diff options
Diffstat (limited to 'lib/Transforms/ObjCARC/ObjCARCOpts.cpp')
| -rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCOpts.cpp | 1308 |
1 files changed, 231 insertions, 1077 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp index f55b77f..4d75658 100644 --- a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp +++ b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp @@ -26,9 +26,11 @@ #include "ObjCARC.h" #include "ARCRuntimeEntryPoints.h" +#include "BlotMapVector.h" #include "DependencyAnalysis.h" #include "ObjCARCAliasAnalysis.h" #include "ProvenanceAnalysis.h" +#include "PtrState.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DenseSet.h" #include "llvm/ADT/STLExtras.h" @@ -45,102 +47,6 @@ using namespace llvm::objcarc; #define DEBUG_TYPE "objc-arc-opts" -/// \defgroup MiscUtils Miscellaneous utilities that are not ARC specific. -/// @{ - -namespace { - /// \brief An associative container with fast insertion-order (deterministic) - /// iteration over its elements. Plus the special blot operation. - template<class KeyT, class ValueT> - class MapVector { - /// Map keys to indices in Vector. - typedef DenseMap<KeyT, size_t> MapTy; - MapTy Map; - - typedef std::vector<std::pair<KeyT, ValueT> > VectorTy; - /// Keys and values. - VectorTy Vector; - - public: - typedef typename VectorTy::iterator iterator; - typedef typename VectorTy::const_iterator const_iterator; - iterator begin() { return Vector.begin(); } - iterator end() { return Vector.end(); } - const_iterator begin() const { return Vector.begin(); } - const_iterator end() const { return Vector.end(); } - -#ifdef XDEBUG - ~MapVector() { - assert(Vector.size() >= Map.size()); // May differ due to blotting. - for (typename MapTy::const_iterator I = Map.begin(), E = Map.end(); - I != E; ++I) { - assert(I->second < Vector.size()); - assert(Vector[I->second].first == I->first); - } - for (typename VectorTy::const_iterator I = Vector.begin(), - E = Vector.end(); I != E; ++I) - assert(!I->first || - (Map.count(I->first) && - Map[I->first] == size_t(I - Vector.begin()))); - } -#endif - - ValueT &operator[](const KeyT &Arg) { - std::pair<typename MapTy::iterator, bool> Pair = - Map.insert(std::make_pair(Arg, size_t(0))); - if (Pair.second) { - size_t Num = Vector.size(); - Pair.first->second = Num; - Vector.push_back(std::make_pair(Arg, ValueT())); - return Vector[Num].second; - } - return Vector[Pair.first->second].second; - } - - std::pair<iterator, bool> - insert(const std::pair<KeyT, ValueT> &InsertPair) { - std::pair<typename MapTy::iterator, bool> Pair = - Map.insert(std::make_pair(InsertPair.first, size_t(0))); - if (Pair.second) { - size_t Num = Vector.size(); - Pair.first->second = Num; - Vector.push_back(InsertPair); - return std::make_pair(Vector.begin() + Num, true); - } - return std::make_pair(Vector.begin() + Pair.first->second, false); - } - - iterator find(const KeyT &Key) { - typename MapTy::iterator It = Map.find(Key); - if (It == Map.end()) return Vector.end(); - return Vector.begin() + It->second; - } - - const_iterator find(const KeyT &Key) const { - typename MapTy::const_iterator It = Map.find(Key); - if (It == Map.end()) return Vector.end(); - return Vector.begin() + It->second; - } - - /// This is similar to erase, but instead of removing the element from the - /// vector, it just zeros out the key in the vector. This leaves iterators - /// intact, but clients must be prepared for zeroed-out keys when iterating. - void blot(const KeyT &Key) { - typename MapTy::iterator It = Map.find(Key); - if (It == Map.end()) return; - Vector[It->second].first = KeyT(); - Map.erase(It); - } - - void clear() { - Map.clear(); - Vector.clear(); - } - }; -} - -/// @} -/// /// \defgroup ARCUtilities Utility declarations/definitions specific to ARC. /// @{ @@ -177,13 +83,14 @@ static const Value *FindSingleUseIdentifiedObject(const Value *Arg) { /// This is a wrapper around getUnderlyingObjCPtr along the lines of /// GetUnderlyingObjects except that it returns early when it sees the first /// alloca. -static inline bool AreAnyUnderlyingObjectsAnAlloca(const Value *V) { +static inline bool AreAnyUnderlyingObjectsAnAlloca(const Value *V, + const DataLayout &DL) { SmallPtrSet<const Value *, 4> Visited; SmallVector<const Value *, 4> Worklist; Worklist.push_back(V); do { const Value *P = Worklist.pop_back_val(); - P = GetUnderlyingObjCPtr(P); + P = GetUnderlyingObjCPtr(P, DL); if (isa<AllocaInst>(P)) return true; @@ -270,293 +177,6 @@ STATISTIC(NumReleasesAfterOpt, #endif namespace { - /// \enum Sequence - /// - /// \brief A sequence of states that a pointer may go through in which an - /// objc_retain and objc_release are actually needed. - enum Sequence { - S_None, - S_Retain, ///< objc_retain(x). - S_CanRelease, ///< foo(x) -- x could possibly see a ref count decrement. - S_Use, ///< any use of x. - S_Stop, ///< like S_Release, but code motion is stopped. - S_Release, ///< objc_release(x). - S_MovableRelease ///< objc_release(x), !clang.imprecise_release. - }; - - raw_ostream &operator<<(raw_ostream &OS, const Sequence S) - LLVM_ATTRIBUTE_UNUSED; - raw_ostream &operator<<(raw_ostream &OS, const Sequence S) { - switch (S) { - case S_None: - return OS << "S_None"; - case S_Retain: - return OS << "S_Retain"; - case S_CanRelease: - return OS << "S_CanRelease"; - case S_Use: - return OS << "S_Use"; - case S_Release: - return OS << "S_Release"; - case S_MovableRelease: - return OS << "S_MovableRelease"; - case S_Stop: - return OS << "S_Stop"; - } - llvm_unreachable("Unknown sequence type."); - } -} - -static Sequence MergeSeqs(Sequence A, Sequence B, bool TopDown) { - // The easy cases. - if (A == B) - return A; - if (A == S_None || B == S_None) - return S_None; - - if (A > B) std::swap(A, B); - if (TopDown) { - // Choose the side which is further along in the sequence. - if ((A == S_Retain || A == S_CanRelease) && - (B == S_CanRelease || B == S_Use)) - return B; - } else { - // Choose the side which is further along in the sequence. - if ((A == S_Use || A == S_CanRelease) && - (B == S_Use || B == S_Release || B == S_Stop || B == S_MovableRelease)) - return A; - // If both sides are releases, choose the more conservative one. - if (A == S_Stop && (B == S_Release || B == S_MovableRelease)) - return A; - if (A == S_Release && B == S_MovableRelease) - return A; - } - - return S_None; -} - -namespace { - /// \brief Unidirectional information about either a - /// retain-decrement-use-release sequence or release-use-decrement-retain - /// reverse sequence. - struct RRInfo { - /// After an objc_retain, the reference count of the referenced - /// object is known to be positive. Similarly, before an objc_release, the - /// reference count of the referenced object is known to be positive. If - /// there are retain-release pairs in code regions where the retain count - /// is known to be positive, they can be eliminated, regardless of any side - /// effects between them. - /// - /// Also, a retain+release pair nested within another retain+release - /// pair all on the known same pointer value can be eliminated, regardless - /// of any intervening side effects. - /// - /// KnownSafe is true when either of these conditions is satisfied. - bool KnownSafe; - - /// True of the objc_release calls are all marked with the "tail" keyword. - bool IsTailCallRelease; - - /// If the Calls are objc_release calls and they all have a - /// clang.imprecise_release tag, this is the metadata tag. - MDNode *ReleaseMetadata; - - /// For a top-down sequence, the set of objc_retains or - /// objc_retainBlocks. For bottom-up, the set of objc_releases. - SmallPtrSet<Instruction *, 2> Calls; - - /// The set of optimal insert positions for moving calls in the opposite - /// sequence. - SmallPtrSet<Instruction *, 2> ReverseInsertPts; - - /// If this is true, we cannot perform code motion but can still remove - /// retain/release pairs. - bool CFGHazardAfflicted; - - RRInfo() : - KnownSafe(false), IsTailCallRelease(false), ReleaseMetadata(nullptr), - CFGHazardAfflicted(false) {} - - void