| /* Functions to support general ended bitmaps. |
| Copyright (C) 1997-2021 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_BITMAP_H |
| #define GCC_BITMAP_H |
| |
| /* Implementation of sparse integer sets as a linked list or tree. |
| |
| This sparse set representation is suitable for sparse sets with an |
| unknown (a priori) universe. |
| |
| Sets are represented as double-linked lists of container nodes of |
| type "struct bitmap_element" or as a binary trees of the same |
| container nodes. Each container node consists of an index for the |
| first member that could be held in the container, a small array of |
| integers that represent the members in the container, and pointers |
| to the next and previous element in the linked list, or left and |
| right children in the tree. In linked-list form, the container |
| nodes in the list are sorted in ascending order, i.e. the head of |
| the list holds the element with the smallest member of the set. |
| In tree form, nodes to the left have a smaller container index. |
| |
| For a given member I in the set: |
| - the element for I will have index is I / (bits per element) |
| - the position for I within element is I % (bits per element) |
| |
| This representation is very space-efficient for large sparse sets, and |
| the size of the set can be changed dynamically without much overhead. |
| An important parameter is the number of bits per element. In this |
| implementation, there are 128 bits per element. This results in a |
| high storage overhead *per element*, but a small overall overhead if |
| the set is very sparse. |
| |
| The storage requirements for linked-list sparse sets are O(E), with E->N |
| in the worst case (a sparse set with large distances between the values |
| of the set members). |
| |
| This representation also works well for data flow problems where the size |
| of the set may grow dynamically, but care must be taken that the member_p, |
| add_member, and remove_member operations occur with a suitable access |
| pattern. |
| |
| The linked-list set representation works well for problems involving very |
| sparse sets. The canonical example in GCC is, of course, the "set of |
| sets" for some CFG-based data flow problems (liveness analysis, dominance |
| frontiers, etc.). |
| |
| For random-access sparse sets of unknown universe, the binary tree |
| representation is likely to be a more suitable choice. Theoretical |
| access times for the binary tree representation are better than those |
| for the linked-list, but in practice this is only true for truely |
| random access. |
| |
| Often the most suitable representation during construction of the set |
| is not the best choice for the usage of the set. For such cases, the |
| "view" of the set can be changed from one representation to the other. |
| This is an O(E) operation: |
| |
| * from list to tree view : bitmap_tree_view |
| * from tree to list view : bitmap_list_view |
| |
| Traversing linked lists or trees can be cache-unfriendly. Performance |
| can be improved by keeping container nodes in the set grouped together |
| in memory, using a dedicated obstack for a set (or group of related |
| sets). Elements allocated on obstacks are released to a free-list and |
| taken off the free list. If multiple sets are allocated on the same |
| obstack, elements freed from one set may be re-used for one of the other |
| sets. This usually helps avoid cache misses. |
| |
| A single free-list is used for all sets allocated in GGC space. This is |
| bad for persistent sets, so persistent sets should be allocated on an |
| obstack whenever possible. |
| |
| For random-access sets with a known, relatively small universe size, the |
| SparseSet or simple bitmap representations may be more efficient than a |
| linked-list set. |
| |
| |
| LINKED LIST FORM |
| ================ |
| |
| In linked-list form, in-order iterations of the set can be executed |
| efficiently. The downside is that many random-access operations are |
| relatively slow, because the linked list has to be traversed to test |
| membership (i.e. member_p/ add_member/remove_member). |
| |
| To improve the performance of this set representation, the last |
| accessed element and its index are cached. For membership tests on |
| members close to recently accessed members, the cached last element |
| improves membership test to a constant-time operation. |
| |
| The following operations can always be performed in O(1) time in |
| list view: |
| |
| * clear : bitmap_clear |
| * smallest_member : bitmap_first_set_bit |
| * choose_one : (not implemented, but could be |
| in constant time) |
| |
| The following operations can be performed in O(E) time worst-case in |
