/* Functions to support general ended bitmaps.
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007 Free Software Foundation, Inc.
+ Copyright (C) 1997-2016 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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#ifndef GCC_BITMAP_H
#define GCC_BITMAP_H
-#include "hashtab.h"
-#include "statistics.h"
+
+/* Implementation of sparse integer sets as a linked list.
+
+ This sparse set representation is suitable for sparse sets with an
+ unknown (a priori) universe. The set is represented as a double-linked
+ list of container nodes (struct bitmap_element). Each 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. The
+ elements 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.
+
+ 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 downside is that many 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:
+
+ * clear : bitmap_clear
+ * choose_one : (not implemented, but could be
+ implemented in constant time)
+
+ The following operations can be performed in O(E) time worst-case (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
+ * remove_member : bitmap_clear_bit
+
+ The following operations can be performed in O(E) time:
+
+ * cardinality : bitmap_count_bits
+ * set_size : bitmap_last_set_bit (but this could
+ in constant time with a pointer to
+ the last element in the chain)
+
+ 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
+
+ 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).
+
+ 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.).
+
+ 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.
+
+ 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. For random-access sets of unknown universe, a hash table
+ or a balanced binary tree representation is likely to be a more suitable
+ choice.
+
+ Traversing linked lists is usually cache-unfriendly, even with the last
+ accessed element cached.
+
+ Cache performance can be improved by keeping the elements 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. */
+
+#include "obstack.h"
+
+/* Bitmap memory usage. */
+struct bitmap_usage: public mem_usage
+{
+ /* 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, mem_usage &total) const
+ {
+ char *location_string = loc->to_string ();
+
+ fprintf (stderr, "%-48s %10" PRIu64 ":%5.1f%%"
+ "%10" PRIu64 "%10" PRIu64 ":%5.1f%%"
+ "%12" PRIu64 "%12" PRIu64 "%10s\n",
+ location_string, (uint64_t)m_allocated,
+ get_percent (m_allocated, total.m_allocated),
+ (uint64_t)m_peak, (uint64_t)m_times,
+ get_percent (m_times, total.m_times),
+ m_nsearches, 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");
+ print_dash_line ();
+ }
+
+ /* 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. */
#define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS)
/* Obstack for allocating bitmaps and elements from. */
-typedef struct bitmap_obstack GTY (())
-{
- struct bitmap_element_def *elements;
- struct bitmap_head_def *heads;
+struct GTY (()) bitmap_obstack {
+ struct bitmap_element *elements;
+ struct bitmap_head *heads;
struct obstack GTY ((skip)) obstack;
-} bitmap_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
bitmap_elt_clear_from to be implemented in unit time rather than
linear in the number of elements to be freed. */
-typedef struct bitmap_element_def GTY(())
-{
- struct bitmap_element_def *next; /* Next element. */
- struct bitmap_element_def *prev; /* Previous element. */
+struct GTY((chain_next ("%h.next"), chain_prev ("%h.prev"))) bitmap_element {
+ struct bitmap_element *next; /* Next element. */
+ struct bitmap_element *prev; /* Previous element. */
unsigned int indx; /* regno/BITMAP_ELEMENT_ALL_BITS. */
BITMAP_WORD bits[BITMAP_ELEMENT_WORDS]; /* Bits that are set. */
-} bitmap_element;
-
-struct bitmap_descriptor;
-/* Head of bitmap linked list. gengtype ignores ifdefs, but for
- statistics we need to add a bitmap descriptor pointer. As it is
- not collected, we can just GTY((skip)) it. */
-
-typedef struct bitmap_head_def GTY(()) {
- bitmap_element *first; /* First element in linked list. */
- bitmap_element *current; /* Last element looked at. */
- unsigned int indx; /* Index of last element looked at. */
- bitmap_obstack *obstack; /* Obstack to allocate elements from.
- If NULL, then use ggc_alloc. */
-#ifdef GATHER_STATISTICS
- struct bitmap_descriptor GTY((skip)) *desc;
-#endif
-} bitmap_head;
+};
+
+/* Head of bitmap linked list. The 'current' member points to something
+ already pointed to by the chain started by first, so GTY((skip)) it. */
+
+struct GTY(()) bitmap_head {
+ unsigned int indx; /* Index of last element looked at. */
+ unsigned int descriptor_id; /* Unique identifier for the allocation
+ site of this bitmap, for detailed
+ statistics gathering. */
+ bitmap_element *first; /* First element in linked list. */
+ bitmap_element * GTY((skip(""))) current; /* Last element looked at. */
+ bitmap_obstack *obstack; /* Obstack to allocate elements from.
