1/* Implement POWERSET runtime actions for CHILL.
2   Copyright (C) 1992,1993 Free Software Foundation, Inc.
3   Author: Wilfried Moser, et al
4
5This file is part of GNU CC.
6
7GNU CC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU CC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GNU CC; see the file COPYING.  If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, MA 02111-1307, USA.  */
21
22/* As a special exception, if you link this library with other files,
23   some of which are compiled with GCC, to produce an executable,
24   this library does not by itself cause the resulting executable
25   to be covered by the GNU General Public License.
26   This exception does not however invalidate any other reasons why
27   the executable file might be covered by the GNU General Public License.  */
28
29#define __CHILL_LIB__
30
31#include <stdio.h>
32#include "powerset.h"
33
34/*
35 * function __powerset_copy
36 *    This is more general than __psslice, since it
37 *    can be told where in the destination powerset (DOFFSET
38 *    parameter) to start storing the slice.
39 *
40 * parameters:
41 *      dps             dest powerset
42 *      dbl             destination bit length
43 *      doffset         offset bit number (zero origin)
44 *	sps		sourcepowerset
45 *	sbl     	source powerset length in bits
46 *      start           starting bit number
47 *      end             ending bit number
48 *
49 * exceptions:
50 *  none
51 *
52 * abstract:
53 *  Extract into a powerset a slice of another powerset.
54 *
55 */
56void
57__pscpy (dps, dbl, doffset, sps, sbl, start, length)
58     SET_WORD      *dps;
59     unsigned long  dbl;
60     unsigned long  doffset;
61     const SET_WORD*sps;
62     unsigned long  sbl;
63     unsigned long  start;
64     unsigned long  length;
65{
66  unsigned long end = start + length - 1;
67  unsigned long src, dst;
68
69  /* assert end >= start;
70     assert end - start + 1 <= dbl;
71     assert "the sets don't overlap in memory" */
72
73  /* assert doffset >= 0 and < dbl */
74
75  for (src = start, dst = doffset; src <= end; src++, dst++)
76    {
77      char tmp;
78
79      if (sbl <= SET_CHAR_SIZE)                /* fetch a bit */
80	tmp = GET_BIT_IN_CHAR (*((SET_CHAR *)sps), src);
81      else if (sbl <= SET_SHORT_SIZE)
82	tmp = GET_BIT_IN_SHORT (*((SET_SHORT *)sps), src);
83      else
84	tmp = GET_BIT_IN_WORD (sps[src / SET_WORD_SIZE], src % SET_WORD_SIZE);
85
86      if (tmp & 1)
87	{
88	  if (dbl <= SET_CHAR_SIZE)            /* store a 1-bit */
89	    SET_BIT_IN_CHAR (*((SET_CHAR *)dps), dst);
90	  else if (dbl <= SET_SHORT_SIZE)
91	    SET_BIT_IN_SHORT (*((SET_SHORT *)dps), dst);
92	  else
93	    SET_BIT_IN_WORD (dps[dst / SET_WORD_SIZE], dst % SET_WORD_SIZE);
94	}
95      else
96	{
97	  if (dbl <= SET_CHAR_SIZE)            /* store a 0-bit */
98	    CLEAR_BIT_IN_CHAR (*((SET_CHAR *)dps), dst);
99	  else if (dbl <= SET_SHORT_SIZE)
100	    CLEAR_BIT_IN_SHORT (*((SET_SHORT *)dps), dst);
101	  else
102	    CLEAR_BIT_IN_WORD (dps[dst / SET_WORD_SIZE], dst % SET_WORD_SIZE);
103	}
104    }
105  if (dbl <= SET_CHAR_SIZE)         /* clear unused bits in output bitstring */
106    {
107      MASK_UNUSED_CHAR_BITS ((SET_CHAR *)dps, dbl);
108    }
109  else if (dbl <= SET_SHORT_SIZE)
110    {
111      MASK_UNUSED_SHORT_BITS ((SET_SHORT *)dps, dbl);
112    }
113  else
114    {
115      MASK_UNUSED_WORD_BITS ((SET_WORD *)(dps + (dbl/SET_WORD_SIZE)),
116			     dbl % SET_WORD_SIZE);
117    }
118}
119