}
}
+/// If we have a top down pointer in the S_Use state, make sure that there are
+/// no CFG hazards by checking the states of various bottom up pointers.
+static void CheckForUseCFGHazard(const Sequence SuccSSeq,
+ const bool SuccSRRIKnownSafe,
+ PtrState &S,
+ bool &SomeSuccHasSame,
+ bool &AllSuccsHaveSame,
+ bool &ShouldContinue) {
+ switch (SuccSSeq) {
+ case S_CanRelease: {
+ if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe) {
+ S.ClearSequenceProgress();
+ break;
+ }
+ ShouldContinue = true;
+ break;
+ }
+ case S_Use:
+ SomeSuccHasSame = true;
+ break;
+ case S_Stop:
+ case S_Release:
+ case S_MovableRelease:
+ if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe)
+ AllSuccsHaveSame = false;
+ break;
+ case S_Retain:
+ llvm_unreachable("bottom-up pointer in retain state!");
+ case S_None:
+ llvm_unreachable("This should have been handled earlier.");
+ }
+}
+
+/// If we have a Top Down pointer in the S_CanRelease state, make sure that
+/// there are no CFG hazards by checking the states of various bottom up
+/// pointers.
+static void CheckForCanReleaseCFGHazard(const Sequence SuccSSeq,
+ const bool SuccSRRIKnownSafe,
+ PtrState &S,
+ bool &SomeSuccHasSame,
+ bool &AllSuccsHaveSame) {
+ switch (SuccSSeq) {
+ case S_CanRelease:
+ SomeSuccHasSame = true;
+ break;
+ case S_Stop:
+ case S_Release:
+ case S_MovableRelease:
+ case S_Use:
+ if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe)
+ AllSuccsHaveSame = false;
+ break;
+ case S_Retain:
+ llvm_unreachable("bottom-up pointer in retain state!");
+ case S_None:
+ llvm_unreachable("This should have been handled earlier.");
+ }
+}
+
/// Check for critical edges, loop boundaries, irreducible control flow, or
/// other CFG structures where moving code across the edge would result in it
/// being executed more.
// 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)
- switch (I->second.GetSeq()) {
- default: break;
- case S_Use: {
- const Value *Arg = I->first;
- const TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
- bool SomeSuccHasSame = false;
- bool AllSuccsHaveSame = true;
- PtrState &S = I->second;
- succ_const_iterator SI(TI), SE(TI, false);
-
- for (; SI != SE; ++SI) {
- Sequence SuccSSeq = S_None;
- bool SuccSRRIKnownSafe = false;
- // If VisitBottomUp has pointer information for this successor, take
- // what we know about it.
- DenseMap<const BasicBlock *, BBState>::iterator BBI =
- BBStates.find(*SI);
- assert(BBI != BBStates.end());
- const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
- SuccSSeq = SuccS.GetSeq();
- SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
- switch (SuccSSeq) {
- case S_None:
- case S_CanRelease: {
- if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe) {
- S.ClearSequenceProgress();
- break;
- }
- continue;
- }
- case S_Use:
- SomeSuccHasSame = true;
- break;
- case S_Stop:
- case S_Release:
- case S_MovableRelease:
- if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe)
- AllSuccsHaveSame = false;
- break;
- case S_Retain:
- llvm_unreachable("bottom-up pointer in retain state!");
- }
- }
- // If the state at the other end of any of the successor edges
- // matches the current state, require all edges to match. This
- // guards against loops in the middle of a sequence.
- if (SomeSuccHasSame && !AllSuccsHaveSame)
+ E = MyStates.top_down_ptr_end(); I != E; ++I) {
+ PtrState &S = I->second;
+ const Sequence Seq = I->second.GetSeq();
+
+ // We only care about S_Retain, S_CanRelease, and S_Use.
+ if (Seq == S_None)
+ continue;
+
+ // Make sure that if extra top down states are added in the future that this
+ // code is updated to handle it.
