d728a30c2
Denys Vlasenko
2021-04-26
Subject
tls: add a patch with optimization which _should_ give better code
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networking/tls_sp_c32.patch+142 -0
| @@ -0,0 +1,142 @@ | |
| + | Somehow, gcc 6+ does this optimization same or better than the below |
| + | hand-written optimized code (gcc seem to eliminate a32[] array, uses 32-bit |
| + | registers/memory for "lower halves" of a32[i] elements). |
| + | |
| + | But there can be arches where gcc won't be this good? |
| + | |
| + | diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c |
| + | index 72a3be537..e8a011ad1 100644 |
| + | --- a/networking/tls_sp_c32.c |
| + | +++ b/networking/tls_sp_c32.c |
| + | @@ -228,51 +228,96 @@ static void sp_256_rshift1_10(sp_digit* r, sp_digit* a) |
| + | static void sp_256_mod_mul_norm_10(sp_digit* r, const sp_digit* a) |
| + | { |
| + | int64_t t[8]; |
| + | - int64_t a32[8]; |
| + | + uint32_t a32; |
| + | int64_t o; |
| + | |
| + | - a32[0] = a[0]; |
| + | - a32[0] |= a[1] << 26; |
| + | - a32[0] &= 0xffffffff; |
| + | - a32[1] = (sp_digit)(a[1] >> 6); |
| + | - a32[1] |= a[2] << 20; |
| + | - a32[1] &= 0xffffffff; |
| + | - a32[2] = (sp_digit)(a[2] >> 12); |
| + | - a32[2] |= a[3] << 14; |
| + | - a32[2] &= 0xffffffff; |
| + | - a32[3] = (sp_digit)(a[3] >> 18); |
| + | - a32[3] |= a[4] << 8; |
| + | - a32[3] &= 0xffffffff; |
| + | - a32[4] = (sp_digit)(a[4] >> 24); |
| + | - a32[4] |= a[5] << 2; |
| + | - a32[4] |= a[6] << 28; |
| + | - a32[4] &= 0xffffffff; |
| + | - a32[5] = (sp_digit)(a[6] >> 4); |
| + | - a32[5] |= a[7] << 22; |
| + | - a32[5] &= 0xffffffff; |
| + | - a32[6] = (sp_digit)(a[7] >> 10); |
| + | - a32[6] |= a[8] << 16; |
| + | - a32[6] &= 0xffffffff; |
| + | - a32[7] = (sp_digit)(a[8] >> 16); |
| + | - a32[7] |= a[9] << 10; |
| + | - a32[7] &= 0xffffffff; |
| + | - |
| + | /* 1 1 0 -1 -1 -1 -1 0 */ |
| + | - t[0] = 0 + a32[0] + a32[1] - a32[3] - a32[4] - a32[5] - a32[6]; |
| + | /* 0 1 1 0 -1 -1 -1 -1 */ |
| + | - t[1] = 0 + a32[1] + a32[2] - a32[4] - a32[5] - a32[6] - a32[7]; |
| + | /* 0 0 1 1 0 -1 -1 -1 */ |
| + | - t[2] = 0 + a32[2] + a32[3] - a32[5] - a32[6] - a32[7]; |
| + | /* -1 -1 0 2 2 1 0 -1 */ |
| + | - t[3] = 0 - a32[0] - a32[1] + 2 * a32[3] + 2 * a32[4] + a32[5] - a32[7]; |
| + | /* 0 -1 -1 0 2 2 1 0 */ |
| + | - t[4] = 0 - a32[1] - a32[2] + 2 * a32[4] + 2 * a32[5] + a32[6]; |
| + | /* 0 0 -1 -1 0 2 2 1 */ |
| + | - t[5] = 0 - a32[2] - a32[3] + 2 * a32[5] + 2 * a32[6] + a32[7]; |
| + | /* -1 -1 0 0 0 1 3 2 */ |
| + | - t[6] = 0 - a32[0] - a32[1] + a32[5] + 3 * a32[6] + 2 * a32[7]; |
