sha/keccak1600.c: add some optimized implementations.

#define ROL64(a, offset) ((offset) ? (((a) << offset) | ((a) >> (64-offset))) \

                                   : a)

#if defined(KECCAK_REF)

/*

 * This is straightforward or "maximum clarity" implementation aiming

 * to resemble section 3.2 of the FIPS PUB 202 "SHA-3 Standard:

 * Permutation-Based Hash and Extendible-Output Functions" as much as

 * possible. With one caveat. Because of the way C stores matrices,

 * references to A[x,y] in the specification are presented as A[y][x].

 * Implementation unrolls inner x-loops so that modulo 5 operations are

 * explicitly pre-computed.

 */

static void Theta(uint64_t A[5][5])

{

    uint64_t C[5], D[5];

    size_t y;

    C[0] = A[0][0] ^ A[1][0] ^ A[2][0] ^ A[3][0] ^ A[4][0];

    C[1] = A[0][1] ^ A[1][1] ^ A[2][1] ^ A[3][1] ^ A[4][1];

    C[2] = A[0][2] ^ A[1][2] ^ A[2][2] ^ A[3][2] ^ A[4][2];

    C[3] = A[0][3] ^ A[1][3] ^ A[2][3] ^ A[3][3] ^ A[4][3];

    C[4] = A[0][4] ^ A[1][4] ^ A[2][4] ^ A[3][4] ^ A[4][4];

    C[0] = A[0][0];

    C[1] = A[0][1];

    C[2] = A[0][2];

    C[3] = A[0][3];

    C[4] = A[0][4];

    for (y = 1; y < 5; y++) {

        C[0] ^= A[y][0];

        C[1] ^= A[y][1];

        C[2] ^= A[y][2];

        C[3] ^= A[y][3];

        C[4] ^= A[y][4];

    }

    D[0] = ROL64(C[1], 1) ^ C[4];

    D[1] = ROL64(C[2], 1) ^ C[0];

    }

}

#elif defined(KECCAK_1X)

/*

 * This implementation is optimization of above code featuring unroll

 * of even y-loops, their fusion and code motion. It also minimizes

 * temporary storage. Compiler would normally do all these things for

 * you, purpose of manual optimization is to provide "unobscured"

 * reference for assembly implementation [in case this approach is

 * chosen for implementation on some platform]. In the nutshell it's

 * equivalent of "plane-per-plane processing" approach discussed in

 * section 2.4 of "Keccak implementation overview".

 */

static void Round(uint64_t A[5][5], size_t i)

{

    uint64_t C[5], D[5], T[2][5];

    static const unsigned char rhotates[5][5] = {

        {  0,  1, 62, 28, 27 },

        { 36, 44,  6, 55, 20 },

        {  3, 10, 43, 25, 39 },

        { 41, 45, 15, 21,  8 },

        { 18,  2, 61, 56, 14 }

    };

    static const uint64_t iotas[] = {

        0x0000000000000001U, 0x0000000000008082U, 0x800000000000808aU,

        0x8000000080008000U, 0x000000000000808bU, 0x0000000080000001U,

        0x8000000080008081U, 0x8000000000008009U, 0x000000000000008aU,

        0x0000000000000088U, 0x0000000080008009U, 0x000000008000000aU,

        0x000000008000808bU, 0x800000000000008bU, 0x8000000000008089U,

        0x8000000000008003U, 0x8000000000008002U, 0x8000000000000080U,

        0x000000000000800aU, 0x800000008000000aU, 0x8000000080008081U,

        0x8000000000008080U, 0x0000000080000001U, 0x8000000080008008U

    };

    assert(i < (sizeof(iotas) / sizeof(iotas[0])));

    C[0] = A[0][0] ^ A[1][0] ^ A[2][0] ^ A[3][0] ^ A[4][0];

    C[1] = A[0][1] ^ A[1][1] ^ A[2][1] ^ A[3][1] ^ A[4][1];

    C[2] = A[0][2] ^ A[1][2] ^ A[2][2] ^ A[3][2] ^ A[4][2];

    C[3] = A[0][3] ^ A[1][3] ^ A[2][3] ^ A[3][3] ^ A[4][3];

