path: root/src/cube_neon.h

// cube_t
typedef struct
{
    uint8x16_t corner;
    uint8x16_t edge;
} cube_t;

// static cube
#define static_cube(c_ufr, c_ubl, c_dfl, c_dbr, c_ufl, c_ubr, c_dfr, c_dbl,                         \
                    e_uf, e_ub, e_db, e_df, e_ur, e_ul, e_dl, e_dr, e_fr, e_fl, e_bl, e_br)         \
    ((cube_t){                                                                                      \
        .corner = {c_ufr, c_ubl, c_dfl, c_dbr, c_ufl, c_ubr, c_dfr, c_dbl, 0, 0, 0, 0, 0, 0, 0, 0}, \
        .edge = {e_uf, e_ub, e_db, e_df, e_ur, e_ul, e_dl, e_dr, e_fr, e_fl, e_bl, e_br, 0, 0, 0, 0}})

// zero cube
#define zero                     \
    (cube_t)                     \
    {                            \
        .corner = vdupq_n_u8(0), \
        .edge = vdupq_n_u8(0)    \
    }

// solved cube
#define solved static_cube( \
    0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)

// Functions
_static void pieces(cube_t *, uint8_t[static 8], uint8_t[static 12]);
_static_inline bool equal(cube_t, cube_t);
_static_inline cube_t invertco(cube_t);
_static_inline cube_t compose_edges(cube_t, cube_t); // implementation similar to portable compose_edges_inplace
_static_inline cube_t compose_corners(cube_t, cube_t); // implementation similar to portable compose_corners_inplace
_static_inline uint8x16_t compose_edges_slim(uint8x16_t, uint8x16_t); // similar to compose_edges but without the cube_t struct
_static_inline uint8x16_t compose_corners_slim(uint8x16_t, uint8x16_t); // similar to compose_corners but without the cube_t struct
_static_inline cube_t compose(cube_t, cube_t);
_static_inline cube_t inverse(cube_t);

_static_inline int64_t coord_co(cube_t);
_static_inline int64_t coord_csep(cube_t);
_static_inline int64_t coord_cocsep(cube_t);
_static_inline int64_t coord_eo(cube_t);
_static_inline int64_t coord_esep(cube_t);

_static_inline void copy_corners(cube_t *, cube_t);
_static_inline void copy_edges(cube_t *, cube_t);
_static_inline void set_eo(cube_t *, int64_t);
_static_inline cube_t invcoord_esep(int64_t);
/*
_static void pieces(cube_t *cube, uint8_t c[static 8], uint8_t e[static 12]) {
    uint8_t aux[32];

    // Store the corner and edge vectors into the aux array
    vst1q_u8(aux, cube->corner);
    vst1q_u8(aux + 16, cube->edge);

    // Copy the required parts to the output arrays
    memcpy(c, aux, 8);
    memcpy(e, aux + 16, 12);
}
*/

_static void 
pieces(cube_t *cube, uint8_t c[static 8], uint8_t e[static 12])
{
    // First 8 bytes of the corner vector are copied from the c array
    vst1_u8(c, vget_low_u8(cube->corner));

    // 12 bytes of the edge vector are copied from the e array
    // First 8 bytes
    vst1_u8(e, vget_low_u8(cube->edge));
    // Next 4 bytes
    vst1_lane_u32((uint32_t *)(e + 8), vreinterpret_u32_u8(vget_high_u8(cube->edge)), 0);
}

_static_inline bool 
equal(cube_t c1, cube_t c2)
{
    uint8x16_t cmp_corner, cmp_edge;
    uint64x2_t cmp_corner_u64, cmp_edge_u64;
    uint64x2_t cmp_result;

    // compare the corner vectors
    cmp_corner = vceqq_u8(c1.corner, c2.corner);
    // compare the edge vectors
    cmp_edge = vceqq_u8(c1.edge, c2.edge);