clear(); - - /// Conservatively merge the two RRInfo. Returns true if a partial merge has - /// occurred, false otherwise. - bool Merge(const RRInfo &Other); - - }; -} - -void RRInfo::clear() { - KnownSafe = false; - IsTailCallRelease = false; - ReleaseMetadata = nullptr; - Calls.clear(); - ReverseInsertPts.clear(); - CFGHazardAfflicted = false; -} - -bool RRInfo::Merge(const RRInfo &Other) { - // Conservatively merge the ReleaseMetadata information. - if (ReleaseMetadata != Other.ReleaseMetadata) - ReleaseMetadata = nullptr; - - // Conservatively merge the boolean state. - KnownSafe &= Other.KnownSafe; - IsTailCallRelease &= Other.IsTailCallRelease; - CFGHazardAfflicted |= Other.CFGHazardAfflicted; - - // Merge the call sets. - Calls.insert(Other.Calls.begin(), Other.Calls.end()); - - // Merge the insert point sets. If there are any differences, - // that makes this a partial merge. - bool Partial = ReverseInsertPts.size() != Other.ReverseInsertPts.size(); - for (Instruction *Inst : Other.ReverseInsertPts) - Partial |= ReverseInsertPts.insert(Inst).second; - return Partial; -} - -namespace { - /// \brief This class summarizes several per-pointer runtime properties which - /// are propogated through the flow graph. - class PtrState { - /// True if the reference count is known to be incremented. - bool KnownPositiveRefCount; - - /// True if we've seen an opportunity for partial RR elimination, such as - /// pushing calls into a CFG triangle or into one side of a CFG diamond. - bool Partial; - - /// The current position in the sequence. - unsigned char Seq : 8; - - /// Unidirectional information about the current sequence. - RRInfo RRI; - - public: - PtrState() : KnownPositiveRefCount(false), Partial(false), - Seq(S_None) {} - - - bool IsKnownSafe() const { - return RRI.KnownSafe; - } - - void SetKnownSafe(const bool NewValue) { - RRI.KnownSafe = NewValue; - } - - bool IsTailCallRelease() const { - return RRI.IsTailCallRelease; - } - - void SetTailCallRelease(const bool NewValue) { - RRI.IsTailCallRelease = NewValue; - } - - bool IsTrackingImpreciseReleases() const { - return RRI.ReleaseMetadata != nullptr; - } - - const MDNode *GetReleaseMetadata() const { - return RRI.ReleaseMetadata; - } - - void SetReleaseMetadata(MDNode *NewValue) { - RRI.ReleaseMetadata = NewValue; - } - - bool IsCFGHazardAfflicted() const { - return RRI.CFGHazardAfflicted; - } - - void SetCFGHazardAfflicted(const bool NewValue) { - RRI.CFGHazardAfflicted = NewValue; - } - - void SetKnownPositiveRefCount() { - DEBUG(dbgs() << "Setting Known Positive.\n"); - KnownPositiveRefCount = true; - } - - void ClearKnownPositiveRefCount() { - DEBUG(dbgs() << "Clearing Known Positive.\n"); - KnownPositiveRefCount = false; - } - - bool HasKnownPositiveRefCount() const { - return KnownPositiveRefCount; - } - - void SetSeq(Sequence NewSeq) { - DEBUG(dbgs() << "Old: " << Seq << "; New: " << NewSeq << "\n"); - Seq = NewSeq; - } - - Sequence GetSeq() const { - return static_cast<Sequence>(Seq); - } - - void ClearSequenceProgress() { - ResetSequenceProgress(S_None); - } - - void ResetSequenceProgress(Sequence NewSeq) { - DEBUG(dbgs() << "Resetting sequence progress.\n"); - SetSeq(NewSeq); - Partial = false; - RRI.clear(); - } - - void Merge(const PtrState &Other, bool TopDown); - - void InsertCall(Instruction *I) { - RRI.Calls.insert(I); - } - - void InsertReverseInsertPt(Instruction *I) { - RRI.ReverseInsertPts.insert(I); - } - - void ClearReverseInsertPts() { - RRI.ReverseInsertPts.clear(); - } - - bool HasReverseInsertPts() const { - return !RRI.ReverseInsertPts.empty(); - } - - const RRInfo &GetRRInfo() const { - return RRI; - } - }; -} - -void -PtrState::Merge(const PtrState &Other, bool TopDown) { - Seq = MergeSeqs(GetSeq(), Other.GetSeq(), TopDown); - KnownPositiveRefCount &= Other.KnownPositiveRefCount; - - // If we're not in a sequence (anymore), drop all associated state. - if (Seq == S_None) { - Partial = false; - RRI.clear(); - } else if (Partial || Other.Partial) { - // If we're doing a merge on a path that's previously seen a partial - // merge, conservatively drop the sequence, to avoid doing partial - // RR elimination. If the branch predicates for the two merge differ, - // mixing them is unsafe. - ClearSequenceProgress(); - } else { - // Otherwise merge the other PtrState's RRInfo into our RRInfo. At this - // point, we know that currently we are not partial. Stash whether or not - // the merge operation caused us to undergo a partial merging of reverse - // insertion points. - Partial = RRI.Merge(Other.RRI); - } -} - -namespace { /// \brief Per-BasicBlock state. class BBState { /// The number of unique control paths from the entry which can reach this @@ -566,20 +186,18 @@ namespace { /// The number of unique control paths to exits from this block. unsigned BottomUpPathCount; - /// A type for PerPtrTopDown and PerPtrBottomUp. - typedef MapVector<const Value *, PtrState> MapTy; - /// The top-down traversal uses this to record information known about a /// pointer at the bottom of each block. - MapTy PerPtrTopDown; + BlotMapVector<const Value *, TopDownPtrState> PerPtrTopDown; /// The bottom-up traversal uses this to record information known about a /// pointer at the top of each block. - MapTy PerPtrBottomUp; + BlotMapVector<const Value *, BottomUpPtrState> PerPtrBottomUp; /// Effective predecessors of the current block ignoring ignorable edges and /// ignored backedges. SmallVector<BasicBlock *, 2> Preds; + /// Effective successors of the current block ignoring ignorable edges and /// ignored backedges. SmallVector<BasicBlock *, 2> Succs; @@ -589,26 +207,38 @@ namespace { BBState() : TopDownPathCount(0), BottomUpPathCount(0) { } - typedef MapTy::iterator ptr_iterator; - typedef MapTy::const_iterator ptr_const_iterator; + typedef decltype(PerPtrTopDown)::iterator top_down_ptr_iterator; + typedef decltype(PerPtrTopDown)::const_iterator const_top_down_ptr_iterator; - ptr_iterator top_down_ptr_begin() { return PerPtrTopDown.begin(); } - ptr_iterator top_down_ptr_end() { return PerPtrTopDown.end(); } - ptr_const_iterator top_down_ptr_begin() const { + top_down_ptr_iterator top_down_ptr_begin() { return PerPtrTopDown.begin(); } + top_down_ptr_iterator top_down_ptr_end() { return PerPtrTopDown.end(); } + const_top_down_ptr_iterator top_down_ptr_begin() const { return PerPtrTopDown.begin(); } - ptr_const_iterator top_down_ptr_end() const { + const_top_down_ptr_iterator top_down_ptr_end() const { return PerPtrTopDown.end(); } + bool hasTopDownPtrs() const { + return !PerPtrTopDown.empty(); + } + + typedef decltype(PerPtrBottomUp)::iterator bottom_up_ptr_iterator; + typedef decltype( + PerPtrBottomUp)::const_iterator const_bottom_up_ptr_iterator; - ptr_iterator bottom_up_ptr_begin() { return PerPtrBottomUp.begin(); } - ptr_iterator bottom_up_ptr_end() { return PerPtrBottomUp.end(); } - ptr_const_iterator bottom_up_ptr_begin() const { + bottom_up_ptr_iterator bottom_up_ptr_begin() { return PerPtrBottomUp.begin(); } - ptr_const_iterator bottom_up_ptr_end() const { + bottom_up_ptr_iterator bottom_up_ptr_end() { return PerPtrBottomUp.end(); } + const_bottom_up_ptr_iterator bottom_up_ptr_begin() const { + return PerPtrBottomUp.begin(); + } + const_bottom_up_ptr_iterator bottom_up_ptr_end() const { return PerPtrBottomUp.end(); } + bool hasBottomUpPtrs() const { + return !PerPtrBottomUp.empty(); + } /// Mark this block as being an entry block, which has one path from the /// entry by definition. @@ -621,20 +251,20 @@ namespace { /// Attempt to find the PtrState object describing the top down state for /// pointer Arg. Return a new initialized PtrState describing the top down /// state for Arg if we do not find one. - PtrState &getPtrTopDownState(const Value *Arg) { + TopDownPtrState &getPtrTopDownState(const Value *Arg) { return PerPtrTopDown[Arg]; } /// Attempt to find the PtrState object describing the bottom up state for /// pointer Arg. Return a new initialized PtrState describing the bottom up /// state for Arg if we do not find one. - PtrState &getPtrBottomUpState(const Value *Arg) { + BottomUpPtrState &getPtrBottomUpState(const Value *Arg) { return PerPtrBottomUp[Arg]; } /// Attempt to find the PtrState object describing the bottom up state for /// pointer Arg. - ptr_iterator findPtrBottomUpState(const Value *Arg) { + bottom_up_ptr_iterator findPtrBottomUpState(const Value *Arg) { return PerPtrBottomUp.find(Arg); } @@ -685,6 +315,11 @@ namespace { const unsigned BBState::OverflowOccurredValue = 0xffffffff; } +namespace llvm { +raw_ostream &operator<<(raw_ostream &OS, + BBState &BBState) LLVM_ATTRIBUTE_UNUSED; +} + void BBState::InitFromPred(const BBState &Other) { PerPtrTopDown = Other.PerPtrTopDown; TopDownPathCount = Other.TopDownPathCount; @@ -724,19 +359,18 @@ void BBState::MergePred(const BBState &Other) { // For each entry in the other set, if our set has an entry with the same key, // merge the entries. Otherwise, copy the entry and merge it with an empty // entry. - for (ptr_const_iterator MI = Other.top_down_ptr_begin(), - ME = Other.top_down_ptr_end(); MI != ME; ++MI) { - std::pair<ptr_iterator, bool> Pair = PerPtrTopDown.insert(*MI); - Pair.first->second.Merge(Pair.second ? PtrState() : MI->second, + for (auto MI = Other.top_down_ptr_begin(), ME = Other.top_down_ptr_end(); + MI != ME; ++MI) { + auto Pair = PerPtrTopDown.insert(*MI); + Pair.first->second.Merge(Pair.second ? TopDownPtrState() : MI->second, /*TopDown=*/true); } // For each entry in our set, if the other set doesn't have an entry with the // same key, force it to merge with an empty entry. - for (ptr_iterator MI = top_down_ptr_begin(), - ME = top_down_ptr_end(); MI != ME; ++MI) + for (auto MI = top_down_ptr_begin(), ME = top_down_ptr_end(); MI != ME; ++MI) if (Other.PerPtrTopDown.find(MI->first) == Other.PerPtrTopDown.end()) - MI->second.Merge(PtrState(), /*TopDown=*/true); + MI->second.Merge(TopDownPtrState(), /*TopDown=*/true); } /// The bottom-up traversal uses this to merge information about successors to @@ -768,304 +402,80 @@ void BBState::MergeSucc(const BBState &Other) { // For each entry in the other set, if our set has an entry with the // same key, merge the entries. Otherwise, copy the entry and merge // it with an empty entry. - for (ptr_const_iterator MI = Other.bottom_up_ptr_begin(), - ME = Other.bottom_up_ptr_end(); MI != ME; ++MI) { - std::pair<ptr_iterator, bool> Pair = PerPtrBottomUp.insert(*MI); - Pair.first->second.Merge(Pair.second ? PtrState() : MI->second, + for (auto MI = Other.bottom_up_ptr_begin(), ME = Other.bottom_up_ptr_end(); + MI != ME; ++MI) { + auto Pair = PerPtrBottomUp.insert(*MI); + Pair.first->second.Merge(Pair.second ? BottomUpPtrState() : MI->second, /*TopDown=*/false); } // For each entry in our set, if the other set doesn't have an entry // with the same key, force it to merge with an empty entry. - for (ptr_iterator MI = bottom_up_ptr_begin(), - ME = bottom_up_ptr_end(); MI != ME; ++MI) + for (auto MI = bottom_up_ptr_begin(), ME = bottom_up_ptr_end(); MI != ME; + ++MI) if (Other.PerPtrBottomUp.find(MI->first) == Other.PerPtrBottomUp.end()) - MI->second.Merge(PtrState(), /*TopDown=*/false); + MI->second.Merge(BottomUpPtrState(), /*TopDown=*/false); } -// Only enable ARC Annotations if we are building a debug version of -// libObjCARCOpts. -#ifndef NDEBUG -#define ARC_ANNOTATIONS -#endif - -// Define some macros along the lines of DEBUG and some helper functions to make -// it cleaner to create annotations in the source code and to no-op when not -// building in debug mode. -#ifdef ARC_ANNOTATIONS - -#include "llvm/Support/CommandLine.h" - -/// Enable/disable ARC sequence annotations. -static cl::opt<bool> -EnableARCAnnotations("enable-objc-arc-annotations", cl::init(false), - cl::desc("Enable emission of arc data flow analysis " - "annotations")); -static cl::opt<bool> -DisableCheckForCFGHazards("disable-objc-arc-checkforcfghazards", cl::init(false), - cl::desc("Disable check for cfg hazards when " - "annotating")); -static cl::opt<std::string> -ARCAnnotationTargetIdentifier("objc-arc-annotation-target-identifier", - cl::init(""), - cl::desc("filter out all data flow annotations " - "but those that apply to the given " - "target llvm identifier.")); - -/// This function appends a unique ARCAnnotationProvenanceSourceMDKind id to an -/// instruction so that we can track backwards when post processing via the llvm -/// arc annotation processor tool. If the function is an -static MDString *AppendMDNodeToSourcePtr(unsigned NodeId, - Value *Ptr) { - MDString *Hash = nullptr; - - // If pointer is a result of an instruction and it does not have a source - // MDNode it, attach a new MDNode onto it. If pointer is a result of - // an instruction and does have a source MDNode attached to it, return a - // reference to said Node. Otherwise just return 0. - if (Instruction *Inst = dyn_cast<Instruction>(Ptr)) { - MDNode *Node; - if (!(Node = Inst->getMetadata(NodeId))) { - // We do not have any node. Generate and attatch the hash MDString to the - // instruction. - - // We just use an MDString to ensure that this metadata gets written out - // of line at the module level and to provide a very simple format - // encoding the information herein. Both of these makes it simpler to - // parse the annotations by a simple external program. - std::string Str; - raw_string_ostream os(Str); - os << "(" << Inst->getParent()->getParent()->getName() << ",%" - << Inst->getName() << ")"; - - Hash = MDString::get(Inst->getContext(), os.str()); - Inst->setMetadata(NodeId, MDNode::get(Inst->getContext(),Hash)); - } else { - // We have a node. Grab its hash and return it. - assert(Node->getNumOperands() == 1 && - "An ARCAnnotationProvenanceSourceMDKind can only have 1 operand."); - Hash = cast<MDString>(Node->getOperand(0)); +raw_ostream &llvm::operator<<(raw_ostream &OS, BBState &BBInfo) { + // Dump the pointers we are tracking. + OS << " TopDown State:\n"; + if (!BBInfo.hasTopDownPtrs()) { + DEBUG(llvm::dbgs() << " NONE!\n"); + } else { + for (auto I = BBInfo.top_down_ptr_begin(), E = BBInfo.top_down_ptr_end(); + I != E; ++I) { + const PtrState &P = I->second; + OS << " Ptr: " << *I->first + << "\n KnownSafe: " << (P.IsKnownSafe()?"true":"false") + << "\n ImpreciseRelease: " + << (P.IsTrackingImpreciseReleases()?"true":"false") << "\n" + << " HasCFGHazards: " + << (P.IsCFGHazardAfflicted()?"true":"false") << "\n" + << " KnownPositive: " + << (P.HasKnownPositiveRefCount()?"true":"false") << "\n" + << " Seq: " + << P.GetSeq() << "\n"; } - } else if (Argument *Arg = dyn_cast<Argument>(Ptr)) { - std::string str; - raw_string_ostream os(str); - os << "(" << Arg->getParent()->getName() << ",%" << Arg->getName() - << ")"; - Hash = MDString::get(Arg->getContext(), os.str()); - } - - return Hash; -} - -static std::string SequenceToString(Sequence A) { - std::string str; - raw_string_ostream os(str); - os << A; - return os.str(); -} - -/// Helper function to change a Sequence into a String object using our overload -/// for raw_ostream so we only have printing code in one location. -static MDString *SequenceToMDString(LLVMContext &Context, - Sequence A) { - return MDString::get(Context, SequenceToString(A)); -} - -/// A simple function to generate a MDNode which describes the change in state -/// for Value *Ptr caused by Instruction *Inst. -static void AppendMDNodeToInstForPtr(unsigned NodeId, - Instruction *Inst, - Value *Ptr, - MDString *PtrSourceMDNodeID, - Sequence OldSeq, - Sequence NewSeq) { - MDNode *Node = nullptr; - Metadata *tmp[3] = {PtrSourceMDNodeID, - SequenceToMDString(Inst->getContext(), OldSeq), - SequenceToMDString(Inst->getContext(), NewSeq)}; - Node = MDNode::get(Inst->getContext(), tmp); - - Inst->setMetadata(NodeId, Node); -} - -/// Add to the beginning of the basic block llvm.ptr.annotations which show the -/// state of a pointer at the entrance to a basic block. -static void GenerateARCBBEntranceAnnotation(const char *Name, BasicBlock *BB, - Value *Ptr, Sequence Seq) { - // If we