给定正整数 N, 求使N < 2^m 成立的最小m（C语言版）

给定n,求使n < 2^m成立的最小m

unsigned int fixsize( unsigned int n ) {
    n |= n >> 1;
    n |= n >> 2;
    n |= n >> 4;
    n |= n >> 8;
    n |= n >> 16;
    return n + 1;
}