4 * @author Sebastian Hack
5 * @brief A bitset implementation.
8 #ifndef __FIRM_BITSET_H
9 #define __FIRM_BITSET_H
17 #include "bitfiddle.h"
19 #include "bitset_std.h"
21 /* #if defined(__GNUC__) && defined(__i386__) */
23 #include "bitset_ia32.h"
26 typedef struct _bitset_t {
31 #define BS_UNIT_SIZE sizeof(unsigned long)
32 #define BS_UNIT_SIZE_BITS (BS_UNIT_SIZE * 8)
33 #define BS_UNIT_MASK (BS_UNIT_SIZE_BITS - 1)
36 * Initialize a bitset.
37 * This functions should not be called.
39 * Note that this function needs three macros which must be provided by the
40 * bitfield implementor:
41 * - _bitset_overall_size(highest_bit) The overall size that must be
42 * allocated for the bitfield in bytes.
43 * - _bitset_units(highest_bit) The number of units that will be
44 * present in the bitfield for a given highest bit.
45 * - _bitset_data_ptr(data, highest_bit) This produces as pointer to the
46 * first unit in the allocated memory area. The main reason for this
47 * macro is, that some bitset implementors want control over memory
50 * @param area A pointer to memory reserved for the bitset.
51 * @param units The number of units that are allocated for the bitset.
52 * @return A pointer to the initialized bitset.
54 static INLINE bitset_t *_bitset_prepare(void *area, unsigned long highest_bit)
57 memset(area, 0, _bitset_overall_size(sizeof(bitset_t), highest_bit));
58 ptr->units = _bitset_units(highest_bit);
59 ptr->data = _bitset_data_ptr(area, sizeof(bitset_t), highest_bit);
64 * Get the capacity of the bitset in bits.
65 * @param bs The bitset.
66 * @return The capacity in bits of the bitset.
68 #define bitset_capacity(bs) ((bs)->units * BS_UNIT_SIZE_BITS)
71 * Allocate a bitset on an obstack.
72 * @param obst The obstack.
73 * @param highest_bit The greatest bit that shall be stored in the set.
74 * @return A pointer to an empty initialized bitset.
76 #define bitset_obstack_alloc(obst,highest_bit) \
77 _bitset_prepare(obstack_alloc(obst, _bitset_overall_size(sizeof(bitset_t), highest_bit)), highest_bit)
80 * Allocate a bitset via malloc.
81 * @param highest_bit The greatest bit that shall be stored in the set.
82 * @return A pointer to an empty initialized bitset.
84 #define bitset_malloc(highest_bit) \
85 _bitset_prepare(malloc(_bitset_overall_size(sizeof(bitset_t), highest_bit)), highest_bit)
88 * Free a bitset allocated with bitset_malloc().
89 * @param bs The bitset.
91 #define bitset_free(bs) free(bs)
94 * Allocate a bitset on the stack via alloca.
95 * @param highest_bit The greatest bit that shall be stored in the set.
96 * @return A pointer to an empty initialized bitset.
98 #define bitset_alloca(highest_bit) \
99 _bitset_prepare(alloca(_bitset_overall_size(sizeof(bitset_t), highest_bit)), highest_bit)
103 * Get the unit which contains a specific bit.
104 * This function is internal.
105 * @param bs The bitset.
106 * @param bit The bit.
107 * @return A pointer to the unit containing the bit.
109 static INLINE unsigned long *_bitset_get_unit(const bitset_t *bs, unsigned long bit)
111 assert(bit < bs->units * BS_UNIT_SIZE_BITS && "Bit too large");
112 return bs->data + bit / BS_UNIT_SIZE_BITS;
116 * Set a bit in the bitset.
117 * @param bs The bitset.
118 * @param bit The bit to set.
120 static INLINE void bitset_set(bitset_t *bs, unsigned long bit)
122 unsigned long *unit = _bitset_get_unit(bs, bit);
123 _bitset_inside_set(unit, bit & BS_UNIT_MASK);
127 * Clear a bit in the bitset.
128 * @param bs The bitset.
129 * @param bit The bit to clear.
131 static INLINE void bitset_clear(bitset_t *bs, unsigned long bit)
133 unsigned long *unit = _bitset_get_unit(bs, bit);
134 _bitset_inside_clear(unit, bit & BS_UNIT_MASK);
137 static INLINE int bitset_is_set(const bitset_t *bs, unsigned long bit)
139 unsigned long *unit = _bitset_get_unit(bs, bit);
140 return _bitset_inside_is_set(unit, bit & BS_UNIT_MASK);
144 * Flip a bit in a bitset.
145 * @param bs The bitset.
146 * @param bit The bit to flip.
148 static INLINE void bitset_flip(bitset_t *bs, unsigned long bit)
150 unsigned long *unit = _bitset_get_unit(bs, bit);
151 _bitset_inside_flip(unit, bit & BS_UNIT_MASK);
155 * Copy a bitset to another.
156 * @param tgt The target bitset.
157 * @param src The source bitset.
158 * @return The target bitset.
160 static INLINE bitset_t *bitset_copy(bitset_t *tgt, const bitset_t *src)
162 unsigned long tu = tgt->units;
163 unsigned long su = src->units;
164 unsigned long min_units = tu < su ? tu : su;
165 memcpy(tgt->data, src->data, min_units * BS_UNIT_SIZE);
167 memset(tgt->data + min_units, 0, BS_UNIT_SIZE * (tu - min_units));
172 * Find the smallest bit set in the bitset.
