// Move all PHI nodes in BB to Succ if they are alive, otherwise
// delete them.
- while (PHINode *PN = dyn_cast<PHINode>(&BB->front()))
+ while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
if (PN->use_empty()) {
// Just remove the dead phi. This happens if Succ's PHIs were the only
// users of the PHI nodes.
PN->eraseFromParent();
- } else {
- // The instruction is alive, so this means that BB must dominate all
- // predecessors of Succ (Since all uses of the PN are after its
- // definition, so in Succ or a block dominated by Succ. If a predecessor
- // of Succ would not be dominated by BB, PN would violate the def before
- // use SSA demand). Therefore, we can simply move the phi node to the
- // next block.
- Succ->getInstList().splice(Succ->begin(),
- BB->getInstList(), BB->begin());
-
- // We need to add new entries for the PHI node to account for
- // predecessors of Succ that the PHI node does not take into
- // account. At this point, since we know that BB dominated succ and all
- // of its predecessors, this means that we should any newly added
- // incoming edges should use the PHI node itself as the value for these
- // edges, because they are loop back edges.
- for (unsigned i = 0, e = OldSuccPreds.size(); i != e; ++i)
- if (OldSuccPreds[i] != BB)
- PN->addIncoming(PN, OldSuccPreds[i]);
+ continue;
}
+
+ // The instruction is alive, so this means that BB must dominate all
+ // predecessors of Succ (Since all uses of the PN are after its
+ // definition, so in Succ or a block dominated by Succ. If a predecessor
+ // of Succ would not be dominated by BB, PN would violate the def before
+ // use SSA demand). Therefore, we can simply move the phi node to the
+ // next block.
+ Succ->getInstList().splice(Succ->begin(),
+ BB->getInstList(), BB->begin());
+
+ // We need to add new entries for the PHI node to account for
+ // predecessors of Succ that the PHI node does not take into
+ // account. At this point, since we know that BB dominated succ and all
+ // of its predecessors, this means that we should any newly added
+ // incoming edges should use the PHI node itself as the value for these
+ // edges, because they are loop back edges.
+ for (unsigned i = 0, e = OldSuccPreds.size(); i != e; ++i)
+ if (OldSuccPreds[i] != BB)
+ PN->addIncoming(PN, OldSuccPreds[i]);
+ }
}
// Everything that jumped to BB now goes to Succ.