diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 5dc9d2c3b71..389ec419b5c 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -2982,6 +2982,21 @@ static bool mergeConditionalStoreToAddress(BasicBlock *PTB, BasicBlock *PFB, if (&*I != PStore && I->mayReadOrWriteMemory()) return false; + // If PostBB has more than two predecessors, we need to split it so we can + // sink the store. + if (std::next(pred_begin(PostBB), 2) != pred_end(PostBB)) { + // We know that QFB's only successor is PostBB. And QFB has a single + // predecessor. If QTB exists, then its only successor is also PostBB. + // If QTB does not exist, then QFB's only predecessor has a conditional + // branch to QFB and PostBB. + BasicBlock *TruePred = QTB ? QTB : QFB->getSinglePredecessor(); + BasicBlock *NewBB = SplitBlockPredecessors(PostBB, { QFB, TruePred}, + "condstore.split"); + if (!NewBB) + return false; + PostBB = NewBB; + } + // OK, we're going to sink the stores to PostBB. The store has to be // conditional though, so first create the predicate. Value *PCond = cast<BranchInst>(PFB->getSinglePredecessor()->getTerminator()) @@ -3117,7 +3132,7 @@ static bool mergeConditionalStores(BranchInst *PBI, BranchInst *QBI, if ((PTB && !HasOnePredAndOneSucc(PTB, PBI->getParent(), QBI->getParent())) || (QTB && !HasOnePredAndOneSucc(QTB, QBI->getParent(), PostBB))) return false; - if (!PostBB->hasNUses(2) || !QBI->getParent()->hasNUses(2)) + if (!QBI->getParent()->hasNUses(2)) return false; // OK, this is a sequence of two diamonds or triangles. |
