diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index ce11e470d05..d14e8291e9e 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3950,7 +3950,7 @@ bool InstCombiner::replacedSelectWithOperand(SelectInst *SI, assert((SIOpd == 1 || SIOpd == 2) && "Invalid select operand!"); if (isChainSelectCmpBranch(SI) && Icmp->getPredicate() == ICmpInst::ICMP_EQ) { BasicBlock *Succ = SI->getParent()->getTerminator()->getSuccessor(1); - // The check for the unique predecessor is not the best that can be + // The check for the single predecessor is not the best that can be // done. But it protects efficiently against cases like when SI's // home block has two successors, Succ and Succ1, and Succ1 predecessor // of Succ. Then SI can't be replaced by SIOpd because the use that gets @@ -3958,8 +3958,10 @@ bool InstCombiner::replacedSelectWithOperand(SelectInst *SI, // guarantees that the path all uses of SI (outside SI's parent) are on // is disjoint from all other paths out of SI. But that information // is more expensive to compute, and the trade-off here is in favor - // of compile-time. - if (Succ->getUniquePredecessor() && dominatesAllUses(SI, Icmp, Succ)) { + // of compile-time. It should also be noticed that we check for a single + // predecessor and not only uniqueness. This to handle the situation when + // Succ and Succ1 points to the same basic block. + if (Succ->getSinglePredecessor() && dominatesAllUses(SI, Icmp, Succ)) { NumSel++; SI->replaceUsesOutsideBlock(SI->getOperand(SIOpd), SI->getParent()); return true; |
