diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/LoopUnroll.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index b0c622b..0a530f5 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -310,6 +310,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, unsigned TripMultiple; unsigned BreakoutTrip; bool ExitOnTrue; + bool InvariantExit; SmallVector<BasicBlock *> ExitingBlocks; }; DenseMap<BasicBlock *, ExitInfo> ExitInfos; @@ -333,6 +334,8 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, (unsigned)GreatestCommonDivisor64(ULO.Count, Info.TripMultiple); } Info.ExitOnTrue = !L->contains(BI->getSuccessor(0)); + Info.InvariantExit = L->isLoopInvariant(BI->getCondition()) && + DT->dominates(ExitingBlock, LatchBlock); Info.ExitingBlocks.push_back(ExitingBlock); LLVM_DEBUG(dbgs() << " Exiting block %" << ExitingBlock->getName() << ": TripCount=" << Info.TripCount @@ -685,6 +688,8 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, auto WillExit = [&](const ExitInfo &Info, unsigned i, unsigned j, bool IsLatch) -> Optional<bool> { + if (Info.InvariantExit && i != 0) + return false; if (CompletelyUnroll) { if (PreserveOnlyFirst) { if (i == 0) |