diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils')
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopSimplify.cpp | 26 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 7 |
2 files changed, 19 insertions, 14 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp index 00cda2af00c..b60e0a150c7 100644 --- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp +++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp @@ -735,6 +735,17 @@ bool llvm::simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, bool PreserveLCSSA) { bool Changed = false; +#ifndef NDEBUG + // If we're asked to preserve LCSSA, the loop nest needs to start in LCSSA + // form. + if (PreserveLCSSA) { + assert(DT && "DT not available."); + assert(LI && "LI not available."); + assert(L->isRecursivelyLCSSAForm(*DT, *LI) && + "Requested to preserve LCSSA, but it's already broken."); + } +#endif + // Worklist maintains our depth-first queue of loops in this nest to process. SmallVector<Loop *, 4> Worklist; Worklist.push_back(L); @@ -814,15 +825,6 @@ bool LoopSimplify::runOnFunction(Function &F) { &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); bool PreserveLCSSA = mustPreserveAnalysisID(LCSSAID); -#ifndef NDEBUG - if (PreserveLCSSA) { - assert(DT && "DT not available."); - assert(LI && "LI not available."); - bool InLCSSA = all_of( - *LI, [&](Loop *L) { return L->isRecursivelyLCSSAForm(*DT, *LI); }); - assert(InLCSSA && "Requested to preserve LCSSA, but it's already broken."); - } -#endif // Simplify each loop nest in the function. for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) @@ -846,10 +848,10 @@ PreservedAnalyses LoopSimplifyPass::run(Function &F, ScalarEvolution *SE = AM.getCachedResult<ScalarEvolutionAnalysis>(F); AssumptionCache *AC = &AM.getResult<AssumptionAnalysis>(F); - // FIXME: This pass should verify that the loops on which it's operating - // are in canonical SSA form, and that the pass itself preserves this form. + // Note that we don't preserve LCSSA in the new PM, if you need it run LCSSA + // after simplifying the loops. for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) - Changed |= simplifyLoop(*I, DT, LI, SE, AC, true /* PreserveLCSSA */); + Changed |= simplifyLoop(*I, DT, LI, SE, AC, /*PreserveLCSSA*/ false); // FIXME: We need to invalidate this to avoid PR28400. Is there a better // solution? diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index 9ea4a4b6810..ea867127c56 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 { |
