The IfConverter::MergeBlocks method appears to be used only to merge a basic

block with its unique predecessor.  Change the code to assert if that is not
the case, instead of trying to handle situations where the block has
multiple predecessors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71744 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2009-05-13 23:54:13 +00:00
parent 2afb3b7251
commit df1ed67890

View File

@ -1187,15 +1187,10 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI) {
ToBBI.BB->splice(ToBBI.BB->end(),
FromBBI.BB, FromBBI.BB->begin(), FromBBI.BB->end());
// Redirect all branches to FromBB to ToBB.
std::vector<MachineBasicBlock *> Preds(FromBBI.BB->pred_begin(),
FromBBI.BB->pred_end());
for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
MachineBasicBlock *Pred = Preds[i];
if (Pred == ToBBI.BB)
continue;
Pred->ReplaceUsesOfBlockWith(FromBBI.BB, ToBBI.BB);
}
// This only works when FromBBI has no predecessors except ToBBI.
assert(FromBBI.BB->pred_size() == 1 &&
*FromBBI.BB->pred_begin() == ToBBI.BB &&
"if-converter not merging block into its unique predecessor");
std::vector<MachineBasicBlock *> Succs(FromBBI.BB->succ_begin(),
FromBBI.BB->succ_end());