Well, that's what I did. Why should I think (or how should I realize) that it's bad? ... P.S. it occurs to me after a few minutes that I'm testing and choosing every time qsort_r calls cmp and not just the one time. If that's the only reason, I guess it's bad enough.

I chose not to put the comparison there because, by doing that, it executes that instruction on every loop iteration, which immensely slows down the total run time. Although there are 2 more lines of code, the actualy number of times that comparison is made is much, much less.

Well, I was aiming for "horrendous" so mission accomplished ;-)