#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
+#include <limits.h>
-#define BITS_PER_LONG (sizeof(unsigned long) * 8)
+typedef unsigned long bitmap_word;
+
+#define BITMAP_WORD_BITS (sizeof(bitmap_word) * CHAR_BIT)
+#define BITMAP_NWORDS(_n) (((_n) + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS)
/*
- * We use an unsigned long to get alignment, but wrap it in a
- * structure for type checking
+ * We wrap each word in a structure for type checking.
*/
typedef struct {
- unsigned long l;
+ bitmap_word w;
} bitmap;
-#define BYTE(_bm, _n) (((unsigned char *)(_bm))[(_n) / 8])
-#define LONG(_bm, _n) (((unsigned long *)(_bm))[(_n) / BITS_PER_LONG])
+static inline size_t bitmap_sizeof(int nbits)
+{
+ return BITMAP_NWORDS(nbits) * sizeof(bitmap_word);
+}
+
+static inline bitmap *bitmap_alloc(int nbits)
+{
+ return malloc(bitmap_sizeof(nbits));
+}
+
+#define BYTE(_bm, _n) (((unsigned char *)(_bm))[(_n) / CHAR_BIT])
#define BIT(_n) (0x80 >> ((_n) % 8))
+#define WORD(_bm, _n) ((_bm)[(_n) / BITMAP_WORD_BITS].w)
#define BYTES(_nbits) ((_nbits) / 8)
#define BITS(_nbits) ((~(0xff >> ((_nbits) % 8))) & 0xff)
int nbits) \
{ \
int n = 0; \
- while ((nbits - n) >= BITS_PER_LONG) { \
- LONG(dst, n) = LONG(src1, n) _op LONG(src2, n); \
- n += BITS_PER_LONG; \
+ while ((nbits - n) >= BITMAP_WORD_BITS) { \
+ WORD(dst, n) = WORD(src1, n) _op WORD(src2, n); \
+ n += BITMAP_WORD_BITS; \
} \
while ((nbits - n) >= 8) { \
BYTE(dst, n) = BYTE(src1, n) _op BYTE(src2, n); \
{
int n = 0;
- while ((nbits - n) >= BITS_PER_LONG) {
- LONG(dst, n) = ~LONG(src, n);
- n += BITS_PER_LONG;
+ while ((nbits - n) >= BITMAP_WORD_BITS) {
+ WORD(dst, n) = ~WORD(src, n);
+ n += BITMAP_WORD_BITS;
}
while ((nbits - n) >= 8) {
BYTE(dst, n) = ~BYTE(src, n);
{
int n = 0;
- while ((nbits - n) >= BITS_PER_LONG) {
- if (LONG(src1, n) & LONG(src2, n))
+ while ((nbits - n) >= BITMAP_WORD_BITS) {
+ if (WORD(src1, n) & WORD(src2, n))
return true;
- n += BITS_PER_LONG;
+ n += BITMAP_WORD_BITS;
}
while ((nbits - n) >= 8) {
if (BYTE(src1, n) & BYTE(src2, n))
{
int n = 0;
- while ((nbits - n) >= BITS_PER_LONG) {
- if (LONG(src1, n) & ~LONG(src2, n))
+ while ((nbits - n) >= BITMAP_WORD_BITS) {
+ if (WORD(src1, n) & ~WORD(src2, n))
return false;
- n += BITS_PER_LONG;
+ n += BITMAP_WORD_BITS;
}
while ((nbits - n) >= 8) {
if (BYTE(src1, n) & ~BYTE(src2, n))
{
int n = 0;
- while ((nbits - n) >= BITS_PER_LONG) {
- if (LONG(bitmap, n) != -1UL)
+ while ((nbits - n) >= BITMAP_WORD_BITS) {
+ if (WORD(bitmap, n) != -1UL)
return false;
- n += BITS_PER_LONG;
+ n += BITMAP_WORD_BITS;
}
while ((nbits - n) >= 8) {
if (BYTE(bitmap, n) != 0xff)
{
int n = 0;
- while ((nbits - n) >= BITS_PER_LONG) {
- if (LONG(bitmap, n))
+ while ((nbits - n) >= BITMAP_WORD_BITS) {
+ if (WORD(bitmap, n))
return false;
- n += BITS_PER_LONG;
+ n += BITMAP_WORD_BITS;
}
while ((nbits - n) >= 8) {
if (BYTE(bitmap, n))
}
-static inline bitmap *bitmap_alloc(int nbits)
-{
- return malloc((nbits + 7) / 8);
-}
-
#undef BYTE
-#undef LONG
+#undef WORD
#undef BIT
#undef BYTES
#undef BITS