LVL_SIZE
#define LVL_START(n) ((LVL_SIZE - 1) << (((n) - 1) * LVL_CLK_SHIFT))
#define LVL_MASK (LVL_SIZE - 1)
#define LVL_OFFS(n) ((n) * LVL_SIZE)
idx = (clk & LVL_MASK) + i * LVL_SIZE;
unsigned end = offset + LVL_SIZE;
return pos < start ? pos + LVL_SIZE - start : -1;
for (lvl = 0; lvl < LVL_DEPTH; lvl++, offset += LVL_SIZE) {
#define WHEEL_SIZE (LVL_SIZE * LVL_DEPTH)