gmp_popcount
    (PHP 4 >= 4.0.4, PHP 5)
gmp_popcount -- Population count
Description
int 
gmp_popcount ( resource a )
     Return the population count of a.
    
Example 1. gmp_popcount() example 
<?php $pop1 = gmp_init("10000101", 2); // 3 1's echo gmp_popcount($pop1) . "\n"; $pop2 = gmp_init("11111110", 2); // 7 1's echo gmp_popcount($pop2) . "\n"; ?>
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      The printout of the above program will be:
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