+ If NULL, then use GGC allocation. */
+};
/* Global data */
extern bitmap_element bitmap_zero_bits; /* Zero bitmap element */
extern void bitmap_clear (bitmap);
/* Copy a bitmap to another bitmap. */
-extern void bitmap_copy (bitmap, 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 (bitmap, bitmap);
+extern bool bitmap_equal_p (const_bitmap, const_bitmap);
/* True if the bitmaps intersect (their AND is non-empty). */
-extern bool bitmap_intersect_p (bitmap, bitmap);
+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 (bitmap, bitmap);
+extern bool bitmap_intersect_compl_p (const_bitmap, const_bitmap);
/* True if MAP is an empty bitmap. */
-#define bitmap_empty_p(MAP) (!(MAP)->first)
+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 (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, bitmap, bitmap);
-extern void bitmap_and_into (bitmap, bitmap);
-extern bool bitmap_and_compl (bitmap, bitmap, bitmap);
-extern bool bitmap_and_compl_into (bitmap, bitmap);
+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, bitmap);
+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, bitmap, bitmap);
-extern bool bitmap_ior_into (bitmap, bitmap);
-extern void bitmap_xor (bitmap, bitmap, bitmap);
-extern void bitmap_xor_into (bitmap, bitmap);
+extern bool bitmap_ior (bitmap, const_bitmap, const_bitmap);
+extern bool bitmap_ior_into (bitmap, const_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, bitmap A, bitmap B, bitmap C);
+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 DST, bitmap B, bitmap C);
+extern bool bitmap_ior_and_compl_into (bitmap A,
+ const_bitmap B, const_bitmap C);
-/* Clear a single register in a register set. */
-extern void bitmap_clear_bit (bitmap, int);
+/* Clear a single bit in a bitmap. Return true if the bit changed. */
+extern bool bitmap_clear_bit (bitmap, int);
-/* Set a single register in a register set. */
-extern void bitmap_set_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 register is set in a register set. */
extern int bitmap_bit_p (bitmap, int);
/* Debug functions to print a bitmap linked list. */
-extern void debug_bitmap (bitmap);
-extern void debug_bitmap_file (FILE *, bitmap);
+extern void debug_bitmap (const_bitmap);
+extern void debug_bitmap_file (FILE *, const_bitmap);
/* Print a bitmap. */
-extern void bitmap_print (FILE *, bitmap, const char *, const char *);
+extern void bitmap_print (FILE *, const_bitmap, const char *, const char *);
/* Initialize and release a bitmap obstack. */
extern void bitmap_obstack_initialize (bitmap_obstack *);
{
head->first = head->current = NULL;
head->obstack = obstack;
-#ifdef GATHER_STATISTICS
- bitmap_register (head PASS_MEM_STAT);
-#endif
+ if (GATHER_STATISTICS)
+ bitmap_register (head PASS_MEM_STAT);
}
#define bitmap_initialize(h,o) bitmap_initialize_stat (h,o MEM_STAT_INFO)
extern void bitmap_obstack_free (bitmap);
/* A few compatibility/functions macros for compatibility with sbitmaps */
-#define dump_bitmap(file, bitmap) bitmap_print (file, bitmap, "", "\n")
-#define bitmap_zero(a) bitmap_clear (a)
-extern unsigned bitmap_first_set_bit (bitmap);
+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(bitmap);
+extern hashval_t bitmap_hash (const_bitmap);
/* Allocate a bitmap from a bit obstack. */
#define BITMAP_ALLOC(OBSTACK) bitmap_obstack_alloc (OBSTACK)
#define BITMAP_GGC_ALLOC() bitmap_gc_alloc ()
/* Do any cleanup needed on a bitmap when it is no longer used. */
-#define BITMAP_FREE(BITMAP) \
- ((void)(bitmap_obstack_free (BITMAP), (BITMAP) = NULL))
+#define BITMAP_FREE(BITMAP) \
+ ((void) (bitmap_obstack_free ((bitmap) BITMAP), (BITMAP) = (bitmap) NULL))
/* Iterator for bitmaps. */
-typedef struct
+struct bitmap_iterator
{
/* Pointer to the current bitmap element. */
bitmap_element *elt1;
it is shifted right, so that the actual bit is always the least
significant bit of ACTUAL. */
BITMAP_WORD bits;
-} bitmap_iterator;
+};
/* Initialize a single bitmap iterator. START_BIT is the first bit to
iterate from. */
static inline void
-bmp_iter_set_init (bitmap_iterator *bi, bitmap map,
+bmp_iter_set_init (bitmap_iterator *bi, const_bitmap map,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map->first;
bitmaps. START_BIT is the bit to commence from. */
static inline void
-bmp_iter_and_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
+bmp_iter_and_init (bitmap_iterator *bi, const_bitmap map1, const_bitmap map2,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map1->first;
*/
static inline void
-bmp_iter_and_compl_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
+bmp_iter_and_compl_init (bitmap_iterator *bi,
+ const_bitmap map1, const_bitmap map2,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map1->first;
*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. */
if (bi->bits)
{
next_bit:
- while (!(bi->bits & 1))
- {
- bi->bits >>= 1;
- *bit_no += 1;
- }
+ bmp_iter_next_bit (bi, bit_no);
return true;
}
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)
if (bi->bits)
{
next_bit:
- while (!(bi->bits & 1))
- {
- bi->bits >>= 1;
- *bit_no += 1;
- }
+ bmp_iter_next_bit (bi, bit_no);
return true;
}
/* 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
}
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)
if (bi->bits)
{
next_bit:
- while (!(bi->bits & 1))
- {
- bi->bits >>= 1;
- *bit_no += 1;
- }
+ bmp_iter_next_bit (bi, bit_no);
return true;
}
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;
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.
projects / thirdparty / gcc.git / blobdiff