freebsd-dev/contrib/gcc/bitmap.c
David E. O'Brien 1952e2e1c1 Enlist the FreeBSD-CURRENT users as testers of what is to become Gcc 3.1.0.
These bits are taken from the FSF anoncvs repo on 1-Feb-2002 08:20 PST.
2002-02-01 18:16:02 +00:00

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/* Functions to support general ended bitmaps.
Copyright (C) 1997, 1998, 1999, 2000, 2001 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
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 COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "rtl.h"
#include "flags.h"
#include "obstack.h"
#include "bitmap.h"
/* Obstack to allocate bitmap elements from. */
static struct obstack bitmap_obstack;
static int bitmap_obstack_init = FALSE;
#ifndef INLINE
#ifndef __GNUC__
#define INLINE
#else
#define INLINE __inline__
#endif
#endif
/* Global data */
bitmap_element bitmap_zero_bits; /* An element of all zero bits. */
static bitmap_element *bitmap_free; /* Freelist of bitmap elements. */
static void bitmap_element_free PARAMS ((bitmap, bitmap_element *));
static bitmap_element *bitmap_element_allocate PARAMS ((void));
static int bitmap_element_zerop PARAMS ((bitmap_element *));
static void bitmap_element_link PARAMS ((bitmap, bitmap_element *));
static bitmap_element *bitmap_find_bit PARAMS ((bitmap, unsigned int));
/* Free a bitmap element. Since these are allocated off the
bitmap_obstack, "free" actually means "put onto the freelist". */
static INLINE void
bitmap_element_free (head, elt)
bitmap head;
bitmap_element *elt;
{
bitmap_element *next = elt->next;
bitmap_element *prev = elt->prev;
if (prev)
prev->next = next;
if (next)
next->prev = prev;
if (head->first == elt)
head->first = next;
/* Since the first thing we try is to insert before current,
make current the next entry in preference to the previous. */
if (head->current == elt)
{
head->current = next != 0 ? next : prev;
if (head->current)
head->indx = head->current->indx;
}
elt->next = bitmap_free;
bitmap_free = elt;
}
/* Allocate a bitmap element. The bits are cleared, but nothing else is. */
static INLINE bitmap_element *
bitmap_element_allocate ()
{
bitmap_element *element;
if (bitmap_free != 0)
{
element = bitmap_free;
bitmap_free = element->next;
}
else
{
/* We can't use gcc_obstack_init to initialize the obstack since
print-rtl.c now calls bitmap functions, and bitmap is linked
into the gen* functions. */
if (!bitmap_obstack_init)
{
bitmap_obstack_init = TRUE;
/* Let particular systems override the size of a chunk. */
#ifndef OBSTACK_CHUNK_SIZE
#define OBSTACK_CHUNK_SIZE 0
#endif
/* Let them override the alloc and free routines too. */
#ifndef OBSTACK_CHUNK_ALLOC
#define OBSTACK_CHUNK_ALLOC xmalloc
#endif
#ifndef OBSTACK_CHUNK_FREE
#define OBSTACK_CHUNK_FREE free
#endif
#if !defined(__GNUC__) || (__GNUC__ < 2)
#define __alignof__(type) 0
#endif
obstack_specify_allocation (&bitmap_obstack, OBSTACK_CHUNK_SIZE,
__alignof__ (bitmap_element),
(void *(*) PARAMS ((long))) OBSTACK_CHUNK_ALLOC,
(void (*) PARAMS ((void *))) OBSTACK_CHUNK_FREE);
}
element = (bitmap_element *) obstack_alloc (&bitmap_obstack,
sizeof (bitmap_element));
}
memset (element->bits, 0, sizeof (element->bits));
return element;
}
/* Release any memory allocated by bitmaps. */
void
bitmap_release_memory ()
{
bitmap_free = 0;
if (bitmap_obstack_init)
{
bitmap_obstack_init = FALSE;
obstack_free (&bitmap_obstack, NULL);
