4 * @author Sebastian Hack
5 * @brief A bitset implementation.
8 #ifndef __FIRM_BITSET_H
9 #define __FIRM_BITSET_H
11 #include "firm_config.h"
19 #include "bitfiddle.h"
21 typedef unsigned int bitset_pos_t;
23 #include "bitset_std.h"
26 #if defined(__GNUC__) && defined(__i386__)
27 #include "bitset_ia32.h"
31 typedef struct _bitset_t {
37 #define BS_UNIT_SIZE sizeof(bitset_unit_t)
38 #define BS_UNIT_SIZE_BITS (BS_UNIT_SIZE * 8)
39 #define BS_UNIT_MASK (BS_UNIT_SIZE_BITS - 1)
42 * Initialize a bitset.
43 * This functions should not be called.
45 * Note that this function needs three macros which must be provided by the
46 * bitfield implementor:
47 * - _bitset_overall_size(size) The overall size that must be
48 * allocated for the bitfield in bytes.
49 * - _bitset_units(size) The number of units that will be
50 * present in the bitfield for a given highest bit.
51 * - _bitset_data_ptr(data, size) This produces as pointer to the
52 * first unit in the allocated memory area. The main reason for this
53 * macro is, that some bitset implementors want control over memory
56 * @param area A pointer to memory reserved for the bitset.
57 * @param size The size of the bitset in bits.
58 * @return A pointer to the initialized bitset.
60 static INLINE bitset_t *_bitset_prepare(void *area, bitset_pos_t size)
63 memset(area, 0, _bitset_overall_size(sizeof(bitset_t), size));
64 ptr->units = _bitset_units(size);
66 ptr->data = _bitset_data_ptr(area, sizeof(bitset_t), size);
71 * Mask out all bits, which are only there, because the number
72 * of bits in the set didn't match a unit size boundary.
73 * @param bs The bitset.
74 * @return The masked bitset.
76 static INLINE bitset_t *_bitset_mask_highest(bitset_t *bs)
78 bitset_pos_t rest = bs->size & BS_UNIT_MASK;
80 bs->data[bs->units - 1] &= (1 << rest) - 1;
85 * Get the capacity of the bitset in bits.
86 * @param bs The bitset.
87 * @return The capacity in bits of the bitset.
89 #define bitset_capacity(bs) ((bs)->units * BS_UNIT_SIZE_BITS)
92 * Get the size of the bitset in bits.
93 * @note Note the difference between capacity and size.
94 * @param bs The bitset.
95 * @return The highest bit which can be set or cleared plus 1.
97 #define bitset_size(bs) ((bs)->size)
100 * Allocate a bitset on an obstack.
101 * @param obst The obstack.
102 * @param size The greatest bit that shall be stored in the set.
103 * @return A pointer to an empty initialized bitset.
105 #define bitset_obstack_alloc(obst,size) \
106 _bitset_prepare(obstack_alloc(obst, _bitset_overall_size(sizeof(bitset_t), size)), size)
109 * Allocate a bitset via malloc.
110 * @param size The greatest bit that shall be stored in the set.
111 * @return A pointer to an empty initialized bitset.
113 #define bitset_malloc(size) \
114 _bitset_prepare(xmalloc(_bitset_overall_size(sizeof(bitset_t), size)), size)
117 * Free a bitset allocated with bitset_malloc().
118 * @param bs The bitset.
120 #define bitset_free(bs) free(bs)
123 * Allocate a bitset on the stack via alloca.
124 * @param size The greatest bit that shall be stored in the set.
125 * @return A pointer to an empty initialized bitset.
127 #define bitset_alloca(size) \
128 _bitset_prepare(alloca(_bitset_overall_size(sizeof(bitset_t), size)), size)
132 * Get the unit which contains a specific bit.
133 * This function is internal.
134 * @param bs The bitset.
135 * @param bit The bit.
136 * @return A pointer to the unit containing the bit.
138 static INLINE bitset_unit_t *_bitset_get_unit(const bitset_t *bs, bitset_pos_t bit)
140 /* assert(bit < bs->units * BS_UNIT_SIZE_BITS && "Bit too large"); */
141 assert(bit <= bs->size && "Bit to large");
142 return bs->data + bit / BS_UNIT_SIZE_BITS;
146 * Set a bit in the bitset.
147 * @param bs The bitset.
148 * @param bit The bit to set.
150 static INLINE void bitset_set(bitset_t *bs, bitset_pos_t bit)
152 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
153 _bitset_inside_set(unit, bit & BS_UNIT_MASK);
157 * Clear a bit in the bitset.
158 * @param bs The bitset.
159 * @param bit The bit to clear.