| list view (with E the number of elements in the linked list), but in |
| O(1) time with a suitable access patterns: |
| |
| * member_p : bitmap_bit_p |
| * add_member : bitmap_set_bit / bitmap_set_range |
| * remove_member : bitmap_clear_bit / bitmap_clear_range |
| |
| The following operations can be performed in O(E) time in list view: |
| |
| * cardinality : bitmap_count_bits |
| * largest_member : bitmap_last_set_bit (but this could |
| in constant time with a pointer to |
| the last element in the chain) |
| * set_size : bitmap_last_set_bit |
| |
| In tree view the following operations can all be performed in O(log E) |
| amortized time with O(E) worst-case behavior. |
| |
| * smallest_member |
| * largest_member |
| * set_size |
| * member_p |
| * add_member |
| * remove_member |
| |
| Additionally, the linked-list sparse set representation supports |
| enumeration of the members in O(E) time: |
| |
| * forall : EXECUTE_IF_SET_IN_BITMAP |
| * set_copy : bitmap_copy |
| * set_intersection : bitmap_intersect_p / |
| bitmap_and / bitmap_and_into / |
| EXECUTE_IF_AND_IN_BITMAP |
| * set_union : bitmap_ior / bitmap_ior_into |
| * set_difference : bitmap_intersect_compl_p / |
| bitmap_and_comp / bitmap_and_comp_into / |
| EXECUTE_IF_AND_COMPL_IN_BITMAP |
| * set_disjuction : bitmap_xor_comp / bitmap_xor_comp_into |
| * set_compare : bitmap_equal_p |
| |
| Some operations on 3 sets that occur frequently in data flow problems |
| are also implemented: |
| |
| * A | (B & C) : bitmap_ior_and_into |
| * A | (B & ~C) : bitmap_ior_and_compl / |
| bitmap_ior_and_compl_into |
| |
| |
| BINARY TREE FORM |
| ================ |
| An alternate "view" of a bitmap is its binary tree representation. |
| For this representation, splay trees are used because they can be |
| implemented using the same data structures as the linked list, with |
| no overhead for meta-data (like color, or rank) on the tree nodes. |
| |
| In binary tree form, random-access to the set is much more efficient |
| than for the linked-list representation. Downsides are the high cost |
| of clearing the set, and the relatively large number of operations |
| necessary to balance the tree. Also, iterating the set members is |
| not supported. |
| |
| As for the linked-list representation, the last accessed element and |
| its index are cached, so that membership tests on the latest accessed |
| members is a constant-time operation. Other lookups take O(logE) |
| time amortized (but O(E) time worst-case). |
| |
| The following operations can always be performed in O(1) time: |
| |
| * choose_one : (not implemented, but could be |
| implemented in constant time) |
| |
| The following operations can be performed in O(logE) time amortized |
| but O(E) time worst-case, but in O(1) time if the same element is |
| accessed. |
| |
| * member_p : bitmap_bit_p |
| * add_member : bitmap_set_bit |
| * remove_member : bitmap_clear_bit |
| |
| The following operations can be performed in O(logE) time amortized |
| but O(E) time worst-case: |
| |
| * smallest_member : bitmap_first_set_bit |
| * largest_member : bitmap_last_set_bit |
| * set_size : bitmap_last_set_bit |
| |
| The following operations can be performed in O(E) time: |
| |
| * clear : bitmap_clear |
| |
| The binary tree sparse set representation does *not* support any form |
| of enumeration, and does also *not* support logical operations on sets. |
| The binary tree representation is only supposed to be used for sets |
| on which many random-access membership tests will happen. */ |
| |
| #include "obstack.h" |
| #include "array-traits.h" |
| |
| /* Bitmap memory usage. */ |
| class bitmap_usage: public mem_usage |
| { |
| public: |
| /* Default contructor. */ |
| bitmap_usage (): m_nsearches (0), m_search_iter (0) {} |
| /* Constructor. */ |
| bitmap_usage (size_t allocated, size_t times, size_t peak, |
| uint64_t nsearches, uint64_t search_iter) |
| : mem_usage (allocated, times, peak), |
| m_nsearches (nsearches), m_search_iter (search_iter) {} |
| |
| /* Sum the usage with SECOND usage. */ |
| bitmap_usage |
| operator+ (const bitmap_usage &second) |
| { |
| return bitmap_usage (m_allocated + second.m_allocated, |
| m_times + second.m_times, |
| m_peak + second.m_peak, |
| m_nsearches + second.m_nsearches, |
| m_search_iter + second.m_search_iter); |
| } |
| |
| /* Dump usage coupled to LOC location, where TOTAL is sum of all rows. */ |
| inline void |
| dump (mem_location *loc, const mem_usage &total) const |
| { |
| char *location_string = loc->to_string (); |
| |
| fprintf (stderr, "%-48s " PRsa (9) ":%5.1f%%" |
| PRsa (9) PRsa (9) ":%5.1f%%" |
| PRsa (11) PRsa (11) "%10s\n", |
| location_string, SIZE_AMOUNT (m_allocated), |
| get_percent (m_allocated, total.m_allocated), |
