diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp index c3761dcf4e8..fa6214f89f0 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -639,6 +639,16 @@ static bool tryToUnrollLoop(Loop *L, DominatorTree &DT, LoopInfo *LI, Count = (std::max(UP.PartialThreshold, 3u) - 2) / (LoopSize - 2); while (Count != 0 && TripCount % Count != 0) Count--; + if (Count <= 1) { + // If there is no Count that is modulo of TripCount, set Count to + // largest power-of-two factor that satisfies the threshold limit. + Count = (std::max(UP.PartialThreshold, 3u) - 2) / (LoopSize - 2); + UnrolledSize = (LoopSize - 2) * Count + 2; + while (Count != 0 && UnrolledSize > UP.PartialThreshold) { + Count >>= 1; + UnrolledSize = (LoopSize - 2) * Count + 2; + } + } } } else if (Unrolling == Runtime) { if (!AllowRuntime && !CountSetExplicitly) { |