173 * @param bs The bitset.
174 * @return The smallest bit set in the bitset.
176 static INLINE unsigned long bitset_min(const bitset_t *bs)
178 unsigned long i, ofs = 0;
180 for(i = 0; i < bs->units; ++i) {
181 unsigned long *unit = &bs->data[i];
182 unsigned long pos = _bitset_inside_ntz(unit);
185 ofs += BS_UNIT_SIZE_BITS;
192 * Find the greatest bit set in the bitset.
193 * @param bs The bitset.
194 * @return The greatest bit set in the bitset.
196 static INLINE unsigned long bitset_max(const bitset_t *bs)
198 unsigned long i, max = 0, ofs = 0;
200 for(i = 0; i < bs->units; ++i) {
201 unsigned long *unit = &bs->data[i];
202 unsigned long pos = _bitset_inside_nlz(unit);
205 ofs += BS_UNIT_SIZE_BITS;
212 * Find the next set bit from a given bit.
213 * @note Note that if pos is set, pos is returned.
214 * @param bs The bitset.
215 * @param pos The bit from which to search for the next set bit.
216 * @return The next set bit from pos on, or -1, if no set bit was found
219 static INLINE unsigned long _bitset_next(const bitset_t *bs,
220 unsigned long pos, int set)
222 unsigned long unit_number = pos / BS_UNIT_SIZE_BITS;
223 unsigned long bit_in_unit = pos & BS_UNIT_MASK;
224 unsigned long in_unit_mask = (1 << bit_in_unit) - 1;
227 * Mask out the bits smaller than pos in the current unit.
228 * We are only interested in bits set higher than pos.
230 unsigned long curr_unit = bs->data[unit_number] & ~in_unit_mask;
232 /* Find the next bit set in the unit. */
233 unsigned long next_in_this_unit
234 = _bitset_inside_ntz_value(set ? curr_unit : ~curr_unit);
236 /* If there is a bit set in the current unit, exit. */
237 if(next_in_this_unit < BS_UNIT_SIZE_BITS)
238 return next_in_this_unit + unit_number * BS_UNIT_SIZE_BITS;
240 /* Else search for set bits in the next units. */
243 for(i = unit_number + 1; i < bs->units; ++i) {
244 unsigned long data = bs->data[i];
245 unsigned long first_set = _bitset_inside_ntz_value(set ? data : ~data);
246 if(first_set < BS_UNIT_SIZE_BITS)
247 return first_set + i * BS_UNIT_SIZE_BITS;
254 #define bitset_next_clear(bs,pos) _bitset_next((bs), (pos), 0)
255 #define bitset_next_set(bs,pos) _bitset_next((bs), (pos), 1)
258 * Convenience macro for bitset iteration.
259 * @param bitset The bitset.
260 * @param elm A unsigned long variable.
262 #define bitset_foreach(bitset,elm) \
263 for(elm = bitset_next_set(bitset,0); elm != -1; elm = bitset_next_set(bitset,elm+1))
266 * Count the bits set.
267 * This can also be seen as the cardinality of the set.
268 * @param bs The bitset.
269 * @return The number of bits set in the bitset.
271 static INLINE unsigned long bitset_popcnt(const bitset_t *bs)
273 unsigned long i, pop = 0;
276 for(i = 0, unit = bs->data; i < bs->units; ++i, ++unit)
277 pop += _bitset_inside_pop(unit);
284 * This sets all bits to zero.
285 * @param bs The bitset.
287 static INLINE void bitset_clear_all(bitset_t *bs)
289 memset(bs->data, 0, BS_UNIT_SIZE * bs->units);
293 * Check, if one bitset is contained by another.
294 * That is, each bit set in lhs is also set in rhs.
295 * @param lhs A bitset.
296 * @param rhs Another bitset.
297 * @return 1, if all bits in lhs are also set in rhs, 0 otherwise.
299 static INLINE int bitset_contains(const bitset_t *lhs, const bitset_t *rhs)
301 unsigned long n = lhs->units < rhs->units ? lhs->units : rhs->units;
304 for(i = 0; i < n; ++i) {
305 unsigned long lu = lhs->data[i];
306 unsigned long ru = rhs->data[i];
313 * If the left hand sinde is a larger bitset than rhs,
314 * we have to check, that all extra bits in lhs are 0
317 for(i = n; i < lhs->units; ++i) {
318 if(lhs->data[i] != 0)
327 * Print a bitset to a stream.
328 * The bitset is printed as a comma seperated list of bits set.
329 * @param file The stream.
330 * @param bs The bitset.
332 static INLINE void bitset_fprint(FILE *file, const bitset_t *bs)
334 const char *prefix = "";
338 for(i = bitset_next_set(bs, 0); i != -1; i = bitset_next_set(bs, i + 1)) {
339 fprintf(file, "%s%u", prefix, i);
346 * Here, the binary operations follow.
347 * And, Or, And Not, Xor are available.
350 #define BINARY_OP(op) \
351 static INLINE bitset_t *bitset_ ## op(bitset_t *tgt, const bitset_t *src) \
354 int n = tgt->units > src->units ? src->units : tgt->units; \
355 for(i = 0; i < n; i += _BITSET_BINOP_UNITS_INC) \
356 _bitset_inside_binop_ ## op(&tgt->data[i], &src->data[i]); \
357 for(i = n; i < tgt->units; i += _BITSET_BINOP_UNITS_INC) \
358 _bitset_inside_binop_with_zero_ ## op(&tgt->data[i]); \