| SIZE_AMOUNT (m_peak), SIZE_AMOUNT (m_times), |
| get_percent (m_times, total.m_times), |
| SIZE_AMOUNT (m_nsearches), SIZE_AMOUNT (m_search_iter), |
| loc->m_ggc ? "ggc" : "heap"); |
| |
| free (location_string); |
| } |
| |
| /* Dump header with NAME. */ |
| static inline void |
| dump_header (const char *name) |
| { |
| fprintf (stderr, "%-48s %11s%16s%17s%12s%12s%10s\n", name, "Leak", "Peak", |
| "Times", "N searches", "Search iter", "Type"); |
| } |
| |
| /* Number search operations. */ |
| uint64_t m_nsearches; |
| /* Number of search iterations. */ |
| uint64_t m_search_iter; |
| }; |
| |
| /* Bitmap memory description. */ |
| extern mem_alloc_description<bitmap_usage> bitmap_mem_desc; |
| |
| /* Fundamental storage type for bitmap. */ |
| |
| typedef unsigned long BITMAP_WORD; |
| /* BITMAP_WORD_BITS needs to be unsigned, but cannot contain casts as |
| it is used in preprocessor directives -- hence the 1u. */ |
| #define BITMAP_WORD_BITS (CHAR_BIT * SIZEOF_LONG * 1u) |
| |
| /* Number of words to use for each element in the linked list. */ |
| |
| #ifndef BITMAP_ELEMENT_WORDS |
| #define BITMAP_ELEMENT_WORDS ((128 + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS) |
| #endif |
| |
| /* Number of bits in each actual element of a bitmap. */ |
| |
| #define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS) |
| |
| /* Obstack for allocating bitmaps and elements from. */ |
| struct bitmap_obstack { |
| struct bitmap_element *elements; |
| bitmap_head *heads; |
| struct obstack obstack; |
| }; |
| |
| /* Bitmap set element. We use a linked list to hold only the bits that |
| are set. This allows for use to grow the bitset dynamically without |
| having to realloc and copy a giant bit array. |
| |
| The free list is implemented as a list of lists. There is one |
| outer list connected together by prev fields. Each element of that |
| outer is an inner list (that may consist only of the outer list |
| element) that are connected by the next fields. The prev pointer |
| is undefined for interior elements. This allows |
| bitmap_elt_clear_from to be implemented in unit time rather than |
| linear in the number of elements to be freed. */ |
| |
| struct GTY((chain_next ("%h.next"))) bitmap_element { |
| /* In list form, the next element in the linked list; |
| in tree form, the left child node in the tree. */ |
| struct bitmap_element *next; |
| /* In list form, the previous element in the linked list; |
| in tree form, the right child node in the tree. */ |
| struct bitmap_element *prev; |
| /* regno/BITMAP_ELEMENT_ALL_BITS. */ |
| unsigned int indx; |
| /* Bits that are set, counting from INDX, inclusive */ |
| BITMAP_WORD bits[BITMAP_ELEMENT_WORDS]; |
| }; |
| |
| /* Head of bitmap linked list. The 'current' member points to something |
| already pointed to by the chain started by first, so GTY((skip)) it. */ |
| |
| class GTY(()) bitmap_head { |
| public: |
| static bitmap_obstack crashme; |
| /* Poison obstack to not make it not a valid initialized GC bitmap. */ |
| CONSTEXPR bitmap_head() |
| : indx (0), tree_form (false), padding (0), alloc_descriptor (0), first (NULL), |
| current (NULL), obstack (&crashme) |
| {} |
| /* Index of last element looked at. */ |
| unsigned int indx; |
| /* False if the bitmap is in list form; true if the bitmap is in tree form. |
| Bitmap iterators only work on bitmaps in list form. */ |
| unsigned tree_form: 1; |
| /* Next integer is shifted, so padding is needed. */ |
| unsigned padding: 2; |
| /* Bitmap UID used for memory allocation statistics. */ |
| unsigned alloc_descriptor: 29; |
| /* In list form, the first element in the linked list; |
| in tree form, the root of the tree. */ |
| bitmap_element *first; |
| /* Last element looked at. */ |
| bitmap_element * GTY((skip(""))) current; |
| /* Obstack to allocate elements from. If NULL, then use GGC allocation. */ |
| bitmap_obstack * GTY((skip(""))) obstack; |
| |
| /* Dump bitmap. */ |
| void dump (); |
| |
| /* Get bitmap descriptor UID casted to an unsigned integer pointer. |
| Shift the descriptor because pointer_hash<Type>::hash is |
| doing >> 3 shift operation. */ |
| unsigned *get_descriptor () |
| { |
| return (unsigned *)(ptrdiff_t)(alloc_descriptor << 3); |
| } |
| }; |
| |
| /* Global data */ |
| extern bitmap_element bitmap_zero_bits; /* Zero bitmap element */ |
| extern bitmap_obstack bitmap_default_obstack; /* Default bitmap obstack */ |
| |
| /* Change the view of the bitmap to list, or tree. */ |
| void bitmap_list_view (bitmap); |
| void bitmap_tree_view (bitmap); |
| |
| /* Clear a bitmap by freeing up the linked list. */ |
| extern void bitmap_clear (bitmap); |
| |
| /* Copy a bitmap to another bitmap. */ |
| extern void bitmap_copy (bitmap, const_bitmap); |
| |
