bool CorrelatedValuePropagation::runOnFunction(Function &F) {
LVI = &getAnalysis<LazyValueInfo>();
- bool Changed = false;
+ bool FnChanged = false;
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
+ bool BBChanged = false;
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ) {
Instruction *II = BI++;
if (SelectInst *SI = dyn_cast<SelectInst>(II))
- Changed |= processSelect(SI);
+ BBChanged |= processSelect(SI);
else if (PHINode *P = dyn_cast<PHINode>(II))
- Changed |= processPHI(P);
+ BBChanged |= processPHI(P);
}
- SimplifyInstructionsInBlock(FI);
+ // Propagating correlated values might leave cruft around.
+ // Try to clean it up before we continue.
+ if (BBChanged)
+ SimplifyInstructionsInBlock(FI);
+
+ FnChanged |= BBChanged;
}
- return Changed;
+ return FnChanged;
}