranchToNormalDest = nullptr; + if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { + + // Add an unconditional branch to make this look like the CallInst case... + CreatedBranchToNormalDest = BranchInst::Create(II->getNormalDest(), TheCall); + + // Split the basic block. This guarantees that no PHI nodes will have to be + // updated due to new incoming edges, and make the invoke case more + // symmetric to the call case. + AfterCallBB = + OrigBB->splitBasicBlock(CreatedBranchToNormalDest->getIterator(), + CalledFunc->getName() + ".exit"); + + } else { // It's a call + // If this is a call instruction, we need to split the basic block that + // the call lives in. + // + AfterCallBB = OrigBB->splitBasicBlock(TheCall->getIterator(), + CalledFunc->getName() + ".exit"); + } + + if (IFI.CallerBFI) { + // Copy original BB's block frequency to AfterCallBB + IFI.CallerBFI->setBlockFreq( + AfterCallBB, IFI.CallerBFI->getBlockFreq(OrigBB).getFrequency()); + } + + // Change the branch that used to go to AfterCallBB to branch to the first + // basic block of the inlined function. + // + Instruction *Br = OrigBB->getTerminator(); + assert(Br && Br->getOpcode() == Instruction::Br && + "splitBasicBlock broken!"); + Br->setOperand(0, &*FirstNewBlock); + + // Now that the function is correct, make it a little bit nicer. In + // particular, move the basic blocks inserted from the end of the function + // into the space made by splitting the source basic block. + Caller->getBasicBlockList().splice(AfterCallBB->getIterator(), + Caller->getBasicBlockList(), FirstNewBlock, + Caller->end()); + + // Handle all of the return instructions that we just cloned in, and eliminate + // any users of the original call/invoke instruction. + Type *RTy = CalledFunc->getReturnType(); + + PHINode *PHI = nullptr; + if (Returns.size() > 1) { + // The PHI node should go at the front of the new basic block to merge all + // possible incoming values. + if (!TheCall->use_empty()) { + PHI = PHINode::Create(RTy, Returns.size(), TheCall->getName(), + &AfterCallBB->front()); + // Anything that used the result of the function call should now use the + // PHI node as their operand. + TheCall->replaceAllUsesWith(PHI); + } + + // Loop over all of the return instructions adding entries to the PHI node + // as appropriate. + if (PHI) { + for (unsigned i = 0, e = Returns.size(); i != e; ++i) { + ReturnInst *RI = Returns[i]; + assert(RI->getReturnValue()->getType() == PHI->getType() && + "Ret value not consistent in function!"); + PHI->addIncoming(RI->getReturnValue(), RI->getParent()); + } + } + + // Add a branch to the merge points and remove return instructions. + DebugLoc Loc; + for (unsigned i = 0, e = Returns.size(); i != e; ++i) { + ReturnInst *RI = Returns[i]; + BranchInst* BI = BranchInst::Create(AfterCallBB, RI); + Loc = RI->getDebugLoc(); + BI->setDebugLoc(Loc); + RI->eraseFromParent(); + } + // We need to set the debug location to *somewhere* inside the + // inlined function. The line number may be nonsensical, but the + // instruction will at least be associated with the right + // function. + if (CreatedBranchToNormalDest) + CreatedBranchToNormalDest->setDebugLoc(Loc); + } else if (!Returns.empty()) { + // Otherwise, if there is exactly one return value, just replace anything + // using the return value of the call with the computed value. + if (!TheCall->use_empty()) { + if (TheCall == Returns[0]->getReturnValue()) + TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); + else + TheCall->replaceAllUsesWith(Returns[0]->getReturnValue()); + } + + // Update PHI nodes that use the ReturnBB to use the AfterCallBB. + BasicBlock *ReturnBB = Returns[0]->getParent(); + ReturnBB->replaceAllUsesWith(AfterCallBB); + + // Splice the code from the return block into the block that it will return + // to, which contains the code that was after the call. + AfterCallBB->getInstList().splice(AfterCallBB->begin(), + ReturnBB->getInstList()); + + if (CreatedBranchToNormalDest) + CreatedBranchToNormalDest->setDebugLoc(Returns[0]->getDebugLoc()); + + // Delete the return instruction now and empty ReturnBB now. + Returns[0]->eraseFromParent(); + ReturnBB->eraseFromParent(); + } else if (!TheCall->use_empty()) { + // No returns, but something is using the return value of the call. Just + // nuke the result. + TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType())); + } + + // Since we are now done with the Call/Invoke, we can delete it. + TheCall->eraseFromParent(); + + // If we inlined any musttail calls and the original return is now + // unreachable, delete it. It can only contain a bitcast and ret. + if (InlinedMustTailCalls && pred_begin(AfterCallBB) == pred_end(AfterCallBB)) + AfterCallBB->eraseFromParent(); + + // We should always be able to fold the entry block of the function into the + // single predecessor of the block... + assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!"); + BasicBlock *CalleeEntry = cast<BranchInst>(Br)->getSuccessor(0); + + // Splice the code entry block into calling block, right before the + // unconditional branch. + CalleeEntry->replaceAllUsesWith(OrigBB); // Update PHI nodes + OrigBB->getInstList().splice(Br->getIterator(), CalleeEntry->getInstList()); + + // Remove the unconditional branch. + OrigBB->getInstList().erase(Br); + + // Now we can remove the CalleeEntry block, which is now empty. + Caller->getBasicBlockList().erase(CalleeEntry); + + // If we inserted a phi node, check to see if it has a single value (e.g. all + // the entries are the same or undef). If so, remove the PHI so it doesn't + // block other optimizations. + if (PHI) { + AssumptionCache *AC = + IFI.GetAssumptionCache ? &(*IFI.GetAssumptionCache)(*Caller) : nullptr; + auto &DL = Caller->getParent()->getDataLayout(); + if (Value *V = SimplifyInstruction(PHI, {DL, nullptr, nullptr, AC})) { + PHI->replaceAllUsesWith(V); + PHI->eraseFromParent(); + } + } + + return true; +} |