1 files changed, 33 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/bitcnt_2.c b/reference/C/CONTRIB/SNIP/bitcnt_2.c
new file mode 100755
index 0000000..9046456
--- /dev/null
+++ b/reference/C/CONTRIB/SNIP/bitcnt_2.c
@@ -0,0 +1,33 @@
+int bitcount(long i)
+{
+      i = ((i & 0xAAAAAAAA) >>  1) + (i & 0x55555555);
+      i = ((i & 0xCCCCCCCC) >>  2) + (i & 0x33333333);
+      i = ((i & 0xF0F0F0F0) >>  4) + (i & 0x0F0F0F0F);
+      i = ((i & 0xFF00FF00) >>  8) + (i & 0x00FF00FF);
+      i = ((i & 0xFFFF0000) >> 16) + (i & 0x0000FFFF);
+      return (int)i;
+}
+
+#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 = bitcount(n);
+            printf("%ld contains %d bit%s set\n",
+                  n, i, plural_text(i));
+      }
+}
+
+#endif /* TEST */