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/* Implement POWERSET runtime actions for CHILL.
Copyright (C) 1992,1993 Free Software Foundation, Inc.
Author: Wilfried Moser, et al
This file is part of GNU CC.
GNU CC 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 CC 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 CC; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#define __CHILL_LIB__
#include "config.h"
#include <stdio.h>
#include "powerset.h"
extern void __cause_ex1 (char *exname, char *file, int lineno);
/*
* function __flsetpowerset
*
* parameters:
* ps powerset
* bitlength length of powerset
* minval set low bound
* filename caller's file name
* lineno caller's line number
*
* returns:
* int largest enumeration value
* exceptions:
* "empty" if set is empty
*
* abstract:
* Find last bit set in a powerset and return the corresponding value.
*
*/
long
__flsetpowerset (ps, bitlength, minval, filename, lineno)
SET_WORD *ps;
unsigned long bitlength;
long minval;
char *filename;
int lineno;
{
unsigned long bitno;
if (bitlength <= SET_CHAR_SIZE)
{
SET_CHAR cset = *((SET_CHAR *)ps);
if (cset != 0)
{
/* found a bit set .. calculate which */
for (bitno = SET_CHAR_SIZE; bitno >= 1; bitno--)
if (GET_BIT_IN_CHAR (cset, bitno - 1))
break;
/* return its index */
return bitno + minval - 1;
}
}
else if (bitlength <= SET_SHORT_SIZE)
{
SET_SHORT sset = *((SET_SHORT *)ps);
if (sset != 0)
{
/* found a bit set .. calculate which */
for (bitno = SET_SHORT_SIZE; bitno >= 1; bitno--)
if (GET_BIT_IN_SHORT (sset, bitno - 1))
break;
/* return its index */
return bitno + minval - 1;
}
}
else /* set composed of array of one or more WORDs */
{
SET_WORD *endp = ps;
SET_WORD *p = ps + BITS_TO_WORDS(bitlength) - 1;
unsigned long cnt;
/* FIXME: bitorder problems? */
for (cnt = ((bitlength - 1) / SET_WORD_SIZE) * SET_WORD_SIZE;
p >= endp; p--, cnt -= SET_WORD_SIZE)
{
SET_WORD c = *p;
if (c)
{
/* found a bit set .. calculate which */
for (bitno = SET_WORD_SIZE; bitno >= 1; bitno--)
if (GET_BIT_IN_WORD (c, bitno - 1))
break;
return cnt + bitno + minval - 1;
}
}
}
/* no bits found - raise exception */
__cause_ex1 ("empty", filename, lineno);
}
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