have a target identifier, make sure that we match it before - // continuing. - if(!ARCAnnotationTargetIdentifier.empty() && - !Ptr->getName().equals(ARCAnnotationTargetIdentifier)) - return; - - Module *M = BB->getParent()->getParent(); - LLVMContext &C = M->getContext(); - Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); - Type *I8XX = PointerType::getUnqual(I8X); - Type *Params[] = {I8XX, I8XX}; - FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), Params, - /*isVarArg=*/false); - Constant *Callee = M->getOrInsertFunction(Name, FTy); - - IRBuilder<> Builder(BB, BB->getFirstInsertionPt()); - - Value *PtrName; - StringRef Tmp = Ptr->getName(); - if (nullptr == (PtrName = M->getGlobalVariable(Tmp, true))) { - Value *ActualPtrName = Builder.CreateGlobalStringPtr(Tmp, - Tmp + "_STR"); - PtrName = new GlobalVariable(*M, I8X, true, GlobalVariable::InternalLinkage, - cast<Constant>(ActualPtrName), Tmp); - } - - Value *S; - std::string SeqStr = SequenceToString(Seq); - if (nullptr == (S = M->getGlobalVariable(SeqStr, true))) { - Value *ActualPtrName = Builder.CreateGlobalStringPtr(SeqStr, - SeqStr + "_STR"); - S = new GlobalVariable(*M, I8X, true, GlobalVariable::InternalLinkage, - cast<Constant>(ActualPtrName), SeqStr); - } - - Builder.CreateCall2(Callee, PtrName, S); -} - -/// Add to the end of the basic block llvm.ptr.annotations which show the state -/// of the pointer at the bottom of the basic block. -static void GenerateARCBBTerminatorAnnotation(const char *Name, BasicBlock *BB, - Value *Ptr, Sequence Seq) { - // If we have a target identifier, make sure that we match it before emitting - // an annotation. - if(!ARCAnnotationTargetIdentifier.empty() && - !Ptr->getName().equals(ARCAnnotationTargetIdentifier)) - return; - - Module *M = BB->getParent()->getParent(); - LLVMContext &C = M->getContext(); - Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); - Type *I8XX = PointerType::getUnqual(I8X); - Type *Params[] = {I8XX, I8XX}; - FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), Params, - /*isVarArg=*/false); - Constant *Callee = M->getOrInsertFunction(Name, FTy); - - IRBuilder<> Builder(BB, std::prev(BB->end())); - - Value *PtrName; - StringRef Tmp = Ptr->getName(); - if (nullptr == (PtrName = M->getGlobalVariable(Tmp, true))) { - Value *ActualPtrName = Builder.CreateGlobalStringPtr(Tmp, - Tmp + "_STR"); - PtrName = new GlobalVariable(*M, I8X, true, GlobalVariable::InternalLinkage, - cast<Constant>(ActualPtrName), Tmp); } - Value *S; - std::string SeqStr = SequenceToString(Seq); - if (nullptr == (S = M->getGlobalVariable(SeqStr, true))) { - Value *ActualPtrName = Builder.CreateGlobalStringPtr(SeqStr, - SeqStr + "_STR"); - S = new GlobalVariable(*M, I8X, true, GlobalVariable::InternalLinkage, - cast<Constant>(ActualPtrName), SeqStr); + OS << " BottomUp State:\n"; + if (!BBInfo.hasBottomUpPtrs()) { + DEBUG(llvm::dbgs() << " NONE!\n"); + } else { + for (auto I = BBInfo.bottom_up_ptr_begin(), E = BBInfo.bottom_up_ptr_end(); + I != E; ++I) { + const PtrState &P = I->second; + OS << " Ptr: " << *I->first + << "\n KnownSafe: " << (P.IsKnownSafe()?"true":"false") + << "\n ImpreciseRelease: " + << (P.IsTrackingImpreciseReleases()?"true":"false") << "\n" + << " HasCFGHazards: " + << (P.IsCFGHazardAfflicted()?"true":"false") << "\n" + << " KnownPositive: " + << (P.HasKnownPositiveRefCount()?"true":"false") << "\n" + << " Seq: " + << P.GetSeq() << "\n"; + } } - Builder.CreateCall2(Callee, PtrName, S); -} -/// Adds a source annotation to pointer and a state change annotation to Inst -/// referencing the source annotation and the old/new state of pointer. -static void GenerateARCAnnotation(unsigned InstMDId, - unsigned PtrMDId, - Instruction *Inst, - Value *Ptr, - Sequence OldSeq, - Sequence NewSeq) { - if (EnableARCAnnotations) { - // If we have a target identifier, make sure that we match it before - // emitting an annotation. - if(!ARCAnnotationTargetIdentifier.empty() && - !Ptr->getName().equals(ARCAnnotationTargetIdentifier)) - return; - - // First generate the source annotation on our pointer. This will return an - // MDString* if Ptr actually comes from an instruction implying we can put - // in a source annotation. If AppendMDNodeToSourcePtr returns 0 (i.e. NULL), - // then we know that our pointer is from an Argument so we put a reference - // to the argument number. - // - // The point of this is to make it easy for the - // llvm-arc-annotation-processor tool to cross reference where the source - // pointer is in the LLVM IR since the LLVM IR parser does not submit such - // information via debug info for backends to use (since why would anyone - // need such a thing from LLVM IR besides in non-standard cases - // [i.e. this]). - MDString *SourcePtrMDNode = - AppendMDNodeToSourcePtr(PtrMDId, Ptr); - AppendMDNodeToInstForPtr(InstMDId, Inst, Ptr, SourcePtrMDNode, OldSeq, - NewSeq); - } + return OS; } -// The actual interface for accessing the above functionality is defined via -// some simple macros which are defined below. We do this so that the user does -// not need to pass in what metadata id is needed resulting in cleaner code and -// additionally since it provides an easy way to conditionally no-op all -// annotation support in a non-debug build. - -/// Use this macro to annotate a sequence state change when processing -/// instructions bottom up, -#define ANNOTATE_BOTTOMUP(inst, ptr, old, new) \ - GenerateARCAnnotation(ARCAnnotationBottomUpMDKind, \ - ARCAnnotationProvenanceSourceMDKind, (inst), \ - const_cast<Value*>(ptr), (old), (new)) -/// Use this macro to annotate a sequence state change when processing -/// instructions top down. -#define ANNOTATE_TOPDOWN(inst, ptr, old, new) \ - GenerateARCAnnotation(ARCAnnotationTopDownMDKind, \ - ARCAnnotationProvenanceSourceMDKind, (inst), \ - const_cast<Value*>(ptr), (old), (new)) - -#define ANNOTATE_BB(_states, _bb, _name, _type, _direction) \ - do { \ - if (EnableARCAnnotations) { \ - for(BBState::ptr_const_iterator I = (_states)._direction##_ptr_begin(), \ - E = (_states)._direction##_ptr_end(); I != E; ++I) { \ - Value *Ptr = const_cast<Value*>(I->first); \ - Sequence Seq = I->second.GetSeq(); \ - GenerateARCBB ## _type ## Annotation(_name, (_bb), Ptr, Seq); \ - } \ - } \ - } while (0) - -#define ANNOTATE_BOTTOMUP_BBSTART(_states, _basicblock) \ - ANNOTATE_BB(_states, _basicblock, "llvm.arc.annotation.bottomup.bbstart", \ - Entrance, bottom_up) -#define ANNOTATE_BOTTOMUP_BBEND(_states, _basicblock) \ - ANNOTATE_BB(_states, _basicblock, "llvm.arc.annotation.bottomup.bbend", \ - Terminator, bottom_up) -#define ANNOTATE_TOPDOWN_BBSTART(_states, _basicblock) \ - ANNOTATE_BB(_states, _basicblock, "llvm.arc.annotation.topdown.bbstart", \ - Entrance, top_down) -#define ANNOTATE_TOPDOWN_BBEND(_states, _basicblock) \ - ANNOTATE_BB(_states, _basicblock, "llvm.arc.annotation.topdown.bbend", \ - Terminator, top_down) - -#else // !ARC_ANNOTATION -// If annotations are off, noop. -#define ANNOTATE_BOTTOMUP(inst, ptr, old, new) -#define ANNOTATE_TOPDOWN(inst, ptr, old, new) -#define ANNOTATE_BOTTOMUP_BBSTART(states, basicblock) -#define ANNOTATE_BOTTOMUP_BBEND(states, basicblock) -#define ANNOTATE_TOPDOWN_BBSTART(states, basicblock) -#define ANNOTATE_TOPDOWN_BBEND(states, basicblock) -#endif // !ARC_ANNOTATION - namespace { + /// \brief The main ARC optimization pass. class ObjCARCOpt : public FunctionPass { bool Changed; ProvenanceAnalysis PA; + + /// A cache of references to runtime entry point constants. ARCRuntimeEntryPoints EP; + /// A cache of MDKinds that can be passed into other functions to propagate + /// MDKind identifiers. + ARCMDKindCache MDKindCache; + // This is used to track if a pointer is stored into an alloca. DenseSet<const Value *> MultiOwnersSet; @@ -1076,24 +486,6 @@ namespace { /// is in fact used in the current function. unsigned UsedInThisFunction; - /// The Metadata Kind for clang.imprecise_release metadata. - unsigned ImpreciseReleaseMDKind; - - /// The Metadata Kind for clang.arc.copy_on_escape