2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
24 #define BITMAP_ULONG_BITS (sizeof(unsigned long) * CHAR_BIT)
26 static inline unsigned long *
27 bitmap_unit__(const unsigned long *bitmap, size_t offset)
29 return CONST_CAST(unsigned long *, &bitmap[offset / BITMAP_ULONG_BITS]);
32 static inline unsigned long
33 bitmap_bit__(size_t offset)
35 return 1UL << (offset % BITMAP_ULONG_BITS);
38 #define BITMAP_N_LONGS(N_BITS) DIV_ROUND_UP(N_BITS, BITMAP_ULONG_BITS)
41 bitmap_n_longs(size_t n_bits)
43 return BITMAP_N_LONGS(n_bits);
47 bitmap_n_bytes(size_t n_bits)
49 return bitmap_n_longs(n_bits) * sizeof(unsigned long int);
52 static inline unsigned long *
53 bitmap_allocate(size_t n_bits)
55 return xzalloc(bitmap_n_bytes(n_bits));
58 /* Initializes bitmap to all-1-bits and returns the bitmap pointer. */
59 static inline unsigned long *
60 bitmap_init1(unsigned long *bitmap, size_t n_bits)
62 size_t n_longs = bitmap_n_longs(n_bits);
63 size_t n_bytes = bitmap_n_bytes(n_bits);
64 size_t r_bits = n_bits % BITMAP_ULONG_BITS;
66 memset(bitmap, 0xff, n_bytes);
68 bitmap[n_longs - 1] >>= BITMAP_ULONG_BITS - r_bits;
73 /* Allocates and returns a bitmap initialized to all-1-bits. */
74 static inline unsigned long *
75 bitmap_allocate1(size_t n_bits)
77 return bitmap_init1(xmalloc(bitmap_n_bytes(n_bits)), n_bits);
80 static inline unsigned long *
81 bitmap_clone(const unsigned long *bitmap, size_t n_bits)
83 return xmemdup(bitmap, bitmap_n_bytes(n_bits));
87 bitmap_free(unsigned long *bitmap)
93 bitmap_is_set(const unsigned long *bitmap, size_t offset)
95 return (*bitmap_unit__(bitmap, offset) & bitmap_bit__(offset)) != 0;
98 static inline unsigned long *
99 bitmap_set1(unsigned long *bitmap, size_t offset)
101 *bitmap_unit__(bitmap, offset) |= bitmap_bit__(offset);
105 static inline unsigned long *
106 bitmap_set0(unsigned long *bitmap, size_t offset)
108 *bitmap_unit__(bitmap, offset) &= ~bitmap_bit__(offset);
112 static inline unsigned long *
113 bitmap_set(unsigned long *bitmap, size_t offset, bool value)
115 return (value) ? bitmap_set1(bitmap, offset) : bitmap_set0(bitmap, offset);
118 /* Sets 'n' bits of a single unit. */
120 bitmap_set_n__(unsigned long *bitmap, size_t start, size_t n, bool value)
122 unsigned long mask = ((1UL << n) - 1) << start % BITMAP_ULONG_BITS;
125 *bitmap_unit__(bitmap, start) |= mask;
127 *bitmap_unit__(bitmap, start) &= ~mask;
131 /* Sets 'count' consecutive bits in 'bitmap', starting at bit offset 'start',
133 static inline unsigned long *
134 bitmap_set_multiple(unsigned long *bitmap, size_t start, size_t count,
137 if (count && start % BITMAP_ULONG_BITS) {
138 size_t n = MIN(count, BITMAP_ULONG_BITS - start % BITMAP_ULONG_BITS);
140 bitmap_set_n__(bitmap, start, n, value);
144 for (; count >= BITMAP_ULONG_BITS; count -= BITMAP_ULONG_BITS) {
145 *bitmap_unit__(bitmap, start) = (unsigned long)!value - 1;
146 start += BITMAP_ULONG_BITS;
149 bitmap_set_n__(bitmap, start, count, value);
154 /* Returns the number of 1-bits in the 'n'-bit bitmap at 'bitmap'. */
156 bitmap_count1(const unsigned long int *bitmap, size_t n)
