diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp index 336a718a056..3bb03124ee6 100644 --- a/lib/Transforms/Scalar/ObjCARC.cpp +++ b/lib/Transforms/Scalar/ObjCARC.cpp @@ -1361,12 +1361,6 @@ namespace { /// with the "tail" keyword. bool IsTailCallRelease; - /// Partial - True of 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. - /// TODO: Consider moving this to PtrState. - bool Partial; - /// ReleaseMetadata - If the Calls are objc_release calls and they all have /// a clang.imprecise_release tag, this is the metadata tag. MDNode *ReleaseMetadata; @@ -1381,7 +1375,7 @@ namespace { RRInfo() : KnownSafe(false), IsRetainBlock(false), - IsTailCallRelease(false), Partial(false), + IsTailCallRelease(false), ReleaseMetadata(0) {} void clear(); @@ -1392,7 +1386,6 @@ void RRInfo::clear() { KnownSafe = false; IsRetainBlock = false; IsTailCallRelease = false; - Partial = false; ReleaseMetadata = 0; Calls.clear(); ReverseInsertPts.clear(); @@ -1402,8 +1395,14 @@ namespace { /// PtrState - This class summarizes several per-pointer runtime properties /// which are propogated through the flow graph. class PtrState { - /// RefCount - The known minimum number of reference count increments. - unsigned RefCount; + /// KnownPositiveRefCount - True if the reference count is known to + /// be incremented. + bool KnownPositiveRefCount; + + /// Partial - True of 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; /// NestCount - The known minimum level of retain+release nesting. unsigned NestCount; @@ -1416,22 +1415,19 @@ namespace { /// TODO: Encapsulate this better. RRInfo RRI; - PtrState() : RefCount(0), NestCount(0), Seq(S_None) {} + PtrState() : KnownPositiveRefCount(false), Partial(false), + NestCount(0), Seq(S_None) {} - void SetAtLeastOneRefCount() { - if (RefCount == 0) RefCount = 1; + void SetKnownPositiveRefCount() { + KnownPositiveRefCount = true; } - void IncrementRefCount() { - if (RefCount != UINT_MAX) ++RefCount; - } - - void DecrementRefCount() { - if (RefCount != 0) --RefCount; + void ClearRefCount() { + KnownPositiveRefCount = false; } bool IsKnownIncremented() const { - return RefCount > 0; + return KnownPositiveRefCount; } void IncrementNestCount() { @@ -1455,7 +1451,12 @@ namespace { } void ClearSequenceProgress() { - Seq = S_None; + ResetSequenceProgress(S_None); + } + + void ResetSequenceProgress(Sequence NewSeq) { + Seq = NewSeq; + Partial = false; RRI.clear(); } @@ -1466,7 +1467,7 @@ namespace { void PtrState::Merge(const PtrState &Other, bool TopDown) { Seq = MergeSeqs(Seq, Other.Seq, TopDown); - RefCount = std::min(RefCount, Other.RefCount); + KnownPositiveRefCount = KnownPositiveRefCount && Other.KnownPositiveRefCount; NestCount = std::min(NestCount, Other.NestCount); // We can't merge a plain objc_retain with an objc_retainBlock. @@ -1475,14 +1476,14 @@ PtrState::Merge(const PtrState &Other, bool TopDown) { // If we're not in a sequence (anymore), drop all associated state. if (Seq == S_None) { + Partial = false; RRI.clear(); - } else if (RRI.Partial || Other.RRI.Partial) { + } 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. - Seq = S_None; - RRI.clear(); + ClearSequenceProgress(); } else { // Conservatively merge the ReleaseMetadata information. if (RRI.ReleaseMetadata != Other.RRI.ReleaseMetadata) @@ -1494,12 +1495,12 @@ PtrState::Merge(const PtrState &Other, bool TopDown) { // Merge the insert point sets. If there are any differences, // that makes this a partial merge. - RRI.Partial = RRI.ReverseInsertPts.size() != - Other.RRI.ReverseInsertPts.size(); + Partial = RRI.ReverseInsertPts.size() != + Other.RRI.ReverseInsertPts.size(); for (SmallPtrSet::const_iterator I = Other.RRI.ReverseInsertPts.begin(), E = Other.RRI.ReverseInsertPts.end(); I != E; ++I) - RRI.Partial |= RRI.ReverseInsertPts.insert(*I); + Partial |= RRI.ReverseInsertPts.insert(*I); } } @@ -2634,16 +2635,13 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, if (S.GetSeq() == S_Release || S.GetSeq() == S_MovableRelease) NestingDetected = true; - S.RRI.clear(); - MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind); - S.SetSeq(ReleaseMetadata ? S_MovableRelease : S_Release); + S.ResetSequenceProgress(ReleaseMetadata ? S_MovableRelease : S_Release); S.RRI.ReleaseMetadata = ReleaseMetadata; S.RRI.KnownSafe = S.IsKnownNested() || S.IsKnownIncremented(); S.RRI.IsTailCallRelease = cast(Inst)->isTailCall(); S.RRI.Calls.insert(Inst); - S.IncrementRefCount(); S.IncrementNestCount(); break; } @@ -2658,8 +2656,7 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, Arg = GetObjCArg(Inst); PtrState &S = MyStates.getPtrBottomUpState(Arg); - S.DecrementRefCount(); - S.SetAtLeastOneRefCount(); + S.SetKnownPositiveRefCount(); S.DecrementNestCount(); switch (S.GetSeq()) { @@ -2709,7 +2706,7 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst, // Check for possible releases. if (CanAlterRefCount(Inst, Ptr, PA, Class)) { - S.DecrementRefCount(); + S.ClearRefCount(); switch (Seq) { case S_Use: S.SetSeq(S_CanRelease); @@ -2852,8 +2849,7 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst, if (S.GetSeq() == S_Retain) NestingDetected = true; - S.SetSeq(S_Retain); - S.RRI.clear(); + S.ResetSequenceProgress(S_Retain); S.RRI.IsRetainBlock = Class == IC_RetainBlock; // Don't check S.IsKnownIncremented() here because it's not // sufficient. @@ -2861,8 +2857,6 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst, S.RRI.Calls.insert(Inst); } - S.SetAtLeastOneRefCount(); - S.IncrementRefCount(); S.IncrementNestCount(); return NestingDetected; } @@ -2870,7 +2864,6 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst, Arg = GetObjCArg(Inst); PtrState &S = MyStates.getPtrTopDownState(Arg); - S.DecrementRefCount(); S.DecrementNestCount(); switch (S.GetSeq()) { @@ -2917,7 +2910,7 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst, // Check for possible releases. if (CanAlterRefCount(Inst, Ptr, PA, Class)) { - S.DecrementRefCount(); + S.ClearRefCount(); switch (Seq) { case S_Retain: S.SetSeq(S_CanRelease);