161 static INLINE void bitset_clear(bitset_t *bs, bitset_pos_t bit)
163 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
164 _bitset_inside_clear(unit, bit & BS_UNIT_MASK);
168 * Check, if a bit is set.
169 * @param bs The bitset.
170 * @param bit The bit to check for.
171 * @return 1, if the bit was set, 0 if not.
173 static INLINE int bitset_is_set(const bitset_t *bs, bitset_pos_t bit)
175 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
176 return _bitset_inside_is_set(unit, bit & BS_UNIT_MASK);
180 * Flip a bit in a bitset.
181 * @param bs The bitset.
182 * @param bit The bit to flip.
184 static INLINE void bitset_flip(bitset_t *bs, bitset_pos_t bit)
186 bitset_unit_t *unit = _bitset_get_unit(bs, bit);
187 _bitset_inside_flip(unit, bit & BS_UNIT_MASK);
191 * Flip the whole bitset.
192 * @param bs The bitset.
194 static INLINE void bitset_flip_all(bitset_t *bs)
197 for(i = 0; i < bs->units; i++)
198 _bitset_inside_flip_unit(&bs->data[i]);
199 _bitset_mask_highest(bs);
203 * Copy a bitset to another.
204 * @param tgt The target bitset.
205 * @param src The source bitset.
206 * @return The target bitset.
208 static INLINE bitset_t *bitset_copy(bitset_t *tgt, const bitset_t *src)
210 bitset_pos_t tu = tgt->units;
211 bitset_pos_t su = src->units;
212 bitset_pos_t min_units = tu < su ? tu : su;
213 memcpy(tgt->data, src->data, min_units * BS_UNIT_SIZE);
215 memset(tgt->data + min_units, 0, BS_UNIT_SIZE * (tu - min_units));
216 return _bitset_mask_highest(tgt);
220 * Find the smallest bit set in the bitset.
221 * @param bs The bitset.
222 * @return The smallest bit set in the bitset.
224 static INLINE bitset_pos_t bitset_min(const bitset_t *bs)
226 bitset_pos_t i, ofs = 0;
228 for(i = 0; i < bs->units; ++i) {
229 bitset_unit_t *unit = &bs->data[i];
230 bitset_pos_t pos = _bitset_inside_ntz(unit);
233 ofs += BS_UNIT_SIZE_BITS;
240 * Find the greatest bit set in the bitset.
241 * @param bs The bitset.
242 * @return The greatest bit set in the bitset.
244 static INLINE bitset_pos_t bitset_max(const bitset_t *bs)
246 bitset_pos_t i, max = 0, ofs = 0;
248 for(i = 0; i < bs->units; ++i) {
249 bitset_unit_t *unit = &bs->data[i];
250 bitset_pos_t pos = _bitset_inside_nlz(unit);
253 ofs += BS_UNIT_SIZE_BITS;
260 * Find the next set bit from a given bit.
261 * @note Note that if pos is set, pos is returned.
262 * @param bs The bitset.
263 * @param pos The bit from which to search for the next set bit.
264 * @return The next set bit from pos on, or -1, if no set bit was found
267 static INLINE bitset_pos_t _bitset_next(const bitset_t *bs,
268 bitset_pos_t pos, int set)
270 bitset_pos_t unit_number = pos / BS_UNIT_SIZE_BITS;
277 bitset_pos_t bit_in_unit = pos & BS_UNIT_MASK;
278 bitset_pos_t in_unit_mask = (1 << bit_in_unit) - 1;
281 * Mask out the bits smaller than pos in the current unit.
282 * We are only interested in bits set higher than pos.
284 bitset_unit_t curr_unit = bs->data[unit_number];
287 * Find the next bit set in the unit.
288 * Mind that this function returns 0, if the unit is -1 and
289 * counts the bits from 1 on.
291 bitset_pos_t next_in_this_unit =
292 _bitset_inside_ntz_value((set ? curr_unit : ~curr_unit) & ~in_unit_mask);
294 /* If there is a bit set in the current unit, exit. */
295 if (next_in_this_unit < BS_UNIT_SIZE_BITS) {
296 res = next_in_this_unit + unit_number * BS_UNIT_SIZE_BITS;
297 return res < bs->size ? res : -1;
300 /* Else search for set bits in the next units. */
303 for(i = unit_number + 1; i < bs->units; ++i) {
304 bitset_unit_t data = bs->data[i];
305 bitset_pos_t first_set =
306 _bitset_inside_ntz_value(set ? data : ~data);
308 if (first_set < BS_UNIT_SIZE_BITS) {
309 res = first_set + i * BS_UNIT_SIZE_BITS;
310 return res < bs->size ? res : -1;
319 #define bitset_next_clear(bs,pos) _bitset_next((bs), (pos), 0)
320 #define bitset_next_set(bs,pos) _bitset_next((bs), (pos), 1)
323 * Convenience macro for bitset iteration.
