在Java Java Java Java .lang中，代码注释“HD, Figure”是什么意思?整数的课吗?

for example, the JDK method java.lang.Integer.numberOfLeadingZeros(int):

例如，JDK方法java.lang.Integer.numberOfLeadingZeros(int):

public static int numberOfLeadingZeros(int i) {
    // HD, Figure 5-6
    if (i == 0)
        return 32;
    int n = 1;
    if (i >>> 16 == 0) { n += 16; i <<= 16; }
    if (i >>> 24 == 0) { n +=  8; i <<=  8; }
    if (i >>> 28 == 0) { n +=  4; i <<=  4; }
    if (i >>> 30 == 0) { n +=  2; i <<=  2; }
    n -= i >>> 31;
    return n;
}

what does the code comment 'HD, Figure 5-6' mean?

代码注释“HD，图5-6”是什么意思?

1 个解决方案

#1

HD = Hacker's Delight. See the the javadoc:

高清=黑客的喜悦。看到javadoc:

Implementation note: The implementations of the "bit twiddling" methods (such as highestOneBit and numberOfTrailingZeros) are based on material from Henry S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002).

实现说明:“位旋转”方法(如highestOneBit和numberOfTrailingZeros)的实现基于小亨利·s·沃伦(Henry s . Warren, Jr.)的《黑客的喜悦》(Addison, 2002)。