///
/// The optimizations performed include elimination of redundant, partially
/// redundant, and inconsequential reference count operations, elimination of
-/// redundant weak pointer operations, pattern-matching and replacement of
-/// low-level operations into higher-level operations, and numerous minor
-/// simplifications.
-///
-/// This file also defines a simple ARC-aware AliasAnalysis.
+/// redundant weak pointer operations, and numerous minor simplifications.
///
/// WARNING: This file knows about certain library functions. It recognizes them
/// by name, and hardwires knowledge of their semantics.
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/Debug.h"
// These special functions make copies of their pointer arguments.
return true;
}
+ case IC_IntrinsicUser:
+ // Use by the use intrinsic is not an escape.
+ continue;
case IC_User:
case IC_None:
// Use by an instruction which copies the value is an escape if the
if (isa<BitCastInst>(UUser) || isa<GetElementPtrInst>(UUser) ||
isa<PHINode>(UUser) || isa<SelectInst>(UUser)) {
- if (!VisitedSet.insert(UUser)) {
+ if (VisitedSet.insert(UUser)) {
DEBUG(dbgs() << "DoesRetainableObjPtrEscape: User copies value. "
"Ptr escapes if result escapes. Adding to list.\n");
Worklist.push_back(UUser);
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.
+ S_MovableRelease ///< objc_release(x), !clang.imprecise_release.
};
raw_ostream &operator<<(raw_ostream &OS, const Sequence S)
KnownPositiveRefCount = true;
}
- void ClearRefCount() {
+ void ClearKnownPositiveRefCount() {
KnownPositiveRefCount = false;
}
- bool IsKnownIncremented() const {
+ bool HasKnownPositiveRefCount() const {
return KnownPositiveRefCount;
}
MI->second.Merge(PtrState(), /*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));
+
+/// 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 = 0;
+
+ // 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));
+ }
+ } 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 = 0;
+ Value *tmp[3] = {PtrSourceMDNodeID,
+ SequenceToMDString(Inst->getContext(),
+ OldSeq),
+ SequenceToMDString(Inst->getContext(),
+ NewSeq)};
+ Node = MDNode::get(Inst->getContext(),
+ ArrayRef<Value*>(tmp, 3));
+
+ 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) {
+ 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),
+ ArrayRef<Type*>(Params, 2),
+ /*isVarArg=*/false);
+ Constant *Callee = M->getOrInsertFunction(Name, FTy);
+
+ IRBuilder<> Builder(BB, BB->getFirstInsertionPt());
+
+ Value *PtrName;
+ StringRef Tmp = Ptr->getName();
+ if (0 == (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 (0 == (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) {
+ 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),
+ ArrayRef<Type*>(Params, 2),
+ /*isVarArg=*/false);
+ Constant *Callee = M->getOrInsertFunction(Name, FTy);
+
+ IRBuilder<> Builder(BB, llvm::prior(BB->end()));
+
+ Value *PtrName;
+ StringRef Tmp = Ptr->getName();
+ if (0 == (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 (0 == (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);
+}
+
+/// 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) {
+ // 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);
+ }
+}
+
+// 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))
+
+#else // !ARC_ANNOTATION
+// If annotations are off, noop.
+#define ANNOTATE_BOTTOMUP(inst, ptr, old, new)
+#define ANNOTATE_TOPDOWN(inst, ptr, old, new)
+#endif // !ARC_ANNOTATION
+
namespace {
/// \brief The main ARC optimization pass.
class ObjCARCOpt : public FunctionPass {
/// 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
+
Constant *getRetainRVCallee(Module *M);
Constant *getAutoreleaseRVCallee(Module *M);
Constant *getReleaseCallee(Module *M);
bool OptimizeRetainRVCall(Function &F, Instruction *RetainRV);
void OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV,
InstructionClass &Class);
+ bool OptimizeRetainBlockCall(Function &F, Instruction *RetainBlock,
+ InstructionClass &Class);
void OptimizeIndividualCalls(Function &F);
void CheckForCFGHazards(const BasicBlock *BB,
// Check that the call is next to the retain.
