4 * @author Sebastian Hack
5 * @brief A bitset implementation.
8 #ifndef __FIRM_BITSET_H
9 #define __FIRM_BITSET_H
16 #include "firm_config.h"
17 #include "bitfiddle.h"
19 typedef unsigned int bitset_pos_t;
21 #include "bitset_std.h"
24 #if defined(__GNUC__) && defined(__i386__)
25 #include "bitset_ia32.h"
29 typedef struct _bitset_t {
35 #define BS_UNIT_SIZE sizeof(bitset_unit_t)
36 #define BS_UNIT_SIZE_BITS (BS_UNIT_SIZE * 8)
37 #define BS_UNIT_MASK (BS_UNIT_SIZE_BITS - 1)
40 * Initialize a bitset.
41 * This functions should not be called.
43 * Note that this function needs three macros which must be provided by the
44 * bitfield implementor:
45 * - _bitset_overall_size(size) The overall size that must be
46 * allocated for the bitfield in bytes.
47 * - _bitset_units(size) The number of units that will be
48 * present in the bitfield for a given highest bit.
49 * - _bitset_data_ptr(data, size) This produces as pointer to the
50 * first unit in the allocated memory area. The main reason for this
51 * macro is, that some bitset implementors want control over memory
54 * @param area A pointer to memory reserved for the bitset.
55 * @param size The size of the bitset in bits.
56 * @return A pointer to the initialized bitset.
58 static INLINE bitset_t *_bitset_prepare(void *area, bitset_pos_t size)
61 memset(area, 0, _bitset_overall_size(sizeof(bitset_t), size));
62 ptr->units = _bitset_units(size);
64 ptr->data = _bitset_data_ptr(area, sizeof(bitset_t), size);
69 * Mask out all bits, which are only there, because the number
70 * of bits in the set didn't match a unit size boundary.
71 * @param bs The bitset.
72 * @return The masked bitset.
74 static INLINE bitset_t *_bitset_mask_highest(bitset_t *bs)
76 bitset_pos_t rest = bs->size & BS_UNIT_MASK;
78 bs->data[bs->units - 1] &= (1 << rest) - 1;
83 * Get the capacity of the bitset in bits.
84 * @param bs The bitset.
85 * @return The capacity in bits of the bitset.
87 #define bitset_capacity(bs) ((bs)->units * BS_UNIT_SIZE_BITS)
90 * Get the size of the bitset in bits.
91 * @note Note the difference between capacity and size.
92 * @param bs The bitset.
93 * @return The highest bit which can be set or cleared plus 1.
95 #define bistet_size(bs) ((bs)->size)
98 * Allocate a bitset on an obstack.
99 * @param obst The obstack.
100 * @param size The greatest bit that shall be stored in the set.
101 * @return A pointer to an empty initialized bitset.
103 #define bitset_obstack_alloc(obst,size) \
104 _bitset_prepare(obstack_alloc(obst, _bitset_overall_size(sizeof(bitset_t), size)), size)
107 * Allocate a bitset via malloc.
108 * @param size The greatest bit that shall be stored in the set.
109 * @return A pointer to an empty initialized bitset.
111 #define bitset_malloc(size) \
112 _bitset_prepare(malloc(_bitset_overall_size(sizeof(bitset_t), size)), size)
115 * Free a bitset allocated with bitset_malloc().
116 * @param bs The bitset.
118 #define bitset_free(bs) free(bs)
121 * Allocate a bitset on the stack via alloca.
122 * @param size The greatest bit that shall be stored in the set.
123 * @return A pointer to an empty initialized bitset.
125 #define bitset_alloca(size) \
126 _bitset_prepare(alloca(_bitset_overall_size(sizeof(bitset_t), size)), size)
130 * Get the unit which contains a specific bit.
131 * This function is internal.
132 * @param bs The bitset.
133 * @param bit The bit.
134 * @return A pointer to the unit containing the bit.
136 static INLINE bitset_unit_t *_bitset_get_unit(const bitset_t *bs, bitset_pos_t bit)
138 /* assert(bit < bs->units * BS_UNIT_SIZE_BITS && "Bit too large"); */
139 assert(bit <= bs->size && "Bit to large");
140 return bs->data + bit / BS_UNIT_SIZE_BITS;
144 * Set a bit in the bitset.
145 * @param bs The bitset.
146 * @param bit The bit to set.
148 static INLINE void bitset_set(bitset_t *bs, bitset_pos_t bit)
150 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
151 _bitset_inside_set(unit, bit & BS_UNIT_MASK);
155 * Clear a bit in the bitset.
