diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LICM.cpp | 71 |
1 files changed, 36 insertions, 35 deletions
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp index 79dc103a774..4c05f42fe0e 100644 --- a/llvm/lib/Transforms/Scalar/LICM.cpp +++ b/llvm/lib/Transforms/Scalar/LICM.cpp @@ -256,27 +256,42 @@ bool LoopInvariantCodeMotion::runOnLoop(Loop *L, AliasAnalysis *AA, // preheader for SSA updater, so also avoid sinking when no preheader // is available. if (!DisablePromotion && Preheader && L->hasDedicatedExits()) { + // Figure out the loop exits and their insertion points SmallVector<BasicBlock *, 8> ExitBlocks; - SmallVector<Instruction *, 8> InsertPts; - PredIteratorCache PIC; - - bool Promoted = false; - - // Loop over all of the alias sets in the tracker object. - for (AliasSet &AS : *CurAST) - Promoted |= promoteLoopAccessesToScalars( - AS, ExitBlocks, InsertPts, PIC, LI, DT, TLI, L, CurAST, &SafetyInfo); - - // Once we have promoted values across the loop body we have to recursively - // reform LCSSA as any nested loop may now have values defined within the - // loop used in the outer loop. - // FIXME: This is really heavy handed. It would be a bit better to use an - // SSAUpdater strategy during promotion that was LCSSA aware and reformed - // it as it went. - if (Promoted) - formLCSSARecursively(*L, *DT, LI, SE); - - Changed |= Promoted; + L->getUniqueExitBlocks(ExitBlocks); + + // We can't insert into a catchswitch. + bool HasCatchSwitch = llvm::any_of(ExitBlocks, [](BasicBlock *Exit) { + return isa<CatchSwitchInst>(Exit->getTerminator()); + }); + + if (!HasCatchSwitch) { + SmallVector<Instruction *, 8> InsertPts; + InsertPts.reserve(ExitBlocks.size()); + for (BasicBlock *ExitBlock : ExitBlocks) + InsertPts.push_back(&*ExitBlock->getFirstInsertionPt()); + + PredIteratorCache PIC; + + bool Promoted = false; + + // Loop over all of the alias sets in the tracker object. + for (AliasSet &AS : *CurAST) + Promoted |= + promoteLoopAccessesToScalars(AS, ExitBlocks, InsertPts, PIC, LI, DT, + TLI, L, CurAST, &SafetyInfo); + + // Once we have promoted values across the loop body we have to + // recursively reform LCSSA as any nested loop may now have values defined + // within the loop used in the outer loop. + // FIXME: This is really heavy handed. It would be a bit better to use an + // SSAUpdater strategy during promotion that was LCSSA aware and reformed + // it as it went. + if (Promoted) + formLCSSARecursively(*L, *DT, LI, SE); + + Changed |= Promoted; + } } // Check that neither this loop nor its parent have had LCSSA broken. LICM is @@ -1016,24 +1031,10 @@ bool llvm::promoteLoopAccessesToScalars( PromotionIsLegal = isAllocLikeFn(Object, TLI) && !PointerMayBeCaptured(Object, true, true); } + if (!PromotionIsLegal) return Changed; - // Figure out the loop exits and their insertion points, if this is the - // first promotion. - if (ExitBlocks.empty()) { - CurLoop->getUniqueExitBlocks(ExitBlocks); - InsertPts.clear(); - InsertPts.reserve(ExitBlocks.size()); - for (BasicBlock *ExitBlock : ExitBlocks) - InsertPts.push_back(&*ExitBlock->getFirstInsertionPt()); - } - - // Can't insert into a catchswitch. - for (BasicBlock *ExitBlock : ExitBlocks) - if (isa<CatchSwitchInst>(ExitBlock->getTerminator())) - return Changed; - // Otherwise, this is safe to promote, lets do it! DEBUG(dbgs() << "LICM: Promoting value stored to in loop: " << *SomePtr << '\n'); |
