diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index ad4c388e406..3999989ec89 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -221,6 +221,12 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, // Are we eliminating the loop control altogether? bool CompletelyUnroll = Count == TripCount; + SmallVector<BasicBlock *, 4> ExitBlocks; + L->getExitBlocks(ExitBlocks); + Loop *ParentL = L->getParentLoop(); + bool AllExitsAreInsideParentLoop = !ParentL || + std::all_of(ExitBlocks.begin(), ExitBlocks.end(), + [&](BasicBlock *BB) { return ParentL->contains(BB); }); // We assume a run-time trip count if the compiler cannot // figure out the loop trip count and the unroll-runtime @@ -554,7 +560,11 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, while (OuterL->getParentLoop() != LatchLoop) OuterL = OuterL->getParentLoop(); - formLCSSARecursively(*OuterL, *DT, LI, SE); + if (CompletelyUnroll && !AllExitsAreInsideParentLoop) + formLCSSARecursively(*OuterL, *DT, LI, SE); + else + assert(OuterL->isLCSSAForm(*DT) && + "Loops should be in LCSSA form after loop-unroll."); } } |