}
}
/* Return nonzero if all bits in an element are zero. */
static INLINE int
bitmap_element_zerop (element)
bitmap_element *element;
{
#if BITMAP_ELEMENT_WORDS == 2
return (element->bits[0] | element->bits[1]) == 0;
#else
int i;
for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
if (element->bits[i] != 0)
return 0;
return 1;
#endif
}
/* Link the bitmap element into the current bitmap linked list. */
static INLINE void
bitmap_element_link (head, element)
bitmap head;
bitmap_element *element;
{
unsigned int indx = element->indx;
bitmap_element *ptr;
/* If this is the first and only element, set it in. */
if (head->first == 0)
{
element->next = element->prev = 0;
head->first = element;
}
/* If this index is less than that of the current element, it goes someplace
before the current element. */
else if (indx < head->indx)
{
for (ptr = head->current;
ptr->prev != 0 && ptr->prev->indx > indx;
ptr = ptr->prev)
;
if (ptr->prev)
ptr->prev->next = element;
else
head->first = element;
element->prev = ptr->prev;
element->next = ptr;
ptr->prev = element;
}
/* Otherwise, it must go someplace after the current element. */
else
{
for (ptr = head->current;
ptr->next != 0 && ptr->next->indx < indx;
ptr = ptr->next)
;
if (ptr->next)
ptr->next->prev = element;
element->next = ptr->next;
element->prev = ptr;
ptr->next = element;
}
/* Set up so this is the first element searched. */
head->current = element;
head->indx = indx;
}
/* Clear a bitmap by freeing the linked list. */
INLINE void
bitmap_clear (head)
bitmap head;
{
bitmap_element *element, *next;
for (element = head->first; element != 0; element = next)
{
next = element->next;
element->next = bitmap_free;
bitmap_free = element;
}
head->first = head->current = 0;
}
/* Copy a bitmap to another bitmap. */
void
bitmap_copy (to, from)
bitmap to;
bitmap from;
{
bitmap_element *from_ptr, *to_ptr = 0;
#if BITMAP_ELEMENT_WORDS != 2
int i;
#endif
bitmap_clear (to);
/* Copy elements in forward direction one at a time */
for (from_ptr = from->first; from_ptr; from_ptr = from_ptr->next)
{
bitmap_element *to_elt = bitmap_element_allocate ();
to_elt->indx = from_ptr->indx;
#if BITMAP_ELEMENT_WORDS == 2
to_elt->bits[0] = from_ptr->bits[0];
to_elt->bits[1] = from_ptr->bits[1];
#else
for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
to_elt->bits[i] = from_ptr->bits[i];
#endif
/* Here we have a special case of bitmap_element_link, for the case
where we know the links are being entered in sequence. */
if (to_ptr == 0)
{
to->first = to->current = to_elt;
to->indx = from_ptr->indx;
to_elt->next = to_elt->prev = 0;
}
else
{
to_elt->prev = to_ptr;
to_elt->next = 0;
to_ptr->next = to_elt;
}
to_ptr = to_elt;
}
}
/* Find a bitmap element that would hold a bitmap's bit.
Update the `current' field even if we can't find an element that
would hold the bitmap's bit to make eventual allocation
faster. */
static INLINE bitmap_element *
bitmap_find_bit (head, bit)
bitmap head;
unsigned int bit;
{
bitmap_element *element;
unsigned HOST_WIDE_INT indx = bit / BITMAP_ELEMENT_ALL_BITS;
if (head->current == 0)
return 0;
if (head->indx > indx)
for (element = head->current;
element->prev != 0 && element->indx > indx;
element = element->prev)
;
else
for (element = head->current;
element->next != 0 && element->indx < indx;
element = element->next)
;
/* `element' is the nearest to the one we want. If it's not the one we