    C[4] = A[0][4] ^ A[1][4] ^ A[2][4] ^ A[3][4] ^ A[4][4];

    D[0] = ROL64(C[1], 1) ^ C[4];

    D[1] = ROL64(C[2], 1) ^ C[0];

    D[2] = ROL64(C[3], 1) ^ C[1];

    D[3] = ROL64(C[4], 1) ^ C[2];

    D[4] = ROL64(C[0], 1) ^ C[3];

    C[0] =       A[0][0] ^ D[0]; /* rotate by 0 */

    C[1] = ROL64(A[1][1] ^ D[1], rhotates[1][1]);

    C[2] = ROL64(A[2][2] ^ D[2], rhotates[2][2]);

    C[3] = ROL64(A[3][3] ^ D[3], rhotates[3][3]);

    C[4] = ROL64(A[4][4] ^ D[4], rhotates[4][4]);

    T[0][0] = A[3][0] ^ D[0]; /* borrow T[0][0] */

    T[0][1] = A[0][1] ^ D[1];

    T[0][2] = A[0][2] ^ D[2];

    T[0][3] = A[0][3] ^ D[3];

    T[0][4] = A[0][4] ^ D[4];

    A[0][0] = C[0] ^ (~C[1] & C[2]) ^ iotas[i];

    A[0][1] = C[1] ^ (~C[2] & C[3]);

    A[0][2] = C[2] ^ (~C[3] & C[4]);

    A[0][3] = C[3] ^ (~C[4] & C[0]);

    A[0][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(T[0][3],        rhotates[0][3]);

    C[1] = ROL64(A[1][4] ^ D[4], rhotates[1][4]);

    C[2] = ROL64(A[2][0] ^ D[0], rhotates[2][0]);

    C[3] = ROL64(A[3][1] ^ D[1], rhotates[3][1]);

    C[4] = ROL64(A[4][2] ^ D[2], rhotates[4][2]);

    T[1][0] = A[1][0] ^ D[0];

    T[1][1] = A[2][1] ^ D[1]; /* borrow T[1][1] */

    T[1][2] = A[1][2] ^ D[2];

    T[1][3] = A[1][3] ^ D[3];

    T[1][4] = A[2][4] ^ D[4]; /* borrow T[1][4] */

    A[1][0] = C[0] ^ (~C[1] & C[2]);

    A[1][1] = C[1] ^ (~C[2] & C[3]);

    A[1][2] = C[2] ^ (~C[3] & C[4]);

    A[1][3] = C[3] ^ (~C[4] & C[0]);

    A[1][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(T[0][1],        rhotates[0][1]);

    C[1] = ROL64(T[1][2],        rhotates[1][2]);

    C[2] = ROL64(A[2][3] ^ D[3], rhotates[2][3]);

    C[3] = ROL64(A[3][4] ^ D[4], rhotates[3][4]);

    C[4] = ROL64(A[4][0] ^ D[0], rhotates[4][0]);

    A[2][0] = C[0] ^ (~C[1] & C[2]);

    A[2][1] = C[1] ^ (~C[2] & C[3]);

    A[2][2] = C[2] ^ (~C[3] & C[4]);

    A[2][3] = C[3] ^ (~C[4] & C[0]);

    A[2][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(T[0][4],        rhotates[0][4]);

    C[1] = ROL64(T[1][0],        rhotates[1][0]);

    C[2] = ROL64(T[1][1],        rhotates[2][1]); /* originally A[2][1] */

    C[3] = ROL64(A[3][2] ^ D[2], rhotates[3][2]);

    C[4] = ROL64(A[4][3] ^ D[3], rhotates[4][3]);

    A[3][0] = C[0] ^ (~C[1] & C[2]);

    A[3][1] = C[1] ^ (~C[2] & C[3]);

    A[3][2] = C[2] ^ (~C[3] & C[4]);

    A[3][3] = C[3] ^ (~C[4] & C[0]);

    A[3][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(T[0][2],        rhotates[0][2]);

    C[1] = ROL64(T[1][3],        rhotates[1][3]);

    C[2] = ROL64(T[1][4],        rhotates[2][4]); /* originally A[2][4] */

    C[3] = ROL64(T[0][0],        rhotates[3][0]); /* originally A[3][0] */

    C[4] = ROL64(A[4][1] ^ D[1], rhotates[4][1]);

