INV DSZ in its natural habitat

[BruceH]

I assume these two statements are used to implement the following types of loop (expressed in C syntax), in which case both have their place.

Code:

/* DSZ */
do {
...
} while (--x != 0)

whereas

Code:

/* INV DSZ (or DSNZ) */
while (--x != 0) {
...
}