| 1 | |
| 2 | #ifdef __GNUC__ |
| 3 | # define likely(x) __builtin_expect((x),1) |
| 4 | # define unlikely(x) __builtin_expect((x),0) |
| 5 | # ifdef __clang__ |
| 6 | # define noinline __attribute__((noinline)) |
| 7 | # else |
| 8 | # define noinline __attribute__((noinline,noclone)) |
| 9 | # endif |
| 10 | # define unused __attribute__((unused)) |
| 11 | #else |
| 12 | # define likely(x) (x) |
| 13 | # define unlikely(x) (x) |
| 14 | # define noinline |
| 15 | # define unused |
| 16 | #endif |
| 17 | |
| 18 | #ifndef __has_builtin |
| 19 | #define __has_builtin(x) 0 |
| 20 | #endif |
| 21 | |
| 22 | #if __has_builtin(__builtin_add_overflow) || (defined(__GNUC__) && __GNUC__ >= 5) |
| 23 | #define add_overflow(a, b, r) __builtin_add_overflow(a, b, &(r)) |
| 24 | #define sub_overflow(a, b, r) __builtin_sub_overflow(a, b, &(r)) |
| 25 | #else |
| 26 | #define add_overflow(a, b, r) ({r = (u32)a + (u32)b; (a ^ ~b) & (a ^ r) & (1u<<31);}) |
| 27 | #define sub_overflow(a, b, r) ({r = (u32)a - (u32)b; (a ^ b) & (a ^ r) & (1u<<31);}) |
| 28 | #endif |
| 29 | |