    // convert the comparison vectors to 64-bit vectors
    cmp_corner_u64 = vreinterpretq_u64_u8(cmp_corner);
    cmp_edge_u64 = vreinterpretq_u64_u8(cmp_edge);

    // combine the comparison vectors
    cmp_result = vandq_u64(cmp_corner_u64, cmp_edge_u64);

    // check if all the bits are set
    return vgetq_lane_u64(cmp_result, 0) == ~0ULL && vgetq_lane_u64(cmp_result, 1) == ~0ULL;
}

_static_inline cube_t invertco(cube_t c)
{
    cube_t ret;

    // Copy the corner vector to an array
    uint8_t corners[16];
    vst1q_u8(corners, c.corner);

    uint8_t corner_result[16] = {0};

    // Process the corners
    for (uint8_t i = 0; i < 8; i++)
    {
        uint8_t piece = corners[i];
        uint8_t orien = ((piece << 1) | (piece >> 1)) & _cobits2;
        corner_result[i] = (piece & _pbits) | orien;
    }

    // Copy the results back to the NEON corner vector
    ret.corner = vld1q_u8(corner_result);

    // Mask to clear the last 64 bits of the corner field
    uint8x16_t mask_last_64 = vsetq_lane_u64(0, vreinterpretq_u64_u8(ret.corner), 1);
    ret.corner = vreinterpretq_u8_u64(mask_last_64);

    // Copy the edge vector as it is
    ret.edge = c.edge;

    // Mask to clear the last 32 bits of the edge field
    uint8x16_t mask_last_32 = vsetq_lane_u32(0, vreinterpretq_u32_u8(ret.edge), 3);
    ret.edge = vreinterpretq_u8_u32(mask_last_32);

    return ret;
}

_static_inline cube_t compose_edges(cube_t c1, cube_t c2)
{
    cube_t ret = {0};

    uint8x16_t edge1 = c1.edge;
    uint8x16_t edge2 = c2.edge;

    // Masks
    uint8x16_t p_bits = vdupq_n_u8(_pbits);
    uint8x16_t eo_bit = vdupq_n_u8(_eobit);

    // Find the index and permutation
    uint8x16_t p = vandq_u8(edge2, p_bits);
    uint8x16_t piece1 = vqtbl1q_u8(edge1, p);

    // Calculate the orientation through XOR
    uint8x16_t orien = vandq_u8(veorq_u8(edge2, piece1), eo_bit);

    // Combine the results
    uint8x16_t result = vorrq_u8(vandq_u8(piece1, p_bits), orien);

    // Mask to clear the last 32 bits of the result
    uint8x16_t mask_last_32 = vsetq_lane_u32(0, vreinterpretq_u32_u8(result), 3);
    result = vreinterpretq_u8_u32(mask_last_32);

    ret.edge = result;
    return ret;
}

_static_inline cube_t compose_corners(cube_t c1, cube_t c2)
{
    cube_t ret = {0};
    uint8x16_t corner1 = c1.corner;
    uint8x16_t corner2 = c2.corner;

    // Masks
    uint8x16_t p_bits = vdupq_n_u8(_pbits);
    uint8x16_t cobits = vdupq_n_u8(_cobits);
    uint8x16_t cobits2 = vdupq_n_u8(_cobits2);
    uint8x16_t twist_cw = vdupq_n_u8(_ctwist_cw);

    // Find the index and permutation
    uint8x16_t p = vandq_u8(corner2, p_bits);
    uint8x16_t piece1 = vqtbl1q_u8(corner1, p);

    // Calculate the orientation
    uint8x16_t aux = vaddq_u8(vandq_u8(corner2, cobits), vandq_u8(piece1, cobits));
    uint8x16_t auy = vshrq_n_u8(vaddq_u8(aux, twist_cw), 2);
    uint8x16_t orien = vandq_u8(vaddq_u8(aux, auy), cobits2);

    // Combine the results
    uint8x16_t result = vorrq_u8(vandq_u8(piece1, p_bits), orien);