+ assert((Seq == S_Retain || Seq == S_CanRelease || Seq == S_Use) &&
+ "Unknown top down sequence state.");
+
+ const Value *Arg = I->first;
+ const TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
+ bool SomeSuccHasSame = false;
+ bool AllSuccsHaveSame = true;
+
+ succ_const_iterator SI(TI), SE(TI, false);
+
+ for (; SI != SE; ++SI) {
+ // If VisitBottomUp has pointer information for this successor, take
+ // what we know about it.
+ const DenseMap<const BasicBlock *, BBState>::iterator BBI =
+ BBStates.find(*SI);
+ assert(BBI != BBStates.end());
+ const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
+ const Sequence SuccSSeq = SuccS.GetSeq();
+
+ // If bottom up, the pointer is in an S_None state, clear the sequence
+ // progress since the sequence in the bottom up state finished
+ // suggesting a mismatch in between retains/releases. This is true for
+ // all three cases that we are handling here: S_Retain, S_Use, and
+ // S_CanRelease.
+ if (SuccSSeq == S_None) {
S.ClearSequenceProgress();
- break;
- }
- case S_CanRelease: {
- const Value *Arg = I->first;
- const TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
- bool SomeSuccHasSame = false;
- bool AllSuccsHaveSame = true;
- PtrState &S = I->second;
- succ_const_iterator SI(TI), SE(TI, false);
-
- for (; SI != SE; ++SI) {
- Sequence SuccSSeq = S_None;
- bool SuccSRRIKnownSafe = false;
- // If VisitBottomUp has pointer information for this successor, take
- // what we know about it.
- DenseMap<const BasicBlock *, BBState>::iterator BBI =
- BBStates.find(*SI);
- assert(BBI != BBStates.end());
- const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
- SuccSSeq = SuccS.GetSeq();
- SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
- switch (SuccSSeq) {
- case S_None: {
- if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe) {
- S.ClearSequenceProgress();
- break;
- }
+ continue;
+ }
+
+ // If we have S_Use or S_CanRelease, perform our check for cfg hazard
+ // checks.
+ const bool SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
+
+ // *NOTE* We do not use Seq from above here since we are allowing for
+ // S.GetSeq() to change while we are visiting basic blocks.
+ switch(S.GetSeq()) {
+ case S_Use: {
+ bool ShouldContinue = false;
+ CheckForUseCFGHazard(SuccSSeq, SuccSRRIKnownSafe, S,
+ SomeSuccHasSame, AllSuccsHaveSame,
+ ShouldContinue);
+ if (ShouldContinue)
continue;
- }
- case S_CanRelease:
- SomeSuccHasSame = true;
- break;
- case S_Stop:
- case S_Release:
- case S_MovableRelease:
- case S_Use:
- if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe)
- AllSuccsHaveSame = false;
- break;
- case S_Retain:
- llvm_unreachable("bottom-up pointer in retain state!");
- }
+ break;
+ }
+ case S_CanRelease: {
+ CheckForCanReleaseCFGHazard(SuccSSeq, SuccSRRIKnownSafe,
+ S, SomeSuccHasSame,
+ AllSuccsHaveSame);
+ break;
+ }
+ case S_Retain:
+ case S_None:
+ case S_Stop:
+ case S_Release:
+ case S_MovableRelease:
+ break;
}
- // If the state at the other end of any of the successor edges
- // matches the current state, require all edges to match. This
- // guards against loops in the middle of a sequence.
- if (SomeSuccHasSame && !AllSuccsHaveSame)
- S.ClearSequenceProgress();
- break;
- }
}
+
+ // If the state at the other end of any of the successor edges
+ // matches the current state, require all edges to match. This
+ // guards against loops in the middle of a sequence.
+ if (SomeSuccHasSame && !AllSuccsHaveSame)
+ S.ClearSequenceProgress();
+ }
}
bool
projects / oota-llvm.git / blobdiff