1 files changed, 11 insertions, 0 deletions

diff --git a/src/arch/portable.h b/src/arch/portable.h
index 26001ee..d673f15 100644
--- a/src/arch/portable.h
+++ b/src/arch/portable.h
@@ -356,3 +356,14 @@ invcoord_epe(uint64_t i)
         return STATIC_CUBE(0, 1, 2, 3, 4, 5, 6, 7,
             0, 1, 2, 3, 4, 5, 6, 7, e[0]+8, e[1]+8, e[2]+8, e[3]+8);
 }
+
+STATIC_INLINE bool
+is_eo_even(cube_t cube)
+{
+        uint8_t i, count;
+
+        for (i = 0, count = 0; i < 12; i++)
+                count += (cube.edge[i] & EOBIT) >> EOSHIFT;
+
+        return count % 2 == 0;
+}