diff options
author | Tobias Klauser <tklauser@distanz.ch> | 2008-01-27 11:37:44 +0100 |
---|---|---|
committer | Tobias Klauser <tklauser@xenon.tklauser.home> | 2008-01-27 11:37:44 +0100 |
commit | 7e0f021a9aec35fd8e6725e87e3313b101d26f5e (patch) | |
tree | b1cacc4b24393f517aeb4610e9e1021f954307a8 /reference/C/CONTRIB/SNIP/lbitops.c |
Initial import (2.0.2-6)2.0.2-6
Diffstat (limited to 'reference/C/CONTRIB/SNIP/lbitops.c')
-rwxr-xr-x | reference/C/CONTRIB/SNIP/lbitops.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/lbitops.c b/reference/C/CONTRIB/SNIP/lbitops.c new file mode 100755 index 0000000..85040be --- /dev/null +++ b/reference/C/CONTRIB/SNIP/lbitops.c @@ -0,0 +1,46 @@ +/*
+** large bit array operations by Scott Dudley
+** with modifications by Auke Reitsma and Bob Stout
+**
+** Public domain
+*/
+
+#include <limits.h>
+
+/*
+** The following macros assume CHAR_BIT is one of either 8, 16, or 32
+*/
+
+#define MASK CHAR_BIT-1
+#define SHIFT ((CHAR_BIT==8)?3:(CHAR_BIT==16)?4:8)
+
+#define BitOff(a,x) ((void)((a)[(x)>>SHIFT] &= ~(1 << ((x)&MASK))))
+#define BitOn(a,x) ((void)((a)[(x)>>SHIFT] |= (1 << ((x)&MASK))))
+#define BitFlip(a,x) ((void)((a)[(x)>>SHIFT] ^= (1 << ((x)&MASK))))
+#define IsBit(a,x) ((a)[(x)>>SHIFT] & (1 << ((x)&MASK)))
+
+#include <stdio.h>
+#include <string.h>
+
+int main(void)
+{
+ char array[64];
+
+ memset(array, '\0', sizeof(array));
+
+ BitOn(array, 5);
+ BitOn(array, 12);
+ BitOn(array, 500);
+
+ if (IsBit(array, 5) && IsBit(array, 12) && IsBit(array, 500))
+ puts("These functions seem to work!");
+ else puts("Something's broken here!");
+
+ BitFlip(array, 12);
+ BitOff(array, 5);
+
+ if (!IsBit(array, 5) && !IsBit(array, 12) && IsBit(array, 500))
+ puts("These functions still seem to work!");
+ else puts("Something's broken here!");
+ return 0;
+}
|