diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/MergeICmps.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/MergeICmps.cpp | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Scalar/MergeICmps.cpp b/llvm/lib/Transforms/Scalar/MergeICmps.cpp index 2275a0b5b89..7730162bfa4 100644 --- a/llvm/lib/Transforms/Scalar/MergeICmps.cpp +++ b/llvm/lib/Transforms/Scalar/MergeICmps.cpp @@ -291,8 +291,8 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi) if (Comparison.doesOtherWork()) { DEBUG(dbgs() << "block '" << Comparison.BB->getName() << "' does extra work besides compare\n"); - if (BlockIdx == 0) { // First block. - // TODO(courbet): The first block can do other things, and we should + if (Comparisons.empty()) { + // TODO(courbet): The initial block can do other things, and we should // split them apart in a separate block before the comparison chain. // Right now we just discard it and make the chain shorter. DEBUG(dbgs() @@ -333,7 +333,12 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi) DEBUG(dbgs() << "\n"); Comparisons.push_back(Comparison); } - assert(!Comparisons.empty() && "chain with no BCE basic blocks"); + + // It is possible we have no suitable comparison to merge. + if (Comparisons.empty()) { + DEBUG(dbgs() << "chain with no BCE basic blocks, no merge\n"); + return; + } EntryBlock_ = Comparisons[0].BB; Comparisons_ = std::move(Comparisons); #ifdef MERGEICMPS_DOT_ON |
