| #include <stdio.h> | |
| #include <stdint.h> | |
| struct X { | |
| unsigned char pad : 4; | |
| uint64_t a : 64; | |
| uint64_t b : 60; | |
| } __attribute__((packed)); | |
| int main (void) | |
| { | |
| struct X x; | |
| uint64_t bad_bits; | |
| x.pad = 255; | |
| x.a = -1ULL; | |
| x.b = -1ULL; | |
| bad_bits = ((uint64_t)-1ULL) ^ *(1+(uint64_t *) &x); | |
| printf("bad bits: %llx\n", bad_bits); | |
| return bad_bits != 0; | |
| } |