    A[4][0] = C[0] ^ (~C[1] & C[2]);

    A[4][1] = C[1] ^ (~C[2] & C[3]);

    A[4][2] = C[2] ^ (~C[3] & C[4]);

    A[4][3] = C[3] ^ (~C[4] & C[0]);

    A[4][4] = C[4] ^ (~C[0] & C[1]);

}

void KeccakF1600(uint64_t A[5][5])

{

    size_t i;

    for (i = 0; i < 24; i++) {

        Round(A, i);

    }

}

#elif defined(KECCAK_2X)

/*

 * This implementation is variant of KECCAK_1X above with outer-most

 * round loop unrolled twice. This allows to take temporary storage

 * out of round procedure and simplify references to it by alternating

 * it with actual data (see round loop below). Just like original, it's

 * rather meant as reference for an assembly implementation. It's likely

 * to provide best instruction per processed byte ratio at minimal

 * round unroll factor...

 */

static void Round(uint64_t R[5][5], uint64_t A[5][5], size_t i)

{

    uint64_t C[5], D[5];

    static const unsigned char rhotates[5][5] = {

        {  0,  1, 62, 28, 27 },

        { 36, 44,  6, 55, 20 },

        {  3, 10, 43, 25, 39 },

        { 41, 45, 15, 21,  8 },

        { 18,  2, 61, 56, 14 }

    };

    static const uint64_t iotas[] = {

        0x0000000000000001U, 0x0000000000008082U, 0x800000000000808aU,

        0x8000000080008000U, 0x000000000000808bU, 0x0000000080000001U,

        0x8000000080008081U, 0x8000000000008009U, 0x000000000000008aU,

        0x0000000000000088U, 0x0000000080008009U, 0x000000008000000aU,

        0x000000008000808bU, 0x800000000000008bU, 0x8000000000008089U,

        0x8000000000008003U, 0x8000000000008002U, 0x8000000000000080U,

        0x000000000000800aU, 0x800000008000000aU, 0x8000000080008081U,

        0x8000000000008080U, 0x0000000080000001U, 0x8000000080008008U

    };

    assert(i < (sizeof(iotas) / sizeof(iotas[0])));

    C[0] = A[0][0] ^ A[1][0] ^ A[2][0] ^ A[3][0] ^ A[4][0];

    C[1] = A[0][1] ^ A[1][1] ^ A[2][1] ^ A[3][1] ^ A[4][1];

    C[2] = A[0][2] ^ A[1][2] ^ A[2][2] ^ A[3][2] ^ A[4][2];

    C[3] = A[0][3] ^ A[1][3] ^ A[2][3] ^ A[3][3] ^ A[4][3];

    C[4] = A[0][4] ^ A[1][4] ^ A[2][4] ^ A[3][4] ^ A[4][4];

    D[0] = ROL64(C[1], 1) ^ C[4];

    D[1] = ROL64(C[2], 1) ^ C[0];

    D[2] = ROL64(C[3], 1) ^ C[1];

    D[3] = ROL64(C[4], 1) ^ C[2];

    D[4] = ROL64(C[0], 1) ^ C[3];

    C[0] =       A[0][0] ^ D[0]; /* rotate by 0 */

    C[1] = ROL64(A[1][1] ^ D[1], rhotates[1][1]);

    C[2] = ROL64(A[2][2] ^ D[2], rhotates[2][2]);

    C[3] = ROL64(A[3][3] ^ D[3], rhotates[3][3]);

    C[4] = ROL64(A[4][4] ^ D[4], rhotates[4][4]);

    R[0][0] = C[0] ^ (~C[1] & C[2]) ^ iotas[i];

    R[0][1] = C[1] ^ (~C[2] & C[3]);

    R[0][2] = C[2] ^ (~C[3] & C[4]);

    R[0][3] = C[3] ^ (~C[4] & C[0]);

    R[0][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(A[0][3] ^ D[3], rhotates[0][3]);

    C[1] = ROL64(A[1][4] ^ D[4], rhotates[1][4]);

    C[2] = ROL64(A[2][0] ^ D[0], rhotates[2][0]);

