2 * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief helper functions for working with raw bitsets
24 * @author Matthias Braun
27 * Raw bitsets are constructed from unsigned int arrays. Additional information
28 * like the size of the bitset or the used memory are not stored for
31 * These bitsets need less space than bitset_t and their representation
32 * as int arrays allows having constant bitsets in the ro data segment.
33 * They should for smaller bitset, whose length is known through other means
34 * (a typical usage case is a set of cpu registers)
36 * The bitset is built as an array of unsigned integers. It is assumed that
37 * exactly 32 bits may be put into each element of the array. If there are
38 * remaining bits, then they should be 0
40 #ifndef FIRM_ADT_RAW_BITSET_H
41 #define FIRM_ADT_RAW_BITSET_H
47 #define BITS_PER_ELEM 32
48 #define BITSET_SIZE_ELEMS(size_bits) ((size_bits)/32 + 1)
49 #define BITSET_SIZE_BYTES(size_bits) (BITSET_SIZE_ELEMS(size_bits)*4)
50 #define BITSET_ELEM(bitset,pos) bitset[pos / 32]
53 * Allocate an empty raw bitset on the stack.
55 * @param res will contain the newly allocated bitset
56 * @param size element size of the bitset
58 #define rbitset_alloca(res, size) \
60 unsigned size_bytes = BITSET_SIZE_BYTES(size); \
61 res = alloca(size_bytes); \
62 memset(res, 0, size_bytes); \
66 * Allocate an empty raw bitset on an obstack.
68 * @param obst the obstack where the bitset is allocated on
69 * @param size element size of the bitset
71 * @return the new bitset
73 static INLINE unsigned *rbitset_obstack_alloc(struct obstack *obst, unsigned size) {
74 unsigned size_bytes = BITSET_SIZE_BYTES(size);
75 unsigned *res = obstack_alloc(obst, size_bytes);
76 memset(res, 0, size_bytes);
82 * Allocate an empty raw bitset including the size on an obstack.
83 * The size of this bitset can be accessed by bitset[-1].
85 * @param obst the obstack where the bitset is allocated on
86 * @param size element size of the bitset
88 * @return the new bitset
90 static INLINE unsigned *rbitset_w_size_obstack_alloc(struct obstack *obst, unsigned size) {
91 unsigned size_bytes = BITSET_SIZE_BYTES(size);
92 unsigned *res = obstack_alloc(obst, size_bytes + sizeof(unsigned));
95 memset(res, 0, size_bytes);
100 /** Return the size of a bitset allocated with a *_w_size_* function */
101 #define rbitset_size(set) (set)[-1]
104 * Duplicate a raw bitset on an obstack.
106 * @param obst the obstack where the bitset is allocated on
107 * @param old_bitset the bitset to be duplicated
108 * @param size element size of the bitset
110 * @return the new bitset
113 unsigned *rbitset_duplicate_obstack_alloc(struct obstack *obst,
114 const unsigned *old_bitset,
117 unsigned size_bytes = BITSET_SIZE_BYTES(size);
118 unsigned *res = obstack_alloc(obst, size_bytes);
119 memcpy(res, old_bitset, size_bytes);
125 * Check if a bitset is empty, ie all bits cleared.
127 static INLINE int rbitset_is_empty(unsigned *bitset, unsigned size) {
128 unsigned i, size_bytes = BITSET_SIZE_BYTES(size);
129 for (i = 0; i < size_bytes; ++i)
130 if (bitset[i]) return 0;
135 * Set a bit at position pos.
137 * @param bitset the bitset
138 * @param pos the position of the bit to be set
140 static INLINE void rbitset_set(unsigned *bitset, unsigned pos) {
141 BITSET_ELEM(bitset,pos) |= 1 << (pos % BITS_PER_ELEM);
145 * Clear a bit at position pos.
147 * @param bitset the bitset
148 * @param pos the position of the bit to be clear
150 static INLINE void rbitset_clear(unsigned *bitset, unsigned pos) {
151 BITSET_ELEM(bitset, pos) &= ~(1 << (pos % BITS_PER_ELEM));
155 * Check if a bit is set at position pos.
157 * @param bitset the bitset
158 * @param pos the position of the bit to check
160 static INLINE int rbitset_is_set(const unsigned *bitset, unsigned pos) {
161 return BITSET_ELEM(bitset, pos) & (1 << (pos % BITS_PER_ELEM));
165 * Calculate the number of set bits (number of elements).
167 * @param bitset the bitset
169 static INLINE unsigned rbitset_popcnt(const unsigned *bitset, unsigned size) {
171 unsigned n = BITSET_SIZE_ELEMS(size);
173 const unsigned *elem = bitset;
175 for(pos = 0; pos < n; ++pos) {
176 res += _bitset_inside_pop(elem);
183 static INLINE unsigned rbitset_next(const unsigned *bitset, unsigned pos, int set) {
185 unsigned elem_pos = pos / BITS_PER_ELEM;
186 unsigned bit_pos = pos % BITS_PER_ELEM;
188 unsigned elem = bitset[elem_pos];
191 * Mask out the bits smaller than pos in the current unit.
192 * We are only interested in bits set higher than pos.
194 unsigned in_elem_mask = (1 << bit_pos) - 1;
198 p = _bitset_inside_ntz_value(elem & ~in_elem_mask);
200 /* If there is a bit set in the current elem, exit. */
201 if(p < BITS_PER_ELEM) {
202 return elem_pos * BITS_PER_ELEM + p;
205 /* Else search for set bits in the next units. */
208 elem = bitset[elem_pos];
212 p = _bitset_inside_ntz_value(elem);
213 if(p < BITS_PER_ELEM) {
214 return elem_pos * BITS_PER_ELEM + p;
223 * Inplace Intersection of two sets.
225 static INLINE void rbitset_and(unsigned *bitset1, const unsigned *bitset2,
228 unsigned i, n = BITSET_SIZE_ELEMS(size);
230 for(i = 0; i < n; ++i) {
231 bitset1[i] &= bitset2[i];
236 * Inplace Union of two sets.
238 static INLINE void rbitset_or(unsigned *bitset1, const unsigned *bitset2,
241 unsigned i, n = BITSET_SIZE_ELEMS(size);
243 for(i = 0; i < n; ++i) {
244 bitset1[i] |= bitset2[i];
249 * Remove all bits in bitset2 from bitset 1.
251 static INLINE void rbitset_andnot(unsigned *bitset1, const unsigned *bitset2,
254 unsigned i, n = BITSET_SIZE_ELEMS(size);
256 for(i = 0; i < n; ++i) {
257 bitset1[i] &= ~bitset2[i];
262 * Xor of two bitsets.
264 static INLINE void rbitset_xor(unsigned *bitset1, const unsigned *bitset2,
267 unsigned i, n = BITSET_SIZE_ELEMS(size);
269 for(i = 0; i < n; ++i) {
270 bitset1[i] ^= bitset2[i];
275 * Copy a raw bitset into an bitset.
279 static INLINE void rbitset_copy_to_bitset(const unsigned *rbitset, bitset_t *bitset) {
280 // TODO optimize me (or remove me)
281 unsigned i, n = bitset_size(bitset);
282 for(i = 0; i < n; ++i) {
283 if(rbitset_is_set(rbitset, i))
284 bitset_set(bitset, i);
288 #endif /* FIRM_ADT_RAW_BITSET_H */