move alpha to x19/x20 to leave x18 unused for OSX
@@ -48,8 +48,8 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#define pCRow2 x14
#define pCRow3 x15
#define pA x16
-#define alphaR x17
-#define alphaI x18
+#define alphaR x19
+#define alphaI x20
#define alpha0_R d10
#define alphaV0_R v10.d[0]
