| /* 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, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| /* As a special exception, if you link this library with other files, |
| some of which are compiled with GCC, to produce an executable, |
| this library does not by itself cause the resulting executable |
| to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why |
| the executable file might be covered by the GNU General Public License. */ |
| |
| #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); |
| } |
| } |