/// Get the single stack slot we can deshadow, or null if no such slot was
/// found.
AllocStackInst *getDeshadowableSlot() {
if (Failed)
return nullptr;
// We must have seen both a store to and a load from the slot to deshadow
// on every exit BB.
if (!HaveEntrySlot) {
DEBUG(llvm::dbgs() << "*** Rejecting deshadow: no store to stack slot\n");
return nullptr;
}
if (!ExitBBs.empty()) {
DEBUG(llvm::dbgs() << "*** Rejecting deshadow: no load from stack slot "
"on some paths\n");
return nullptr;
}
return TheSlot;
}
