https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68000
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |INVALID Status|UNCONFIRMED |RESOLVED --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- So take: p->x + 1 == p->y If p->x == 255 and p->y == 0. The above will be false due to C integer promotion rules. The other two testcases have the case where p->x == 255 and p->y == 0 will be true. Basically foo is not the same as the other two.