https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89223
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> --- The chrec in question is {8, +, 0xfffffffffffffffffffffffffffffffe}_1 which wraps. The dependence code basically assumes infinite precision integers (which we don't have) and thus cannot really handle the case of wrapping IVs.