324 * @param bitset The bitset.
325 * @param elm A unsigned long variable.
327 #define bitset_foreach(bitset,elm) \
328 for(elm = bitset_next_set(bitset,0); elm != -1; elm = bitset_next_set(bitset,elm+1))
331 #define bitset_foreach_clear(bitset,elm) \
332 for(elm = bitset_next_clear(bitset,0); elm != -1; elm = bitset_next_clear(bitset,elm+1))
335 * Count the bits set.
336 * This can also be seen as the cardinality of the set.
337 * @param bs The bitset.
338 * @return The number of bits set in the bitset.
340 static INLINE bitset_pos_t bitset_popcnt(const bitset_t *bs)
342 bitset_pos_t i, pop = 0;
345 for(i = 0, unit = bs->data; i < bs->units; ++i, ++unit)
346 pop += _bitset_inside_pop(unit);
353 * This sets all bits to zero.
354 * @param bs The bitset.
356 static INLINE bitset_t *bitset_clear_all(bitset_t *bs)
358 memset(bs->data, 0, BS_UNIT_SIZE * bs->units);
364 * This sets all bits to one.
365 * @param bs The bitset.
367 static INLINE bitset_t *bitset_set_all(bitset_t *bs)
369 memset(bs->data, -1, bs->units * BS_UNIT_SIZE);
370 return _bitset_mask_highest(bs);
374 * Check, if one bitset is contained by another.
375 * That is, each bit set in lhs is also set in rhs.
376 * @param lhs A bitset.
377 * @param rhs Another bitset.
378 * @return 1, if all bits in lhs are also set in rhs, 0 otherwise.
380 static INLINE int bitset_contains(const bitset_t *lhs, const bitset_t *rhs)
382 bitset_pos_t n = lhs->units < rhs->units ? lhs->units : rhs->units;
385 for(i = 0; i < n; ++i) {
386 bitset_unit_t lu = lhs->data[i];
387 bitset_unit_t ru = rhs->data[i];
394 * If the left hand sinde is a larger bitset than rhs,
395 * we have to check, that all extra bits in lhs are 0
398 for(i = n; i < lhs->units; ++i) {
399 if(lhs->data[i] != 0)
408 * Treat the bitset as a number and subtract 1.
409 * @param bs The bitset.
410 * @return The same bitset.
412 static INLINE void bitset_minus1(bitset_t *bs)
414 #define _SH (sizeof(bitset_unit_t) * 8 - 1)
418 for(i = 0; i < bs->units; ++i) {
419 bitset_unit_t unit = bs->data[i];
420 bitset_unit_t um1 = unit - 1;
424 if(((unit >> _SH) ^ (um1 >> _SH)) == 0)
431 * Print a bitset to a stream.
432 * The bitset is printed as a comma separated list of bits set.
433 * @param file The stream.
434 * @param bs The bitset.
436 static INLINE void bitset_fprint(FILE *file, const bitset_t *bs)
438 const char *prefix = "";
442 for(i = bitset_next_set(bs, 0); i != -1; i = bitset_next_set(bs, i + 1)) {
443 fprintf(file, "%s%u", prefix, i);
449 static INLINE void bitset_debug_fprint(FILE *file, const bitset_t *bs)
453 fprintf(file, "%u:", bs->units);
454 for(i = 0; i < bs->units; ++i)
455 fprintf(file, " " BITSET_UNIT_FMT, bs->data[i]);
459 * Here, the binary operations follow.
460 * And, Or, And Not, Xor are available.
462 #define BINARY_OP(op) \
463 static INLINE bitset_t *bitset_ ## op(bitset_t *tgt, const bitset_t *src) \
466 bitset_pos_t n = tgt->units > src->units ? src->units : tgt->units; \
467 for(i = 0; i < n; i += _BITSET_BINOP_UNITS_INC) \
468 _bitset_inside_binop_ ## op(&tgt->data[i], &src->data[i]); \
470 _bitset_clear_rest(&tgt->data[i], tgt->units - i); \
471 return _bitset_mask_highest(tgt); \
475 * Define the clear rest macro for the and, since it is the only case,
476 * were non existed (treated as 0) units in the src must be handled.
477 * For all other operations holds: x Op 0 = x for Op in { Andnot, Or, Xor }
479 * For and, each bitset implementer has to provide the macro
480 * _bitset_clear_units(data, n), which clears n units from the pointer
483 #define _bitset_clear_rest(data,n) _bitset_inside_clear_units(data, n)
485 #undef _bitset_clear_rest
486 #define _bitset_clear_rest(data,n)