libchill/setbitps.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, 59 Temple Place - Suite 330,
  20 Boston, 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 extern void __cause_ex1 (char *exname, char *file, int lineno);
  35
  36 /*
  37  * function __setbitpowerset
  38  *
  39  * parameters:
  40  *      set             destination set
  41  *      bitlength       length of powerset in bits
  42  *      minval          lowest valid set value
  43  *      bitno           bit number within set
  44  *      new_value       zero or one - (new bit value)
  45  *
  46  * returns:
  47  *      int             1 .. found
  48  *                      0 .. not found
  49  *
  50  * exceptions:
  51  *  rangefail
  52  *
  53  * abstract:
  54  *  checks if a given value is included in a powerset
  55  *
  56  */
  57 void
  58 __setbitpowerset (powerset, bitlength, minval, bitno, new_value, filename, lineno)
  59      SET_WORD      *powerset;
  60      unsigned long  bitlength;
  61      long           minval;
  62      long           bitno;
  63      char           new_value; /* booleans are represented as 8 bit value */
  64      char *         filename;
  65      int            lineno;
  66 {
  67   if (powerset == NULL
  68       || bitno < minval
  69       || (bitno - minval) >= bitlength)
  70     __cause_ex1 ("rangefail", filename, lineno);
  71
  72   bitno -= minval;
  73   if (bitlength <= SET_CHAR_SIZE)
  74     {
  75       if (new_value & 1)
  76         SET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  77       else
  78         CLEAR_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  79     }
  80   else if (bitlength <= SET_SHORT_SIZE)
  81     {
  82       if (new_value & 1)
  83         SET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  84       else
  85         CLEAR_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  86     }
  87   else
  88     {
  89       powerset += (bitno/SET_WORD_SIZE);
  90       bitno %= SET_WORD_SIZE;
  91       if (new_value & 1)
  92         SET_BIT_IN_WORD (*powerset, bitno);
  93       else
  94         CLEAR_BIT_IN_WORD (*powerset, bitno);
  95     }
  96 }