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- /* Simple bitmaps.
- Copyright (C) 1999-2015 Free Software Foundation, Inc.
- This file is part of GCC.
- GCC is free software; you can redistribute it and/or modify it under
- the terms of the GNU General Public License as published by the Free
- Software Foundation; either version 3, or (at your option) any later
- version.
- GCC is distributed in the hope that it will be useful, but WITHOUT ANY
- WARRANTY; without even the implied warranty of MERCHANTABILITY or
- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- for more details.
- You should have received a copy of the GNU General Public License
- along with GCC; see the file COPYING3. If not see
- <http://www.gnu.org/licenses/>. */
- #ifndef GCC_SBITMAP_H
- #define GCC_SBITMAP_H
- /* Implementation of sets using simple bitmap vectors.
- This set representation is suitable for non-sparse sets with a known
- (a priori) universe. The set is represented as a simple array of the
- host's fastest unsigned integer. For a given member I in the set:
- - the element for I will be at sbitmap[I / (bits per element)]
- - the position for I within element is I % (bits per element)
- This representation is very space-efficient for large non-sparse sets
- with random access patterns.
- The following operations can be performed in O(1) time:
- * set_size : SBITMAP_SIZE
- * member_p : bitmap_bit_p
- * add_member : bitmap_set_bit
- * remove_member : bitmap_clear_bit
- Most other operations on this set representation are O(U) where U is
- the size of the set universe:
- * clear : bitmap_clear
- * choose_one : bitmap_first_set_bit /
- bitmap_last_set_bit
- * forall : EXECUTE_IF_SET_IN_BITMAP
- * set_copy : bitmap_copy
- * set_intersection : bitmap_and
- * set_union : bitmap_ior
- * set_difference : bitmap_and_compl
- * set_disjuction : (not implemented)
- * set_compare : bitmap_equal_p
- Some operations on 3 sets that occur frequently in in data flow problems
- are also implemented:
- * A | (B & C) : bitmap_or_and
- * A | (B & ~C) : bitmap_ior_and_compl
- * A & (B | C) : bitmap_and_or
- Most of the set functions have two variants: One that returns non-zero
- if members were added or removed from the target set, and one that just
- performs the operation without feedback. The former operations are a
- bit more expensive but the result can often be used to avoid iterations
- on other sets.
- Allocating a bitmap is done with sbitmap_alloc, and resizing is
- performed with sbitmap_resize.
- The storage requirements for simple bitmap sets is O(U) where U is the
- size of the set universe (colloquially the number of bits in the bitmap).
- This set representation works well for relatively small data flow problems
- (there are special routines for that, see sbitmap_vector_*). The set
- operations can be vectorized and there is almost no computating overhead,
- so that even sparse simple bitmap sets outperform dedicated sparse set
- representations like linked-list bitmaps. For larger problems, the size
- overhead of simple bitmap sets gets too high and other set representations
- have to be used. */
- #define SBITMAP_ELT_BITS (HOST_BITS_PER_WIDEST_FAST_INT * 1u)
- #define SBITMAP_ELT_TYPE unsigned HOST_WIDEST_FAST_INT
- struct simple_bitmap_def
- {
- unsigned char *popcount; /* Population count. */
- unsigned int n_bits; /* Number of bits. */
- unsigned int size; /* Size in elements. */
- SBITMAP_ELT_TYPE elms[1]; /* The elements. */
- };
- /* Return the set size needed for N elements. */
- #define SBITMAP_SET_SIZE(N) (((N) + SBITMAP_ELT_BITS - 1) / SBITMAP_ELT_BITS)
- /* Return the number of bits in BITMAP. */
- #define SBITMAP_SIZE(BITMAP) ((BITMAP)->n_bits)
- /* Test if bit number bitno in the bitmap is set. */
- static inline SBITMAP_ELT_TYPE
- bitmap_bit_p (const_sbitmap map, int bitno)
- {
- size_t i = bitno / SBITMAP_ELT_BITS;
- unsigned int s = bitno % SBITMAP_ELT_BITS;
- return (map->elms[i] >> s) & (SBITMAP_ELT_TYPE) 1;
- }
- /* Set bit number BITNO in the sbitmap MAP. */
- static inline void
- bitmap_set_bit (sbitmap map, int bitno)
- {
- gcc_checking_assert (! map->popcount);
- map->elms[bitno / SBITMAP_ELT_BITS]
- |= (SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS;
- }
- /* Reset bit number BITNO in the sbitmap MAP. */
- static inline void
- bitmap_clear_bit (sbitmap map, int bitno)
- {
- gcc_checking_assert (! map->popcount);
- map->elms[bitno / SBITMAP_ELT_BITS]