metadata. - unsigned CopyOnEscapeMDKind; - - /// The Metadata Kind for clang.arc.no_objc_arc_exceptions metadata. - unsigned NoObjCARCExceptionsMDKind; - -#ifdef ARC_ANNOTATIONS - /// The Metadata Kind for llvm.arc.annotation.bottomup metadata. - unsigned ARCAnnotationBottomUpMDKind; - /// The Metadata Kind for llvm.arc.annotation.topdown metadata. - unsigned ARCAnnotationTopDownMDKind; - /// The Metadata Kind for llvm.arc.annotation.provenancesource metadata. - unsigned ARCAnnotationProvenanceSourceMDKind; -#endif // ARC_ANNOATIONS - bool OptimizeRetainRVCall(Function &F, Instruction *RetainRV); void OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV, ARCInstKind &Class); @@ -1102,47 +494,41 @@ namespace { void CheckForCFGHazards(const BasicBlock *BB, DenseMap<const BasicBlock *, BBState> &BBStates, BBState &MyStates) const; - bool VisitInstructionBottomUp(Instruction *Inst, - BasicBlock *BB, - MapVector<Value *, RRInfo> &Retains, + bool VisitInstructionBottomUp(Instruction *Inst, BasicBlock *BB, + BlotMapVector<Value *, RRInfo> &Retains, BBState &MyStates); bool VisitBottomUp(BasicBlock *BB, DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains); + BlotMapVector<Value *, RRInfo> &Retains); bool VisitInstructionTopDown(Instruction *Inst, DenseMap<Value *, RRInfo> &Releases, BBState &MyStates); bool VisitTopDown(BasicBlock *BB, DenseMap<const BasicBlock *, BBState> &BBStates, DenseMap<Value *, RRInfo> &Releases); - bool Visit(Function &F, - DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains, + bool Visit(Function &F, DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains, DenseMap<Value *, RRInfo> &Releases); void MoveCalls(Value *Arg, RRInfo &RetainsToMove, RRInfo &ReleasesToMove, - MapVector<Value *, RRInfo> &Retains, + BlotMapVector<Value *, RRInfo> &Retains, DenseMap<Value *, RRInfo> &Releases, - SmallVectorImpl<Instruction *> &DeadInsts, - Module *M); - - bool ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains, - DenseMap<Value *, RRInfo> &Releases, - Module *M, - SmallVectorImpl<Instruction *> &NewRetains, - SmallVectorImpl<Instruction *> &NewReleases, - SmallVectorImpl<Instruction *> &DeadInsts, - RRInfo &RetainsToMove, - RRInfo &ReleasesToMove, - Value *Arg, - bool KnownSafe, - bool &AnyPairsCompletelyEliminated); + SmallVectorImpl<Instruction *> &DeadInsts, Module *M); + + bool + PairUpRetainsAndReleases(DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains, + DenseMap<Value *, RRInfo> &Releases, Module *M, + SmallVectorImpl<Instruction *> &NewRetains, + SmallVectorImpl<Instruction *> &NewReleases, + SmallVectorImpl<Instruction *> &DeadInsts, + RRInfo &RetainsToMove, RRInfo &ReleasesToMove, + Value *Arg, bool KnownSafe, + bool &AnyPairsCompletelyEliminated); bool PerformCodePlacement(DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains, - DenseMap<Value *, RRInfo> &Releases, - Module *M); + BlotMapVector<Value *, RRInfo> &Retains, + DenseMap<Value *, RRInfo> &Releases, Module *M); void OptimizeWeakCalls(Function &F); @@ -1238,7 +624,7 @@ ObjCARCOpt::OptimizeRetainRVCall(Function &F, Instruction *RetainRV) { "objc_retain since the operand is not a return value.\n" "Old = " << *RetainRV << "\n"); - Constant *NewDecl = EP.get(ARCRuntimeEntryPoints::EPT_Retain); + Constant *NewDecl = EP.get(ARCRuntimeEntryPointKind::Retain); cast<CallInst>(RetainRV)->setCalledFunction(NewDecl); DEBUG(dbgs() << "New = " << *RetainRV << "\n"); @@ -1274,7 +660,7 @@ void ObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, "Old = " << *AutoreleaseRV << "\n"); CallInst *AutoreleaseRVCI = cast<CallInst>(AutoreleaseRV); - Constant *NewDecl = EP.get(ARCRuntimeEntryPoints::EPT_Autorelease); + Constant *NewDecl = EP.get(ARCRuntimeEntryPointKind::Autorelease); AutoreleaseRVCI->setCalledFunction(NewDecl); AutoreleaseRVCI->setTailCall(false); // Never tail call objc_autorelease. Class = ARCInstKind::Autorelease; @@ -1380,10 +766,11 @@ void ObjCARCOpt::OptimizeIndividualCalls(Function &F) { // Create the declaration lazily. LLVMContext &C = Inst->getContext(); - Constant *Decl = EP.get(ARCRuntimeEntryPoints::EPT_Release); + Constant *Decl = EP.get(ARCRuntimeEntryPointKind::Release); CallInst *NewCall = CallInst::Create(Decl, Call->getArgOperand(0), "", Call); - NewCall->setMetadata(ImpreciseReleaseMDKind, MDNode::get(C, None)); + NewCall->setMetadata(MDKindCache.get(ARCMDKindID::ImpreciseRelease), + MDNode::get(C, None)); DEBUG(dbgs() << "Replacing autorelease{,RV}(x) with objc_release(x) " "since x is otherwise unused.\nOld: " << *Call << "\nNew: " @@ -1547,7 +934,7 @@ void ObjCARCOpt::OptimizeIndividualCalls(Function &F) { /// no CFG hazards by checking the states of various bottom up pointers. static void CheckForUseCFGHazard(const Sequence SuccSSeq, const bool SuccSRRIKnownSafe, - PtrState &S, + TopDownPtrState &S, bool &SomeSuccHasSame, bool &AllSuccsHaveSame, bool &NotAllSeqEqualButKnownSafe, @@ -1585,7 +972,7 @@ static void CheckForUseCFGHazard(const Sequence SuccSSeq, /// pointers. static void CheckForCanReleaseCFGHazard(const Sequence SuccSSeq, const bool SuccSRRIKnownSafe, - PtrState &S, + TopDownPtrState &S, bool &SomeSuccHasSame, bool &AllSuccsHaveSame, bool &NotAllSeqEqualButKnownSafe) { @@ -1618,9 +1005,9 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB, BBState &MyStates) const { // If any top-down local-use or possible-dec has a succ which is earlier in // the sequence, forget it. - for (BBState::ptr_iterator I = MyStates.top_down_ptr_begin(), - E = MyStates.top_down_ptr_end(); I != E; ++I) { - PtrState &S = I->second; + for (auto I = MyStates.top_down_ptr_begin(), E = MyStates.top_down_ptr_end(); + I != E; ++I) { + TopDownPtrState &S = I->second; const Sequence Seq = I->second.GetSeq(); // We only care about S_Retain, S_CanRelease, and S_Use. @@ -1646,7 +1033,7 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB, const DenseMap<const BasicBlock *, BBState>::iterator BBI = BBStates.find(*SI); assert(BBI != BBStates.end()); - const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg); + const BottomUpPtrState &SuccS = BBI->second.getPtrBottomUpState(Arg); const Sequence SuccSSeq = SuccS.GetSeq(); // If bottom up, the pointer is in an S_None state, clear the sequence @@ -1705,44 +1092,21 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB, } } -bool -ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, - BasicBlock *BB, - MapVector<Value *, RRInfo> &Retains, - BBState &MyStates) { +bool ObjCARCOpt::VisitInstructionBottomUp( + Instruction *Inst, BasicBlock *BB, BlotMapVector<Value *, RRInfo> &Retains, + BBState &MyStates) { bool NestingDetected = false; ARCInstKind Class = GetARCInstKind(Inst); const Value *Arg = nullptr; - DEBUG(dbgs() << "Class: " << Class << "\n"); + DEBUG(dbgs() << " Class: " << Class << "\n"); switch (Class) { case ARCInstKind::Release: { Arg = GetArgRCIdentityRoot(Inst); - PtrState &S = MyStates.getPtrBottomUpState(Arg); - - // If we see two releases in a row on the same pointer. If so, make - // a note, and we'll cicle back to revisit it after we've - // hopefully eliminated the second release, which may allow us to - // eliminate the first release too. - // Theoretically we could implement removal of nested retain+release - // pairs by making PtrState hold a stack of states, but this is - // simple and avoids adding overhead for the non-nested case. - if (S.GetSeq() == S_Release || S.GetSeq() == S_MovableRelease) { - DEBUG(dbgs() << "Found nested releases (i.e. a release pair)\n"); - NestingDetected = true; - } - - MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind); - Sequence NewSeq = ReleaseMetadata ? S_MovableRelease : S_Release; - ANNOTATE_BOTTOMUP(Inst, Arg, S.GetSeq(), NewSeq); - S.ResetSequenceProgress(NewSeq); - S.SetReleaseMetadata(ReleaseMetadata); - S.SetKnownSafe(S.HasKnownPositiveRefCount()); - S.SetTailCallRelease(cast<CallInst>(Inst)->isTailCall()); - S.InsertCall(Inst); - S.SetKnownPositiveRefCount(); + BottomUpPtrState &S = MyStates.getPtrBottomUpState(Arg); + NestingDetected |= S.InitBottomUp(MDKindCache, Inst); break; } case ARCInstKind::RetainBlock: @@ -1753,35 +1117,16 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, case ARCInstKind::Retain: case ARCInstKind::RetainRV: { Arg = GetArgRCIdentityRoot(Inst); - - PtrState &S = MyStates.getPtrBottomUpState(Arg); - S.SetKnownPositiveRefCount(); - - Sequence OldSeq = S.GetSeq(); - switch (OldSeq) { - case S_Stop: - case S_Release: - case S_MovableRelease: - case S_Use: - // If OldSeq is not S_Use or OldSeq is S_Use and we are tracking an - // imprecise release, clear our reverse insertion points. - if (OldSeq != S_Use || S.IsTrackingImpreciseReleases()) - S.ClearReverseInsertPts(); - // FALL THROUGH - case S_CanRelease: - // Don't do retain+release tracking for ARCInstKind::RetainRV, - // because it's - // better to let it remain as the first instruction after a call. - if (Class != ARCInstKind::RetainRV) + BottomUpPtrState &S = MyStates.getPtrBottomUpState(Arg); + if (S.MatchWithRetain()) { + // Don't do retain+release tracking for ARCInstKind::RetainRV, because + // it's better to let it remain as the first instruction after a call. + if (Class != ARCInstKind::RetainRV) { + DEBUG(llvm::dbgs() << " Matching with: " << *Inst << "\n"); Retains[Inst] = S.GetRRInfo(); + } S.ClearSequenceProgress(); - break; - case S_None: - break; - case S_Retain: - llvm_unreachable("bottom-up pointer in retain state!"); } - ANNOTATE_BOTTOMUP(Inst, Arg, OldSeq, S.GetSeq()); // A retain moving bottom up can be a use. break; } @@ -1807,9 +1152,10 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, // in the presence of allocas we only unconditionally remove pointers if // both our retain and our release are KnownSafe. if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { - if (AreAnyUnderlyingObjectsAnAlloca(SI->getPointerOperand())) { - BBState::ptr_iterator I = MyStates.findPtrBottomUpState( - GetRCIdentityRoot(SI->getValueOperand())); + const DataLayout &DL = BB->getModule()->getDataLayout(); + if (AreAnyUnderlyingObjectsAnAlloca(SI->getPointerOperand(), DL)) { + auto I = MyStates.findPtrBottomUpState( + GetRCIdentityRoot(SI->getValueOperand())); if (I != MyStates.bottom_up_ptr_end()) MultiOwnersSet.insert(I->first); } @@ -1821,90 +1167,26 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, // Consider any other possible effects of this instruction on each // pointer being tracked. - for (BBState::ptr_iterator MI = MyStates.bottom_up_ptr_begin(), - ME = MyStates.bottom_up_ptr_end(); MI != ME; ++MI) { + for (auto MI = MyStates.bottom_up_ptr_begin(), + ME = MyStates.bottom_up_ptr_end(); + MI != ME; ++MI) { const Value *Ptr = MI->first; if (Ptr == Arg) continue; // Handled above. - PtrState &S = MI->second; - Sequence Seq = S.GetSeq(); + BottomUpPtrState &S = MI->second; - // Check for possible releases. - if (CanAlterRefCount(Inst, Ptr, PA, Class)) { - DEBUG(dbgs() << "CanAlterRefCount: Seq: " << Seq << "; " << *Ptr - << "\n"); - S.ClearKnownPositiveRefCount(); - switch (Seq) { - case S_Use: - S.SetSeq(S_CanRelease); - ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S.GetSeq()); - continue; - case S_CanRelease: - case S_Release: - case S_MovableRelease: - case S_Stop: - case S_None: - break; - case S_Retain: - llvm_unreachable("bottom-up pointer in retain state!"); - } - } + if (S.HandlePotentialAlterRefCount(Inst, Ptr, PA, Class)) + continue; - // Check for possible direct uses. - switch (Seq) { - case S_Release: - case S_MovableRelease: - if (CanUse(Inst, Ptr, PA, Class)) { - DEBUG(dbgs() << "CanUse: Seq: " << Seq << "; " << *Ptr - << "\n"); - assert(!S.HasReverseInsertPts()); - // If this is an invoke instruction, we're scanning it as part of - // one of its successor blocks, since we can't insert code after it - // in its own block, and we don't want to split critical edges. - if (isa<InvokeInst>(Inst)) - S.InsertReverseInsertPt(BB->getFirstInsertionPt()); - else - S.InsertReverseInsertPt(std::next(BasicBlock::iterator(Inst))); - S.SetSeq(S_Use); - ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use); - } else if (Seq == S_Release && IsUser(Class)) { - DEBUG(dbgs() << "PreciseReleaseUse: Seq: " << Seq << "; " << *Ptr - << "\n"); - // Non-movable releases depend on any possible objc pointer use. - S.SetSeq(S_Stop); - ANNOTATE_BOTTOMUP(Inst, Ptr, S_Release, S_Stop); - assert(!S.HasReverseInsertPts()); - // As above; handle invoke specially. - if (isa<InvokeInst>(Inst)) - S.InsertReverseInsertPt(BB->getFirstInsertionPt()); - else - S.InsertReverseInsertPt(std::next(BasicBlock::iterator(Inst))); - } - break; - case S_Stop: - if (CanUse(Inst, Ptr, PA, Class)) { - DEBUG(dbgs() << "PreciseStopUse: Seq: " << Seq << "; " << *Ptr - << "\n"); - S.SetSeq(S_Use); - ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use); - } - break; - case S_CanRelease: - case S_Use: - case S_None: - break; - case S_Retain: - llvm_unreachable("bottom-up pointer in retain state!"); - } + S.HandlePotentialUse(BB, Inst, Ptr, PA, Class); } return NestingDetected; } -bool -ObjCARCOpt::VisitBottomUp(BasicBlock *BB, - DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains) { +bool ObjCARCOpt::VisitBottomUp(BasicBlock *BB, + DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains) { DEBUG(dbgs() << "\n== ObjCARCOpt::VisitBottomUp ==\n"); @@ -1929,9 +1211,8 @@ ObjCARCOpt::VisitBottomUp(BasicBlock *BB, } } - // If ARC Annotations are enabled, output the current state of pointers at the - // bottom of the basic block. - ANNOTATE_BOTTOMUP_BBEND(MyStates, BB); + DEBUG(llvm::dbgs() << "Before:\n" << BBStates[BB] << "\n" + << "Performing Dataflow:\n"); // Visit all the instructions, bottom-up. for (BasicBlock::iterator I = BB->end(), E = BB->begin(); I != E; --I) { @@ -1941,7 +1222,7 @@ ObjCARCOpt::VisitBottomUp(BasicBlock *BB, if (isa<InvokeInst>(Inst)) continue; - DEBUG(dbgs() << "Visiting " << *Inst << "\n"); + DEBUG(dbgs() << " Visiting " << *Inst << "\n"); NestingDetected |= VisitInstructionBottomUp(Inst, BB, Retains, MyStates); } @@ -1956,9 +1237,7 @@ ObjCARCOpt::VisitBottomUp(BasicBlock *BB, NestingDetected |= VisitInstructionBottomUp(II, BB, Retains, MyStates); } - // If ARC Annotations are enabled, output the current state of pointers at the - // top of the basic block. - ANNOTATE_BOTTOMUP_BBSTART(MyStates, BB); + DEBUG(llvm::dbgs() << "\nFinal State:\n" << BBStates[BB] << "\n"); return NestingDetected; } @@ -1971,144 +1250,63 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst, ARCInstKind Class = GetARCInstKind(Inst); const Value *Arg = nullptr; + DEBUG(llvm::dbgs() << " Class: " << Class << "\n"); + switch (Class) { case ARCInstKind::RetainBlock: // In OptimizeIndividualCalls, we have strength reduced all optimizable // objc_retainBlocks to objc_retains. Thus at this point any - // objc_retainBlocks that we see are not optimizable. + // objc_retainBlocks that we see are not optimizable. We need to break since + // a retain can be a potential use. break; case ARCInstKind::Retain: case ARCInstKind::RetainRV: { Arg = GetArgRCIdentityRoot(Inst); - - PtrState &S = MyStates.getPtrTopDownState(Arg); - - // Don't do retain+release tracking for ARCInstKind::RetainRV, because - // it's - // better to let it remain as the first instruction after a call. - if (Class != ARCInstKind::RetainRV) { - // If we see two retains in a row on the same pointer. If so, make - // a note, and we'll cicle back to revisit it after we've - // hopefully eliminated the second retain, which may allow us to - // eliminate the first retain too. - // Theoretically we could implement removal of nested retain+release - // pairs by making PtrState hold a stack of states, but this is - // simple and avoids adding overhead for the non-nested case. - if (S.GetSeq() == S_Retain) - NestingDetected = true; - - ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_Retain); - S.ResetSequenceProgress(S_Retain); - S.SetKnownSafe(S.HasKnownPositiveRefCount()); - S.InsertCall(Inst); - } - - S.SetKnownPositiveRefCount(); - + TopDownPtrState &S = MyStates.getPtrTopDownState(Arg); + NestingDetected |= S.InitTopDown(Class, Inst); // A retain can be a potential use; procede to the generic checking // code below. break; } case ARCInstKind::Release: { Arg = GetArgRCIdentityRoot(Inst); - - PtrState &S = MyStates.getPtrTopDownState(Arg); - S.ClearKnownPositiveRefCount(); - - Sequence OldSeq = S.GetSeq(); - - MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind); - - switch (OldSeq) { - case S_Retain: - case S_CanRelease: - if (OldSeq == S_Retain || ReleaseMetadata != nullptr) - S.ClearReverseInsertPts(); - // FALL THROUGH - case S_Use: - S.SetReleaseMetadata(ReleaseMetadata); - S.SetTailCallRelease(cast<CallInst>(Inst)->isTailCall()); + TopDownPtrState &S = MyStates.getPtrTopDownState(Arg); + // Try to form a tentative pair in between this release instruction and the + // top down pointers that we are tracking. + if (S.MatchWithRelease(MDKindCache, Inst)) { + // If we succeed, copy S's RRInfo into the Release -> {Retain Set + // Map}. Then we clear S. + DEBUG(llvm::dbgs() << " Matching with: " << *Inst << "\n"); Releases[Inst] = S.GetRRInfo(); - ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_None); S.ClearSequenceProgress(); - break; - case S_None: - break; - case S_Stop: - case S_Release: - case S_MovableRelease: - llvm_unreachable("top-down pointer in release state!"); } break; } case ARCInstKind::AutoreleasepoolPop: // Conservatively, clear MyStates for all known pointers. MyStates.clearTopDownPointers(); - return NestingDetected; + return false; case ARCInstKind::AutoreleasepoolPush: case ARCInstKind::None: - // These are irrelevant. - return NestingDetected; + // These can not be uses of + return false; default: break; } // Consider any other possible effects of this instruction on each // pointer being tracked. - for (BBState::ptr_iterator MI = MyStates.top_down_ptr_begin(), - ME = MyStates.top_down_ptr_end(); MI != ME; ++MI) { + for (auto MI = MyStates.top_down_ptr_begin(), + ME = MyStates.top_down_ptr_end(); + MI != ME; ++MI) { const Value *Ptr = MI->first; if (Ptr == Arg) continue; // Handled above. - PtrState &S = MI->second; - Sequence Seq = S.GetSeq(); - - // Check for possible releases. - if (CanAlterRefCount(Inst, Ptr, PA, Class)) { - DEBUG(dbgs() << "CanAlterRefCount: Seq: " << Seq << "; " << *Ptr - << "\n"); - S.ClearKnownPositiveRefCount(); - switch (Seq) { - case S_Retain: - S.SetSeq(S_CanRelease); - ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_CanRelease); - assert(!S.HasReverseInsertPts()); - S.InsertReverseInsertPt(Inst); - - // One call can't cause a transition from S_Retain to S_CanRelease - // and S_CanRelease to S_Use. If we've made the first transition, - // we're done. - continue; - case S_Use: - case S_CanRelease: - case S_None: - break; - case S_Stop: - case S_Release: - case S_MovableRelease: - llvm_unreachable("top-down pointer in release state!"); - } - } + TopDownPtrState &S = MI->second; + if (S.HandlePotentialAlterRefCount(Inst, Ptr, PA, Class)) + continue; - // Check for possible direct uses. - switch (Seq) { - case S_CanRelease: - if (CanUse(Inst, Ptr, PA, Class)) { - DEBUG(dbgs() << "CanUse: Seq: " << Seq << "; " << *Ptr - << "\n"); - S.SetSeq(S_Use); - ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_Use); - } - break; - case S_Retain: - case S_Use: - case S_None: - break; - case S_Stop: - case S_Release: - case S_MovableRelease: - llvm_unreachable("top-down pointer in release state!"); - } + S.HandlePotentialUse(Inst, Ptr, PA, Class); } return NestingDetected; @@ -2140,27 +1338,22 @@ ObjCARCOpt::VisitTopDown(BasicBlock *BB, } } - // If ARC Annotations are enabled, output the current state of pointers at the - // top of the basic block. - ANNOTATE_TOPDOWN_BBSTART(MyStates, BB); + DEBUG(llvm::dbgs() << "Before:\n" << BBStates[BB] << "\n" + << "Performing Dataflow:\n"); // Visit all the instructions, top-down. for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { Instruction *Inst = I; - DEBUG(dbgs() << "Visiting " << *Inst << "\n"); + DEBUG(dbgs() << " Visiting " << *Inst << "\n"); NestingDetected |= VisitInstructionTopDown(Inst, Releases, MyStates); } - // If ARC Annotations are enabled, output the current state of pointers at the - // bottom of the basic block. - ANNOTATE_TOPDOWN_BBEND(MyStates, BB); - -#ifdef ARC_ANNOTATIONS - if (!(EnableARCAnnotations && DisableCheckForCFGHazards)) -#endif + DEBUG(llvm::dbgs() << "\nState Before Checking for CFG Hazards:\n" + << BBStates[BB] << "\n\n"); CheckForCFGHazards(BB, BBStates, MyStates); + DEBUG(llvm::dbgs() << "Final State:\n" << BBStates[BB] << "\n"); return NestingDetected; } @@ -2246,11 +1439,10 @@ ComputePostOrders(Function &F, } // Visit the function both top-down and bottom-up. -bool -ObjCARCOpt::Visit(Function &F, - DenseMap<const BasicBlock *, BBState> &BBStates, - MapVector<Value *, RRInfo> &Retains, - DenseMap<Value *, RRInfo> &Releases) { +bool ObjCARCOpt::Visit(Function &F, + DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains, + DenseMap<Value *, RRInfo> &Releases) { // Use reverse-postorder traversals, because we magically know that loops // will be well behaved, i.e. they won't repeatedly call retain on a single @@ -2260,7 +1452,7 @@ ObjCARCOpt::Visit(Function &F, SmallVector<BasicBlock *, 16> PostOrder; SmallVector<BasicBlock *, 16> ReverseCFGPostOrder; ComputePostOrders(F, PostOrder, ReverseCFGPostOrder, - NoObjCARCExceptionsMDKind, + MDKindCache.get(ARCMDKindID::NoObjCARCExceptions), BBStates); // Use reverse-postorder on the reverse CFG for bottom-up. @@ -2281,10 +1473,9 @@ ObjCARCOpt::Visit(Function &F, } /// Move the calls in RetainsToMove and ReleasesToMove. -void ObjCARCOpt::MoveCalls(Value *Arg, - RRInfo &RetainsToMove, +void ObjCARCOpt::MoveCalls(Value *Arg, RRInfo &RetainsToMove, RRInfo &ReleasesToMove, - MapVector<Value *, RRInfo> &Retains, + BlotMapVector<Value *, RRInfo> &Retains, DenseMap<Value *, RRInfo> &Releases, SmallVectorImpl<Instruction *> &DeadInsts, Module *M) { @@ -2297,7 +1488,7 @@ void ObjCARCOpt::MoveCalls(Value *Arg, for (Instruction *InsertPt : ReleasesToMove.ReverseInsertPts) { Value *MyArg = ArgTy == ParamTy ? Arg : new BitCastInst(Arg, ParamTy, "", InsertPt); - Constant *Decl = EP.get(ARCRuntimeEntryPoints::EPT_Retain); + Constant *Decl = EP.get(ARCRuntimeEntryPointKind::Retain); CallInst *Call = CallInst::Create(Decl, MyArg, "", InsertPt); Call->setDoesNotThrow(); Call->setTailCall(); @@ -2308,11 +1499,11 @@ void ObjCARCOpt::MoveCalls(Value *Arg, for (Instruction *InsertPt : RetainsToMove.ReverseInsertPts) { Value *MyArg = ArgTy == ParamTy ? Arg : new BitCastInst(Arg, ParamTy, "", InsertPt); - Constant *Decl = EP.get(ARCRuntimeEntryPoints::EPT_Release); + Constant *Decl = EP.get(ARCRuntimeEntryPointKind::Release); CallInst *Call = CallInst::Create(Decl, MyArg, "", InsertPt); // Attach a clang.imprecise_release metadata tag, if appropriate. if (MDNode *M = ReleasesToMove.ReleaseMetadata) - Call->setMetadata(ImpreciseReleaseMDKind, M); + Call->setMetadata(MDKindCache.get(ARCMDKindID::ImpreciseRelease), M); Call->setDoesNotThrow(); if (ReleasesToMove.IsTailCallRelease) Call->setTailCall(); @@ -2335,20 +1526,15 @@ void ObjCARCOpt::MoveCalls(Value *Arg, } -bool -ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> - &BBStates, - MapVector<Value *, RRInfo> &Retains, - DenseMap<Value *, RRInfo> &Releases, - Module *M, - SmallVectorImpl<Instruction *> &NewRetains, - SmallVectorImpl<Instruction *> &NewReleases, - SmallVectorImpl<Instruction *> &DeadInsts, - RRInfo &RetainsToMove, - RRInfo &ReleasesToMove, - Value *Arg, - bool KnownSafe, - bool &AnyPairsCompletelyEliminated) { +bool ObjCARCOpt::PairUpRetainsAndReleases( + DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains, + DenseMap<Value *, RRInfo> &Releases, Module *M, + SmallVectorImpl<Instruction *> &NewRetains, + SmallVectorImpl<Instruction *> &NewReleases, + SmallVectorImpl<Instruction *> &DeadInsts, RRInfo &RetainsToMove, + RRInfo &ReleasesToMove, Value *Arg, bool KnownSafe, + bool &AnyPairsCompletelyEliminated) { // If a pair happens in a region where it is