+ if (PHINode *UsePhi = dyn_cast<PHINode>(DU.NarrowUse)) {
+ if (LI->getLoopFor(UsePhi->getParent()) != L) {
+ // For LCSSA phis, sink the truncate outside the loop.
+ // After SimplifyCFG most loop exit targets have a single predecessor.
+ // Otherwise fall back to a truncate within the loop.
+ if (UsePhi->getNumOperands() != 1)
+ truncateIVUse(DU, DT);
+ else {
+ PHINode *WidePhi =
+ PHINode::Create(DU.WideDef->getType(), 1, UsePhi->getName() + ".wide",
+ UsePhi);
+ WidePhi->addIncoming(DU.WideDef, UsePhi->getIncomingBlock(0));
+ IRBuilder<> Builder(WidePhi->getParent()->getFirstInsertionPt());
+ Value *Trunc = Builder.CreateTrunc(WidePhi, DU.NarrowDef->getType());
+ UsePhi->replaceAllUsesWith(Trunc);
+ DeadInsts.push_back(UsePhi);
+ DEBUG(dbgs() << "INDVARS: Widen lcssa phi " << *UsePhi
+ << " to " << *WidePhi << "\n");
+ }
+ return 0;
+ }
+ }