    C[3] = ROL64(A[3][1] ^ D[1], rhotates[3][1]);

    C[4] = ROL64(A[4][2] ^ D[2], rhotates[4][2]);

    R[1][0] = C[0] ^ (~C[1] & C[2]);

    R[1][1] = C[1] ^ (~C[2] & C[3]);

    R[1][2] = C[2] ^ (~C[3] & C[4]);

    R[1][3] = C[3] ^ (~C[4] & C[0]);

    R[1][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(A[0][1] ^ D[1], rhotates[0][1]);

    C[1] = ROL64(A[1][2] ^ D[2], rhotates[1][2]);

    C[2] = ROL64(A[2][3] ^ D[3], rhotates[2][3]);

    C[3] = ROL64(A[3][4] ^ D[4], rhotates[3][4]);

    C[4] = ROL64(A[4][0] ^ D[0], rhotates[4][0]);

    R[2][0] = C[0] ^ (~C[1] & C[2]);

    R[2][1] = C[1] ^ (~C[2] & C[3]);

    R[2][2] = C[2] ^ (~C[3] & C[4]);

    R[2][3] = C[3] ^ (~C[4] & C[0]);

    R[2][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(A[0][4] ^ D[4], rhotates[0][4]);

    C[1] = ROL64(A[1][0] ^ D[0], rhotates[1][0]);

    C[2] = ROL64(A[2][1] ^ D[1], rhotates[2][1]);

    C[3] = ROL64(A[3][2] ^ D[2], rhotates[3][2]);

    C[4] = ROL64(A[4][3] ^ D[3], rhotates[4][3]);

    R[3][0] = C[0] ^ (~C[1] & C[2]);

    R[3][1] = C[1] ^ (~C[2] & C[3]);

    R[3][2] = C[2] ^ (~C[3] & C[4]);

    R[3][3] = C[3] ^ (~C[4] & C[0]);

    R[3][4] = C[4] ^ (~C[0] & C[1]);

    C[0] = ROL64(A[0][2] ^ D[2], rhotates[0][2]);

    C[1] = ROL64(A[1][3] ^ D[3], rhotates[1][3]);

    C[2] = ROL64(A[2][4] ^ D[4], rhotates[2][4]);

    C[3] = ROL64(A[3][0] ^ D[0], rhotates[3][0]);

    C[4] = ROL64(A[4][1] ^ D[1], rhotates[4][1]);

    R[4][0] = C[0] ^ (~C[1] & C[2]);

    R[4][1] = C[1] ^ (~C[2] & C[3]);

    R[4][2] = C[2] ^ (~C[3] & C[4]);

    R[4][3] = C[3] ^ (~C[4] & C[0]);

    R[4][4] = C[4] ^ (~C[0] & C[1]);

}

void KeccakF1600(uint64_t A[5][5])

{

    uint64_t T[5][5];

    size_t i;

    for (i = 0; i < 24; i += 2) {

        Round(T, A, i);

        Round(A, T, i + 1);

    }

}

#else

/*

 * This implementation is KECCAK_1X from above combined 4 times with

 * a twist that allows to omit temporary storage and perform in-place

 * processing. It's discussed in section 2.5 of "Keccak implementation

 * overview". It's likely to be best suited for processors with large

 * register bank...

 */

static void FourRounds(uint64_t A[5][5], size_t i)

{

    uint64_t B[5], C[5], D[5];

    static const unsigned char rhotates[5][5] = {

        {  0,  1, 62, 28, 27 },

        { 36, 44,  6, 55, 20 },

        {  3, 10, 43, 25, 39 },

        { 41, 45, 15, 21,  8 },

        { 18,  2, 61, 56, 14 }

    };

    static const uint64_t iotas[] = {

        0x0000000000000001U, 0x0000000000008082U, 0x800000000000808aU,

        0x8000000080008000U, 0x000000000000808bU, 0x0000000080000001U,

        0x8000000080008081U, 0x8000000000008009U, 0x000000000000008aU,

        0x0000000000000088U, 0x0000000080008009U, 0x000000008000000aU,

        0x000000008000808bU, 0x800000000000008bU, 0x8000000000008089U,

        0x8000000000008003U, 0x8000000000008002U, 0x8000000000000080U,

        0x000000000000800aU, 0x800000008000000aU, 0x8000000080008081U,

        0x8000000000008080U, 0x0000000080000001U, 0x8000000080008008U

    };

    assert(i <= (sizeof(iotas) / sizeof(iotas[0]) - 4));