known that the reference count // is already incremented, we can similarly ignore possible decrements unless // we are dealing with a retainable object with multiple provenance sources. @@ -2369,15 +1555,14 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> for (SmallVectorImpl<Instruction *>::const_iterator NI = NewRetains.begin(), NE = NewRetains.end(); NI != NE; ++NI) { Instruction *NewRetain = *NI; - MapVector<Value *, RRInfo>::const_iterator It = Retains.find(NewRetain); + auto It = Retains.find(NewRetain); assert(It != Retains.end()); const RRInfo &NewRetainRRI = It->second; KnownSafeTD &= NewRetainRRI.KnownSafe; MultipleOwners = MultipleOwners || MultiOwnersSet.count(GetArgRCIdentityRoot(NewRetain)); for (Instruction *NewRetainRelease : NewRetainRRI.Calls) { - DenseMap<Value *, RRInfo>::const_iterator Jt = - Releases.find(NewRetainRelease); + auto Jt = Releases.find(NewRetainRelease); if (Jt == Releases.end()) return false; const RRInfo &NewRetainReleaseRRI = Jt->second; @@ -2446,15 +1631,13 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> for (SmallVectorImpl<Instruction *>::const_iterator NI = NewReleases.begin(), NE = NewReleases.end(); NI != NE; ++NI) { Instruction *NewRelease = *NI; - DenseMap<Value *, RRInfo>::const_iterator It = - Releases.find(NewRelease); + auto It = Releases.find(NewRelease); assert(It != Releases.end()); const RRInfo &NewReleaseRRI = It->second; KnownSafeBU &= NewReleaseRRI.KnownSafe; CFGHazardAfflicted |= NewReleaseRRI.CFGHazardAfflicted; for (Instruction *NewReleaseRetain : NewReleaseRRI.Calls) { - MapVector<Value *, RRInfo>::const_iterator Jt = - Retains.find(NewReleaseRetain); + auto Jt = Retains.find(NewReleaseRetain); if (Jt == Retains.end()) return false; const RRInfo &NewReleaseRetainRRI = Jt->second; @@ -2506,11 +1689,8 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> if (NewRetains.empty()) break; } - // If the pointer is known incremented in 1 direction and we do not have - // MultipleOwners, we can safely remove the retain/releases. Otherwise we need - // to be known safe in both directions. - bool UnconditionallySafe = (KnownSafeTD && KnownSafeBU) || - ((KnownSafeTD || KnownSafeBU) && !MultipleOwners); + // We can only remove pointers if we are known safe in both directions. + bool UnconditionallySafe = KnownSafeTD && KnownSafeBU; if (UnconditionallySafe) { RetainsToMove.ReverseInsertPts.clear(); ReleasesToMove.ReverseInsertPts.clear(); @@ -2540,12 +1720,6 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> if (OldDelta != 0) return false; -#ifdef ARC_ANNOTATIONS - // Do not move calls if ARC annotations are requested. - if (EnableARCAnnotations) - return false; -#endif // ARC_ANNOTATIONS - Changed = true; assert(OldCount != 0 && "Unreachable code?"); NumRRs += OldCount - NewCount; @@ -2558,12 +1732,10 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState> /// Identify pairings between the retains and releases, and delete and/or move /// them. -bool -ObjCARCOpt::PerformCodePlacement(DenseMap<const BasicBlock *, BBState> - &BBStates, - MapVector<Value *, RRInfo> &Retains, - DenseMap<Value *, RRInfo> &Releases, - Module *M) { +bool ObjCARCOpt::PerformCodePlacement( + DenseMap<const BasicBlock *, BBState> &BBStates, + BlotMapVector<Value *, RRInfo> &Retains, + DenseMap<Value *, RRInfo> &Releases, Module *M) { DEBUG(dbgs() << "\n== ObjCARCOpt::PerformCodePlacement ==\n"); bool AnyPairsCompletelyEliminated = false; @@ -2574,8 +1746,9 @@ ObjCARCOpt::PerformCodePlacement(DenseMap<const BasicBlock *, BBState> SmallVector<Instruction *, 8> DeadInsts; // Visit each retain. - for (MapVector<Value *, RRInfo>::const_iterator I = Retains.begin(), - E = Retains.end(); I != E; ++I) { + for (BlotMapVector<Value *, RRInfo>::const_iterator I = Retains.begin(), + E = Retains.end(); + I != E; ++I) { Value *V = I->first; if (!V) continue; // blotted @@ -2602,11 +1775,10 @@ ObjCARCOpt::PerformCodePlacement(DenseMap<const BasicBlock *, BBState> // Connect the dots between the top-down-collected RetainsToMove and // bottom-up-collected ReleasesToMove to form sets of related calls. NewRetains.push_back(Retain); - bool PerformMoveCalls = - ConnectTDBUTraversals(BBStates, Retains, Releases, M, NewRetains, - NewReleases, DeadInsts, RetainsToMove, - ReleasesToMove, Arg, KnownSafe, - AnyPairsCompletelyEliminated); + bool PerformMoveCalls = PairUpRetainsAndReleases( + BBStates, Retains, Releases, M, NewRetains, NewReleases, DeadInsts, + RetainsToMove, ReleasesToMove, Arg, KnownSafe, + AnyPairsCompletelyEliminated); if (PerformMoveCalls) { // Ok, everything checks out and we're all set. Let's move/delete some @@ -2678,7 +1850,7 @@ void ObjCARCOpt::OptimizeWeakCalls(Function &F) { Changed = true; // If the load has a builtin retain, insert a plain retain for it. if (Class == ARCInstKind::LoadWeakRetained) { - Constant *Decl = EP.get(ARCRuntimeEntryPoints::EPT_Retain); + Constant *Decl = EP.get(ARCRuntimeEntryPointKind::Retain); CallInst *CI = CallInst::Create(Decl, EarlierCall, "", Call); CI->setTailCall(); } @@ -2707,7 +1879,7 @@ void ObjCARCOpt::OptimizeWeakCalls(Function &F) { Changed = true; // If the load has a builtin retain, insert a plain retain for it. if (Class == ARCInstKind::LoadWeakRetained) { - Constant *Decl = EP.get(ARCRuntimeEntryPoints::EPT_Retain); + Constant *Decl = EP.get(ARCRuntimeEntryPointKind::Retain); CallInst *CI = CallInst::Create(Decl, EarlierCall, "", Call); CI->setTailCall(); } @@ -2795,7 +1967,7 @@ bool ObjCARCOpt::OptimizeSequences(Function &F) { // map stays valid when we get around to rewriting code and calls get // replaced by arguments. DenseMap<Value *, RRInfo> Releases; - MapVector<Value *, RRInfo> Retains; + BlotMapVector<Value *, RRInfo> Retains; // This is used during the traversal of the function to track the // states for each identified object at each block. @@ -2828,8 +2000,7 @@ HasSafePathToPredecessorCall(const Value *Arg, Instruction *Retain, if (DepInsts.size() != 1) return false; - CallInst *Call = - dyn_cast_or_null<CallInst>(*DepInsts.begin()); + auto *Call = dyn_cast_or_null<CallInst>(*DepInsts.begin()); // Check that the pointer is the return value of the call. if (!Call || Arg != Call) @@ -2857,8 +2028,7 @@ FindPredecessorRetainWithSafePath(const Value *Arg, BasicBlock *BB, if (DepInsts.size() != 1) return nullptr; - CallInst *Retain = - dyn_cast_or_null<CallInst>(*DepInsts.begin()); + auto *Retain = dyn_cast_or_null<CallInst>(*DepInsts.begin()); // Check that we found a retain with the same argument. if (!Retain || !IsRetain(GetBasicARCInstKind(Retain)) || @@ -2883,8 +2053,7 @@ FindPredecessorAutoreleaseWithSafePath(const Value *Arg, BasicBlock *BB, if (DepInsts.size() != 1) return nullptr; - CallInst *Autorelease = - dyn_cast_or_null<CallInst>(*DepInsts.begin()); + auto *Autorelease = dyn_cast_or_null<CallInst>(*DepInsts.begin()); if (!Autorelease) return nullptr; ARCInstKind AutoreleaseClass = GetBasicARCInstKind(Autorelease); @@ -2999,28 +2168,13 @@ bool ObjCARCOpt::doInitialization(Module &M) { if (!Run) return false; - // Identify the imprecise release metadata kind. - ImpreciseReleaseMDKind = - M.getContext().getMDKindID("clang.imprecise_release"); - CopyOnEscapeMDKind = - M.getContext().getMDKindID("clang.arc.copy_on_escape"); - NoObjCARCExceptionsMDKind = - M.getContext().getMDKindID("clang.arc.no_objc_arc_exceptions"); -#ifdef ARC_ANNOTATIONS - ARCAnnotationBottomUpMDKind = - M.getContext().getMDKindID("llvm.arc.annotation.bottomup"); - ARCAnnotationTopDownMDKind = - M.getContext().getMDKindID("llvm.arc.annotation.topdown"); - ARCAnnotationProvenanceSourceMDKind = - M.getContext().getMDKindID("llvm.arc.annotation.provenancesource"); -#endif // ARC_ANNOTATIONS - // Intuitively, objc_retain and others are nocapture, however in practice // they are not, because they return their argument value. And objc_release // calls finalizers which can have arbitrary side effects. + MDKindCache.init(&M); // Initialize our runtime entry point cache. - EP.Initialize(&M); + EP.init(&M); return false; } |