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tls: shrink sp_256_mod_mul_norm_10 more

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function                                             old     new   delta
sp_256_mod_mul_norm_10                              1439    1305    -134

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-04-27 13:31:26 +02:00
parent 646e856294
commit 840ae69615
1 changed files with 17 additions and 17 deletions
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34
networking/tls_sp_c32.c
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@ -557,24 +557,24 @@ static void sp_256_mod_mul_norm_10(sp_digit* r, const sp_digit* a)
t[3] -= o;
t[6] -= o;
t[7] += o;
t[1] += t[0] >> 32; t[0] &= 0xffffffff;
t[2] += t[1] >> 32; t[1] &= 0xffffffff;
t[3] += t[2] >> 32; t[2] &= 0xffffffff;
t[4] += t[3] >> 32; t[3] &= 0xffffffff;
t[5] += t[4] >> 32; t[4] &= 0xffffffff;
t[6] += t[5] >> 32; t[5] &= 0xffffffff;
t[7] += t[6] >> 32; t[6] &= 0xffffffff;
t[1] += t[0] >> 32; //t[0] &= 0xffffffff;
t[2] += t[1] >> 32; //t[1] &= 0xffffffff;
t[3] += t[2] >> 32; //t[2] &= 0xffffffff;
t[4] += t[3] >> 32; //t[3] &= 0xffffffff;
t[5] += t[4] >> 32; //t[4] &= 0xffffffff;
t[6] += t[5] >> 32; //t[5] &= 0xffffffff;
t[7] += t[6] >> 32; //t[6] &= 0xffffffff; - (uint32_t)t[i] casts below accomplish masking
r[0] = 0x3ffffff & ((sp_digit)(t[0]));
r[1] = 0x3ffffff & ((sp_digit)(t[0] >> 26) | ((sp_digit)t[1] << 6));
r[2] = 0x3ffffff & ((sp_digit)(t[1] >> 20) | ((sp_digit)t[2] << 12));
r[3] = 0x3ffffff & ((sp_digit)(t[2] >> 14) | ((sp_digit)t[3] << 18));
r[4] = 0x3ffffff & ((sp_digit)(t[3] >> 8) | ((sp_digit)t[4] << 24));
r[5] = 0x3ffffff & ((sp_digit)t[4] >> 2); /* small shift, ok to cast t[4] to narrower type */
r[6] = 0x3ffffff & ((sp_digit)(t[4] >> 28) | ((sp_digit)t[5] << 4));
r[7] = 0x3ffffff & ((sp_digit)(t[5] >> 22) | ((sp_digit)t[6] << 10));
r[8] = 0x3ffffff & ((sp_digit)(t[6] >> 16) | ((sp_digit)t[7] << 16));
r[9] = ((sp_digit)(t[7] >> 10));
r[0] = 0x3ffffff & ((sp_digit)((uint32_t)t[0]));
r[1] = 0x3ffffff & ((sp_digit)((uint32_t)t[0] >> 26) | ((sp_digit)t[1] << 6));
r[2] = 0x3ffffff & ((sp_digit)((uint32_t)t[1] >> 20) | ((sp_digit)t[2] << 12));
r[3] = 0x3ffffff & ((sp_digit)((uint32_t)t[2] >> 14) | ((sp_digit)t[3] << 18));
r[4] = 0x3ffffff & ((sp_digit)((uint32_t)t[3] >> 8) | ((sp_digit)t[4] << 24));
r[5] = 0x3ffffff & ((sp_digit)((uint32_t)t[4] >> 2));
r[6] = 0x3ffffff & ((sp_digit)((uint32_t)t[4] >> 28) | ((sp_digit)t[5] << 4));
r[7] = 0x3ffffff & ((sp_digit)((uint32_t)t[5] >> 22) | ((sp_digit)t[6] << 10));
r[8] = 0x3ffffff & ((sp_digit)((uint32_t)t[6] >> 16) | ((sp_digit)t[7] << 16));
r[9] = ((sp_digit)((uint32_t)t[7] >> 10));
}
/* Map the Montgomery form projective co-ordinate point to an affine point.