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/*
** Bit counter by Ratko Tomic
*/
int bit_count(long x)
{
int n = 0;
/*
** The loop will execute once for each bit of x set, this is in average
** twice as fast as the shift/test method.
*/
if (x) do
n++;
while (0 != (x = x&(x-1)))
;
return(n);
}
#ifdef TEST
#include <stdio.h>
#include <stdlib.h>
#define plural_text(n) &"s"[(1 == (n))]
void main(int argc, char *argv[])
{
long n;
while(--argc)
{
int i;
n = atol(*++argv);
i = bit_count(n);
printf("%ld contains %d bit%s set\n",
n, i, plural_text(i));
}
}
#endif /* TEST */
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