| /* Move a bitmap to another bitmap. */ |
| extern void bitmap_move (bitmap, bitmap); |
| |
| /* True if two bitmaps are identical. */ |
| extern bool bitmap_equal_p (const_bitmap, const_bitmap); |
| |
| /* True if the bitmaps intersect (their AND is non-empty). */ |
| extern bool bitmap_intersect_p (const_bitmap, const_bitmap); |
| |
| /* True if the complement of the second intersects the first (their |
| AND_COMPL is non-empty). */ |
| extern bool bitmap_intersect_compl_p (const_bitmap, const_bitmap); |
| |
| /* True if MAP is an empty bitmap. */ |
| inline bool bitmap_empty_p (const_bitmap map) |
| { |
| return !map->first; |
| } |
| |
| /* True if the bitmap has only a single bit set. */ |
| extern bool bitmap_single_bit_set_p (const_bitmap); |
| |
| /* Count the number of bits set in the bitmap. */ |
| extern unsigned long bitmap_count_bits (const_bitmap); |
| |
| /* Count the number of unique bits set across the two bitmaps. */ |
| extern unsigned long bitmap_count_unique_bits (const_bitmap, const_bitmap); |
| |
| /* Boolean operations on bitmaps. The _into variants are two operand |
| versions that modify the first source operand. The other variants |
| are three operand versions that to not destroy the source bitmaps. |
| The operations supported are &, & ~, |, ^. */ |
| extern void bitmap_and (bitmap, const_bitmap, const_bitmap); |
| extern bool bitmap_and_into (bitmap, const_bitmap); |
| extern bool bitmap_and_compl (bitmap, const_bitmap, const_bitmap); |
| extern bool bitmap_and_compl_into (bitmap, const_bitmap); |
| #define bitmap_compl_and(DST, A, B) bitmap_and_compl (DST, B, A) |
| extern void bitmap_compl_and_into (bitmap, const_bitmap); |
| extern void bitmap_clear_range (bitmap, unsigned int, unsigned int); |
| extern void bitmap_set_range (bitmap, unsigned int, unsigned int); |
| extern bool bitmap_ior (bitmap, const_bitmap, const_bitmap); |
| extern bool bitmap_ior_into (bitmap, const_bitmap); |
| extern bool bitmap_ior_into_and_free (bitmap, bitmap *); |
| extern void bitmap_xor (bitmap, const_bitmap, const_bitmap); |
| extern void bitmap_xor_into (bitmap, const_bitmap); |
| |
| /* DST = A | (B & C). Return true if DST changes. */ |
| extern bool bitmap_ior_and_into (bitmap DST, const_bitmap B, const_bitmap C); |
| /* DST = A | (B & ~C). Return true if DST changes. */ |
| extern bool bitmap_ior_and_compl (bitmap DST, const_bitmap A, |
| const_bitmap B, const_bitmap C); |
| /* A |= (B & ~C). Return true if A changes. */ |
| extern bool bitmap_ior_and_compl_into (bitmap A, |
| const_bitmap B, const_bitmap C); |
| |
| /* Clear a single bit in a bitmap. Return true if the bit changed. */ |
| extern bool bitmap_clear_bit (bitmap, int); |
| |
| /* Set a single bit in a bitmap. Return true if the bit changed. */ |
| extern bool bitmap_set_bit (bitmap, int); |
| |
| /* Return true if a bit is set in a bitmap. */ |
| extern int bitmap_bit_p (const_bitmap, int); |
| |
| /* Set and get multiple bit values in a sparse bitmap. This allows a bitmap to |
| function as a sparse array of bit patterns where the patterns are |
| multiples of power of 2. This is more efficient than performing this as |
| multiple individual operations. */ |
| void bitmap_set_aligned_chunk (bitmap, unsigned int, unsigned int, BITMAP_WORD); |
| BITMAP_WORD bitmap_get_aligned_chunk (const_bitmap, unsigned int, unsigned int); |
| |
| /* Debug functions to print a bitmap. */ |
| extern void debug_bitmap (const_bitmap); |
| extern void debug_bitmap_file (FILE *, const_bitmap); |
| |
| /* Print a bitmap. */ |
| extern void bitmap_print (FILE *, const_bitmap, const char *, const char *); |
| |
| /* Initialize and release a bitmap obstack. */ |
| extern void bitmap_obstack_initialize (bitmap_obstack *); |
| extern void bitmap_obstack_release (bitmap_obstack *); |
| extern void bitmap_register (bitmap MEM_STAT_DECL); |
| extern void dump_bitmap_statistics (void); |
| |
| /* Initialize a bitmap header. OBSTACK indicates the bitmap obstack |
| to allocate from, NULL for GC'd bitmap. */ |
| |
| static inline void |
| bitmap_initialize (bitmap head, bitmap_obstack *obstack CXX_MEM_STAT_INFO) |
| { |
| head->first = head->current = NULL; |
| head->indx = head->tree_form = 0; |
| head->padding = 0; |
| head->alloc_descriptor = 0; |
| head->obstack = obstack; |
| if (GATHER_STATISTICS) |
| bitmap_register (head PASS_MEM_STAT); |
| } |
| |
| /* Release a bitmap (but not its head). This is suitable for pairing with |
| bitmap_initialize. */ |
| |
| static inline void |
| bitmap_release (bitmap head) |
| { |
| bitmap_clear (head); |
| /* Poison the obstack pointer so the obstack can be safely released. |
| Do not zero it as the bitmap then becomes initialized GC. */ |
| head->obstack = &bitmap_head::crashme; |
| } |
| |
