LCSSA() : LoopPass(&ID) {}
// Cached analysis information for the current function.
- LoopInfo *LI;
DominatorTree *DT;
std::vector<BasicBlock*> LoopBlocks;
PredIteratorCache PredCache;
///
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
+
+ // LCSSA doesn't actually require LoopSimplify, but the PassManager
+ // doesn't know how to schedule LoopSimplify by itself.
AU.addRequiredID(LoopSimplifyID);
AU.addPreservedID(LoopSimplifyID);
AU.addRequiredTransitive<LoopInfo>();
bool LCSSA::runOnLoop(Loop *TheLoop, LPPassManager &LPM) {
L = TheLoop;
- LI = &LPM.getAnalysis<LoopInfo>();
DT = &getAnalysis<DominatorTree>();
// Get the set of exiting blocks.
SSAUpdate.Initialize(Inst);
// Insert the LCSSA phi's into all of the exit blocks dominated by the
- // value., and add them to the Phi's map.
+ // value, and add them to the Phi's map.
for (SmallVectorImpl<BasicBlock*>::const_iterator BBI = ExitBlocks.begin(),
BBE = ExitBlocks.end(); BBI != BBE; ++BBI) {
BasicBlock *ExitBB = *BBI;
PN->reserveOperandSpace(PredCache.GetNumPreds(ExitBB));
// Add inputs from inside the loop for this PHI.
- for (BasicBlock **PI = PredCache.GetPreds(ExitBB); *PI; ++PI)
+ for (BasicBlock **PI = PredCache.GetPreds(ExitBB); *PI; ++PI) {
PN->addIncoming(Inst, *PI);
+
+ // If the exit block has a predecessor not within the loop, arrange for
+ // the incoming value use corresponding to that predecessor to be
+ // rewritten in terms of a different LCSSA PHI.
+ if (!inLoop(*PI))
+ UsesToRewrite.push_back(
+ &PN->getOperandUse(
+ PN->getOperandNumForIncomingValue(PN->getNumIncomingValues()-1)));
+ }
// Remember that this phi makes the value alive in this block.
SSAUpdate.AddAvailableValue(ExitBB, PN);