diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/LoopUnroll.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index 9ea4a4b..ea86712 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -750,7 +750,10 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force, // loops too). // TODO: That potentially might be compile-time expensive. We should try // to fix the loop-simplified form incrementally. - simplifyLoop(OuterL, DT, LI, SE, AC, PreserveLCSSA); + // Note that we only preserve LCSSA at this stage if we need to and if we + // won't end up fixing it. If we end up fixing it anyways, we don't need + // to preserve it here and in fact we can't because it isn't correct. + simplifyLoop(OuterL, DT, LI, SE, AC, PreserveLCSSA && !NeedToFixLCSSA); // LCSSA must be performed on the outermost affected loop. The unrolled // loop's last loop latch is guaranteed to be in the outermost loop after @@ -762,7 +765,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force, if (NeedToFixLCSSA) formLCSSARecursively(*OuterL, *DT, LI, SE); - else + else if (PreserveLCSSA) assert(OuterL->isLCSSAForm(*DT) && "Loops should be in LCSSA form after loop-unroll."); } else { |