1/* A simple, memory-efficient bitset implementation.
2
3   Copyright (C) 2009-2012 Free Software Foundation, Inc.
4
5   This file is part of Bison, the GNU Compiler Compiler.
6
7   This program is free software: you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation, either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#ifndef SBITSET_H_
21# define SBITSET_H_
22
23typedef unsigned char *Sbitset;
24typedef size_t Sbitset__Index;
25#define SBITSET__INDEX__CONVERSION_SPEC "zu"
26
27#define Sbitset__nbytes(NBITS) \
28  (((NBITS) + CHAR_BIT - 1) / CHAR_BIT)
29#define Sbitset__byteAddress(SELF, INDEX) \
30  (((SELF) + (INDEX) / CHAR_BIT))
31#define Sbitset__bit_mask(INDEX) \
32  (1 << (CHAR_BIT - 1 - (INDEX) % CHAR_BIT))
33#define Sbitset__last_byte_mask(NBITS) \
34  (UCHAR_MAX << (CHAR_BIT - 1 - ((NBITS) - 1) % CHAR_BIT))
35
36/* nbits must not be 0.  */
37Sbitset Sbitset__new (Sbitset__Index nbits);
38Sbitset Sbitset__new_on_obstack (Sbitset__Index nbits,
39                                 struct obstack *obstackp);
40void Sbitset__delete (Sbitset self);
41
42#define Sbitset__test(SELF, INDEX)                                            \
43  ((*Sbitset__byteAddress ((SELF), (INDEX)) & Sbitset__bit_mask (INDEX)) != 0)
44
45bool Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits);
46
47void Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file);
48
49#define Sbitset__set(SELF, INDEX)                                             \
50do {                                                                          \
51  *Sbitset__byteAddress ((SELF), (INDEX)) =                                   \
52    *Sbitset__byteAddress ((SELF), (INDEX)) | Sbitset__bit_mask (INDEX);      \
53} while(0)
54
55#define Sbitset__reset(SELF, INDEX)                                           \
56do {                                                                          \
57  *Sbitset__byteAddress ((SELF), (INDEX)) =                                   \
58    *Sbitset__byteAddress ((SELF), (INDEX)) & ~Sbitset__bit_mask (INDEX);     \
59} while(0)
60
61/* NBITS is the size of the bitset.  More than NBITS bits might be reset.  */
62#define Sbitset__zero(SELF, NBITS)                                            \
63do {                                                                          \
64  memset (SELF, 0, Sbitset__nbytes (NBITS));                                  \
65} while(0)
66
67/* NBITS is the size of the bitset.  More than NBITS bits might be set.  */
68#define Sbitset__ones(SELF, NBITS)                                            \
69do {                                                                          \
70  memset (SELF, UCHAR_MAX, Sbitset__nbytes (NBITS));                          \
71} while(0)
72
73/* NBITS is the size of every bitset.  More than NBITS bits might be set.  */
74#define Sbitset__or(SELF, OTHER1, OTHER2, NBITS)                              \
75do {                                                                          \
76  Sbitset ptr_self = (SELF);                                                  \
77  Sbitset ptr_other1 = (OTHER1);                                              \
78  Sbitset ptr_other2 = (OTHER2);                                              \
79  Sbitset end_self = ptr_self + Sbitset__nbytes (NBITS);                      \
80  for (; ptr_self < end_self; ++ptr_self, ++ptr_other1, ++ptr_other2)         \
81    *ptr_self = *ptr_other1 | *ptr_other2;                                    \
82} while(0)
83
84#define SBITSET__FOR_EACH(SELF, NBITS, ITER, INDEX)                           \
85  for ((ITER) = (SELF); (ITER) < (SELF) + Sbitset__nbytes (NBITS); ++(ITER))  \
86    if (*(ITER) != 0)                                                         \
87      for ((INDEX) = ((ITER)-(SELF))*CHAR_BIT;                                \
88           (INDEX) < (NBITS) && (SELF)+(INDEX)/CHAR_BIT < (ITER)+1;           \
89           ++(INDEX))                                                         \
90        if (((*ITER) & Sbitset__bit_mask (INDEX)) != 0)
91
92#endif /* !SBITSET_H_ */
93