want, the one we want doesn't exist. */
head->current = element;
head->indx = element->indx;
if (element != 0 && element->indx != indx)
element = 0;
return element;
}
/* Clear a single bit in a bitmap. */
void
bitmap_clear_bit (head, bit)
bitmap head;
int bit;
{
bitmap_element *ptr = bitmap_find_bit (head, bit);
if (ptr != 0)
{
unsigned bit_num = bit % (unsigned) HOST_BITS_PER_WIDE_INT;
unsigned word_num = ((bit / (unsigned) HOST_BITS_PER_WIDE_INT)
% BITMAP_ELEMENT_WORDS);
ptr->bits[word_num] &= ~ (((unsigned HOST_WIDE_INT) 1) << bit_num);
/* If we cleared the entire word, free up the element */
if (bitmap_element_zerop (ptr))
bitmap_element_free (head, ptr);
}
}
/* Set a single bit in a bitmap. */
void
bitmap_set_bit (head, bit)
bitmap head;
int bit;
{
bitmap_element *ptr = bitmap_find_bit (head, bit);
unsigned word_num
= ((bit / (unsigned) HOST_BITS_PER_WIDE_INT) % BITMAP_ELEMENT_WORDS);
unsigned bit_num = bit % (unsigned) HOST_BITS_PER_WIDE_INT;
unsigned HOST_WIDE_INT bit_val = ((unsigned HOST_WIDE_INT) 1) << bit_num;
if (ptr == 0)
{
ptr = bitmap_element_allocate ();
ptr->indx = bit / BITMAP_ELEMENT_ALL_BITS;
ptr->bits[word_num] = bit_val;
bitmap_element_link (head, ptr);
}
else
ptr->bits[word_num] |= bit_val;
}
/* Return whether a bit is set within a bitmap. */
int
bitmap_bit_p (head, bit)
bitmap head;
int bit;
{
bitmap_element *ptr;
unsigned bit_num;
unsigned word_num;
ptr = bitmap_find_bit (head, bit);
if (ptr == 0)
return 0;
bit_num = bit % (unsigned) HOST_BITS_PER_WIDE_INT;
word_num
= ((bit / (unsigned) HOST_BITS_PER_WIDE_INT) % BITMAP_ELEMENT_WORDS);
return (ptr->bits[word_num] >> bit_num) & 1;
}
/* Return the bit number of the first set bit in the bitmap, or -1
if the bitmap is empty. */
int
bitmap_first_set_bit (a)
bitmap a;
{
bitmap_element *ptr = a->first;
unsigned HOST_WIDE_INT word;
unsigned word_num, bit_num;
if (ptr == NULL)
return -1;
#if BITMAP_ELEMENT_WORDS == 2
word_num = 0, word = ptr->bits[0];
if (word == 0)
word_num = 1, word = ptr->bits[1];
#else
for (word_num = 0; word_num < BITMAP_ELEMENT_WORDS; ++word_num)
if ((word = ptr->bits[word_num]) != 0)
break;
#endif
/* Binary search for the first set bit. */
/* ??? It'd be nice to know if ffs or ffsl was available. */
bit_num = 0;
word = word & -word;
#if HOST_BITS_PER_WIDE_INT > 64
#error "Fill out the table."
#endif
#if HOST_BITS_PER_WIDE_INT > 32
if ((word & 0xffffffff) == 0)
word >>= 32, bit_num += 32;
#endif
if ((word & 0xffff) == 0)
word >>= 16, bit_num += 16;
if ((word & 0xff) == 0)
word >>= 8, bit_num += 8;
if (word & 0xf0)
bit_num += 4;
if (word & 0xcc)
bit_num += 2;
if (word & 0xaa)
bit_num += 1;
return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
+ word_num * HOST_BITS_PER_WIDE_INT
+ bit_num);
}
/* Return the bit number of the last set bit in the bitmap, or -1
if the bitmap is empty. */
int
bitmap_last_set_bit (a)
bitmap a;
{
bitmap_element *ptr = a->first;
unsigned HOST_WIDE_INT word;
unsigned word_num, bit_num;
if (ptr == NULL)
return -1;
while (ptr->next != NULL)
ptr = ptr->next;
#if BITMAP_ELEMENT_WORDS == 2
word_num = 1, word = ptr->bits[1];
if (word == 0)
word_num = 0, word = ptr->bits[0];
#else
for (word_num = BITMAP_ELEMENT_WORDS; word_num-- > 0; )
if ((word = ptr->bits[word_num]) != 0)
break;
#endif
/* Binary search for the last set bit. */
bit_num = 0;
#if HOST_BITS_PER_WIDE_INT > 64
#error "Fill out the table."