    // Mask to clear the last 64 bits of the result
    uint8x16_t mask_last_64 = vsetq_lane_u64(0, vreinterpretq_u64_u8(result), 1);
    result = vreinterpretq_u8_u64(mask_last_64);

    ret.corner = result;
    return ret;
}
_static_inline uint8x16_t compose_edges_slim(uint8x16_t edge1, uint8x16_t edge2)
{
    // Masks
    uint8x16_t p_bits = vdupq_n_u8(_pbits);
    uint8x16_t eo_bit = vdupq_n_u8(_eobit);

    // Find the index and permutation
    uint8x16_t p = vandq_u8(edge2, p_bits);
    uint8x16_t piece1 = vqtbl1q_u8(edge1, p);

    // Calculate the orientation through XOR
    uint8x16_t orien = vandq_u8(veorq_u8(edge2, piece1), eo_bit);

    // Combine the results
    uint8x16_t ret = vorrq_u8(vandq_u8(piece1, p_bits), orien);

    // Mask to clear the last 32 bits of the result
    uint8x16_t mask_last_32 = vsetq_lane_u32(0, vreinterpretq_u32_u8(ret), 3);
    ret = vreinterpretq_u8_u32(mask_last_32);

    return ret;
}
_static_inline uint8x16_t compose_corners_slim(uint8x16_t corner1, uint8x16_t corner2)
{
    // Masks
    uint8x16_t p_bits = vdupq_n_u8(_pbits);
    uint8x16_t cobits = vdupq_n_u8(_cobits);
    uint8x16_t cobits2 = vdupq_n_u8(_cobits2);
    uint8x16_t twist_cw = vdupq_n_u8(_ctwist_cw);

    // Find the index and permutation
    uint8x16_t p = vandq_u8(corner2, p_bits);
    uint8x16_t piece1 = vqtbl1q_u8(corner1, p);

    // Calculate the orientation
    uint8x16_t aux = vaddq_u8(vandq_u8(corner2, cobits), vandq_u8(piece1, cobits));
    uint8x16_t auy = vshrq_n_u8(vaddq_u8(aux, twist_cw), 2);
    uint8x16_t orien = vandq_u8(vaddq_u8(aux, auy), cobits2);

    // Combine the results
    uint8x16_t ret = vorrq_u8(vandq_u8(piece1, p_bits), orien);

    // Mask to clear the last 64 bits of the result
    uint8x16_t mask_last_64 = vsetq_lane_u64(0, vreinterpretq_u64_u8(ret), 1);
    ret = vreinterpretq_u8_u64(mask_last_64);

    return ret;
}
_static_inline cube_t compose(cube_t c1, cube_t c2)
{
    cube_t ret = {0};

    ret.edge = compose_edges_slim(c1.edge, c2.edge);
    ret.corner = compose_corners_slim(c1.corner, c2.corner);

    return ret;
}

_static_inline cube_t inverse(cube_t cube)
{
    uint8_t i, piece, orien;
    cube_t ret;

    // Temp arrays to store the NEON vectors
    uint8_t edges[16];
    uint8_t corners[16];

    // Copy the NEON vectors to the arrays
    vst1q_u8(edges, cube.edge);
    vst1q_u8(corners, cube.corner);

    uint8_t edge_result[16] = {0};
    uint8_t corner_result[16] = {0};

    // Process the edges
    for (i = 0; i < 12; i++)
    {
        piece = edges[i];
        orien = piece & _eobit;
        edge_result[piece & _pbits] = i | orien;
    }

    // Process the corners
    for (i = 0; i < 8; i++)
    {
        piece = corners[i];
        orien = ((piece << 1) | (piece >> 1)) & _cobits2;
        corner_result[piece & _pbits] = i | orien;
    }

