freebsd-dev/contrib/gcc/f/bit.c
1999-10-16 06:09:09 +00:00

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/* bit.c -- Implementation File (module.c template V1.0)
Copyright (C) 1995 Free Software Foundation, Inc.
Contributed by James Craig Burley.
This file is part of GNU Fortran.
GNU Fortran 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.
GNU Fortran 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 GNU Fortran; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.
Related Modules:
None
Description:
Tracks arrays of booleans in useful ways.
Modifications:
*/
/* Include files. */
#include "proj.h"
#include "glimits.j"
#include "bit.h"
#include "malloc.h"
/* Externals defined here. */
/* Simple definitions and enumerations. */
/* Internal typedefs. */
/* Private include files. */
/* Internal structure definitions. */
/* Static objects accessed by functions in this module. */
/* Static functions (internal). */
/* Internal macros. */
/* ffebit_count -- Count # of bits set a particular way
ffebit b; // the ffebit object
ffebitCount offset; // 0..size-1
bool value; // FALSE (0), TRUE (1)
ffebitCount range; // # bits to test
ffebitCount number; // # bits equal to value
ffebit_count(b,offset,value,range,&number);
Sets <number> to # bits at <offset> through <offset + range - 1> set to
<value>. If <range> is 0, <number> is set to 0. */
void
ffebit_count (ffebit b, ffebitCount offset, bool value, ffebitCount range,
ffebitCount *number)
{
ffebitCount element;
ffebitCount bitno;
assert (offset + range <= b->size);
for (*number = 0; range != 0; --range, ++offset)
{
element = offset / CHAR_BIT;
bitno = offset % CHAR_BIT;
if (value
== ((b->bits[element] & ((unsigned char) 1 << bitno)) == 0 ? FALSE : TRUE))
++ * number;
}
}
/* ffebit_new -- Create a new ffebit object
ffebit b;
ffebit_kill(b);
Destroys an ffebit object obtained via ffebit_new. */
void
ffebit_kill (ffebit b)
{
malloc_kill_ks (b->pool, b,
offsetof (struct _ffebit_, bits)
+ (b->size + CHAR_BIT - 1) / CHAR_BIT);
}
/* ffebit_new -- Create a new ffebit object
ffebit b;
mallocPool pool;
ffebitCount size;
b = ffebit_new(pool,size);
Allocates an ffebit object that holds the values of <size> bits in pool
<pool>. */
ffebit
ffebit_new (mallocPool pool, ffebitCount size)
{
ffebit b;
b = malloc_new_zks (pool, "ffebit",
offsetof (struct _ffebit_, bits)
+ (size + CHAR_BIT - 1) / CHAR_BIT,
0);
b->pool = pool;
b->size = size;
return b;
}
/* ffebit_set -- Set value of # of bits
ffebit b; // the ffebit object
ffebitCount offset; // 0..size-1
bool value; // FALSE (0), TRUE (1)
ffebitCount length; // # bits to set starting at offset (usually 1)
ffebit_set(b,offset,value,length);
Sets bit #s <offset> through <offset + length - 1> to <value>. */
void
ffebit_set (ffebit b, ffebitCount offset, bool value, ffebitCount length)
{
ffebitCount i;
ffebitCount element;
ffebitCount bitno;
assert (offset + length <= b->size);
for (i = 0; i < length; ++i, ++offset)
{
element = offset / CHAR_BIT;
bitno = offset % CHAR_BIT;
b->bits[element] = (((unsigned char) (value ? 1 : 0)) << bitno)
| (b->bits[element] & ~((unsigned char) 1 << bitno));
}
}
/* ffebit_test -- Test value of # of bits
ffebit b; // the ffebit object
ffebitCount offset; // 0..size-1
bool value; // FALSE (0), TRUE (1)
ffebitCount length; // # bits with same value
ffebit_test(b,offset,&value,&length);
Returns value of bits at <offset> through <offset + length - 1> in
<value>. If <offset> is already at the end of the bit array (if
offset == ffebit_size(b)), <length> is set to 0 and <value> is
undefined. */
void
ffebit_test (ffebit b, ffebitCount offset, bool *value, ffebitCount *length)
{
ffebitCount i;
ffebitCount element;
ffebitCount bitno;
if (offset >= b->size)
{
assert (offset == b->size);
*length = 0;
return;
}
element = offset / CHAR_BIT;
bitno = offset % CHAR_BIT;
*value = (b->bits[element] & ((unsigned char) 1 << bitno)) == 0 ? FALSE : TRUE;
*length = 1;
for (i = b->size - offset - 1, ++offset; i != 0; --i, ++offset, ++*length)
{
element = offset / CHAR_BIT;
bitno = offset % CHAR_BIT;
if (*value
!= ((b->bits[element] & ((unsigned char) 1 << bitno)) == 0 ? FALSE : TRUE))
break;
}
}