/* +++Date last modified: 05-Jul-1997 */ /* ** Bit counter by Ratko Tomic */ #include "bitcount-bitops.h" int CDECL bitcount(long i) { i = ((i & 0xAAAAAAAAL) >> 1) + (i & 0x55555555L); i = ((i & 0xCCCCCCCCL) >> 2) + (i & 0x33333333L); i = ((i & 0xF0F0F0F0L) >> 4) + (i & 0x0F0F0F0FL); i = ((i & 0xFF00FF00L) >> 8) + (i & 0x00FF00FFL); i = ((i & 0xFFFF0000L) >> 16) + (i & 0x0000FFFFL); return (int)i; } #ifdef TEST #include #include "snip_str.h" /* For plural_text() macro */ main(int argc, char *argv[]) { long n; while(--argc) { int i; n = atol(*++argv); i = bitcount(n); printf("%ld contains %d bit%s set\n", n, i, plural_text(i)); } return 0; } #endif /* TEST */