//
// FIXME: this needs to eliminate an induction variable even if it's being
// compared against some value to decide loop termination.
- if (PN->hasOneUse()) {
- SmallPtrSet<PHINode *, 2> PHIs;
- for (Instruction *J = dyn_cast<Instruction>(*PN->use_begin());
- J && J->hasOneUse() && !J->mayWriteToMemory();
- J = dyn_cast<Instruction>(*J->use_begin())) {
- // If we find the original PHI, we've discovered a cycle.
- if (J == PN) {
- // Break the cycle and mark the PHI for deletion.
- SE->deleteValueFromRecords(PN);
- PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
- DeadInsts.insert(PN);
- Changed = true;
- break;
- }
- // If we find a PHI more than once, we're on a cycle that
- // won't prove fruitful.
- if (isa<PHINode>(J) && !PHIs.insert(cast<PHINode>(J)))
- break;
+ if (!PN->hasOneUse())
+ continue;
+
+ SmallPtrSet<PHINode *, 4> PHIs;
+ for (Instruction *J = dyn_cast<Instruction>(*PN->use_begin());
+ J && J->hasOneUse() && !J->mayWriteToMemory();
+ J = dyn_cast<Instruction>(*J->use_begin())) {
+ // If we find the original PHI, we've discovered a cycle.
+ if (J == PN) {
+ // Break the cycle and mark the PHI for deletion.
+ SE->deleteValueFromRecords(PN);
+ PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
+ DeadInsts.insert(PN);
+ Changed = true;
+ break;
}
+ // If we find a PHI more than once, we're on a cycle that
+ // won't prove fruitful.
+ if (isa<PHINode>(J) && !PHIs.insert(cast<PHINode>(J)))
+ break;
}
}
DeleteTriviallyDeadInstructions(DeadInsts);