    /* Round 4*n */

    C[0] = A[0][0] ^ A[1][0] ^ A[2][0] ^ A[3][0] ^ A[4][0];

    C[1] = A[0][1] ^ A[1][1] ^ A[2][1] ^ A[3][1] ^ A[4][1];

    C[2] = A[0][2] ^ A[1][2] ^ A[2][2] ^ A[3][2] ^ A[4][2];

    C[3] = A[0][3] ^ A[1][3] ^ A[2][3] ^ A[3][3] ^ A[4][3];

    C[4] = A[0][4] ^ A[1][4] ^ A[2][4] ^ A[3][4] ^ A[4][4];

    D[0] = ROL64(C[1], 1) ^ C[4];

    D[1] = ROL64(C[2], 1) ^ C[0];

    D[2] = ROL64(C[3], 1) ^ C[1];

    D[3] = ROL64(C[4], 1) ^ C[2];

    D[4] = ROL64(C[0], 1) ^ C[3];

    B[0] =       A[0][0] ^ D[0]; /* rotate by 0 */

    B[1] = ROL64(A[1][1] ^ D[1], rhotates[1][1]);

    B[2] = ROL64(A[2][2] ^ D[2], rhotates[2][2]);

    B[3] = ROL64(A[3][3] ^ D[3], rhotates[3][3]);

    B[4] = ROL64(A[4][4] ^ D[4], rhotates[4][4]);

    C[0] = A[0][0] = B[0] ^ (~B[1] & B[2]) ^ iotas[i];

    C[1] = A[1][1] = B[1] ^ (~B[2] & B[3]);

    C[2] = A[2][2] = B[2] ^ (~B[3] & B[4]);

    C[3] = A[3][3] = B[3] ^ (~B[4] & B[0]);

    C[4] = A[4][4] = B[4] ^ (~B[0] & B[1]);

    B[0] = ROL64(A[0][3] ^ D[3], rhotates[0][3]);

    B[1] = ROL64(A[1][4] ^ D[4], rhotates[1][4]);

    B[2] = ROL64(A[2][0] ^ D[0], rhotates[2][0]);

    B[3] = ROL64(A[3][1] ^ D[1], rhotates[3][1]);

    B[4] = ROL64(A[4][2] ^ D[2], rhotates[4][2]);

    C[0] ^= A[2][0] = B[0] ^ (~B[1] & B[2]);

    C[1] ^= A[3][1] = B[1] ^ (~B[2] & B[3]);

    C[2] ^= A[4][2] = B[2] ^ (~B[3] & B[4]);

    C[3] ^= A[0][3] = B[3] ^ (~B[4] & B[0]);

    C[4] ^= A[1][4] = B[4] ^ (~B[0] & B[1]);

    B[0] = ROL64(A[0][1] ^ D[1], rhotates[0][1]);

    B[1] = ROL64(A[1][2] ^ D[2], rhotates[1][2]);

    B[2] = ROL64(A[2][3] ^ D[3], rhotates[2][3]);

    B[3] = ROL64(A[3][4] ^ D[4], rhotates[3][4]);

    B[4] = ROL64(A[4][0] ^ D[0], rhotates[4][0]);

    C[0] ^= A[4][0] = B[0] ^ (~B[1] & B[2]);

    C[1] ^= A[0][1] = B[1] ^ (~B[2] & B[3]);

    C[2] ^= A[1][2] = B[2] ^ (~B[3] & B[4]);

    C[3] ^= A[2][3] = B[3] ^ (~B[4] & B[0]);

    C[4] ^= A[3][4] = B[4] ^ (~B[0] & B[1]);

    B[0] = ROL64(A[0][4] ^ D[4], rhotates[0][4]);

    B[1] = ROL64(A[1][0] ^ D[0], rhotates[1][0]);

    B[2] = ROL64(A[2][1] ^ D[1], rhotates[2][1]);

    B[3] = ROL64(A[3][2] ^ D[2], rhotates[3][2]);