LoopUnroll: only allow non-modulo Partial unrolling when Runtime=true
Patch by Evgeny Stupachenko <evstupac@gmail.com>.
llvm-svn: 265558
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index fa6214f..e5a9513 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -639,10 +639,12 @@
Count = (std::max(UP.PartialThreshold, 3u) - 2) / (LoopSize - 2);
while (Count != 0 && TripCount % Count != 0)
Count--;
- if (Count <= 1) {
+ if (AllowRuntime && 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);
+ // As we'll create fixup loop, do the type of unrolling only if
+ // runtime unrolling is allowed.
+ Count = DefaultUnrollRuntimeCount;
UnrolledSize = (LoopSize - 2) * Count + 2;
while (Count != 0 && UnrolledSize > UP.PartialThreshold) {
Count >>= 1;