no libc, start on socket x11

Common/zord.h

@@ -0,0 +1,36 @@
+#ifndef COM_ZORD_H
+#define COM_ZORD_H
+#include <stdint.h>
+
+// #include <immintrin.h>
+
+extern const uint16_t com_zord_morton_table[];
+
+/* Z-filling curve to help with cache and data locality. */
+static inline uint32_t com_zord_order(uint16_t x, uint16_t y) {
+  return (com_zord_morton_table[y >> 8] << 17) |
+         (com_zord_morton_table[x >> 8] << 16) |
+         (com_zord_morton_table[y & 0xFF] << 1) |
+         (com_zord_morton_table[x & 0xFF]);
+
+  // return _pdep_u32(x, 0x55555555) | _pdep_u32(y, 0xAAAAAAAA);
+}
+
+/* https://en.wikipedia.org/wiki/Z-order_curve#Coordinate_values*/
+static inline uint32_t com_zord_inc_x(uint32_t z) {
+  return (((z | 0b10101010) + 1) & 0b01010101) | (z & 0b10101010);
+}
+
+static inline uint32_t com_zord_dec_x(uint32_t z) {
+  return (((z & 0b01010101) - 1) & 0b01010101) | (z & 0b10101010);
+}
+
+static inline uint32_t com_zord_inc_y(uint32_t z) {
+  return (((z | 0b01010101) + 1) & 0b10101010) | (z & 0b01010101);
+}
+
+static inline uint32_t com_zord_dec_y(uint32_t z) {
+  return (((z & 0b10101010) - 1) & 0b10101010) | (z & 0b01010101);
+}
+
+#endif