156 * @param bs The bitset.
157 * @param bit The bit to clear.
159 static INLINE void bitset_clear(bitset_t *bs, bitset_pos_t bit)
161 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
162 _bitset_inside_clear(unit, bit & BS_UNIT_MASK);
166 * Check, if a bit is set.
167 * @param bs The bitset.
168 * @param bit The bit to check for.
169 * @return 1, if the bit was set, 0 if not.
171 static INLINE int bitset_is_set(const bitset_t *bs, bitset_pos_t bit)
173 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
174 return _bitset_inside_is_set(unit, bit & BS_UNIT_MASK);
178 * Flip a bit in a bitset.
179 * @param bs The bitset.
180 * @param bit The bit to flip.
182 static INLINE void bitset_flip(bitset_t *bs, bitset_pos_t bit)
184 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
185 _bitset_inside_flip(unit, bit & BS_UNIT_MASK);
189 * Copy a bitset to another.
190 * @param tgt The target bitset.
191 * @param src The source bitset.
192 * @return The target bitset.
194 static INLINE bitset_t *bitset_copy(bitset_t *tgt, const bitset_t *src)
196 bitset_pos_t tu = tgt->units;
197 bitset_pos_t su = src->units;
198 bitset_pos_t min_units = tu < su ? tu : su;
199 memcpy(tgt->data, src->data, min_units * BS_UNIT_SIZE);
201 memset(tgt->data + min_units, 0, BS_UNIT_SIZE * (tu - min_units));
202 return _bitset_mask_highest(tgt);
206 * Find the smallest bit set in the bitset.
207 * @param bs The bitset.
208 * @return The smallest bit set in the bitset.
210 static INLINE bitset_pos_t bitset_min(const bitset_t *bs)
212 bitset_pos_t i, ofs = 0;
214 for(i = 0; i < bs->units; ++i) {
215 bitset_unit_t *unit = &bs->data[i];
216 bitset_pos_t pos = _bitset_inside_ntz(unit);
219 ofs += BS_UNIT_SIZE_BITS;
226 * Find the greatest bit set in the bitset.
227 * @param bs The bitset.
228 * @return The greatest bit set in the bitset.
230 static INLINE bitset_pos_t bitset_max(const bitset_t *bs)
232 bitset_pos_t i, max = 0, ofs = 0;
234 for(i = 0; i < bs->units; ++i) {
235 bitset_unit_t *unit = &bs->data[i];
236 bitset_pos_t pos = _bitset_inside_nlz(unit);
239 ofs += BS_UNIT_SIZE_BITS;
246 * Find the next set bit from a given bit.
247 * @note Note that if pos is set, pos is returned.
248 * @param bs The bitset.
249 * @param pos The bit from which to search for the next set bit.
250 * @return The next set bit from pos on, or -1, if no set bit was found
253 static INLINE bitset_pos_t _bitset_next(const bitset_t *bs,
254 bitset_pos_t pos, int set)
256 bitset_pos_t unit_number = pos / BS_UNIT_SIZE_BITS;
258 if(unit_number >= bs->units)
262 bitset_pos_t bit_in_unit = pos & BS_UNIT_MASK;
263 bitset_pos_t in_unit_mask = (1 << bit_in_unit) - 1;
266 * Mask out the bits smaller than pos in the current unit.
267 * We are only interested in bits set higher than pos.
269 bitset_unit_t curr_unit = bs->data[unit_number];
272 * Find the next bit set in the unit.
273 * Mind that this function returns 0, if the unit is -1 and
274 * counts the bits from 1 on.
276 bitset_pos_t next_in_this_unit =
277 _bitset_inside_ntz_value((set ? curr_unit : ~curr_unit) & ~in_unit_mask);
279 /* If there is a bit set in the current unit, exit. */
280 if(next_in_this_unit < BS_UNIT_SIZE_BITS)
281 return next_in_this_unit + unit_number * BS_UNIT_SIZE_BITS;
283 /* Else search for set bits in the next units. */
286 for(i = unit_number + 1; i < bs->units; ++i) {
287 bitset_unit_t data = bs->data[i];
288 bitset_pos_t first_set =
289 _bitset_inside_ntz_value(set ? data : ~data);
291 if(first_set < BS_UNIT_SIZE_BITS)
292 return first_set + i * BS_UNIT_SIZE_BITS;
300 #define bitset_next_clear(bs,pos) _bitset_next((bs), (pos), 0)
301 #define bitset_next_set(bs,pos) _bitset_next((bs), (pos), 1)
304 * Convenience macro for bitset iteration.
