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 int arrays. Additional information
28 * like the size of the bitset or the used memory aren't saved 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
45 #include "bitset_std.h"
48 #define BITS_PER_ELEM 32
49 #define BITSET_SIZE_ELEMS(size_bits) ((size_bits)/32 + 1)
50 #define BITSET_SIZE_BYTES(size_bits) (BITSET_SIZE_ELEMS(size_bits)*4)
51 #define BITSET_ELEM(bitset,pos) bitset[pos / 32]
54 * Allocate an empty raw bitset on the stack.
56 * @param res will contain the newly allocated bitset
57 * @param size element size of the bitset
59 #define rbitset_alloca(res, size) \
61 unsigned size_bytes = BITSET_SIZE_BYTES(size); \
62 res = alloca(size_bytes); \
63 memset(res, 0, size_bytes); \
67 * Allocate an empty raw bitset on an obstack.
69 * @param obst the obstack where the bitset is allocated on
70 * @param size element size of the bitset
72 * @return the new bitset
74 static INLINE unsigned *rbitset_obstack_alloc(struct obstack *obst, unsigned size) {
75 unsigned size_bytes = BITSET_SIZE_BYTES(size);
76 unsigned *res = obstack_alloc(obst, size_bytes);
77 memset(res, 0, size_bytes);
83 * Duplicate a raw bitset on an obstack.
85 * @param obst the obstack where the bitset is allocated on
86 * @param old_bitset the bitset to be duplicated
87 * @param size element size of the bitset
89 * @return the new bitset
92 unsigned *rbitset_duplicate_obstack_alloc(struct obstack *obst,
93 const unsigned *old_bitset,
96 unsigned size_bytes = BITSET_SIZE_BYTES(size);
97 unsigned *res = obstack_alloc(obst, size_bytes);
98 memcpy(res, old_bitset, size_bytes);
104 * Set a bit at position pos.
106 * @param bitset the bitset
107 * @param pos the position of the bit to be set
109 static INLINE void rbitset_set(unsigned *bitset, unsigned pos) {
110 BITSET_ELEM(bitset,pos) |= 1 << (pos % BITS_PER_ELEM);
114 * Clear a bit at position pos.
116 * @param bitset the bitset
117 * @param pos the position of the bit to be clear
119 static INLINE void rbitset_clear(unsigned *bitset, unsigned pos) {
120 BITSET_ELEM(bitset, pos) &= ~(1 << (pos % BITS_PER_ELEM));
124 * Check if a bit is set at position pos.
126 * @param bitset the bitset
127 * @param pos the position of the bit to check
129 static INLINE int rbitset_is_set(const unsigned *bitset, unsigned pos) {
130 return BITSET_ELEM(bitset, pos) & (1 << (pos % BITS_PER_ELEM));
134 * Calculate the number of set bits (number of elements).
136 * @param bitset the bitset
138 static INLINE unsigned rbitset_popcnt(const unsigned *bitset, unsigned size) {
140 unsigned n = BITSET_SIZE_ELEMS(size);
142 const unsigned *elem = bitset;
144 for(pos = 0; pos < n; ++pos) {
145 res += _bitset_inside_pop(elem);
152 static INLINE unsigned rbitset_next(const unsigned *bitset, unsigned pos, int set) {
154 unsigned elem_pos = pos / BITS_PER_ELEM;
155 unsigned bit_pos = pos % BITS_PER_ELEM;
157 unsigned elem = bitset[elem_pos];
160 * Mask out the bits smaller than pos in the current unit.
161 * We are only interested in bits set higher than pos.
163 unsigned in_elem_mask = (1 << bit_pos) - 1;
167 p = _bitset_inside_ntz_value(elem & ~in_elem_mask);
169 /* If there is a bit set in the current elem, exit. */
170 if(p < BITS_PER_ELEM) {
171 return elem_pos * BITS_PER_ELEM + p;
174 /* Else search for set bits in the next units. */
177 elem = bitset[elem_pos];
181 p = _bitset_inside_ntz_value(elem);
182 if(p < BITS_PER_ELEM) {
183 return elem_pos * BITS_PER_ELEM + p;
192 * Inplace Intersection of two sets.
194 static INLINE void rbitset_and(unsigned *bitset1, const unsigned *bitset2,
197 unsigned i, n = BITSET_SIZE_ELEMS(size);
199 for(i = 0; i < n; ++i) {
200 bitset1[i] &= bitset2[i];
205 * Inplace Union of two sets.
207 static INLINE void rbitset_or(unsigned *bitset1, const unsigned *bitset2,
210 unsigned i, n = BITSET_SIZE_ELEMS(size);
212 for(i = 0; i < n; ++i) {
213 bitset1[i] |= bitset2[i];
218 * Remove all bits in bitset2 from bitset 1.
220 static INLINE void rbitset_andnot(unsigned *bitset1, const unsigned *bitset2,
223 unsigned i, n = BITSET_SIZE_ELEMS(size);
225 for(i = 0; i < n; ++i) {
226 bitset1[i] &= ~bitset2[i];
231 * Xor of two bitsets.
233 static INLINE void rbitset_xor(unsigned *bitset1, const unsigned *bitset2,
236 unsigned i, n = BITSET_SIZE_ELEMS(size);
238 for(i = 0; i < n; ++i) {
239 bitset1[i] ^= bitset2[i];
244 * Copy a raw bitset into an bitset.
248 static INLINE void rbitset_copy_to_bitset(const unsigned *rbitset, bitset_t *bitset) {
249 // TODO optimize me (or remove me)
250 unsigned i, n = bitset_size(bitset);
251 for(i = 0; i < n; ++i) {
252 if(rbitset_is_set(rbitset, i))
253 bitset_set(bitset, i);
257 #endif /* FIRM_ADT_RAW_BITSET_H */