| /* Allocate and free bitmaps from obstack, malloc and gc'd memory. */ |
| extern bitmap bitmap_alloc (bitmap_obstack *obstack CXX_MEM_STAT_INFO); |
| #define BITMAP_ALLOC bitmap_alloc |
| extern bitmap bitmap_gc_alloc (ALONE_CXX_MEM_STAT_INFO); |
| #define BITMAP_GGC_ALLOC bitmap_gc_alloc |
| extern void bitmap_obstack_free (bitmap); |
| |
| /* A few compatibility/functions macros for compatibility with sbitmaps */ |
| inline void dump_bitmap (FILE *file, const_bitmap map) |
| { |
| bitmap_print (file, map, "", "\n"); |
| } |
| extern void debug (const bitmap_head &ref); |
| extern void debug (const bitmap_head *ptr); |
| |
| extern unsigned bitmap_first_set_bit (const_bitmap); |
| extern unsigned bitmap_last_set_bit (const_bitmap); |
| |
| /* Compute bitmap hash (for purposes of hashing etc.) */ |
| extern hashval_t bitmap_hash (const_bitmap); |
| |
| /* Do any cleanup needed on a bitmap when it is no longer used. */ |
| #define BITMAP_FREE(BITMAP) \ |
| ((void) (bitmap_obstack_free ((bitmap) BITMAP), (BITMAP) = (bitmap) NULL)) |
| |
| /* Iterator for bitmaps. */ |
| |
| struct bitmap_iterator |
| { |
| /* Pointer to the current bitmap element. */ |
| bitmap_element *elt1; |
| |
| /* Pointer to 2nd bitmap element when two are involved. */ |
| bitmap_element *elt2; |
| |
| /* Word within the current element. */ |
| unsigned word_no; |
| |
| /* Contents of the actually processed word. When finding next bit |
| it is shifted right, so that the actual bit is always the least |
| significant bit of ACTUAL. */ |
| BITMAP_WORD bits; |
| }; |
| |
| /* Initialize a single bitmap iterator. START_BIT is the first bit to |
| iterate from. */ |
| |
| static inline void |
| bmp_iter_set_init (bitmap_iterator *bi, const_bitmap map, |
| unsigned start_bit, unsigned *bit_no) |
| { |
| bi->elt1 = map->first; |
| bi->elt2 = NULL; |
| |
| gcc_checking_assert (!map->tree_form); |
| |
| /* Advance elt1 until it is not before the block containing start_bit. */ |
| while (1) |
| { |
| if (!bi->elt1) |
| { |
| bi->elt1 = &bitmap_zero_bits; |
| break; |
| } |
| |
| if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS) |
| break; |
| bi->elt1 = bi->elt1->next; |
| } |
| |
| /* We might have gone past the start bit, so reinitialize it. */ |
| if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS) |
| start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| |
| /* Initialize for what is now start_bit. */ |
| bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS; |
| bi->bits = bi->elt1->bits[bi->word_no]; |
| bi->bits >>= start_bit % BITMAP_WORD_BITS; |
| |
| /* If this word is zero, we must make sure we're not pointing at the |
| first bit, otherwise our incrementing to the next word boundary |
| will fail. It won't matter if this increment moves us into the |
| next word. */ |
| start_bit += !bi->bits; |
| |
| *bit_no = start_bit; |
| } |
| |
| /* Initialize an iterator to iterate over the intersection of two |
| bitmaps. START_BIT is the bit to commence from. */ |
| |
| static inline void |
| bmp_iter_and_init (bitmap_iterator *bi, const_bitmap map1, const_bitmap map2, |
| unsigned start_bit, unsigned *bit_no) |
| { |
| bi->elt1 = map1->first; |
| bi->elt2 = map2->first; |
| |
| gcc_checking_assert (!map1->tree_form && !map2->tree_form); |
| |
| /* Advance elt1 until it is not before the block containing |
| start_bit. */ |
| while (1) |
| { |
| if (!bi->elt1) |
| { |
| bi->elt2 = NULL; |
| break; |
| } |
| |
| if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS) |
| break; |
| bi->elt1 = bi->elt1->next; |
| } |
| |
| /* Advance elt2 until it is not before elt1. */ |
| while (1) |
| { |
| if (!bi->elt2) |
| { |
| bi->elt1 = bi->elt2 = &bitmap_zero_bits; |
| break; |
| } |
| |
| if (bi->elt2->indx >= bi->elt1->indx) |
| break; |
| bi->elt2 = bi->elt2->next; |
| } |
| |
| /* If we're at the same index, then we have some intersecting bits. */ |
| if (bi->elt1->indx == bi->elt2->indx) |
| { |
| /* We might have advanced beyond the start_bit, so reinitialize |
| for that. */ |
| if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS) |
| start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| |
| bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS; |
| bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no]; |
| bi->bits >>= start_bit % BITMAP_WORD_BITS; |
| } |
| else |
| { |
| /* Otherwise we must immediately advance elt1, so initialize for |
| that. */ |
| bi->word_no = BITMAP_ELEMENT_WORDS - 1; |
| bi->bits = 0; |
| } |
| |
| /* If this word is zero, we must make sure we're not pointing at the |
| first bit, otherwise our incrementing to the next word boundary |
| will fail. It won't matter if this increment moves us into the |
| next word. */ |
| start_bit += !bi->bits; |
| |