| + | /* 1 0 -1 -1 -1 -1 0 3 */ |
| + | - t[7] = 0 + a32[0] - a32[2] - a32[3] - a32[4] - a32[5] + 3 * a32[7]; |
| + | + //t[0] = 0 + a32[0] + a32[1] - a32[3] - a32[4] - a32[5] - a32[6] ; |
| + | + //t[1] = 0 + a32[1] + a32[2] - a32[4] - a32[5] - a32[6] - a32[7] ; |
| + | + //t[2] = 0 + a32[2] + a32[3] - a32[5] - a32[6] - a32[7] ; |
| + | + //t[3] = 0 - a32[0] - a32[1] + 2*a32[3] + 2*a32[4] + a32[5] - a32[7] ; |
| + | + //t[4] = 0 - a32[1] - a32[2] + 2*a32[4] + 2*a32[5] + a32[6] ; |
| + | + //t[5] = 0 - a32[2] - a32[3] + 2*a32[5] + 2*a32[6] + a32[7] ; |
| + | + //t[6] = 0 - a32[0] - a32[1] + a32[5] + 3*a32[6] + 2*a32[7]; |
| + | + //t[7] = 0 + a32[0] - a32[2] - a32[3] - a32[4] - a32[5] + 3*a32[7]; |
| + | + |
| + | +#define A32 (int64_t)a32 |
| + | + a32 = a[0]; |
| + | + a32 |= a[1] << 26; |
| + | + t[0] = 0 + A32; |
| + | + t[3] = 0 - A32; |
| + | + t[6] = 0 - A32; |
| + | + t[7] = 0 + A32; |
| + | + |
| + | + a32 = (sp_digit)(a[1] >> 6); |
| + | + a32 |= a[2] << 20; |
| + | + t[0] += A32 ; |
| + | + t[1] = 0 + A32; |
| + | + t[3] -= A32 ; |
| + | + t[4] = 0 - A32; |
| + | + t[6] -= A32 ; |
| + | + |
| + | + a32 = (sp_digit)(a[2] >> 12); |
| + | + a32 |= a[3] << 14; |
| + | + t[1] += A32 ; |
| + | + t[2] = 0 + A32; |
| + | + t[4] -= A32 ; |
| + | + t[5] = 0 - A32; |
| + | + t[7] -= A32 ; |
| + | + |
| + | + a32 = (sp_digit)(a[3] >> 18); |
| + | + a32 |= a[4] << 8; |
| + | + t[0] -= A32 ; |
| + | + t[2] += A32 ; |
| + | + t[3] += 2*A32; |
| + | + t[5] -= A32 ; |
| + | + t[7] -= A32 ; |
| + | + |
| + | + a32 = (sp_digit)(a[4] >> 24); |
| + | + a32 |= a[5] << 2; |
| + | + a32 |= a[6] << 28; |
| + | + t[0] -= A32 ; |
| + | + t[1] -= A32 ; |
| + | + t[3] += 2*A32; |
| + | + t[4] += 2*A32; |
| + | + t[7] -= A32 ; |
| + | + |
| + | + a32 = (sp_digit)(a[6] >> 4); |
| + | + a32 |= a[7] << 22; |
| + | + t[0] -= A32 ; |
| + | + t[1] -= A32 ; |
| + | + t[2] -= A32 ; |
| + | + t[3] += A32 ; |
| + | + t[4] += 2*A32; |
| + | + t[5] += 2*A32; |
| + | + t[6] += A32 ; |
| + | + t[7] -= A32 ; |
| + | + |
| + | + a32 = (sp_digit)(a[7] >> 10); |
| + | + a32 |= a[8] << 16; |
| + | + t[0] -= A32 ; |
| + | + t[1] -= A32 ; |
| + | + t[2] -= A32 ; |
| + | + t[4] += A32 ; |
| + | + t[5] += 2*A32; |
| + | + t[6] += 3*A32; |
| + | + |
| + | + a32 = (sp_digit)(a[8] >> 16); |
| + | + a32 |= a[9] << 10; |
| + | + t[1] -= A32 ; |
| + | + t[2] -= A32 ; |
| + | + t[3] -= A32 ; |
| + | + t[5] += A32 ; |
| + | + t[6] += 2*A32; |
| + | + t[7] += 3*A32; |
| + | +#undef A32 |
| + | |
| + | t[1] += t[0] >> 32; t[0] &= 0xffffffff; |
| + | t[2] += t[1] >> 32; t[1] &= 0xffffffff; |