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, 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 __inbitstring
  37  *
  38  * parameters:
  39  *      bitno           bit number within set
  40  *      powerset        the powerset
  41  *      bitlength       length of powerset in bits
  42  *      minval          number of lowest bit stored
  43  *      fname           filename of caller
  44  *      lineno          linenumber of caller
  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 bitstring
  55  *
  56  */
  57 int
  58 __inbitstring (bitno, powerset, bitlength, minval, fname, lineno)
  59      unsigned long  bitno;
  60      SET_WORD      *powerset;
  61      unsigned long  bitlength;
  62      long           minval;
  63      char          *fname;
  64      int            lineno;
  65
  66 {
  67   if (powerset == NULL
  68       || bitno < minval
  69       || (bitno - minval) >= bitlength)
  70     __cause_ex1 ("rangefail", fname, lineno);
  71
  72   bitno -= minval;
  73   if (bitlength <= SET_CHAR_SIZE)
  74     return GET_BIT_IN_CHAR (*((SET_CHAR *)powerset), bitno);
  75   else if (bitlength <= SET_SHORT_SIZE)
  76     return GET_BIT_IN_SHORT (*((SET_SHORT *)powerset), bitno);
  77   else
  78     return GET_BIT_IN_WORD (powerset[bitno / SET_WORD_SIZE],
  79                             bitno % SET_WORD_SIZE);
  80 }