libchill/ltps.c

   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 /* As a special exception, if you link this library with other files,
  22    some of which are compiled with GCC, to produce an executable,
  23    this library does not by itself cause the resulting executable
  24    to be covered by the GNU General Public License.
  25    This exception does not however invalidate any other reasons why
  26    the executable file might be covered by the GNU General Public License.  */
  27
  28 #define __CHILL_LIB__
  29
  30 #include <stdio.h>
  31 #include "powerset.h"
  32
  33 /*
  34  * function __ltpowerset
  35  *
  36  * parameters:
  37  *      left            powerset
  38  *      right           powerset
  39  *      bitlength       length of powerset
  40  *
  41  * returns:
  42  *      int             1 .. left is proper subset of right
  43  *                           (excludes case where left == right)
  44  *                      0 .. not
  45  *
  46  * abstract:
  47  *  check if one powerset is included in another
  48  *
  49  */
  50 int
  51 __ltpowerset (left, right, bitlength)
  52      SET_WORD      *left;
  53      SET_WORD      *right;
  54      unsigned long  bitlength;
  55 {
  56   if (bitlength <= SET_CHAR_SIZE)
  57     {
  58       if ((*((SET_CHAR *)left) & *((SET_CHAR *)right))
  59           != *((SET_CHAR *)left))
  60         return 0;
  61       if (*((SET_CHAR *)left) != *((SET_CHAR *)right))
  62         return 1;
  63       return 0;
  64     }
  65   else if (bitlength <= SET_SHORT_SIZE)
  66     {
  67       if ((*((SET_SHORT *)left) & *((SET_SHORT *)right))
  68           != *((SET_SHORT *)left))
  69         return 0;
  70       if (*((SET_SHORT *)left) != *((SET_SHORT *)right))
  71         return 1;
  72       return 0;
  73     }
  74   else
  75     {
  76       SET_WORD  *endp = left + BITS_TO_WORDS(bitlength);
  77       int all_equal = 1;              /* assume all bits are equal */
  78
  79       while (left < endp)
  80         {
  81           if ((*right & *left) != *left)
  82             return 0;
  83           if (*left != *right)
  84             all_equal = 0;
  85           left++;
  86           right++;
  87         }
  88       if (left == endp && all_equal)    /* exclude TRUE return for == case */
  89         return 0;
  90       return 1;
  91     }
  92 }