BasicBlock::const_iterator I = Call;
++I;
- while (isNoopInstruction(I)) ++I;
+ while (IsNoopInstruction(I)) ++I;
if (&*I != Retain)
return;
if (Call->getParent() == RetainRV->getParent()) {
BasicBlock::const_iterator I = Call;
++I;
- while (isNoopInstruction(I)) ++I;
+ while (IsNoopInstruction(I)) ++I;
if (&*I == RetainRV)
return false;
} else if (const InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
BasicBlock *RetainRVParent = RetainRV->getParent();
if (II->getNormalDest() == RetainRVParent) {
BasicBlock::const_iterator I = RetainRVParent->begin();
- while (isNoopInstruction(I)) ++I;
+ while (IsNoopInstruction(I)) ++I;
if (&*I == RetainRV)
return false;
}
// pointer. In this case, we can delete the pair.
BasicBlock::iterator I = RetainRV, Begin = RetainRV->getParent()->begin();
if (I != Begin) {
- do --I; while (I != Begin && isNoopInstruction(I));
+ do --I; while (I != Begin && IsNoopInstruction(I));
if (GetBasicInstructionClass(I) == IC_AutoreleaseRV &&
GetObjCArg(I) == Arg) {
Changed = true;
}
+// \brief Attempt to strength reduce objc_retainBlock calls to objc_retain
+// calls.
+//
+// Specifically: If an objc_retainBlock call has the copy_on_escape metadata and
+// does not escape (following the rules of block escaping), strength reduce the
+// objc_retainBlock to an objc_retain.
+//
+// TODO: If an objc_retainBlock call is dominated period by a previous
+// objc_retainBlock call, strength reduce the objc_retainBlock to an
+// objc_retain.
+bool
+ObjCARCOpt::OptimizeRetainBlockCall(Function &F, Instruction *Inst,
+ InstructionClass &Class) {
+ assert(GetBasicInstructionClass(Inst) == Class);
+ assert(IC_RetainBlock == Class);
+
+ // If we can not optimize Inst, return false.
+ if (!IsRetainBlockOptimizable(Inst))
+ return false;
+
+ CallInst *RetainBlock = cast<CallInst>(Inst);
+ RetainBlock->setCalledFunction(getRetainCallee(F.getParent()));
+ // Remove copy_on_escape metadata.
+ RetainBlock->setMetadata(CopyOnEscapeMDKind, 0);
+ Class = IC_Retain;
+
+ return true;
+}
+
/// Visit each call, one at a time, and make simplifications without doing any
/// additional analysis.
void ObjCARCOpt::OptimizeIndividualCalls(Function &F) {
case IC_InitWeak:
case IC_DestroyWeak: {
CallInst *CI = cast<CallInst>(Inst);
- if (isNullOrUndef(CI->getArgOperand(0))) {
+ if (IsNullOrUndef(CI->getArgOperand(0))) {
Changed = true;
Type *Ty = CI->getArgOperand(0)->getType();
new StoreInst(UndefValue::get(cast<PointerType>(Ty)->getElementType()),
case IC_CopyWeak:
case IC_MoveWeak: {
CallInst *CI = cast<CallInst>(Inst);
- if (isNullOrUndef(CI->getArgOperand(0)) ||
- isNullOrUndef(CI->getArgOperand(1))) {
+ if (IsNullOrUndef(CI->getArgOperand(0)) ||
+ IsNullOrUndef(CI->getArgOperand(1))) {
Changed = true;
Type *Ty = CI->getArgOperand(0)->getType();
new StoreInst(UndefValue::get(cast<PointerType>(Ty)->getElementType()),
}
break;
}
+ case IC_RetainBlock:
+ // If we strength reduce an objc_retainBlock to amn objc_retain, continue
+ // onto the objc_retain peephole optimizations. Otherwise break.
+ if (!OptimizeRetainBlockCall(F, Inst, Class))
+ break;
+ // FALLTHROUGH
case IC_Retain:
OptimizeRetainCall(F, Inst);
break;
const Value *Arg = GetObjCArg(Inst);
// ARC calls with null are no-ops. Delete them.