- &= ~((SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS);
- }
- /* The iterator for sbitmap. */
- struct sbitmap_iterator {
- /* The pointer to the first word of the bitmap. */
- const SBITMAP_ELT_TYPE *ptr;
- /* The size of the bitmap. */
- unsigned int size;
- /* The current word index. */
- unsigned int word_num;
- /* The current bit index (not modulo SBITMAP_ELT_BITS). */
- unsigned int bit_num;
- /* The words currently visited. */
- SBITMAP_ELT_TYPE word;
- };
- /* Initialize the iterator I with sbitmap BMP and the initial index
- MIN. */
- static inline void
- bmp_iter_set_init (sbitmap_iterator *i, const_sbitmap bmp,
- unsigned int min, unsigned *bit_no ATTRIBUTE_UNUSED)
- {
- i->word_num = min / (unsigned int) SBITMAP_ELT_BITS;
- i->bit_num = min;
- i->size = bmp->size;
- i->ptr = bmp->elms;
- if (i->word_num >= i->size)
- i->word = 0;
- else
- i->word = (i->ptr[i->word_num]
- >> (i->bit_num % (unsigned int) SBITMAP_ELT_BITS));
- }
- /* Return true if we have more bits to visit, in which case *N is set
- to the index of the bit to be visited. Otherwise, return
- false. */
- static inline bool
- bmp_iter_set (sbitmap_iterator *i, unsigned int *n)
- {
- /* Skip words that are zeros. */
- for (; i->word == 0; i->word = i->ptr[i->word_num])
- {
- i->word_num++;
- /* If we have reached the end, break. */
- if (i->word_num >= i->size)
- return false;
- i->bit_num = i->word_num * SBITMAP_ELT_BITS;
- }
- /* Skip bits that are zero. */
- for (; (i->word & 1) == 0; i->word >>= 1)
- i->bit_num++;
- *n = i->bit_num;
- return true;
- }
- /* Advance to the next bit. */
- static inline void
- bmp_iter_next (sbitmap_iterator *i, unsigned *bit_no ATTRIBUTE_UNUSED)
- {
- i->word >>= 1;
- i->bit_num++;
- }
- /* Loop over all elements of SBITMAP, starting with MIN. In each
- iteration, N is set to the index of the bit being visited. ITER is
- an instance of sbitmap_iterator used to iterate the bitmap. */
- #ifndef EXECUTE_IF_SET_IN_BITMAP
- /* See bitmap.h for the other definition of EXECUTE_IF_SET_IN_BITMAP. */
- #define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER) \
- for (bmp_iter_set_init (&(ITER), (BITMAP), (MIN), &(BITNUM)); \
- bmp_iter_set (&(ITER), &(BITNUM)); \
- bmp_iter_next (&(ITER), &(BITNUM)))
- #endif
- inline void sbitmap_free (sbitmap map)
- {
- free (map->popcount);
- free (map);
- }
- inline void sbitmap_vector_free (sbitmap * vec)
- {
- free (vec);
- }
- extern void dump_bitmap (FILE *, const_sbitmap);
- extern void debug_raw (const simple_bitmap_def &ref);
- extern void debug_raw (const simple_bitmap_def *ptr);
- extern void dump_bitmap_file (FILE *, const_sbitmap);
- extern void debug (const simple_bitmap_def &ref);
- extern void debug (const simple_bitmap_def *ptr);
- extern void dump_bitmap_vector (FILE *, const char *, const char *, sbitmap *,
- int);
- extern sbitmap sbitmap_alloc (unsigned int);
- extern sbitmap sbitmap_alloc_with_popcount (unsigned int);
- extern sbitmap *sbitmap_vector_alloc (unsigned int, unsigned int);
- extern sbitmap sbitmap_resize (sbitmap, unsigned int, int);
- extern void bitmap_copy (sbitmap, const_sbitmap);
- extern int bitmap_equal_p (const_sbitmap, const_sbitmap);
- extern bool bitmap_empty_p (const_sbitmap);
- extern void bitmap_clear (sbitmap);
- extern void bitmap_ones (sbitmap);
- extern void bitmap_vector_clear (sbitmap *, unsigned int);
- extern void bitmap_vector_ones (sbitmap *, unsigned int);
- extern bool bitmap_ior_and_compl (sbitmap, const_sbitmap,
- const_sbitmap, const_sbitmap);
- extern void bitmap_and_compl (sbitmap, const_sbitmap, const_sbitmap);
- extern void bitmap_not (sbitmap, const_sbitmap);
- extern bool bitmap_or_and (sbitmap, const_sbitmap,
- const_sbitmap, const_sbitmap);
- extern bool bitmap_and_or (sbitmap, const_sbitmap,
- const_sbitmap, const_sbitmap);
- extern bool bitmap_intersect_p (const_sbitmap, const_sbitmap);
- extern bool bitmap_and (sbitmap, const_sbitmap, const_sbitmap);
- extern bool bitmap_ior (sbitmap, const_sbitmap, const_sbitmap);
- extern bool bitmap_xor (sbitmap, const_sbitmap, const_sbitmap);
- extern bool bitmap_subset_p (const_sbitmap, const_sbitmap);
- extern int bitmap_first_set_bit (const_sbitmap);
- extern int bitmap_last_set_bit (const_sbitmap);
- extern void debug_bitmap (const_sbitmap);
- extern sbitmap sbitmap_realloc (sbitmap, unsigned int);
- extern unsigned long sbitmap_popcount (const_sbitmap, unsigned long);
- #endif /* ! GCC_SBITMAP_H */
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