Calculate a ceiling 'power of 2' value without assembler or loop

calc_power_of_2.h

static inline uint32_t calc_power_of_2(uint32_t n)
{
  --n;
  n |= (n >> 1);
  n |= (n >> 2);
  n |= (n >> 4);
  n |= (n >> 8);
  n |= (n >> 16);
  ++n;
  return n;
}