diff options
Diffstat (limited to 'lib/VMCore/BasicBlock.cpp')
| -rw-r--r-- | lib/VMCore/BasicBlock.cpp | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp index 49bd8cf7be..95eab23edf 100644 --- a/lib/VMCore/BasicBlock.cpp +++ b/lib/VMCore/BasicBlock.cpp @@ -12,7 +12,7 @@ //===----------------------------------------------------------------------===// #include "llvm/BasicBlock.h" -#include "llvm/Constant.h" +#include "llvm/Constants.h" #include "llvm/Instructions.h" #include "llvm/Type.h" #include "llvm/Support/CFG.h" @@ -134,7 +134,8 @@ BasicBlock *BasicBlock::getSinglePredecessor() { // update the PHI nodes that reside in the block. Note that this should be // called while the predecessor still refers to this block. // -void BasicBlock::removePredecessor(BasicBlock *Pred) { +void BasicBlock::removePredecessor(BasicBlock *Pred, + bool DontDeleteUselessPHIs) { 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!"); @@ -164,10 +165,12 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { if (this == Other) max_idx = 3; } - if (max_idx <= 2) { // <= Two predecessors BEFORE I remove one? + // <= Two predecessors BEFORE I remove one? + if (max_idx <= 2 && !DontDeleteUselessPHIs) { // Yup, loop through and nuke the PHI nodes while (PHINode *PN = dyn_cast<PHINode>(&front())) { - PN->removeIncomingValue(Pred); // Remove the predecessor first... + // Remove the predecessor first. + PN->removeIncomingValue(Pred, !DontDeleteUselessPHIs); // If the PHI _HAD_ two uses, replace PHI node with its now *single* value if (max_idx == 2) { @@ -175,7 +178,7 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { PN->replaceAllUsesWith(PN->getOperand(0)); else // We are left with an infinite loop with no entries: kill the PHI. - PN->replaceAllUsesWith(Constant::getNullValue(PN->getType())); + PN->replaceAllUsesWith(UndefValue::get(PN->getType())); getInstList().pop_front(); // Remove the PHI node } @@ -187,7 +190,7 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { // PHI nodes. Iterate over each PHI node fixing them up PHINode *PN; for (iterator II = begin(); (PN = dyn_cast<PHINode>(II)); ++II) - PN->removeIncomingValue(Pred); + PN->removeIncomingValue(Pred, false); } } |