Added avx2 moves

1 files changed, 44 insertions, 5 deletions

diff --git a/src/cube.c b/src/cube.c
index 73f50af..401895e 100644
--- a/src/cube.c
+++ b/src/cube.c
@@ -269,6 +269,7 @@ static char *transstr[] = {
         [BLm] = "mirrored BL",
 };
 
+static inline cube_t inline_compose(cube_t, cube_t);
 static bool isconsistent(cube_t);
 static cube_t flipallcorners(cube_t);
 static uint8_t readco(char *);
@@ -909,18 +910,49 @@ cube_t
 inverse(cube_t c)
 {
         /* TODO: optimize for avx2 */
-        uint8_t i, piece, orien;
         cube_t ret;
 
-        setzero(ret);
-
 #ifdef DEBUG
         if (!isconsistent(c)) {
                 fprintf(stderr, "inverse error, inconsistent cube\n");
+                setzero(ret);
                 return ret;
         }
 #endif
 
+#ifdef CUBE_AVX2
+        /* Method taken from Andrew Skalski's vcube[1]. The addition sequence
+         * was generated using [2].
+         * [1] https://github.com/Voltara/vcube
+         * [2] http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
+         */
+        cube_t v3, vi;
+
+        v3 = _mm256_shuffle_epi8(c, c);
+        v3 = _mm256_shuffle_epi8(v3, c);
+        vi = _mm256_shuffle_epi8(v3, v3);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, v3);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, c);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        vi = _mm256_shuffle_epi8(vi, v3);
+        vi = _mm256_shuffle_epi8(vi, vi);
+        ret = _mm256_shuffle_epi8(vi, c);
+        
+        return flipallcorners(ret);
+#else
+        uint8_t i, piece, orien;
+
+        setzero(ret);
+
         for (i = 0; i < 12; i++) {
                 piece = get_edge(c, i);
                 orien = piece & _eobit;
@@ -932,12 +964,13 @@ inverse(cube_t c)
                 orien = ((piece << 1) | (piece >> 1)) & _cobits2;
                 set_corner(ret, piece & _pbits, i | orien);
         }
+#endif
 
         return ret;
 }
 
-cube_t
-compose(cube_t c1, cube_t c2)
+static inline cube_t
+inline_compose(cube_t c1, cube_t c2)
 {
         cube_t ret;
 
@@ -992,6 +1025,12 @@ compose(cube_t c1, cube_t c2)
 }
 
 cube_t
+compose(cube_t c1, cube_t c2)
+{
+        return inline_compose(c1, c2);
+}
+
+cube_t
 transform(cube_t c, trans_t t)
 {
         cube_t ret;