libchill/inbitstr.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 __inbitstring
  38  *
  39  * parameters:
  40  *      bitno           bit number within set
  41  *      powerset        the powerset
  42  *      bitlength       length of powerset in bits
  43  *      minval          number of lowest bit stored
  44  *      fname           filename of caller
  45  *      lineno          linenumber of caller
  46  *
  47  * returns:
  48  *      int             1 .. found
  49  *                      0 .. not found
  50  *
  51  * exceptions:
  52  *  rangefail
  53  *
  54  * abstract:
  55  *  checks if a given value is included in a bitstring
  56  *
  57  */
  58 int
  59 __inbitstring (bitno, powerset, bitlength, minval, fname, lineno)
  60      unsigned long  bitno;
  61      SET_WORD      *powerset;
  62      unsigned long  bitlength;
  63      long           minval;
  64      char          *fname;
  65      int            lineno;
  66
  67 {
  68   if (powerset == NULL
  69       || bitno < minval
  70       || (bitno - minval) >= bitlength)
  71     __cause_ex1 ("rangefail", fname, lineno);
  72
  73   bitno -= minval;
  74   if (bitlength <= SET_CHAR_SIZE)
  75     return GET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  76   else if (bitlength <= SET_SHORT_SIZE)
  77     return GET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  78   else
  79     return GET_BIT_IN_WORD (powerset[bitno / SET_WORD_SIZE],
  80                             bitno % SET_WORD_SIZE);
  81 }