Critical comment in jdk: // HD source, section 2-1

Question

I just stumbled upon this comment.

public static int lowestOneBit(int i) { // HD, Section 2-1 return i & -i; } 

in 1.5 java source. What does this comment mean? Is this a link to a book? specification?

Answer 1

HD probably refers to Henry C. Warren's Hacker Delight . Indeed, this formula appears on page 11, section 2-1.