[gcc.git] / libchill / cardps.c

/* 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 <stdio.h>
#include "powerset.h"


/*
 * function __cardpowerset
 *
 * parameters:
 *	ps		powerset
 *	bitlength	length of powerset
 *
 * returns:
 *	long		number of set bits
 *
 * exceptions:
 *  none
 *
 * abstract:
 *  returns the number of set bit's in a powerset
 *
 */

/* bit_count[I] is number of '1' bits in I. */
static
const unsigned char __four_bit_count[16] = {
    0, 1, 1, 2,
    1, 2, 2, 3,
    1, 2, 2, 3,
    2, 3, 3, 4 };

long
__cardpowerset (ps, bitlength)
     SET_WORD      *ps;
     unsigned long  bitlength;
{
  unsigned long	count = 0;
  if (bitlength <= SET_CHAR_SIZE)
    {
      register SET_CHAR	c = *((SET_CHAR *)ps);
      /* count 4 bits at a time. */
      while (c > 0)
	{
	  count += __four_bit_count[c & 15];
	  c >>= 4;
	}
      return count;
    }
  else if (bitlength <= SET_SHORT_SIZE)
    {
      register SET_SHORT c = *((SET_SHORT *)ps);
      /* count 4 bits at a time. */
      while (c > 0)
	{
	  count += __four_bit_count[c & 15];
	  c >>= 4;
	}
      return count;
    }
  else
    {
      register SET_WORD	*p = ps;
      SET_WORD *endp = p + BITS_TO_WORDS(bitlength);
    
      while (p < endp)
	{
	  register SET_WORD c = *p++;
	  /* count 4 bits at a time. */
	  while (c > 0)
	    {
	      count += __four_bit_count[c & 15];
	      c >>= 4;
	    }
	}
      return (count);
    }
}
Commit	Line	Data
b79f73df JL	1	/* Implement POWERSET runtime actions for CHILL.
	2	Copyright (C) 1992,1993 Free Software Foundation, Inc.
	3	Author: Wilfried Moser, et al
	4
	5	This file is part of GNU CC.
	6
	7	GNU CC is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2, or (at your option)
	10	any later version.
	11
	12	GNU CC is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with GNU CC; see the file COPYING. If not, write to
	19	the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
	20
	21	#define __CHILL_LIB__
	22
b79f73df JL	23	#include <stdio.h>
	24	#include "powerset.h"
	25
	26
	27	/*
	28	* function __cardpowerset
	29	*
	30	* parameters:
	31	* ps powerset
	32	* bitlength length of powerset
	33	*
	34	* returns:
	35	* long number of set bits
	36	*
	37	* exceptions:
	38	* none
	39	*
	40	* abstract:
	41	* returns the number of set bit's in a powerset
	42	*
	43	*/
	44
	45	/* bit_count[I] is number of '1' bits in I. */
	46	static
	47	const unsigned char __four_bit_count[16] = {
	48	0, 1, 1, 2,
	49	1, 2, 2, 3,
	50	1, 2, 2, 3,
	51	2, 3, 3, 4 };
	52
	53	long
	54	__cardpowerset (ps, bitlength)
	55	SET_WORD *ps;
	56	unsigned long bitlength;
	57	{
	58	unsigned long count = 0;
	59	if (bitlength <= SET_CHAR_SIZE)
	60	{
	61	register SET_CHAR c = ((SET_CHAR )ps);
	62	/* count 4 bits at a time. */
	63	while (c > 0)
	64	{
	65	count += __four_bit_count[c & 15];
	66	c >>= 4;
	67	}
	68	return count;
	69	}
	70	else if (bitlength <= SET_SHORT_SIZE)
	71	{
	72	register SET_SHORT c = ((SET_SHORT )ps);
	73	/* count 4 bits at a time. */
	74	while (c > 0)
	75	{
	76	count += __four_bit_count[c & 15];
	77	c >>= 4;
	78	}
	79	return count;
	80	}
	81	else
	82	{
	83	register SET_WORD *p = ps;
	84	SET_WORD *endp = p + BITS_TO_WORDS(bitlength);
	85
	86	while (p < endp)
87	{
88	register SET_WORD c = *p++;
89	/* count 4 bits at a time. */
90	while (c > 0)
91	{
92	count += __four_bit_count[c & 15];
93	c >>= 4;
94	}
95	}
96	return (count);
97	}
98	}