lokinet/crypto/chacha20/dolbeau/u1.h

while (bytes >= 64) {
    __m128i       x_0, x_1, x_2, x_3;
    __m128i       t_1;
    const __m128i rot16 =
        _mm_set_epi8(13, 12, 15, 14, 9, 8, 11, 10, 5, 4, 7, 6, 1, 0, 3, 2);
    const __m128i rot8 =
        _mm_set_epi8(14, 13, 12, 15, 10, 9, 8, 11, 6, 5, 4, 7, 2, 1, 0, 3);

    uint32_t in12;
    uint32_t in13;
    int      i;

    x_0 = _mm_loadu_si128((__m128i*) (x + 0));
    x_1 = _mm_loadu_si128((__m128i*) (x + 4));
    x_2 = _mm_loadu_si128((__m128i*) (x + 8));
    x_3 = _mm_loadu_si128((__m128i*) (x + 12));

    for (i = 0; i < ROUNDS; i += 2) {
        x_0 = _mm_add_epi32(x_0, x_1);
        x_3 = _mm_xor_si128(x_3, x_0);
        x_3 = _mm_shuffle_epi8(x_3, rot16);

        x_2 = _mm_add_epi32(x_2, x_3);
        x_1 = _mm_xor_si128(x_1, x_2);

        t_1 = x_1;
        x_1 = _mm_slli_epi32(x_1, 12);
        t_1 = _mm_srli_epi32(t_1, 20);
        x_1 = _mm_xor_si128(x_1, t_1);

        x_0 = _mm_add_epi32(x_0, x_1);
        x_3 = _mm_xor_si128(x_3, x_0);
        x_0 = _mm_shuffle_epi32(x_0, 0x93);
        x_3 = _mm_shuffle_epi8(x_3, rot8);

        x_2 = _mm_add_epi32(x_2, x_3);
        x_3 = _mm_shuffle_epi32(x_3, 0x4e);
        x_1 = _mm_xor_si128(x_1, x_2);
        x_2 = _mm_shuffle_epi32(x_2, 0x39);

        t_1 = x_1;
        x_1 = _mm_slli_epi32(x_1, 7);
        t_1 = _mm_srli_epi32(t_1, 25);
        x_1 = _mm_xor_si128(x_1, t_1);

        x_0 = _mm_add_epi32(x_0, x_1);
        x_3 = _mm_xor_si128(x_3, x_0);
        x_3 = _mm_shuffle_epi8(x_3, rot16);

        x_2 = _mm_add_epi32(x_2, x_3);
        x_1 = _mm_xor_si128(x_1, x_2);

        t_1 = x_1;
        x_1 = _mm_slli_epi32(x_1, 12);
        t_1 = _mm_srli_epi32(t_1, 20);
        x_1 = _mm_xor_si128(x_1, t_1);

        x_0 = _mm_add_epi32(x_0, x_1);
        x_3 = _mm_xor_si128(x_3, x_0);
        x_0 = _mm_shuffle_epi32(x_0, 0x39);
        x_3 = _mm_shuffle_epi8(x_3, rot8);

        x_2 = _mm_add_epi32(x_2, x_3);
        x_3 = _mm_shuffle_epi32(x_3, 0x4e);
        x_1 = _mm_xor_si128(x_1, x_2);
        x_2 = _mm_shuffle_epi32(x_2, 0x93);

        t_1 = x_1;
        x_1 = _mm_slli_epi32(x_1, 7);
        t_1 = _mm_srli_epi32(t_1, 25);
        x_1 = _mm_xor_si128(x_1, t_1);
    }
    x_0 = _mm_add_epi32(x_0, _mm_loadu_si128((__m128i*) (x + 0)));
    x_1 = _mm_add_epi32(x_1, _mm_loadu_si128((__m128i*) (x + 4)));
    x_2 = _mm_add_epi32(x_2, _mm_loadu_si128((__m128i*) (x + 8)));
    x_3 = _mm_add_epi32(x_3, _mm_loadu_si128((__m128i*) (x + 12)));
    x_0 = _mm_xor_si128(x_0, _mm_loadu_si128((__m128i*) (m + 0)));
    x_1 = _mm_xor_si128(x_1, _mm_loadu_si128((__m128i*) (m + 16)));
    x_2 = _mm_xor_si128(x_2, _mm_loadu_si128((__m128i*) (m + 32)));
    x_3 = _mm_xor_si128(x_3, _mm_loadu_si128((__m128i*) (m + 48)));
    _mm_storeu_si128((__m128i*) (c + 0), x_0);
    _mm_storeu_si128((__m128i*) (c + 16), x_1);
    _mm_storeu_si128((__m128i*) (c + 32), x_2);
    _mm_storeu_si128((__m128i*) (c + 48), x_3);

    in12 = x[12];
    in13 = x[13];
    in12++;
    if (in12 == 0) {
        in13++;
    }
    x[12] = in12;
    x[13] = in13;

    bytes -= 64;
    c += 64;
    m += 64;
}