https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118572
--- Comment #3 from Sam James <sjames at gcc dot gnu.org> --- ``` __attribute__((noipa)) int test(char c) { return (((0x80 & (c&0xff)) != 0) && ((0xc0 & (c&0xff)) == 0x80)); } int main() { if (test(0x80) == 0) __builtin_abort(); } ```