libchill/xorps.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 #define __CHILL_LIB__
  22
  23 #include <stdio.h>
  24 #include "powerset.h"
  25
  26 /*
  27  * function __xorpowerset
  28  *
  29  * parameters:
  30  *      out             return from __xorpowerset
  31  *      left            left powerset
  32  *      right           right powerset
  33  *      bitlength       length of powerset in bits
  34  *
  35  * returns:
  36  *      void
  37  *
  38  * exceptions:
  39  *  none
  40  *
  41  * abstract:
  42  *  xor's 2 powersets
  43  *
  44  */
  45
  46 void
  47 __xorpowerset (out, left, right, bitlength)
  48      SET_WORD      *out;
  49      SET_WORD      *left;
  50      SET_WORD      *right;
  51      unsigned long  bitlength;
  52 {
  53   if (bitlength <= SET_CHAR_SIZE)
  54     {
  55       *((SET_CHAR *)out) = *((SET_CHAR *)left) ^
  56                            *((SET_CHAR *)right);
  57       MASK_UNUSED_CHAR_BITS((SET_CHAR *)out, bitlength);
  58     }
  59   else if (bitlength <= SET_SHORT_SIZE)
  60     {
  61       *((SET_SHORT *)out) = *((SET_SHORT *)left) ^
  62                             *((SET_SHORT *)right);
  63       MASK_UNUSED_SHORT_BITS((SET_SHORT *)out, bitlength);
  64     }
  65   else
  66     {
  67       unsigned long len = BITS_TO_WORDS(bitlength);
  68       register unsigned long i;
  69
  70       for (i = 0; i < len; i++)
  71         out[i] = left[i] ^ right[i];
  72       MASK_UNUSED_WORD_BITS ((out + len - 1),
  73                              bitlength % SET_WORD_SIZE);
  74     }
  75 }