4 * @author Sebastian Hack
5 * @brief A bitset implementation.
8 #ifndef __FIRM_BITSET_H
9 #define __FIRM_BITSET_H
11 #include "firm_config.h"
25 #include "bitfiddle.h"
27 typedef unsigned int bitset_pos_t;
29 #include "bitset_std.h"
32 #if defined(__GNUC__) && defined(__i386__)
33 #include "bitset_ia32.h"
37 typedef struct _bitset_t {
43 #define BS_UNIT_SIZE sizeof(bitset_unit_t)
44 #define BS_UNIT_SIZE_BITS (BS_UNIT_SIZE * 8)
45 #define BS_UNIT_MASK (BS_UNIT_SIZE_BITS - 1)
48 * Initialize a bitset.
49 * This functions should not be called.
51 * Note that this function needs three macros which must be provided by the
52 * bitfield implementor:
53 * - _bitset_overall_size(size) The overall size that must be
54 * allocated for the bitfield in bytes.
55 * - _bitset_units(size) The number of units that will be
56 * present in the bitfield for a given highest bit.
57 * - _bitset_data_ptr(data, size) This produces as pointer to the
58 * first unit in the allocated memory area. The main reason for this
59 * macro is, that some bitset implementors want control over memory
62 * @param area A pointer to memory reserved for the bitset.
63 * @param size The size of the bitset in bits.
64 * @return A pointer to the initialized bitset.
66 static INLINE bitset_t *_bitset_prepare(void *area, bitset_pos_t size)
69 memset(area, 0, _bitset_overall_size(sizeof(bitset_t), size));
70 ptr->units = _bitset_units(size);
72 ptr->data = _bitset_data_ptr(area, sizeof(bitset_t), size);
77 * Mask out all bits, which are only there, because the number
78 * of bits in the set didn't match a unit size boundary.
79 * @param bs The bitset.
80 * @return The masked bitset.
82 static INLINE bitset_t *_bitset_mask_highest(bitset_t *bs)
84 bitset_pos_t rest = bs->size & BS_UNIT_MASK;
86 bs->data[bs->units - 1] &= (1 << rest) - 1;
91 * Get the capacity of the bitset in bits.
92 * @param bs The bitset.
93 * @return The capacity in bits of the bitset.
95 #define bitset_capacity(bs) ((bs)->units * BS_UNIT_SIZE_BITS)
98 * Get the size of the bitset in bits.
99 * @note Note the difference between capacity and size.
100 * @param bs The bitset.
101 * @return The highest bit which can be set or cleared plus 1.
103 #define bitset_size(bs) ((bs)->size)
106 * Allocate a bitset on an obstack.
107 * @param obst The obstack.
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_obstack_alloc(obst,size) \
112 _bitset_prepare(obstack_alloc(obst, _bitset_overall_size(sizeof(bitset_t), size)), size)
115 * Allocate a bitset via malloc.
116 * @param size The greatest bit that shall be stored in the set.
117 * @return A pointer to an empty initialized bitset.
119 #define bitset_malloc(size) \
120 _bitset_prepare(xmalloc(_bitset_overall_size(sizeof(bitset_t), size)), size)
123 * Free a bitset allocated with bitset_malloc().
124 * @param bs The bitset.
126 #define bitset_free(bs) free(bs)
129 * Allocate a bitset on the stack via alloca.
130 * @param size The greatest bit that shall be stored in the set.
131 * @return A pointer to an empty initialized bitset.
133 #define bitset_alloca(size) \
134 _bitset_prepare(alloca(_bitset_overall_size(sizeof(bitset_t), size)), size)
138 * Get the unit which contains a specific bit.
139 * This function is internal.
140 * @param bs The bitset.
141 * @param bit The bit.
142 * @return A pointer to the unit containing the bit.
144 static INLINE bitset_unit_t *_bitset_get_unit(const bitset_t *bs, bitset_pos_t bit)
146 /* assert(bit < bs->units * BS_UNIT_SIZE_BITS && "Bit too large"); */
147 assert(bit <= bs->size && "Bit to large");
148 return bs->data + bit / BS_UNIT_SIZE_BITS;
152 * Set a bit in the bitset.
153 * @param bs The bitset.
154 * @param bit The bit to set.
156 static INLINE void bitset_set(bitset_t *bs, bitset_pos_t bit)
158 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
159 _bitset_inside_set(unit, bit & BS_UNIT_MASK);
163 * Clear a bit in the bitset.
164 * @param bs The bitset.
165 * @param bit The bit to clear.
