Spill store without spill load

I have a kernel which when forced to a certain number of registers reports “8 bytes stack frame, 4 bytes spill stores, 0 bytes spill loads”. I’m a bit confused by this. Surely if there are no spill loads then there is no need to store anything? I’ve used cuobjdump and I can’t actually see any sign of the spill store (assuming I’m looking for an LST).