Hi,

I wonder how could I find closest lower power of two to a given unsigned integer. The best way would be to get the bit position of most significant bit set. But how would I find it it with as few bitwise operations as possible? I must avoid any cycle, plus, I do not want to use the look up table as I find it uninteligent.

unsigned round_down_to_power_of_2(unsigned x) {
  return 0x80000000u >> __builtin_clz(x);
}