| *bit_no = start_bit; |
| } |
| |
| /* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2. */ |
| |
| static inline void |
| bmp_iter_and_compl_init (bitmap_iterator *bi, |
| const_bitmap map1, const_bitmap map2, |
| unsigned start_bit, unsigned *bit_no) |
| { |
| bi->elt1 = map1->first; |
| bi->elt2 = map2->first; |
| |
| gcc_checking_assert (!map1->tree_form && !map2->tree_form); |
| |
| /* Advance elt1 until it is not before the block containing start_bit. */ |
| while (1) |
| { |
| if (!bi->elt1) |
| { |
| bi->elt1 = &bitmap_zero_bits; |
| break; |
| } |
| |
| if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS) |
| break; |
| bi->elt1 = bi->elt1->next; |
| } |
| |
| /* Advance elt2 until it is not before elt1. */ |
| while (bi->elt2 && bi->elt2->indx < bi->elt1->indx) |
| bi->elt2 = bi->elt2->next; |
| |
| /* We might have advanced beyond the start_bit, so reinitialize for |
| that. */ |
| if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS) |
| start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| |
| bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS; |
| bi->bits = bi->elt1->bits[bi->word_no]; |
| if (bi->elt2 && bi->elt1->indx == bi->elt2->indx) |
| bi->bits &= ~bi->elt2->bits[bi->word_no]; |
| bi->bits >>= start_bit % BITMAP_WORD_BITS; |
| |
| /* If this word is zero, we must make sure we're not pointing at the |
| first bit, otherwise our incrementing to the next word boundary |
| will fail. It won't matter if this increment moves us into the |
| next word. */ |
| start_bit += !bi->bits; |
| |
| *bit_no = start_bit; |
| } |
| |
| /* Advance to the next bit in BI. We don't advance to the next |
| nonzero bit yet. */ |
| |
| static inline void |
| bmp_iter_next (bitmap_iterator *bi, unsigned *bit_no) |
| { |
| bi->bits >>= 1; |
| *bit_no += 1; |
| } |
| |
| /* Advance to first set bit in BI. */ |
| |
| static inline void |
| bmp_iter_next_bit (bitmap_iterator * bi, unsigned *bit_no) |
| { |
| #if (GCC_VERSION >= 3004) |
| { |
| unsigned int n = __builtin_ctzl (bi->bits); |
| gcc_assert (sizeof (unsigned long) == sizeof (BITMAP_WORD)); |
| bi->bits >>= n; |
| *bit_no += n; |
| } |
| #else |
| while (!(bi->bits & 1)) |
| { |
| bi->bits >>= 1; |
| *bit_no += 1; |
| } |
| #endif |
| } |
| |
| /* Advance to the next nonzero bit of a single bitmap, we will have |
| already advanced past the just iterated bit. Return true if there |
| is a bit to iterate. */ |
| |
| static inline bool |
| bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no) |
| { |
| /* If our current word is nonzero, it contains the bit we want. */ |
| if (bi->bits) |
| { |
| next_bit: |
| bmp_iter_next_bit (bi, bit_no); |
| return true; |
| } |
| |
| /* Round up to the word boundary. We might have just iterated past |
| the end of the last word, hence the -1. It is not possible for |
| bit_no to point at the beginning of the now last word. */ |
| *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1) |
| / BITMAP_WORD_BITS * BITMAP_WORD_BITS); |
| bi->word_no++; |
| |
| while (1) |
| { |
| /* Find the next nonzero word in this elt. */ |
| while (bi->word_no != BITMAP_ELEMENT_WORDS) |
| { |
| bi->bits = bi->elt1->bits[bi->word_no]; |
| if (bi->bits) |
| goto next_bit; |
| *bit_no += BITMAP_WORD_BITS; |
| bi->word_no++; |
| } |
| |
| /* Make sure we didn't remove the element while iterating. */ |
| gcc_checking_assert (bi->elt1->indx != -1U); |
| |
| /* Advance to the next element. */ |
| bi->elt1 = bi->elt1->next; |
| if (!bi->elt1) |
| return false; |
| *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| bi->word_no = 0; |
| } |
| } |
| |
| /* Advance to the next nonzero bit of an intersecting pair of |
| bitmaps. We will have already advanced past the just iterated bit. |
| Return true if there is a bit to iterate. */ |
| |
| static inline bool |
| bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no) |
| { |
| /* If our current word is nonzero, it contains the bit we want. */ |
| if (bi->bits) |
| { |
| next_bit: |
| bmp_iter_next_bit (bi, bit_no); |
| return true; |
| } |
| |
| /* Round up to the word boundary. We might have just iterated past |
| the end of the last word, hence the -1. It is not possible for |
| bit_no to point at the beginning of the now last word. */ |
| *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1) |
| / BITMAP_WORD_BITS * BITMAP_WORD_BITS); |
| bi->word_no++; |
| |
| while (1) |
| { |
| /* Find the next nonzero word in this elt. */ |
| while (bi->word_no != BITMAP_ELEMENT_WORDS) |
| { |
| bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no]; |
| if (bi->bits) |
| goto next_bit; |
| *bit_no += BITMAP_WORD_BITS; |
| bi->word_no++; |
| } |
| |
| /* Advance to the next identical element. */ |
| do |
| { |
