diff options
Diffstat (limited to 'llvm/lib/CodeGen/CodeGenPrepare.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/CodeGenPrepare.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index 1e04f7918ee..14f56279e85 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -655,6 +655,16 @@ bool CodeGenPrepare::isMergingEmptyBlockProfitable(BasicBlock *BB, BB->getSinglePredecessor()->getSingleSuccessor())) return false; + // Skip merging if the block's successor is also a successor to any callbr + // that leads to this block. + // FIXME: Is this really needed? Is this a correctness issue? + for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) { + if (auto *CBI = dyn_cast<CallBrInst>((*PI)->getTerminator())) + for (unsigned i = 0, e = CBI->getNumSuccessors(); i != e; ++i) + if (DestBB == CBI->getSuccessor(i)) + return false; + } + // Try to skip merging if the unique predecessor of BB is terminated by a // switch or indirect branch instruction, and BB is used as an incoming block // of PHIs in DestBB. In such case, merging BB and DestBB would cause ISel to |