#endif
#if HOST_BITS_PER_WIDE_INT > 32
if (word & ~ (unsigned HOST_WIDE_INT) 0xffffffff)
word >>= 32, bit_num += 32;
#endif
if (word & 0xffff0000)
word >>= 16, bit_num += 16;
if (word & 0xff00)
word >>= 8, bit_num += 8;
if (word & 0xf0)
word >>= 4, bit_num += 4;
if (word & 0xc)
word >>= 2, bit_num += 2;
if (word & 0x2)
bit_num += 1;
return (ptr->indx * BITMAP_ELEMENT_ALL_BITS
+ word_num * HOST_BITS_PER_WIDE_INT
+ bit_num);
}
/* Store in bitmap TO the result of combining bitmap FROM1 and FROM2 using
a specific bit manipulation. Return true if TO changes. */
int
bitmap_operation (to, from1, from2, operation)
bitmap to;
bitmap from1;
bitmap from2;
enum bitmap_bits operation;
{
#define HIGHEST_INDEX (unsigned int) ~0
bitmap_element *from1_ptr = from1->first;
bitmap_element *from2_ptr = from2->first;
unsigned int indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
unsigned int indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
bitmap_element *to_ptr = to->first;
bitmap_element *from1_tmp;
bitmap_element *from2_tmp;
bitmap_element *to_tmp;
unsigned int indx;
int changed = 0;
#if BITMAP_ELEMENT_WORDS == 2
#define DOIT(OP) \
do { \
unsigned HOST_WIDE_INT t0, t1, f10, f11, f20, f21; \
f10 = from1_tmp->bits[0]; \
f20 = from2_tmp->bits[0]; \
t0 = f10 OP f20; \
changed |= (t0 != to_tmp->bits[0]); \
f11 = from1_tmp->bits[1]; \
f21 = from2_tmp->bits[1]; \
t1 = f11 OP f21; \
changed |= (t1 != to_tmp->bits[1]); \
to_tmp->bits[0] = t0; \
to_tmp->bits[1] = t1; \
} while (0)
#else
#define DOIT(OP) \
do { \
unsigned HOST_WIDE_INT t, f1, f2; \
int i; \
for (i = 0; i < BITMAP_ELEMENT_WORDS; ++i) \
{ \
f1 = from1_tmp->bits[i]; \
f2 = from2_tmp->bits[i]; \
t = f1 OP f2; \
changed |= (t != to_tmp->bits[i]); \
to_tmp->bits[i] = t; \
} \
} while (0)
#endif
to->first = to->current = 0;
while (from1_ptr != 0 || from2_ptr != 0)
{
/* Figure out whether we need to substitute zero elements for
missing links. */
if (indx1 == indx2)
{
indx = indx1;
from1_tmp = from1_ptr;
from2_tmp = from2_ptr;
from1_ptr = from1_ptr->next;
indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
from2_ptr = from2_ptr->next;
indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
}
else if (indx1 < indx2)
{
indx = indx1;
from1_tmp = from1_ptr;
from2_tmp = &bitmap_zero_bits;
from1_ptr = from1_ptr->next;
indx1 = (from1_ptr) ? from1_ptr->indx : HIGHEST_INDEX;
}
else
{
indx = indx2;
from1_tmp = &bitmap_zero_bits;
from2_tmp = from2_ptr;
from2_ptr = from2_ptr->next;
indx2 = (from2_ptr) ? from2_ptr->indx : HIGHEST_INDEX;
}
/* Find the appropriate element from TO. Begin by discarding
elements that we've skipped. */
while (to_ptr && to_ptr->indx < indx)
{
changed = 1;
to_tmp = to_ptr;
to_ptr = to_ptr->next;
to_tmp->next = bitmap_free;
bitmap_free = to_tmp;
}
if (to_ptr && to_ptr->indx == indx)
{
to_tmp = to_ptr;
to_ptr = to_ptr->next;
}
else
to_tmp = bitmap_element_allocate ();
/* Do the operation, and if any bits are set, link it into the
linked list. */
switch (operation)
{
default:
abort ();
case BITMAP_AND:
DOIT (&);
break;
case BITMAP_AND_COMPL:
DOIT (&~);
