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| author | Reid Kleckner <reid@kleckner.net> | 2009-09-30 20:15:38 +0000 |
|---|---|---|
| committer | Reid Kleckner <reid@kleckner.net> | 2009-09-30 20:15:38 +0000 |
| commit | c277ab08a24d2dbe9b4ff1a9154ea6115ed6a4e3 (patch) | |
| tree | 961f33a75eced084518a387d00095b6a98782d25 /lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp | |
| parent | 69cc57c3259249cd9e64735ba79da2ce0e64a4b5 (diff) | |
Fix integer overflow in instruction scheduling. This can happen if we have
basic blocks that are so long that their size overflows a short.
Also assert that overflow does not happen in the future, as requested by Evan.
This fixes PR4401.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83159 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp index d1930b1a2c..7eac4d81bb 100644 --- a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp +++ b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp @@ -134,17 +134,17 @@ void ScheduleDAGFast::Schedule() { /// the AvailableQueue if the count reaches zero. Also update its cycle bound. void ScheduleDAGFast::ReleasePred(SUnit *SU, SDep *PredEdge) { SUnit *PredSU = PredEdge->getSUnit(); - --PredSU->NumSuccsLeft; - + #ifndef NDEBUG - if (PredSU->NumSuccsLeft < 0) { + if (PredSU->NumSuccsLeft == 0) { errs() << "*** Scheduling failed! ***\n"; PredSU->dump(this); errs() << " has been released too many times!\n"; llvm_unreachable(0); } #endif - + --PredSU->NumSuccsLeft; + // If all the node's successors are scheduled, this node is ready // to be scheduled. Ignore the special EntrySU node. if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU) { |