log2
log2(long n)
log2(int size)
#define log2 grub_log2
#define log2(n) ffz(~(n))
#define log2 grub_log2
#define log2 grub_log2
#define log2 grub_log2
#undef log2
#define log2(x) __tgmath_log2(x)
log2(double x) {
log2(uint_t x)