1 files changed, 28 insertions, 0 deletions

diff --git a/src/arch/common.h b/src/arch/common.h
index cd2d36e..d8d2305 100644
--- a/src/arch/common.h
+++ b/src/arch/common.h
@@ -17,3 +17,31 @@ _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_inline void invcoord_esep_array(int64_t, int64_t, uint8_t[static 12]);
+
+_static_inline void
+invcoord_esep_array(int64_t set1, int64_t set2, uint8_t mem[static 12])
+{
+        int64_t bit1, bit2, i, j, jj, k, l, s, v, w, is1;
+        uint8_t slice[3] = {0};
+
+        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);
+        }
+}