break;
case BITMAP_IOR:
DOIT (|);
break;
case BITMAP_IOR_COMPL:
DOIT (|~);
break;
case BITMAP_XOR:
DOIT (^);
break;
}
if (! bitmap_element_zerop (to_tmp))
{
to_tmp->indx = indx;
bitmap_element_link (to, to_tmp);
}
else
{
to_tmp->next = bitmap_free;
bitmap_free = to_tmp;
}
}
/* If we have elements of TO left over, free the lot. */
if (to_ptr)
{
changed = 1;
for (to_tmp = to_ptr; to_tmp->next ; to_tmp = to_tmp->next)
continue;
to_tmp->next = bitmap_free;
bitmap_free = to_ptr;
}
#undef DOIT
return changed;
}
/* Return true if two bitmaps are identical. */
int
bitmap_equal_p (a, b)
bitmap a;
bitmap b;
{
bitmap_head c;
int ret;
c.first = c.current = 0;
ret = ! bitmap_operation (&c, a, b, BITMAP_XOR);
bitmap_clear (&c);
return ret;
}
/* Or into bitmap TO bitmap FROM1 and'ed with the complement of
bitmap FROM2. */
void
bitmap_ior_and_compl (to, from1, from2)
bitmap to;
bitmap from1;
bitmap from2;
{
bitmap_head tmp;
tmp.first = tmp.current = 0;
bitmap_operation (&tmp, from1, from2, BITMAP_AND_COMPL);
bitmap_operation (to, to, &tmp, BITMAP_IOR);
bitmap_clear (&tmp);
}
int
bitmap_union_of_diff (dst, a, b, c)
bitmap dst;
bitmap a;
bitmap b;
bitmap c;
{
bitmap_head tmp;
int changed;
tmp.first = tmp.current = 0;
bitmap_operation (&tmp, b, c, BITMAP_AND_COMPL);
changed = bitmap_operation (dst, &tmp, a, BITMAP_IOR);
bitmap_clear (&tmp);
return changed;
}
/* Initialize a bitmap header. */
bitmap
bitmap_initialize (head)
bitmap head;
{
head->first = head->current = 0;
return head;
}
/* Debugging function to print out the contents of a bitmap. */
void
debug_bitmap_file (file, head)
FILE *file;
bitmap head;
{
bitmap_element *ptr;
fprintf (file, "\nfirst = ");
fprintf (file, HOST_PTR_PRINTF, (PTR) head->first);
fprintf (file, " current = ");
fprintf (file, HOST_PTR_PRINTF, (PTR) head->current);
fprintf (file, " indx = %u\n", head->indx);
for (ptr = head->first; ptr; ptr = ptr->next)
{
int i, j, col = 26;
fprintf (file, "\t");
fprintf (file, HOST_PTR_PRINTF, (PTR) ptr);
fprintf (file, " next = ");
fprintf (file, HOST_PTR_PRINTF, (PTR) ptr->next);
fprintf (file, " prev = ");
fprintf (file, HOST_PTR_PRINTF, (PTR) ptr->prev);
fprintf (file, " indx = %u\n\t\tbits = {", ptr->indx);
for (i = 0; i < BITMAP_ELEMENT_WORDS; i++)
for (j = 0; j < HOST_BITS_PER_WIDE_INT; j++)
if ((ptr->bits[i] >> j) & 1)
{
if (col > 70)
{
fprintf (file, "\n\t\t\t");
col = 24;
}
fprintf (file, " %u", (ptr->indx * BITMAP_ELEMENT_ALL_BITS
+ i * HOST_BITS_PER_WIDE_INT + j));
col += 4;
}
fprintf (file, " }\n");
}
}
/* Function to be called from the debugger to print the contents
of a bitmap. */
void
debug_bitmap (head)
bitmap head;
{
debug_bitmap_file (stdout, head);
}
/* Function to print out the contents of a bitmap. Unlike debug_bitmap_file,
it does not print anything but the bits. */
void
bitmap_print (file, head, prefix, suffix)
FILE *file;
bitmap head;
const char *prefix;
const char *suffix;
{
const char *comma = "";
int i;
fputs (prefix, file);
EXECUTE_IF_SET_IN_BITMAP (head, 0, i,
{
fprintf (file, "%s%d", comma, i);
comma = ", ";
});
fputs (suffix, file);
}