- if (isNullOrUndef(Arg)) {
+ if (IsNullOrUndef(Arg)) {
Changed = true;
++NumNoops;
DEBUG(dbgs() << "ObjCARCOpt::OptimizeIndividualCalls: ARC calls with "
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming =
StripPointerCastsAndObjCCalls(PN->getIncomingValue(i));
- if (isNullOrUndef(Incoming))
+ if (IsNullOrUndef(Incoming))
HasNull = true;
else if (cast<TerminatorInst>(PN->getIncomingBlock(i)->back())
.getNumSuccessors() != 1) {
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming =
StripPointerCastsAndObjCCalls(PN->getIncomingValue(i));
- if (!isNullOrUndef(Incoming)) {
+ if (!IsNullOrUndef(Incoming)) {
CallInst *Clone = cast<CallInst>(CInst->clone());
Value *Op = PN->getIncomingValue(i);
Instruction *InsertPos = &PN->getIncomingBlock(i)->back();
}
MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind);
- S.ResetSequenceProgress(ReleaseMetadata ? S_MovableRelease : S_Release);
+ Sequence NewSeq = ReleaseMetadata ? S_MovableRelease : S_Release;
+ ANNOTATE_BOTTOMUP(Inst, Arg, S.GetSeq(), NewSeq);
+ S.ResetSequenceProgress(NewSeq);
S.RRI.ReleaseMetadata = ReleaseMetadata;
- S.RRI.KnownSafe = S.IsKnownIncremented();
+ S.RRI.KnownSafe = S.HasKnownPositiveRefCount();
S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall();
S.RRI.Calls.insert(Inst);
-
S.SetKnownPositiveRefCount();
break;
}
case IC_RetainBlock:
- // An objc_retainBlock call with just a use may need to be kept,
- // because it may be copying a block from the stack to the heap.
- if (!IsRetainBlockOptimizable(Inst))
- break;
- // FALLTHROUGH
+ // 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.
+ break;
case IC_Retain:
case IC_RetainRV: {
Arg = GetObjCArg(Inst);
PtrState &S = MyStates.getPtrBottomUpState(Arg);
S.SetKnownPositiveRefCount();
- switch (S.GetSeq()) {
+ Sequence OldSeq = S.GetSeq();
+ switch (OldSeq) {
case S_Stop:
case S_Release:
case S_MovableRelease:
case S_Retain:
llvm_unreachable("bottom-up pointer in retain state!");
}
+ ANNOTATE_BOTTOMUP(Inst, Arg, OldSeq, S.GetSeq());
return NestingDetected;
}
case IC_AutoreleasepoolPop:
// Check for possible releases.
if (CanAlterRefCount(Inst, Ptr, PA, Class)) {
- S.ClearRefCount();
+ 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:
else
S.RRI.ReverseInsertPts.insert(llvm::next(BasicBlock::iterator(Inst)));
S.SetSeq(S_Use);
- } else if (Seq == S_Release &&
- (Class == IC_User || Class == IC_CallOrUser)) {
+ ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use);
+ } else if (Seq == S_Release && IsUser(Class)) {
// Non-movable releases depend on any possible objc pointer use.
S.SetSeq(S_Stop);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, S_Release, S_Stop);
assert(S.RRI.ReverseInsertPts.empty());
// As above; handle invoke specially.
if (isa<InvokeInst>(Inst))
}
break;
case S_Stop:
- if (CanUse(Inst, Ptr, PA, Class))
+ if (CanUse(Inst, Ptr, PA, Class)) {
S.SetSeq(S_Use);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use);
+ }
break;
case S_CanRelease:
case S_Use:
assert(I != BBStates.end());
MyStates.MergeSucc(I->second);
}
+ }
+
+#ifdef ARC_ANNOTATIONS
+ if (EnableARCAnnotations) {
+ // If ARC Annotations are enabled, output the current state of pointers at the
+ // bottom of the basic block.
+ for(BBState::ptr_const_iterator I = MyStates.bottom_up_ptr_begin(),
+ E = MyStates.bottom_up_ptr_end(); I != E; ++I) {
+ Value *Ptr = const_cast<Value*>(I->first);
+ Sequence Seq = I->second.GetSeq();
+ GenerateARCBBTerminatorAnnotation("llvm.arc.annotation.bottomup.bbend",
+ BB, Ptr, Seq);
+ }
}
+#endif
+
// Visit all the instructions, bottom-up.
for (BasicBlock::iterator I = BB->end(), E = BB->begin(); I != E; --I) {
NestingDetected |= VisitInstructionBottomUp(II, BB, Retains, MyStates);
}
+#ifdef ARC_ANNOTATIONS
+ if (EnableARCAnnotations) {
+ // If ARC Annotations are enabled, output the current state of pointers at the
+ // top of the basic block.
+ for(BBState::ptr_const_iterator I = MyStates.bottom_up_ptr_begin(),
+ E = MyStates.bottom_up_ptr_end(); I != E; ++I) {
+ Value *Ptr = const_cast<Value*>(I->first);
+ Sequence Seq = I->second.GetSeq();
+ GenerateARCBBEntranceAnnotation("llvm.arc.annotation.bottomup.bbstart",
+ BB, Ptr, Seq);
+ }
+ }
+#endif
+
return NestingDetected;
}
switch (Class) {
case IC_RetainBlock:
- // An objc_retainBlock call with just a use may need to be kept,
- // because it may be copying a block from the stack to the heap.