305 * @param bitset The bitset.
306 * @param elm A unsigned long variable.
308 #define bitset_foreach(bitset,elm) \
309 for(elm = bitset_next_set(bitset,0); elm != -1; elm = bitset_next_set(bitset,elm+1))
312 #define bitset_foreach_clear(bitset,elm) \
313 for(elm = bitset_next_clear(bitset,0); elm != -1; elm = bitset_next_clear(bitset,elm+1))
316 * Count the bits set.
317 * This can also be seen as the cardinality of the set.
318 * @param bs The bitset.
319 * @return The number of bits set in the bitset.
321 static INLINE bitset_pos_t bitset_popcnt(const bitset_t *bs)
323 bitset_pos_t i, pop = 0;
326 for(i = 0, unit = bs->data; i < bs->units; ++i, ++unit)
327 pop += _bitset_inside_pop(unit);
334 * This sets all bits to zero.
335 * @param bs The bitset.
337 static INLINE bitset_t *bitset_clear_all(bitset_t *bs)
339 memset(bs->data, 0, BS_UNIT_SIZE * bs->units);
345 * This sets all bits to one.
346 * @param bs The bitset.
348 static INLINE bitset_t *bitset_set_all(bitset_t *bs)
350 memset(bs->data, -1, bs->units * BS_UNIT_SIZE);
351 return _bitset_mask_highest(bs);
355 * Check, if one bitset is contained by another.
356 * That is, each bit set in lhs is also set in rhs.
357 * @param lhs A bitset.
358 * @param rhs Another bitset.
359 * @return 1, if all bits in lhs are also set in rhs, 0 otherwise.
361 static INLINE int bitset_contains(const bitset_t *lhs, const bitset_t *rhs)
363 bitset_pos_t n = lhs->units < rhs->units ? lhs->units : rhs->units;
366 for(i = 0; i < n; ++i) {
367 bitset_unit_t lu = lhs->data[i];
368 bitset_unit_t ru = rhs->data[i];
375 * If the left hand sinde is a larger bitset than rhs,
376 * we have to check, that all extra bits in lhs are 0
379 for(i = n; i < lhs->units; ++i) {
380 if(lhs->data[i] != 0)
389 * Treat the bitset as a number and subtract 1.
390 * @param bs The bitset.
391 * @return The same bitset.
393 static INLINE void bitset_minus1(bitset_t *bs)
395 #define _SH (sizeof(bitset_unit_t) * 8 - 1)
399 for(i = 0; i < bs->units; ++i) {
400 bitset_unit_t unit = bs->data[i];
401 bitset_unit_t um1 = unit - 1;
405 if(((unit >> _SH) ^ (um1 >> _SH)) == 0)
412 * Print a bitset to a stream.
413 * The bitset is printed as a comma seperated list of bits set.
414 * @param file The stream.
415 * @param bs The bitset.
417 static INLINE void bitset_fprint(FILE *file, const bitset_t *bs)
419 const char *prefix = "";
423 for(i = bitset_next_set(bs, 0); i != -1; i = bitset_next_set(bs, i + 1)) {
424 fprintf(file, "%s%u", prefix, i);
430 static INLINE void bitset_debug_fprint(FILE *file, const bitset_t *bs)
434 fprintf(file, "%u:", bs->units);
435 for(i = 0; i < bs->units; ++i)
436 fprintf(file, " " BITSET_UNIT_FMT, bs->data[i]);
440 * Here, the binary operations follow.
441 * And, Or, And Not, Xor are available.
443 #define BINARY_OP(op) \
444 static INLINE bitset_t *bitset_ ## op(bitset_t *tgt, const bitset_t *src) \
447 bitset_pos_t n = tgt->units > src->units ? src->units : tgt->units; \
448 for(i = 0; i < n; i += _BITSET_BINOP_UNITS_INC) \
449 _bitset_inside_binop_ ## op(&tgt->data[i], &src->data[i]); \
451 _bitset_clear_rest(&tgt->data[i], tgt->units - i); \
452 return _bitset_mask_highest(tgt); \
456 * Define the clear rest macro for the and, since it is the only case,
457 * were non existed (treated as 0) units in the src must be handled.
458 * For all other operations holds: x Op 0 = x for Op in { Andnot, Or, Xor }
460 * For and, each bitset implementer has to provide the macro
461 * _bitset_clear_units(data, n), which clears n units from the pointer
464 #define _bitset_clear_rest(data,n) _bitset_inside_clear_units(data, n)
466 #undef _bitset_clear_rest
467 #define _bitset_clear_rest(data,n)