    // Copy the results back to the NEON vectors
    ret.edge = vld1q_u8(edge_result);
    ret.corner = vld1q_u8(corner_result);

    return ret;
}

_static_inline int64_t coord_co(cube_t c)
{
    // Temp array to store the NEON vector
    uint8_t mem[16];
    vst1q_u8(mem, c.corner);

    int i, p;
    int64_t ret;

    for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 3)
        ret += p * (mem[i] >> _coshift);

    return ret;
}

_static_inline int64_t
coord_csep(cube_t c)
{
    // Temp array to store the NEON vector
    uint8_t mem[16];
    vst1q_u8(mem, c.corner);

    int64_t ret = 0;
    int i, p;
    for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 2)
        ret += p * ((mem[i] & _csepbit) >> 2);

    return ret;
    return 0;
}

_static_inline int64_t
coord_cocsep(cube_t c)
{
    return (coord_co(c) << 7) + coord_csep(c);
}

_static_inline int64_t coord_eo(cube_t c)
{
    int64_t ret = 0;
    int64_t p = 1;

    // Temp array to store the NEON vector
    uint8_t mem[16];
    vst1q_u8(mem, c.edge);

    for (int i = 1; i < 12; i++, p *= 2)
    {
        ret += p * (mem[i] >> _eoshift);
    }

    return ret;
}

_static_inline int64_t coord_esep(cube_t c)
{
    int64_t i, j, jj, k, l, ret1, ret2, bit1, bit2, is1;

    // Temp array to store the NEON vector
    uint8_t mem[16];
    vst1q_u8(mem, c.edge);

    for (i = 0, j = 0, k = 4, l = 4, ret1 = 0, ret2 = 0; i < 12; i++)
    {
        bit1 = (mem[i] & _esepbit1) >> 2;
        bit2 = (mem[i] & _esepbit2) >> 3;
        is1 = (1 - bit2) * bit1;

        ret1 += bit2 * binomial[11 - i][k];
        k -= bit2;

        jj = j < 8;
        ret2 += jj * is1 * binomial[7 - (j * jj)][l];
        l -= is1;
        j += (1 - bit2);
    }

    return ret1 * 70 + ret2;
}

_static_inline void
copy_corners(cube_t *dst, cube_t src)
{
    dst->corner = src.corner;
}

_static_inline void
copy_edges(cube_t *dst, cube_t src)
{
    dst->edge = src.edge;
}

_static_inline void
set_eo(cube_t *cube, int64_t eo)
{
    // Temp array to store the NEON vector
    uint8_t mem[16];
    vst1q_u8(mem, cube->edge);
    uint8_t i, sum, flip;

    for (sum = 0, i = 1; i < 12; i++, eo >>= 1)
    {
        flip = eo % 2;
        sum += flip;
        mem[i] = (mem[i] & ~_eobit) | (_eobit * flip);
    }
    mem[0] = (mem[0] & ~_eobit) | (_eobit * (sum % 2));

    // Copy the results back to the NEON vector
    cube->edge = vld1q_u8(mem);
    return;
}

_static_inline cube_t
invcoord_esep(int64_t esep)
{
    cube_t ret;
    int64_t bit1, bit2, i, j, jj, k, l, s, v, w, is1, set1, set2;
    uint8_t slice[3] = {0};

    ret = solved;
    uint8_t mem[16];
    set1 = esep % 70;
    set2 = esep / 70;

    for (i = 0, j = 0, k = 4, l = 4; i < 12; i++)
    {
        v = binomial[11 - i][k];
        jj = j < 8;
        w = jj * binomial[7 - (j * jj)][l];
        bit2 = set2 >= v;
        bit1 = set1 >= w;
        is1 = (1 - bit2) * bit1;

        set2 -= bit2 * v;
        k -= bit2;
        set1 -= is1 * w;
        l -= is1;
        j += (1 - bit2);
        s = 2 * bit2 + (1 - bit2) * bit1;

        mem[i] = (slice[s]++) | (uint8_t)(s << 2);
    }

    ret.edge = vld1q_u8(mem);
    return ret;
}