gnu/dist/bc/dc/dc-regdef.h

   1 /*
   2  * definitions for dc's "register" declarations
   3  *
   4  * Copyright (C) 1994 Free Software Foundation, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, you can either send email to this
  18  * program's author (see below) or write to:
  19  *
  20  *    The Free Software Foundation, Inc.
  21  *    59 Temple Place, Suite 330
  22  *    Boston, MA 02111 USA
  23  */
  24
  25 #ifdef HAVE_LIMITS_H
  26 # include <limits.h>    /* UCHAR_MAX */
  27 #endif
  28
  29 /* determine how many register stacks there are */
  30 #ifndef DC_REGCOUNT
  31 # ifndef UCHAR_MAX
  32 #  define DC_REGCOUNT 256
  33 # else
  34 #  define DC_REGCOUNT (UCHAR_MAX+1)
  35 # endif
  36 #endif /* not DC_REGCOUNT */
  37
  38 /* efficiency hack for masking arbritrary integers to 0..(DC_REGCOUNT-1) */
  39 #if (DC_REGCOUNT & (DC_REGCOUNT-1)) == 0        /* DC_REGCOUNT is power of 2 */
  40 # define regmap(r)      ((r) & (DC_REGCOUNT-1))
  41 #else
  42 # define regmap(r)      ((r) % DC_REGCOUNT)
  43 #endif