SYN_STRIDE
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE, y += SYN_STRIDE) {
for (; x < xend; x += SYN_STRIDE, y += SYN_STRIDE) {
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE, y += SYN_STRIDE,
z += SYN_STRIDE) {
for (; y < yend; y += SYN_STRIDE, z += SYN_STRIDE) {
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE) {
for (; x < xend; x += SYN_STRIDE) {
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE) {
for (; x < xend; x += SYN_STRIDE) {
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE, y += SYN_STRIDE) {
for (; y < yend; y += SYN_STRIDE) {
for (; d < dend; d += SYN_STRIDE, x += SYN_STRIDE, y += SYN_STRIDE) {
for (; y < yend; y += SYN_STRIDE) {