99 * Count the number of '1' bits in a word.

100 *

101 * Having completed this, I'm ready for an interview at Google.

102 *

103 * TODO? there's a parallel version w/o loops. Performance not currently

104 * important.

105 */

106 static int countOnes(u4 val)

107 {

108 int count = 0;

109

110 while (val != 0) {

111 val &= val-1;

112 count++;

113 }

114

115 return count;

116 }