https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117682
--- Comment #3 from Robin Dapp <rdapp at gcc dot gnu.org> --- The issue is in the way we construct an interleaved VLA const pattern. For efficiency we try to use a larger element width, here 16 bits, to initialize two values in one. I believe this doesn't go along well with -fwrapv but need to see where exactly we take a wrong turn.