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/*
* Mesa 3-D graphics library
*
* Copyright (C) 2006 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* \file bitset.h
* \brief Bitset of arbitrary size definitions.
* \author Michal Krol
*/
#ifndef BITSET_H
#define BITSET_H
#include "util/bitscan.h"
#include "util/macros.h"
/****************************************************************************
* generic bitset implementation
*/
#define BITSET_WORD unsigned int
#define BITSET_WORDBITS (sizeof (BITSET_WORD) * 8)
/* bitset declarations
*/
#define BITSET_WORDS(bits) (((bits) + BITSET_WORDBITS - 1) / BITSET_WORDBITS)
#define BITSET_DECLARE(name, bits) BITSET_WORD name[BITSET_WORDS(bits)]
/* bitset operations
*/
#define BITSET_COPY(x, y) memcpy( (x), (y), sizeof (x) )
#define BITSET_EQUAL(x, y) (memcmp( (x), (y), sizeof (x) ) == 0)
#define BITSET_ZERO(x) memset( (x), 0, sizeof (x) )
#define BITSET_ONES(x) memset( (x), 0xff, sizeof (x) )
#define BITSET_BITWORD(b) ((b) / BITSET_WORDBITS)
#define BITSET_BIT(b) (1u << ((b) % BITSET_WORDBITS))
/* single bit operations
*/
#define BITSET_TEST(x, b) (((x)[BITSET_BITWORD(b)] & BITSET_BIT(b)) != 0)
#define BITSET_SET(x, b) ((x)[BITSET_BITWORD(b)] |= BITSET_BIT(b))
#define BITSET_CLEAR(x, b) ((x)[BITSET_BITWORD(b)] &= ~BITSET_BIT(b))
#define BITSET_MASK(b) (((b) % BITSET_WORDBITS == 0) ? ~0 : BITSET_BIT(b) - 1)
#define BITSET_RANGE(b, e) ((BITSET_MASK((e) + 1)) & ~(BITSET_BIT(b) - 1))
/* bit range operations
*/
#define BITSET_TEST_RANGE(x, b, e) \
(BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \
(((x)[BITSET_BITWORD(b)] & BITSET_RANGE(b, e)) != 0) : \
(assert (!"BITSET_TEST_RANGE: bit range crosses word boundary"), 0))
#define BITSET_SET_RANGE(x, b, e) \
(BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \
((x)[BITSET_BITWORD(b)] |= BITSET_RANGE(b, e)) : \
(assert (!"BITSET_SET_RANGE: bit range crosses word boundary"), 0))
#define BITSET_CLEAR_RANGE(x, b, e) \
(BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \
((x)[BITSET_BITWORD(b)] &= ~BITSET_RANGE(b, e)) : \
(assert (!"BITSET_CLEAR_RANGE: bit range crosses word boundary"), 0))
/* Get first bit set in a bitset.
*/
static inline int
__bitset_ffs(const BITSET_WORD *x, int n)
{
int i;
for (i = 0; i < n; i++) {
if (x[i])
return ffs(x[i]) + BITSET_WORDBITS * i;
}
return 0;
}
#define BITSET_FFS(x) __bitset_ffs(x, ARRAY_SIZE(x))
static inline unsigned
__bitset_next_set(unsigned i, BITSET_WORD *tmp,
const BITSET_WORD *set, unsigned size)
{
unsigned bit, word;
/* NOTE: The initial conditions for this function are very specific. At
* the start of the loop, the tmp variable must be set to *set and the
* initial i value set to 0. This way, if there is a bit set in the first
* word, we ignore the i-value and just grab that bit (so 0 is ok, even
* though 0 may be returned). If the first word is 0, then the value of
* `word` will be 0 and we will go on to look at the second word.
*/
word = BITSET_BITWORD(i);
while (*tmp == 0) {
word++;
if (word >= BITSET_WORDS(size))
return size;
*tmp = set[word];
}
/* Find the next set bit in the non-zero word */
bit = ffs(*tmp) - 1;
/* Unset the bit */
*tmp &= ~(1ull << bit);
return word * BITSET_WORDBITS + bit;
}
/**
* Iterates over each set bit in a set
*
* @param __i iteration variable, bit number
* @param __set the bitset to iterate (will not be modified)
* @param __size number of bits in the set to consider
*/
#define BITSET_FOREACH_SET(__i, __set, __size) \
for (BITSET_WORD __tmp = *(__set), *__foo = &__tmp; __foo != NULL; __foo = NULL) \
for (__i = 0; \
(__i = __bitset_next_set(__i, &__tmp, __set, __size)) < __size;)
#ifdef __cplusplus
/**
* Simple C++ wrapper of a bitset type of static size, with value semantics
* and basic bitwise arithmetic operators. The operators defined below are
* expected to have the same semantics as the same operator applied to other
* fundamental integer types. T is the name of the struct to instantiate
* it as, and N is the number of bits in the bitset.
*/
#define DECLARE_BITSET_T(T, N) struct T { \
EXPLICIT_CONVERSION \
operator bool() const \
{ \
for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
if (words[i]) \
return true; \
return false; \
} \
\
T & \
operator=(int x) \
{ \
const T c = {{ (BITSET_WORD)x }}; \
return *this = c; \
} \
\
friend bool \
operator==(const T &b, const T &c) \
{ \
return BITSET_EQUAL(b.words, c.words); \
} \
\
friend bool \
operator!=(const T &b, const T &c) \
{ \
return !(b == c); \
} \
\
friend bool \
operator==(const T &b, int x) \
{ \
const T c = {{ (BITSET_WORD)x }}; \
return b == c; \
} \
\
friend bool \
operator!=(const T &b, int x) \
{ \
return !(b == x); \
} \
\
friend T \
operator~(const T &b) \
{ \
T c; \
for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
c.words[i] = ~b.words[i]; \
return c; \
} \
\
T & \
operator|=(const T &b) \
{ \
for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
words[i] |= b.words[i]; \
return *this; \
} \
\
friend T \
operator|(const T &b, const T &c) \
{ \
T d = b; \
d |= c; \
return d; \
} \
\
T & \
operator&=(const T &b) \
{ \
for (unsigned i = 0; i < BITSET_WORDS(N); i++) \
words[i] &= b.words[i]; \
return *this; \
} \
\
friend T \
operator&(const T &b, const T &c) \
{ \
T d = b; \
d &= c; \
return d; \
} \
\
bool \
test(unsigned i) const \
{ \
return BITSET_TEST(words, i); \
} \
\
T & \
set(unsigned i) \
{ \
BITSET_SET(words, i); \
return *this; \
} \
\
T & \
clear(unsigned i) \
{ \
BITSET_CLEAR(words, i); \
return *this; \
} \
\
BITSET_WORD words[BITSET_WORDS(N)]; \
}
#endif
#endif