167 static INLINE void bitset_clear(bitset_t *bs, bitset_pos_t bit)
169 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
170 _bitset_inside_clear(unit, bit & BS_UNIT_MASK);
174 * Check, if a bit is set.
175 * @param bs The bitset.
176 * @param bit The bit to check for.
177 * @return 1, if the bit was set, 0 if not.
179 static INLINE int bitset_is_set(const bitset_t *bs, bitset_pos_t bit)
181 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
182 return _bitset_inside_is_set(unit, bit & BS_UNIT_MASK);
186 * Flip a bit in a bitset.
187 * @param bs The bitset.
188 * @param bit The bit to flip.
190 static INLINE void bitset_flip(bitset_t *bs, bitset_pos_t bit)
192 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
193 _bitset_inside_flip(unit, bit & BS_UNIT_MASK);
197 * Flip the whole bitset.
198 * @param bs The bitset.
200 static INLINE void bitset_flip_all(bitset_t *bs)
203 for(i = 0; i < bs->units; i++)
204 _bitset_inside_flip_unit(&bs->data[i]);
205 _bitset_mask_highest(bs);
209 * Copy a bitset to another.
210 * @param tgt The target bitset.
211 * @param src The source bitset.
212 * @return The target bitset.
214 static INLINE bitset_t *bitset_copy(bitset_t *tgt, const bitset_t *src)
216 bitset_pos_t tu = tgt->units;
217 bitset_pos_t su = src->units;
218 bitset_pos_t min_units = tu < su ? tu : su;
219 memcpy(tgt->data, src->data, min_units * BS_UNIT_SIZE);
221 memset(tgt->data + min_units, 0, BS_UNIT_SIZE * (tu - min_units));
222 return _bitset_mask_highest(tgt);
226 * Find the smallest bit set in the bitset.
227 * @param bs The bitset.
228 * @return The smallest bit set in the bitset.
230 static INLINE bitset_pos_t bitset_min(const bitset_t *bs)
232 bitset_pos_t i, 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_ntz(unit);
239 ofs += BS_UNIT_SIZE_BITS;
246 * Find the greatest bit set in the bitset.
247 * @param bs The bitset.
248 * @return The greatest bit set in the bitset.
250 static INLINE bitset_pos_t bitset_max(const bitset_t *bs)
252 bitset_pos_t i, max = 0, ofs = 0;
254 for(i = 0; i < bs->units; ++i) {
255 bitset_unit_t *unit = &bs->data[i];
256 bitset_pos_t pos = _bitset_inside_nlz(unit);
259 ofs += BS_UNIT_SIZE_BITS;
266 * Find the next set bit from a given bit.
267 * @note Note that if pos is set, pos is returned.
268 * @param bs The bitset.
269 * @param pos The bit from which to search for the next set bit.
270 * @return The next set bit from pos on, or -1, if no set bit was found
273 static INLINE bitset_pos_t _bitset_next(const bitset_t *bs,
274 bitset_pos_t pos, int set)
276 bitset_pos_t unit_number = pos / BS_UNIT_SIZE_BITS;
283 bitset_pos_t bit_in_unit = pos & BS_UNIT_MASK;
284 bitset_pos_t in_unit_mask = (1 << bit_in_unit) - 1;
287 * Mask out the bits smaller than pos in the current unit.
288 * We are only interested in bits set higher than pos.
290 bitset_unit_t curr_unit = bs->data[unit_number];
293 * Find the next bit set in the unit.
294 * Mind that this function returns 0, if the unit is -1 and
295 * counts the bits from 1 on.
297 bitset_pos_t next_in_this_unit =
298 _bitset_inside_ntz_value((set ? curr_unit : ~curr_unit) & ~in_unit_mask);
300 /* If there is a bit set in the current unit, exit. */
301 if (next_in_this_unit < BS_UNIT_SIZE_BITS) {
302 res = next_in_this_unit + unit_number * BS_UNIT_SIZE_BITS;
303 return res < bs->size ? res : -1;
306 /* Else search for set bits in the next units. */
309 for(i = unit_number + 1; i < bs->units; ++i) {
310 bitset_unit_t data = bs->data[i];
311 bitset_pos_t first_set =
312 _bitset_inside_ntz_value(set ? data : ~data);
314 if (first_set < BS_UNIT_SIZE_BITS) {
315 res = first_set + i * BS_UNIT_SIZE_BITS;
316 return res < bs->size ? res : -1;
325 #define bitset_next_clear(bs,pos) _bitset_next((bs), (pos), 0)
326 #define bitset_next_set(bs,pos) _bitset_next((bs), (pos), 1)
329 * Convenience macro for bitset iteration.
