diff options
Diffstat (limited to 'lib/Transforms/Utils/Local.cpp')
-rw-r--r-- | lib/Transforms/Utils/Local.cpp | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 0046945485..b1dd733ffe 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -536,9 +536,9 @@ static bool CanPropagatePredecessorsForPHIs(BasicBlock *BB, BasicBlock *Succ) { /// TryToSimplifyUncondBranchFromEmptyBlock - BB is known to contain an /// unconditional branch, and contains no instructions other than PHI nodes, -/// potential side-effect free intrinsics and the branch. If possible, -/// eliminate BB by rewriting all the predecessors to branch to the successor -/// block and return true. If we can't transform, return false. +/// potential debug intrinsics and the branch. If possible, eliminate BB by +/// rewriting all the predecessors to branch to the successor block and return +/// true. If we can't transform, return false. bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) { assert(BB != &BB->getParent()->getEntryBlock() && "TryToSimplifyUncondBranchFromEmptyBlock called on entry block!"); @@ -613,15 +613,13 @@ bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) { } } - if (Succ->getSinglePredecessor()) { - // BB is the only predecessor of Succ, so Succ will end up with exactly - // the same predecessors BB had. - - // Copy over any phi, debug or lifetime instruction. - BB->getTerminator()->eraseFromParent(); - Succ->getInstList().splice(Succ->begin(), BB->getInstList()); - } else { - while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) { + while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) { + if (Succ->getSinglePredecessor()) { + // BB is the only predecessor of Succ, so Succ will end up with exactly + // the same predecessors BB had. + Succ->getInstList().splice(Succ->begin(), + BB->getInstList(), BB->begin()); + } else { // We explicitly check for such uses in CanPropagatePredecessorsForPHIs. assert(PN->use_empty() && "There shouldn't be any uses here!"); PN->eraseFromParent(); |