- if (!IsRetainBlockOptimizable(Inst))
- break;
- // FALLTHROUGH
+ // 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.
+ break;
case IC_Retain:
case IC_RetainRV: {
Arg = GetObjCArg(Inst);
if (S.GetSeq() == S_Retain)
NestingDetected = true;
+ ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_Retain);
S.ResetSequenceProgress(S_Retain);
S.RRI.IsRetainBlock = Class == IC_RetainBlock;
- S.RRI.KnownSafe = S.IsKnownIncremented();
+ S.RRI.KnownSafe = S.HasKnownPositiveRefCount();
S.RRI.Calls.insert(Inst);
}
Arg = GetObjCArg(Inst);
PtrState &S = MyStates.getPtrTopDownState(Arg);
- S.ClearRefCount();
+ S.ClearKnownPositiveRefCount();
switch (S.GetSeq()) {
case S_Retain:
S.RRI.ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind);
S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall();
Releases[Inst] = S.RRI;
+ ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_None);
S.ClearSequenceProgress();
break;
case S_None:
// Check for possible releases.
if (CanAlterRefCount(Inst, Ptr, PA, Class)) {
- S.ClearRefCount();
+ S.ClearKnownPositiveRefCount();
switch (Seq) {
case S_Retain:
S.SetSeq(S_CanRelease);
+ ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_CanRelease);
assert(S.RRI.ReverseInsertPts.empty());
S.RRI.ReverseInsertPts.insert(Inst);
// Check for possible direct uses.
switch (Seq) {
case S_CanRelease:
- if (CanUse(Inst, Ptr, PA, Class))
+ if (CanUse(Inst, Ptr, PA, Class)) {
S.SetSeq(S_Use);
+ ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_Use);
+ }
break;
case S_Retain:
case S_Use:
}
}
+#ifdef ARC_ANNOTATIONS
+ if (EnableARCAnnotations) {
+ // If ARC Annotations are enabled, output the current state of pointers at the
+ // top of the basic block.
+ for(BBState::ptr_const_iterator I = MyStates.top_down_ptr_begin(),
+ E = MyStates.top_down_ptr_end(); I != E; ++I) {
+ Value *Ptr = const_cast<Value*>(I->first);
+ Sequence Seq = I->second.GetSeq();
+ GenerateARCBBEntranceAnnotation("llvm.arc.annotation.topdown.bbstart",
+ BB, Ptr, Seq);
+ }
+ }
+#endif
+
// Visit all the instructions, top-down.
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
Instruction *Inst = I;
NestingDetected |= VisitInstructionTopDown(Inst, Releases, MyStates);
}
+#ifdef ARC_ANNOTATIONS
+ if (EnableARCAnnotations) {
+ // If ARC Annotations are enabled, output the current state of pointers at the
+ // bottom of the basic block.
+ for(BBState::ptr_const_iterator I = MyStates.top_down_ptr_begin(),
+ E = MyStates.top_down_ptr_end(); I != E; ++I) {
+ Value *Ptr = const_cast<Value*>(I->first);
+ Sequence Seq = I->second.GetSeq();
+ GenerateARCBBTerminatorAnnotation("llvm.arc.annotation.topdown.bbend",
+ BB, Ptr, Seq);
+ }
+ }
+#endif
+
CheckForCFGHazards(BB, BBStates, MyStates);
return NestingDetected;
}
ReleasesToMove, Arg, KnownSafe,
AnyPairsCompletelyEliminated);
+#ifdef ARC_ANNOTATIONS
+ // Do not move calls if ARC annotations are requested. If we were to move
+ // calls in this case, we would not be able
+ PerformMoveCalls = PerformMoveCalls && !EnableARCAnnotations;
+#endif // ARC_ANNOTATIONS
+
if (PerformMoveCalls) {
// Ok, everything checks out and we're all set. Let's move/delete some
// code!
goto clobbered;
case IC_AutoreleasepoolPush:
case IC_None:
+ case IC_IntrinsicUser:
case IC_User:
// Weak pointers are only modified through the weak entry points
// (and arbitrary calls, which could call the weak entry points).
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
projects / oota-llvm.git / blobdiff