| /* Make sure we didn't remove the element while iterating. */ |
| gcc_checking_assert (bi->elt1->indx != -1U); |
| |
| /* Advance elt1 while it is less than elt2. We always want |
| to advance one elt. */ |
| do |
| { |
| bi->elt1 = bi->elt1->next; |
| if (!bi->elt1) |
| return false; |
| } |
| while (bi->elt1->indx < bi->elt2->indx); |
| |
| /* Make sure we didn't remove the element while iterating. */ |
| gcc_checking_assert (bi->elt2->indx != -1U); |
| |
| /* Advance elt2 to be no less than elt1. This might not |
| advance. */ |
| while (bi->elt2->indx < bi->elt1->indx) |
| { |
| bi->elt2 = bi->elt2->next; |
| if (!bi->elt2) |
| return false; |
| } |
| } |
| while (bi->elt1->indx != bi->elt2->indx); |
| |
| *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| bi->word_no = 0; |
| } |
| } |
| |
| /* Advance to the next nonzero bit in the intersection of |
| complemented bitmaps. We will have already advanced past the just |
| iterated bit. */ |
| |
| static inline bool |
| bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no) |
| { |
| /* If our current word is nonzero, it contains the bit we want. */ |
| if (bi->bits) |
| { |
| next_bit: |
| bmp_iter_next_bit (bi, bit_no); |
| return true; |
| } |
| |
| /* Round up to the word boundary. We might have just iterated past |
| the end of the last word, hence the -1. It is not possible for |
| bit_no to point at the beginning of the now last word. */ |
| *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1) |
| / BITMAP_WORD_BITS * BITMAP_WORD_BITS); |
| bi->word_no++; |
| |
| while (1) |
| { |
| /* Find the next nonzero word in this elt. */ |
| while (bi->word_no != BITMAP_ELEMENT_WORDS) |
| { |
| bi->bits = bi->elt1->bits[bi->word_no]; |
| if (bi->elt2 && bi->elt2->indx == bi->elt1->indx) |
| bi->bits &= ~bi->elt2->bits[bi->word_no]; |
| if (bi->bits) |
| goto next_bit; |
| *bit_no += BITMAP_WORD_BITS; |
| bi->word_no++; |
| } |
| |
| /* Make sure we didn't remove the element while iterating. */ |
| gcc_checking_assert (bi->elt1->indx != -1U); |
| |
| /* Advance to the next element of elt1. */ |
| bi->elt1 = bi->elt1->next; |
| if (!bi->elt1) |
| return false; |
| |
| /* Make sure we didn't remove the element while iterating. */ |
| gcc_checking_assert (! bi->elt2 || bi->elt2->indx != -1U); |
| |
| /* Advance elt2 until it is no less than elt1. */ |
| while (bi->elt2 && bi->elt2->indx < bi->elt1->indx) |
| bi->elt2 = bi->elt2->next; |
| |
| *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS; |
| bi->word_no = 0; |
| } |
| } |
| |
| /* If you are modifying a bitmap you are currently iterating over you |
| have to ensure to |
| - never remove the current bit; |
| - if you set or clear a bit before the current bit this operation |
| will not affect the set of bits you are visiting during the iteration; |
| - if you set or clear a bit after the current bit it is unspecified |
| whether that affects the set of bits you are visiting during the |
| iteration. |
| If you want to remove the current bit you can delay this to the next |
| iteration (and after the iteration in case the last iteration is |
| affected). */ |
| |
| /* Loop over all bits set in BITMAP, starting with MIN and setting |
| BITNUM to the bit number. ITER is a bitmap iterator. BITNUM |
| should be treated as a read-only variable as it contains loop |
| state. */ |
| |
| #ifndef EXECUTE_IF_SET_IN_BITMAP |
| /* See sbitmap.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 |
| |
| /* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN |
| and setting BITNUM to the bit number. ITER is a bitmap iterator. |
| BITNUM should be treated as a read-only variable as it contains |
| loop state. */ |
| |
| #define EXECUTE_IF_AND_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \ |
| for (bmp_iter_and_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \ |
| &(BITNUM)); \ |
| bmp_iter_and (&(ITER), &(BITNUM)); \ |
| bmp_iter_next (&(ITER), &(BITNUM))) |
| |
| /* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN |
| and setting BITNUM to the bit number. ITER is a bitmap iterator. |
| BITNUM should be treated as a read-only variable as it contains |
| loop state. */ |
| |
| #define EXECUTE_IF_AND_COMPL_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \ |
| for (bmp_iter_and_compl_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \ |
| &(BITNUM)); \ |
| bmp_iter_and_compl (&(ITER), &(BITNUM)); \ |
| bmp_iter_next (&(ITER), &(BITNUM))) |
| |
| /* A class that ties the lifetime of a bitmap to its scope. */ |
| class auto_bitmap |
| { |
| public: |
| auto_bitmap (ALONE_CXX_MEM_STAT_INFO) |
| { bitmap_initialize (&m_bits, &bitmap_default_obstack PASS_MEM_STAT); } |
| explicit auto_bitmap (bitmap_obstack *o CXX_MEM_STAT_INFO) |
| { bitmap_initialize (&m_bits, o PASS_MEM_STAT); } |
