diff options
Diffstat (limited to 'libblake_blake2s_force_update.c')
| -rw-r--r-- | libblake_blake2s_force_update.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/libblake_blake2s_force_update.c b/libblake_blake2s_force_update.c index 925d381..5330ab2 100644 --- a/libblake_blake2s_force_update.c +++ b/libblake_blake2s_force_update.c @@ -8,6 +8,24 @@ libblake_blake2s_force_update(struct libblake_blake2s_state *state, const void * size_t off = 0; for (; len - off >= 64; off += 64) { + /* The following optimisations have been tested: + * + * 1) + * `*(uint64_t *)state->t += 64;` + * result: slower + * + * 2) + * using `__builtin_add_overflow` + * result: no difference + * + * These testes where preformed on amd64 with a compile-time + * assumption that `UINT_LEAST32_C(0xFFFFffff) + 1 == 0`, + * which the compiler accepted and those included the attempted + * optimisations. + * + * UNLIKELY does not seem to make any difference, but it + * does change the output, theoretically of the better. + */ state->t[0] = (state->t[0] + 64) & UINT_LEAST32_C(0xFFFFffff); if (state->t[0] < 64) state->t[1] = (state->t[1] + 1) & UINT_LEAST32_C(0xFFFFffff); |