diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/Local.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/Local.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index a42ef0c..baec51a 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -1019,12 +1019,14 @@ CanRedirectPredsOfEmptyBBToSucc(BasicBlock *BB, BasicBlock *Succ, const SmallPtrSetImpl<BasicBlock *> &SuccPreds, BasicBlock *&CommonPred) { - // There must be phis in BB, otherwise BB will be merged into Succ directly - if (BB->phis().empty() || Succ->phis().empty()) + // When Succ has no phis, BB may be merged into Succ directly. We don't need + // to redirect the predecessors of BB in this case. + if (Succ->phis().empty()) return false; - // BB must have predecessors not shared that can be redirected to Succ - if (!BB->hasNPredecessorsOrMore(2)) + // BB must have multiple different predecessors, so that at least one of + // predecessors can be redirected to Succ, except the common predecessor. + if (BB->getUniquePredecessor() || pred_empty(BB)) return false; // Get single common predecessors of both BB and Succ |