/// DontDeleteUselessPHIs will keep PHIs that have one value or the same
/// value for all entries.
///
- void removePredecessor(BasicBlock *Pred, bool DontDeleteUselessPHIs = false);
+ /// OnlyDeleteOne will only remove one entry from a PHI, in case there were
+ /// duplicate entries for the Pred.
+ ///
+ void removePredecessor(BasicBlock *Pred, bool DontDeleteUselessPHIs = false,
+ bool OnlyDeleteOne = false);
/// splitBasicBlock - This splits a basic block into two at the specified
/// instruction. Note that all instructions BEFORE the specified iterator
/// called while the predecessor still refers to this block.
///
void BasicBlock::removePredecessor(BasicBlock *Pred,
- bool DontDeleteUselessPHIs) {
+ bool DontDeleteUselessPHIs,
+ bool OnlyDeleteOne) {
assert((hasNUsesOrMore(16)||// Reduce cost of this assertion for complex CFGs.
find(pred_begin(this), pred_end(this), Pred) != pred_end(this)) &&
"removePredecessor: BB is not a predecessor!");
- if (Pred == getUnwindDest())
- setUnwindDest(NULL);
-
if (InstList.empty()) return;
PHINode *APN = dyn_cast<PHINode>(&front());
if (!APN) return; // Quick exit.
// Yup, loop through and nuke the PHI nodes
while (PHINode *PN = dyn_cast<PHINode>(&front())) {
// Remove the predecessor first.
- PN->removeIncomingValue(Pred, !DontDeleteUselessPHIs);
+ if (OnlyDeleteOne) {
+ int idx = PN->getBasicBlockIndex(Pred);
+ PN->removeIncomingValue(idx, !DontDeleteUselessPHIs);
+ } else
+ PN->removeIncomingValue(Pred, !DontDeleteUselessPHIs);
// If the PHI _HAD_ two uses, replace PHI node with its now *single* value
if (max_idx == 2) {
PHINode *PN;
for (iterator II = begin(); (PN = dyn_cast<PHINode>(II)); ) {
++II;
- PN->removeIncomingValue(Pred, false);
+ if (OnlyDeleteOne) {
+ int idx = PN->getBasicBlockIndex(Pred);
+ PN->removeIncomingValue(idx, false);
+ } else
+ PN->removeIncomingValue(Pred, false);
+
// If all incoming values to the Phi are the same, we can replace the Phi
// with that value.
Value* PNV = 0;