| ~auto_bitmap () { bitmap_clear (&m_bits); } |
| // Allow calling bitmap functions on our bitmap. |
| operator bitmap () { return &m_bits; } |
| |
| private: |
| // Prevent making a copy that references our bitmap. |
| auto_bitmap (const auto_bitmap &); |
| auto_bitmap &operator = (const auto_bitmap &); |
| #if __cplusplus >= 201103L |
| auto_bitmap (auto_bitmap &&); |
| auto_bitmap &operator = (auto_bitmap &&); |
| #endif |
| |
| bitmap_head m_bits; |
| }; |
| |
| /* Base class for bitmap_view; see there for details. */ |
| template<typename T, typename Traits = array_traits<T> > |
| class base_bitmap_view |
| { |
| public: |
| typedef typename Traits::element_type array_element_type; |
| |
| base_bitmap_view (const T &, bitmap_element *); |
| operator const_bitmap () const { return &m_head; } |
| |
| private: |
| base_bitmap_view (const base_bitmap_view &); |
| |
| bitmap_head m_head; |
| }; |
| |
| /* Provides a read-only bitmap view of a single integer bitmask or a |
| constant-sized array of integer bitmasks, or of a wrapper around such |
| bitmasks. */ |
| template<typename T, typename Traits> |
| class bitmap_view<T, Traits, true> : public base_bitmap_view<T, Traits> |
| { |
| public: |
| bitmap_view (const T &array) |
| : base_bitmap_view<T, Traits> (array, m_bitmap_elements) {} |
| |
| private: |
| /* How many bitmap_elements we need to hold a full T. */ |
| static const size_t num_bitmap_elements |
| = CEIL (CHAR_BIT |
| * sizeof (typename Traits::element_type) |
| * Traits::constant_size, |
| BITMAP_ELEMENT_ALL_BITS); |
| bitmap_element m_bitmap_elements[num_bitmap_elements]; |
| }; |
| |
| /* Initialize the view for array ARRAY, using the array of bitmap |
| elements in BITMAP_ELEMENTS (which is known to contain enough |
| entries). */ |
| template<typename T, typename Traits> |
| base_bitmap_view<T, Traits>::base_bitmap_view (const T &array, |
| bitmap_element *bitmap_elements) |
| { |
| m_head.obstack = NULL; |
| |
| /* The code currently assumes that each element of ARRAY corresponds |
| to exactly one bitmap_element. */ |
| const size_t array_element_bits = CHAR_BIT * sizeof (array_element_type); |
| STATIC_ASSERT (BITMAP_ELEMENT_ALL_BITS % array_element_bits == 0); |
| size_t array_step = BITMAP_ELEMENT_ALL_BITS / array_element_bits; |
| size_t array_size = Traits::size (array); |
| |
| /* Process each potential bitmap_element in turn. The loop is written |
| this way rather than per array element because usually there are |
| only a small number of array elements per bitmap element (typically |
| two or four). The inner loops should therefore unroll completely. */ |
| const array_element_type *array_elements = Traits::base (array); |
| unsigned int indx = 0; |
| for (size_t array_base = 0; |
| array_base < array_size; |
| array_base += array_step, indx += 1) |
| { |
| /* How many array elements are in this particular bitmap_element. */ |
| unsigned int array_count |
| = (STATIC_CONSTANT_P (array_size % array_step == 0) |
| ? array_step : MIN (array_step, array_size - array_base)); |
| |
| /* See whether we need this bitmap element. */ |
| array_element_type ior = array_elements[array_base]; |
| for (size_t i = 1; i < array_count; ++i) |
| ior |= array_elements[array_base + i]; |
| if (ior == 0) |
| continue; |
| |
| /* Grab the next bitmap element and chain it. */ |
| bitmap_element *bitmap_element = bitmap_elements++; |
| if (m_head.current) |
| m_head.current->next = bitmap_element; |
| else |
| m_head.first = bitmap_element; |
| bitmap_element->prev = m_head.current; |
| bitmap_element->next = NULL; |
| bitmap_element->indx = indx; |
| m_head.current = bitmap_element; |
| m_head.indx = indx; |
| |
| /* Fill in the bits of the bitmap element. */ |
| if (array_element_bits < BITMAP_WORD_BITS) |
| { |
| /* Multiple array elements fit in one element of |
| bitmap_element->bits. */ |
| size_t array_i = array_base; |
| for (unsigned int word_i = 0; word_i < BITMAP_ELEMENT_WORDS; |
| ++word_i) |
| { |
| BITMAP_WORD word = 0; |
| for (unsigned int shift = 0; |
| shift < BITMAP_WORD_BITS && array_i < array_size; |
| shift += array_element_bits) |
| word |= array_elements[array_i++] << shift; |
| bitmap_element->bits[word_i] = word; |
| } |
| } |
| else |
| { |
| /* Array elements are the same size as elements of |
| bitmap_element->bits, or are an exact multiple of that size. */ |
| unsigned int word_i = 0; |
| for (unsigned int i = 0; i < array_count; ++i) |
| for (unsigned int shift = 0; shift < array_element_bits; |
| shift += BITMAP_WORD_BITS) |
| bitmap_element->bits[word_i++] |
| = array_elements[array_base + i] >> shift; |
| while (word_i < BITMAP_ELEMENT_WORDS) |
| bitmap_element->bits[word_i++] = 0; |
| } |
| } |
| } |
| |
| #endif /* GCC_BITMAP_H */ |