https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86428
Martin Sebor <msebor at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |ASSIGNED Last reconfirmed| |2018-07-06 Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> --- Another test case for the same limitation: const char a[4] = "123"; const char b[4] = "123"; int f (void) { return __builtin_memcmp (a, b, 4); // folded } const char c[4] = "123\0"; // sizeof "123\0" == 5 int g (void) { return __builtin_memcmp (a, c, 4); // not folded } The solution seems simple: change the string_constant() function to avoid considering as string constants the strings of the last form, i.e., those with more initializers than fit in the array they're stored in).