https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85420
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Franz Sirl from comment #3) > Hmm, this maybe creduce'd too much, the original source reads more like > > strcpy(b, b + a + 10); > > which would be only UB for sure if strlen(b + a + 10) >= 9, or? If b was actually a larger array, then yes, otherwise even b + 10 would be UB.