1 /* Implement POWERSET runtime actions for CHILL.
2 Copyright (C) 1992,1993 Free Software Foundation, Inc.
3 Author: Wilfried Moser, et al
5 This file is part of GNU CC.
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)
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.
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. */
27 * function __flsetclrpowerset
31 * bitlength length of powerset
34 * int -1 .. nothing found
35 * >= 0 .. index of last set bit
40 * Find last bit set in a powerset and return the corresponding value
41 * in *out and clear this bit. Return 0 for no more found, else 1.
45 __flsetclrpowerset (ps
, bitlength
, first_bit
)
47 unsigned long bitlength
;
53 if (bitlength
<= SET_CHAR_SIZE
)
55 for (bitno
= bitlength
- 1; bitno
>= first_bit
; bitno
--)
56 if (GET_BIT_IN_CHAR (*((SET_CHAR
*)ps
), bitno
))
58 return bitno
< first_bit
? -1 : bitno
;
60 else if (bitlength
<= SET_SHORT_SIZE
)
62 for (bitno
= bitlength
- 1; bitno
>= first_bit
; bitno
--)
63 if (GET_BIT_IN_SHORT (*((SET_SHORT
*)ps
), bitno
))
65 return bitno
< first_bit
? -1 : bitno
;
71 bitno
= bitlength
- 1;
72 if (bitno
< first_bit
)
74 p
= &ps
[(unsigned) bitno
/ SET_WORD_SIZE
];
76 if (((unsigned) bitlength
% SET_WORD_SIZE
) != 0)
77 MASK_UNUSED_WORD_BITS(&c
, (unsigned) bitlength
% SET_WORD_SIZE
);
81 bitno
-= ((unsigned) bitno
% SET_WORD_SIZE
) + 1;
82 while (bitno
>= first_bit
)
87 bitno
-= SET_WORD_SIZE
;
91 for (; bitno
>= first_bit
; bitno
--)
93 if (GET_BIT_IN_WORD (c
, (unsigned) bitno
% SET_WORD_SIZE
))