git.distorted.org.uk Git - u/mdw/catacomb/blob - math/mptypes.c

   1 /* -*-c-*-
   2  *
   3  * Generate `mptypes.h' header file for current architecture
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #define _GNU_SOURCE
  31 #include "config.h"
  32
  33 #include <stdio.h>
  34 #include <limits.h>
  35 #if __STDC_VERSION__ >= 199900l
  36 #  include <stdint.h>
  37 #  include <inttypes.h>
  38 #endif
  39
  40 /*----- Data types --------------------------------------------------------*/
  41
  42 /* --- Hack for GCC --- *
  43  *
  44  * WG14 in their infinite wisdom decided not to use the GCC constant name.
  45  */
  46
  47 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)
  48 #  define EXT __extension__
  49 #else
  50 #  define EXT
  51 #endif
  52
  53 #if defined(ULONG_LONG_MAX) && !defined(ULLONG_MAX)
  54 #  define ULLONG_MAX ULONG_LONG_MAX
  55 #endif
  56
  57 /* --- Choose the largest integer type --- */
  58
  59 #if defined(UINTMAX_MAX) && defined(PRIuMAX)
  60   typedef uintmax_t umax;
  61 # define P_UMAX PRIuMAX
  62 #elif defined(ULLONG_MAX)
  63   EXT typedef unsigned long long umax;
  64 # define P_UMAX "llu"
  65 #else
  66   typedef unsigned long umax;
  67 # define P_UMAX "lu"
  68 #endif
  69
  70 /* --- Table of interesting types --- *
  71  *
  72  * These are in preference order.
  73  */
  74
  75 enum {
  76   f_stdint = 1u,
  77   f_ext = 2u
  78 };
  79
  80 struct itype {
  81   const char *name;
  82   const char *suff;
  83   umax max;
  84   unsigned flags;
  85   unsigned bits;
  86 } tytab[] = {
  87   { "unsigned int",             "u",    UINT_MAX,               0 },
  88   { "unsigned short",           "u",    USHRT_MAX,              0 },
  89   { "unsigned long",            "ul",   ULONG_MAX,              0 },
  90 #ifdef ULLONG_MAX
  91   { "unsigned long long",       "ull",  EXT ULLONG_MAX,         f_ext },
  92 #endif
  93 #ifdef UINTMAX_MAX
  94   { "uintmax_t",                "u",    UINTMAX_MAX,            f_stdint },
  95 #endif
  96   { 0,                          0 },
  97 };
  98
  99 typedef struct itype itype;
 100
 101 /*----- Main code ---------------------------------------------------------*/
 102
 103 int main(int argc, char *argv[])
 104 {
 105   itype *i;
 106   itype *largest, *mpw, *mpd;
 107   const static char *extstr = "CATACOMB_MPTYPES_EXTENSION ";
 108   unsigned p2;
 109
 110   /* --- Find the bitcounts --- */
 111
 112   for (i = tytab; i->name; i++) {
 113     unsigned bits;
 114     umax u = i->max;
 115     for (bits = 0; u; bits++)
 116       u >>= 1;
 117     i->bits = bits;
 118   }
 119
 120   /* --- Now try to find the interesting types --- *
 121    *
 122    * The first thing to do is to find the largest type.  Then I find the
 123    * `best' type which is less than half that size, and then the `best' type
 124    * which is twice as big as that one.
 125    */
 126
 127 #if defined(FORCE_MPW_CUSSID)
 128   largest = mpd = &tytab[3];
 129   mpw = &tytab[2];
 130   mpw->bits = 19; mpw->max = 0x7ffff;
 131   mpd->bits = 38; mpd->max = 0x3fffffffffll;
 132 #elif defined(FORCE_MPW_SHORT)
 133   largest = mpd = &tytab[2];
 134   mpw = &tytab[1];
 135   mpw->bits = 16; mpw->max = 0xffff;
 136   mpd->bits = 32; mpd->max = 0xffffffff;
 137 #else
 138   largest = tytab;
 139   for (i = tytab; i->name; i++) {
 140     if (i->bits > largest->bits)
 141       largest = i;
 142   }
 143   for (mpw = 0, i = tytab; i->name; i++) {
 144     if (i->bits * 2 <= largest->bits && (!mpw || i->bits > mpw->bits))
 145       mpw = i;
 146   }
 147   if (!mpw)
 148     mpw = tytab;
 149   for (mpd = 0, i = tytab; i->name; i++) {
 150     if (i->bits >= mpw->bits * 2 && (!mpd || i->bits < mpd->bits))
 151       mpd = i;
 152   }
 153   if (!mpd) {
 154     static itype w, d;
 155     d = w = *mpw;
 156     w.bits /= 2; w.max = ~(~((umax)0) << w.bits);
 157     d.bits = w.bits * 2; d.max = ~(~((umax)0) << d.bits);
 158     mpw = &w; mpd = &d;
 159   }
 160 #endif
 161   for (p2 = 1; (p2 << 1) < mpw->bits; p2 <<= 1);
 162
 163   /* --- Output time --- */
 164
 165   puts("\
 166 /* -*-c-*-\n\
 167  *\n\
 168  * mptypes.h [generated]\n\
 169  */\n\
 170 \n\
 171 #ifndef CATACOMB_MPTYPES_H\n\
 172 #define CATACOMB_MPTYPES_H\n\
 173 ");
 174   if ((mpd->flags | mpw->flags) & f_stdint) {
 175     puts("\
 176 #if __STDC_VERSION__ >= 199900l\n\
 177 #  include <stdint.h>\n\
 178 #endif\n\
 179 ");
 180   }
 181   if ((mpd->flags | mpw->flags) & f_ext) {
 182     printf("\
 183 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)\n\
 184 #  define %s __extension__\n\
 185 #else\n\
 186 #  define %s\n\
 187 #endif\n\
 188 ", extstr, extstr);
 189   }
 190   printf("\
 191 %stypedef %s mpw;\n\
 192 #define MPW_BITS %u\n\
 193 #define MPW_P2 %u\n\
 194 #define MPW_MAX %s%" P_UMAX "%s\n\
 195 \n\
 196 %stypedef %s mpd;\n\
 197 #define MPD_BITS %u\n\
 198 #define MPD_MAX %s%" P_UMAX "%s\n\
 199 \n\
 200 #endif\n\
 201 ",
 202   mpw->flags & f_ext ? extstr : "", mpw->name,
 203   mpw->bits, p2,
 204   mpw->flags & f_ext ? extstr : "", mpw->max, mpw->suff,
 205   mpd->flags & f_ext ? extstr : "", mpd->name,
 206   mpd->bits,
 207   mpd->flags & f_ext ? extstr : "", mpd->max, mpd->suff);
 208
 209   return (0);
 210 }
 211
 212 /*----- That's all, folks -------------------------------------------------*/