diff options
Diffstat (limited to 'lib/Transforms/Scalar/JumpThreading.cpp')
-rw-r--r-- | lib/Transforms/Scalar/JumpThreading.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index 3d218a6585..90094a8da2 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -606,6 +606,16 @@ static unsigned GetBestDestForJumpOnUndef(BasicBlock *BB) { return MinSucc; } +static bool hasAddressTakenAndUsed(BasicBlock *BB) { + if (!BB->hasAddressTaken()) return false; + + // If the block has its address taken, it may be a tree of dead constants + // hanging off of it. These shouldn't keep the block alive. + BlockAddress *BA = BlockAddress::get(BB); + BA->removeDeadConstantUsers(); + return !BA->use_empty(); +} + /// ProcessBlock - If there are any predecessors whose control can be threaded /// through to a successor, transform them now. bool JumpThreading::ProcessBlock(BasicBlock *BB) { @@ -621,7 +631,7 @@ bool JumpThreading::ProcessBlock(BasicBlock *BB) { // predecessors of our predecessor block. if (BasicBlock *SinglePred = BB->getSinglePredecessor()) { if (SinglePred->getTerminator()->getNumSuccessors() == 1 && - SinglePred != BB) { + SinglePred != BB && !hasAddressTakenAndUsed(BB)) { // If SinglePred was a loop header, BB becomes one. if (LoopHeaders.erase(SinglePred)) LoopHeaders.insert(BB); |