161 BUILD_ASSERT(ULONG_MAX <= UINT64_MAX);
162 for (i = 0; i < BITMAP_N_LONGS(n); i++) {
163 count += count_1bits(bitmap[i]);
168 /* "dst &= arg;" for n-bit dst and arg. */
169 static inline unsigned long *
170 bitmap_and(unsigned long *dst, const unsigned long *arg, size_t n)
174 for (i = 0; i < BITMAP_N_LONGS(n); i++) {
180 /* "dst |= arg;" for n-bit dst and arg. */
181 static inline unsigned long *
182 bitmap_or(unsigned long *dst, const unsigned long *arg, size_t n)
186 for (i = 0; i < BITMAP_N_LONGS(n); i++) {
192 /* "dst = ~dst;" for n-bit dst. */
193 static inline unsigned long *
194 bitmap_not(unsigned long *dst, size_t n)
198 for (i = 0; i < n / BITMAP_ULONG_BITS; i++) {
201 if (n % BITMAP_ULONG_BITS) {
202 dst[i] ^= (1UL << (n % BITMAP_ULONG_BITS)) - 1;
207 /* Compares the 'n' bits in bitmaps 'a' and 'b'. Returns true if all bits are
208 * equal, false otherwise. */
210 bitmap_equal(const unsigned long *a, const unsigned long *b, size_t n)
212 if (memcmp(a, b, n / BITMAP_ULONG_BITS * sizeof(unsigned long))) {
215 if (n % BITMAP_ULONG_BITS) {
216 unsigned long mask = (1UL << n % BITMAP_ULONG_BITS) - 1;
217 unsigned long diff = *bitmap_unit__(a, n) ^ *bitmap_unit__(b, n);
219 return !(diff & mask);
224 /* Scans 'bitmap' from bit offset 'start' to 'end', excluding 'end' itself.
225 * Returns the bit offset of the lowest-numbered bit set to 'target', or 'end'
226 * if all of the bits are set to '!target'. 'target' is typically a
227 * compile-time constant, so it makes sense to inline this. Compiler may also
228 * optimize parts away depending on the 'start' and 'end' values passed in. */
230 bitmap_scan(const unsigned long *bitmap, bool target, size_t start, size_t end)
232 if (OVS_LIKELY(start < end)) {
233 unsigned long *p, unit;
235 p = bitmap_unit__(bitmap, start);
236 unit = (target ? *p : ~*p) >> (start % BITMAP_ULONG_BITS);
238 start -= start % BITMAP_ULONG_BITS; /* Round down. */
239 start += BITMAP_ULONG_BITS; /* Start of the next unit. */
241 for (; start < end; start += BITMAP_ULONG_BITS) {
242 unit = target ? *++p : ~*++p;
250 start += raw_ctz(unit); /* unit != 0 */
251 if (OVS_LIKELY(start < end)) {
258 /* Returns true if all of the 'n' bits in 'bitmap' are 0,
259 * false if at least one bit is a 1.*/
261 bitmap_is_all_zeros(const unsigned long *bitmap, size_t n)
263 return bitmap_scan(bitmap, true, 0, n) == n;
266 #define BITMAP_FOR_EACH_1_RANGE(IDX, BEGIN, END, BITMAP) \
267 for ((IDX) = bitmap_scan(BITMAP, true, BEGIN, END); (IDX) < (END); \
268 (IDX) = bitmap_scan(BITMAP, true, (IDX) + 1, END))
269 #define BITMAP_FOR_EACH_1(IDX, SIZE, BITMAP) \
270 BITMAP_FOR_EACH_1_RANGE(IDX, 0, SIZE, BITMAP)
272 /* More efficient access to a map of single ulong. */
273 #define ULONG_FOR_EACH_1(IDX, MAP) \
274 for (unsigned long map__ = (MAP); \
275 map__ && (((IDX) = raw_ctz(map__)), true); \
276 map__ = zero_rightmost_1bit(map__))
278 #define ULONG_SET0(MAP, OFFSET) ((MAP) &= ~(1UL << (OFFSET)))
279 #define ULONG_SET1(MAP, OFFSET) ((MAP) |= 1UL << (OFFSET))
281 #endif /* bitmap.h */