tls: P256: remove redundant zeroing in sp_256_map_8

Previous change made it obvious that we zero out already-zeroed high bits

function                                             old     new   delta
sp_256_ecc_mulmod_8                                  534     494     -40

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-11-27 15:50:40 +01:00
parent 4415f7bc06
commit 8cbb70365f

View File

@ -1062,7 +1062,6 @@ static void sp_256_map_8(sp_point* r, sp_point* p)
/* x /= z^2 */
sp_256to512z_mont_mul_8(r->x, p->x, t2 /*, p256_mod, p256_mp_mod*/);
memset(r->x + 8, 0, sizeof(r->x) / 2);
sp_512to256_mont_reduce_8(r->x /*, p256_mod, p256_mp_mod*/);
/* Reduce x to less than modulus */
if (sp_256_cmp_8(r->x, p256_mod) >= 0)
@ -1071,7 +1070,6 @@ static void sp_256_map_8(sp_point* r, sp_point* p)
/* y /= z^3 */
sp_256to512z_mont_mul_8(r->y, p->y, t1 /*, p256_mod, p256_mp_mod*/);
memset(r->y + 8, 0, sizeof(r->y) / 2);
sp_512to256_mont_reduce_8(r->y /*, p256_mod, p256_mp_mod*/);
/* Reduce y to less than modulus */
if (sp_256_cmp_8(r->y, p256_mod) >= 0)