diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp b/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp index 524b268..bf882d7 100644 --- a/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp @@ -465,10 +465,6 @@ static bool canProfitablyRuntimeUnrollMultiExitLoop( Loop *L, SmallVectorImpl<BasicBlock *> &OtherExits, BasicBlock *LatchExit, bool UseEpilogRemainder) { - // Priority goes to UnrollRuntimeMultiExit if it's supplied. - if (UnrollRuntimeMultiExit.getNumOccurrences()) - return UnrollRuntimeMultiExit; - // The main pain point with multi-exit loop unrolling is that once unrolled, // we will not be able to merge all blocks into a straight line code. // There are branches within the unrolled loop that go to the OtherExits. @@ -633,14 +629,20 @@ bool llvm::UnrollRuntimeLoopRemainder( if (!PreserveLCSSA) return false; - if (!RuntimeUnrollMultiExit && - !canProfitablyRuntimeUnrollMultiExitLoop(L, OtherExits, LatchExit, - UseEpilogRemainder)) { - LLVM_DEBUG( - dbgs() - << "Multiple exit/exiting blocks in loop and multi-exit unrolling not " - "enabled!\n"); - return false; + // Priority goes to UnrollRuntimeMultiExit if it's supplied. + if (UnrollRuntimeMultiExit.getNumOccurrences()) { + if (!UnrollRuntimeMultiExit) + return false; + } else { + // Otherwise perform multi-exit unrolling, if either the target indicates + // it is profitable or the general profitability heuristics apply. + if (!RuntimeUnrollMultiExit && + !canProfitablyRuntimeUnrollMultiExitLoop(L, OtherExits, LatchExit, + UseEpilogRemainder)) { + LLVM_DEBUG(dbgs() << "Multiple exit/exiting blocks in loop and " + "multi-exit unrolling not enabled!\n"); + return false; + } } } // Use Scalar Evolution to compute the trip count. This allows more loops to |