Merge branch 'ld/p4-cleanup-processes'
[git] / ewah / bitmap.c
1 /**
2  * Copyright 2013, GitHub, Inc
3  * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
4  *      David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include "cache.h"
20 #include "ewok.h"
21
22 #define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD))
23 #define EWAH_BLOCK(x) (x / BITS_IN_EWORD)
24
25 struct bitmap *bitmap_word_alloc(size_t word_alloc)
26 {
27         struct bitmap *bitmap = xmalloc(sizeof(struct bitmap));
28         bitmap->words = xcalloc(word_alloc, sizeof(eword_t));
29         bitmap->word_alloc = word_alloc;
30         return bitmap;
31 }
32
33 struct bitmap *bitmap_new(void)
34 {
35         return bitmap_word_alloc(32);
36 }
37
38 void bitmap_set(struct bitmap *self, size_t pos)
39 {
40         size_t block = EWAH_BLOCK(pos);
41
42         if (block >= self->word_alloc) {
43                 size_t old_size = self->word_alloc;
44                 self->word_alloc = block ? block * 2 : 1;
45                 REALLOC_ARRAY(self->words, self->word_alloc);
46                 memset(self->words + old_size, 0x0,
47                         (self->word_alloc - old_size) * sizeof(eword_t));
48         }
49
50         self->words[block] |= EWAH_MASK(pos);
51 }
52
53 int bitmap_get(struct bitmap *self, size_t pos)
54 {
55         size_t block = EWAH_BLOCK(pos);
56         return block < self->word_alloc &&
57                 (self->words[block] & EWAH_MASK(pos)) != 0;
58 }
59
60 struct ewah_bitmap *bitmap_to_ewah(struct bitmap *bitmap)
61 {
62         struct ewah_bitmap *ewah = ewah_new();
63         size_t i, running_empty_words = 0;
64         eword_t last_word = 0;
65
66         for (i = 0; i < bitmap->word_alloc; ++i) {
67                 if (bitmap->words[i] == 0) {
68                         running_empty_words++;
69                         continue;
70                 }
71
72                 if (last_word != 0)
73                         ewah_add(ewah, last_word);
74
75                 if (running_empty_words > 0) {
76                         ewah_add_empty_words(ewah, 0, running_empty_words);
77                         running_empty_words = 0;
78                 }
79
80                 last_word = bitmap->words[i];
81         }
82
83         ewah_add(ewah, last_word);
84         return ewah;
85 }
86
87 struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah)
88 {
89         struct bitmap *bitmap = bitmap_new();
90         struct ewah_iterator it;
91         eword_t blowup;
92         size_t i = 0;
93
94         ewah_iterator_init(&it, ewah);
95
96         while (ewah_iterator_next(&blowup, &it)) {
97                 ALLOC_GROW(bitmap->words, i + 1, bitmap->word_alloc);
98                 bitmap->words[i++] = blowup;
99         }
100
101         bitmap->word_alloc = i;
102         return bitmap;
103 }
104
105 void bitmap_and_not(struct bitmap *self, struct bitmap *other)
106 {
107         const size_t count = (self->word_alloc < other->word_alloc) ?
108                 self->word_alloc : other->word_alloc;
109
110         size_t i;
111
112         for (i = 0; i < count; ++i)
113                 self->words[i] &= ~other->words[i];
114 }
115
116 void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other)
117 {
118         size_t original_size = self->word_alloc;
119         size_t other_final = (other->bit_size / BITS_IN_EWORD) + 1;
120         size_t i = 0;
121         struct ewah_iterator it;
122         eword_t word;
123
124         if (self->word_alloc < other_final) {
125                 self->word_alloc = other_final;
126                 REALLOC_ARRAY(self->words, self->word_alloc);
127                 memset(self->words + original_size, 0x0,
128                         (self->word_alloc - original_size) * sizeof(eword_t));
129         }
130
131         ewah_iterator_init(&it, other);
132
133         while (ewah_iterator_next(&word, &it))
134                 self->words[i++] |= word;
135 }
136
137 size_t bitmap_popcount(struct bitmap *self)
138 {
139         size_t i, count = 0;
140
141         for (i = 0; i < self->word_alloc; ++i)
142                 count += ewah_bit_popcount64(self->words[i]);
143
144         return count;
145 }
146
147 int bitmap_equals(struct bitmap *self, struct bitmap *other)
148 {
149         struct bitmap *big, *small;
150         size_t i;
151
152         if (self->word_alloc < other->word_alloc) {
153                 small = self;
154                 big = other;
155         } else {
156                 small = other;
157                 big = self;
158         }
159
160         for (i = 0; i < small->word_alloc; ++i) {
161                 if (small->words[i] != big->words[i])
162                         return 0;
163         }
164
165         for (; i < big->word_alloc; ++i) {
166                 if (big->words[i] != 0)
167                         return 0;
168         }
169
170         return 1;
171 }
172
173 void bitmap_reset(struct bitmap *bitmap)
174 {
175         memset(bitmap->words, 0x0, bitmap->word_alloc * sizeof(eword_t));
176 }
177
178 void bitmap_free(struct bitmap *bitmap)
179 {
180         if (bitmap == NULL)
181                 return;
182
183         free(bitmap->words);
184         free(bitmap);
185 }