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, 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 extern void __cause_ex1 (char *exname, char *file, int lineno);
  34
  35 /*
  36  * function __setbitpowerset
  37  *
  38  * parameters:
  39  *      set             destination set
  40  *      bitlength       length of powerset in bits
  41  *      minval          lowest valid set value
  42  *      bitno           bit number within set
  43  *      new_value       zero or one - (new bit value)
  44  *
  45  * returns:
  46  *      int             1 .. found
  47  *                      0 .. not found
  48  *
  49  * exceptions:
  50  *  rangefail
  51  *
  52  * abstract:
  53  *  checks if a given value is included in a powerset
  54  *
  55  */
  56 void
  57 __setbitpowerset (powerset, bitlength, minval, bitno, new_value, filename, lineno)
  58      SET_WORD      *powerset;
  59      unsigned long  bitlength;
  60      long           minval;
  61      long           bitno;
  62      char           new_value; /* booleans are represented as 8 bit value */
  63      char *         filename;
  64      int            lineno;
  65 {
  66   if (powerset == NULL
  67       || bitno < minval
  68       || (bitno - minval) >= bitlength)
  69     __cause_ex1 ("rangefail", filename, lineno);
  70
  71   bitno -= minval;
  72   if (bitlength <= SET_CHAR_SIZE)
  73     {
  74       if (new_value & 1)
  75         SET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  76       else
  77         CLEAR_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  78     }
  79   else if (bitlength <= SET_SHORT_SIZE)
  80     {
  81       if (new_value & 1)
  82         SET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  83       else
  84         CLEAR_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  85     }
  86   else
  87     {
  88       powerset += (bitno/SET_WORD_SIZE);
  89       bitno %= SET_WORD_SIZE;
  90       if (new_value & 1)
  91         SET_BIT_IN_WORD (*powerset, bitno);
  92       else
  93         CLEAR_BIT_IN_WORD (*powerset, bitno);
  94     }
  95 }