330 * @param bitset The bitset.
331 * @param elm A unsigned long variable.
333 #define bitset_foreach(bitset,elm) \
334 for(elm = bitset_next_set(bitset,0); elm != -1; elm = bitset_next_set(bitset,elm+1))
337 #define bitset_foreach_clear(bitset,elm) \
338 for(elm = bitset_next_clear(bitset,0); elm != -1; elm = bitset_next_clear(bitset,elm+1))
341 * Count the bits set.
342 * This can also be seen as the cardinality of the set.
343 * @param bs The bitset.
344 * @return The number of bits set in the bitset.
346 static INLINE bitset_pos_t bitset_popcnt(const bitset_t *bs)
348 bitset_pos_t i, pop = 0;
351 for(i = 0, unit = bs->data; i < bs->units; ++i, ++unit)
352 pop += _bitset_inside_pop(unit);
359 * This sets all bits to zero.
360 * @param bs The bitset.
362 static INLINE bitset_t *bitset_clear_all(bitset_t *bs)
364 memset(bs->data, 0, BS_UNIT_SIZE * bs->units);
370 * This sets all bits to one.
371 * @param bs The bitset.
373 static INLINE bitset_t *bitset_set_all(bitset_t *bs)
375 memset(bs->data, -1, bs->units * BS_UNIT_SIZE);
376 return _bitset_mask_highest(bs);
380 * Check, if one bitset is contained by another.
381 * That is, each bit set in lhs is also set in rhs.
382 * @param lhs A bitset.
383 * @param rhs Another bitset.
384 * @return 1, if all bits in lhs are also set in rhs, 0 otherwise.
386 static INLINE int bitset_contains(const bitset_t *lhs, const bitset_t *rhs)
388 bitset_pos_t n = lhs->units < rhs->units ? lhs->units : rhs->units;
391 for(i = 0; i < n; ++i) {
392 bitset_unit_t lu = lhs->data[i];
393 bitset_unit_t ru = rhs->data[i];
400 * If the left hand sinde is a larger bitset than rhs,
401 * we have to check, that all extra bits in lhs are 0
404 for(i = n; i < lhs->units; ++i) {
405 if(lhs->data[i] != 0)
414 * Treat the bitset as a number and subtract 1.
415 * @param bs The bitset.
416 * @return The same bitset.
418 static INLINE void bitset_minus1(bitset_t *bs)
420 #define _SH (sizeof(bitset_unit_t) * 8 - 1)
424 for(i = 0; i < bs->units; ++i) {
425 bitset_unit_t unit = bs->data[i];
426 bitset_unit_t um1 = unit - 1;
430 if(((unit >> _SH) ^ (um1 >> _SH)) == 0)
437 * Print a bitset to a stream.
438 * The bitset is printed as a comma separated list of bits set.
439 * @param file The stream.
440 * @param bs The bitset.
442 static INLINE void bitset_fprint(FILE *file, const bitset_t *bs)
444 const char *prefix = "";
448 for(i = bitset_next_set(bs, 0); i != -1; i = bitset_next_set(bs, i + 1)) {
449 fprintf(file, "%s%u", prefix, i);
455 static INLINE void bitset_debug_fprint(FILE *file, const bitset_t *bs)
459 fprintf(file, "%u:", bs->units);
460 for(i = 0; i < bs->units; ++i)
461 fprintf(file, " " BITSET_UNIT_FMT, bs->data[i]);
465 * Here, the binary operations follow.
466 * And, Or, And Not, Xor are available.
468 #define BINARY_OP(op) \
469 static INLINE bitset_t *bitset_ ## op(bitset_t *tgt, const bitset_t *src) \
472 bitset_pos_t n = tgt->units > src->units ? src->units : tgt->units; \
473 for(i = 0; i < n; i += _BITSET_BINOP_UNITS_INC) \
474 _bitset_inside_binop_ ## op(&tgt->data[i], &src->data[i]); \
476 _bitset_clear_rest(&tgt->data[i], tgt->units - i); \
477 return _bitset_mask_highest(tgt); \
481 * Define the clear rest macro for the and, since it is the only case,
482 * were non existed (treated as 0) units in the src must be handled.
483 * For all other operations holds: x Op 0 = x for Op in { Andnot, Or, Xor }
485 * For and, each bitset implementer has to provide the macro
486 * _bitset_clear_units(data, n), which clears n units from the pointer
489 #define _bitset_clear_rest(data,n) _bitset_inside_clear_units(data, n)
491 #undef _bitset_clear_rest
492 #define _bitset_clear_rest(data,n)