1 files changed, 272 insertions, 0 deletions

diff --git a/src/arch/portable.h b/src/arch/portable.h
new file mode 100644
index 0000000..b8330af
--- /dev/null
+++ b/src/arch/portable.h
@@ -0,0 +1,272 @@
+#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 }, \
+        .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 } })
+#define zero static_cube( \
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+#define solved static_cube( \
+    0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
+
+_static void
+pieces(cube_t *cube, uint8_t c[static 8], uint8_t e[static 12])
+{
+        memcpy(c, cube->corner, 8);
+        memcpy(e, cube->edge, 12);
+}
+
+_static_inline bool
+equal(cube_t c1, cube_t c2)
+{
+        uint8_t i;
+        bool ret;
+
+        ret = true;
+        for (i = 0; i < 8; i++)
+                ret = ret && c1.corner[i] == c2.corner[i];
+        for (i = 0; i < 12; i++)
+                ret = ret && c1.edge[i] == c2.edge[i];
+
+        return ret;
+}
+
+_static_inline cube_t
+invertco(cube_t c)
+{
+        uint8_t i, piece, orien;
+        cube_t ret;
+
+        ret = c;
+        for (i = 0; i < 8; i++) {
+                piece = c.corner[i];
+                orien = ((piece << 1) | (piece >> 1)) & _cobits2;
+                ret.corner[i] = (piece & _pbits) | orien;
+        }
+
+        return ret;
+}
+
+_static_inline void
+compose_edges_inplace(cube_t c1, cube_t c2, cube_t *ret)
+{
+        uint8_t i, piece1, piece2, p, orien;
+
+        for (i = 0; i < 12; i++) {
+                piece2 = c2.edge[i];
+                p = piece2 & _pbits;
+                piece1 = c1.edge[p];
+                orien = (piece2 ^ piece1) & _eobit;
+                ret->edge[i] = (piece1 & _pbits) | orien;
+        }
+}
+
+_static_inline void
+compose_corners_inplace(cube_t c1, cube_t c2, cube_t *ret)
+{
+        uint8_t i, piece1, piece2, p, orien, aux, auy;
+
+        for (i = 0; i < 8; i++) {
+                piece2 = c2.corner[i];
+                p = piece2 & _pbits;
+                piece1 = c1.corner[p];
+                aux = (piece2 & _cobits) + (piece1 & _cobits);
+                auy = (aux + _ctwist_cw) >> 2;
+                orien = (aux + auy) & _cobits2;
+                ret->corner[i] = (piece1 & _pbits) | orien;
+        }
+}
+
+_static_inline cube_t
+compose_edges(cube_t c1, cube_t c2)
+{
+        cube_t ret = zero;
+
+        compose_edges_inplace(c1, c2, &ret);
+
+        return ret;
+}
+
+_static_inline cube_t
+compose_corners(cube_t c1, cube_t c2)
+{
+        cube_t ret = zero;
+
+        compose_corners_inplace(c1, c2, &ret);
+
+        return ret;
+}
+
+_static_inline cube_t
+compose(cube_t c1, cube_t c2)
+{
+        cube_t ret = zero;
+
+        compose_edges_inplace(c1, c2, &ret);
+        compose_corners_inplace(c1, c2, &ret);
+
+        return ret;
+}
+
+cube_t
+inverse(cube_t cube)
+{
+        uint8_t i, piece, orien;
+        cube_t ret;
+
+        for (i = 0; i < 12; i++) {
+                piece = cube.edge[i];
+                orien = piece & _eobit;
+                ret.edge[piece & _pbits] = i | orien;
+        }
+
+        for (i = 0; i < 8; i++) {
+                piece = cube.corner[i];
+                orien = ((piece << 1) | (piece >> 1)) & _cobits2;
+                ret.corner[piece & _pbits] = i | orien;
+        }
+
+        return ret;
+}
+
+_static_inline int64_t
+coord_co(cube_t c)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 3)
+                ret += p * (c.corner[i] >> _coshift);
+
+        return ret;
+}
+
+/*
+For corner separation, we consider the axis (a.k.a. tetrad) each
+corner belongs to as 0 or 1 and we translate this sequence into binary.
+Ignoring the last bit, we have a value up to 2^7, but not all values are
+possible. Encoding this as a number from 0 to C(8,4) would save about 40%
+of space, but we are not going to use this coordinate in large tables.
+*/
+_static_inline int64_t
+coord_csep(cube_t c)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 2)
+                ret += p * ((c.corner[i] & _csepbit) >> 2);
+
+        return ret;
+}
+
+_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)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 1, p = 1; i < 12; i++, p *= 2)
+                ret += p * (c.edge[i] >> _eoshift);
+
+        return ret;
+}
+
+/*
+We encode the edge separation as a number from 0 to C(12,4)*C(8,4).
+It can be seen as the composition of two "subset index" coordinates.
+*/
+_static_inline int64_t
+coord_esep(cube_t c)
+{
+        int64_t i, j, jj, k, l, ret1, ret2, bit1, bit2, is1;
+
+        for (i = 0, j = 0, k = 4, l = 4, ret1 = 0, ret2 = 0; i < 12; i++) {
+                /* Simple version:
+                if (c.edge[i] & _esepbit2) {
+                        ret1 += binomial[11-i][k--];
+                } else {
+                        if (c.edge[i] & _esepbit1)
+                                ret2 += binomial[7-j][l--];
+                        j++;
+                }
+                */
+
+                bit1 = (c.edge[i] & _esepbit1) >> 2;
+                bit2 = (c.edge[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 *dest, cube_t src)
+{
+        memcpy(&dest->corner, src.corner, sizeof(src.corner));
+}
+
+_static_inline void
+copy_edges(cube_t *dest, cube_t src)
+{
+        memcpy(&dest->edge, src.edge, sizeof(src.edge));
+}
+
+_static_inline void
+set_eo(cube_t *cube, int64_t eo)
+{
+        uint8_t i, sum, flip;
+
+        for (sum = 0, i = 1; i < 12; i++, eo >>= 1) {
+                flip = eo % 2;
+                sum += flip;
+                cube->edge[i] = (cube->edge[i] & ~_eobit) | (_eobit * flip);
+        }
+        cube->edge[0] = (cube->edge[0] & ~_eobit) | (_eobit * (sum % 2));
+}
+
+_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;
+        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;
+
+                ret.edge[i] = (slice[s]++) | (uint8_t)(s << 2);
+        }
+
+        return ret;
+}