https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61743
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- We fail to determine an upper bound on the number of iterations for those loops. With 4.9 I only see one loop completely unrolled, that at t.c:20. 4.8 doesn't unroll any loop either. 4.9 seems to conclude that by Statement *pretmp_81[j_51] = _39; is probably executed at most 7 (bounded by 7) + 1 times in loop 4. which also is seen on trunk. It would be interesting to know what makes us decide otherwise in the end (can you bisect this?)
