AppPkg/Applications/ArithChk/arithchk.c

   1 /** @file
   2     Program to generate an arith.h for use with the gdtoa binary to decimal and decimal to binary
   3     conversion library.
   4
   5   Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution. The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14   Copyright (C) 1997, 1998 Lucent Technologies
  15   All Rights Reserved
  16
  17   Permission to use, copy, modify, and distribute this software and
  18   its documentation for any purpose and without fee is hereby
  19   granted, provided that the above copyright notice appear in all
  20   copies and that both that the copyright notice and this
  21   permission notice and warranty disclaimer appear in supporting
  22   documentation, and that the name of Lucent or any of its entities
  23   not be used in advertising or publicity pertaining to
  24   distribution of the software without specific, written prior
  25   permission.
  26
  27   LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  28   INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
  29   IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
  30   SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  31   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
  32   IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  33   ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
  34   THIS SOFTWARE.
  35
  36   NetBSD: arithchk.c,v 1.2 2006/01/25 15:27:42 kleink Exp
  37 ****************************************************************/
  38 #include  <sys/EfiCdefs.h>
  39
  40 /* Try to deduce arith.h from arithmetic properties. */
  41
  42 #include <stdio.h>
  43
  44 static int dalign;
  45
  46 typedef struct  Akind {
  47   char *name;
  48   int   kind;
  49 } Akind;
  50
  51 static Akind  IEEE_LITTLE_ENDIAN  = { "IEEE_LITTLE_ENDIAN", 1 };
  52 static Akind  IEEE_BIG_ENDIAN     = { "IEEE_BIG_ENDIAN", 2 };
  53 static Akind  IBM                 = { "IBM", 3 };
  54 static Akind  VAX                 = { "VAX", 4 };
  55 static Akind  CRAY                = { "CRAY", 5};
  56
  57 static Akind *
  58 Lcheck()
  59 {
  60   union {
  61     double d;
  62     long L[2];
  63   } u;
  64   struct {
  65     double d;
  66     long L;
  67   } x[2];
  68
  69   if (sizeof(x) > 2*(sizeof(double) + sizeof(long)))
  70     dalign = 1;
  71   u.L[0] = u.L[1] = 0;
  72   u.d = 1e13;
  73   if (u.L[0] == 1117925532 && u.L[1] == -448790528)
  74     return &IEEE_BIG_ENDIAN;
  75   if (u.L[1] == 1117925532 && u.L[0] == -448790528)
  76     return &IEEE_LITTLE_ENDIAN;
  77   if (u.L[0] == -2065213935 && u.L[1] == 10752)
  78     return &VAX;
  79   if (u.L[0] == 1267827943 && u.L[1] == 704643072)
  80     return &IBM;
  81   return 0;
  82   }
  83
  84  static Akind *
  85 icheck()
  86 {
  87   union {
  88     double d;
  89     int L[2];
  90     } u;
  91   struct {
  92     double d;
  93     int L;
  94     } x[2];
  95
  96   if (sizeof(x) > 2*(sizeof(double) + sizeof(int)))
  97     dalign = 1;
  98   u.L[0] = u.L[1] = 0;
  99   u.d = 1e13;
 100   if (u.L[0] == 1117925532 && u.L[1] == -448790528)
 101     return &IEEE_BIG_ENDIAN;
 102   if (u.L[1] == 1117925532 && u.L[0] == -448790528)
 103     return &IEEE_LITTLE_ENDIAN;
 104   if (u.L[0] == -2065213935 && u.L[1] == 10752)
 105     return &VAX;
 106   if (u.L[0] == 1267827943 && u.L[1] == 704643072)
 107     return &IBM;
 108   return 0;
 109   }
 110
 111 char *emptyfmt = "";  /* avoid possible warning message with printf("") */
 112
 113  static Akind *
 114 ccheck()
 115 {
 116   union {
 117     double d;
 118     long L;
 119     } u;
 120   long Cray1;
 121
 122   /* Cray1 = 4617762693716115456 -- without overflow on non-Crays */
 123   Cray1 = printf(emptyfmt) < 0 ? 0 : 4617762;
 124   if (printf(emptyfmt, Cray1) >= 0)
 125     Cray1 = 1000000*Cray1 + 693716;
 126   if (printf(emptyfmt, Cray1) >= 0)
 127     Cray1 = 1000000*Cray1 + 115456;
 128   u.d = 1e13;
 129   if (u.L == Cray1)
 130     return &CRAY;
 131   return 0;
 132   }
 133
 134  static int
 135 fzcheck()
 136 {
 137   double a, b;
 138   int i;
 139
 140   a = 1.;
 141   b = .1;
 142   for(i = 155;; b *= b, i >>= 1) {
 143     if (i & 1) {
 144       a *= b;
 145       if (i == 1)
 146         break;
 147       }
 148     }
 149   b = a * a;
 150   return b == 0.;
 151   }
 152
 153  int
 154 main()
 155 {
 156   Akind *a = 0;
 157   int Ldef = 0;
 158   FILE *f;
 159
 160 #ifdef WRITE_ARITH_H  /* for Symantec's buggy "make" */
 161   f = fopen("arith.h", "w");
 162   if (!f) {
 163     printf("Cannot open arith.h\n");
 164     return 1;
 165     }
 166 #else
 167   f = stdout;
 168 #endif
 169
 170   if (sizeof(double) == 2*sizeof(long))
 171     a = Lcheck();
 172   else if (sizeof(double) == 2*sizeof(int)) {
 173     Ldef = 1;
 174     a = icheck();
 175     }
 176   else if (sizeof(double) == sizeof(long))
 177     a = ccheck();
 178   if (a) {
 179     fprintf(f, "#define %s\n#define Arith_Kind_ASL %d\n",
 180       a->name, a->kind);
 181     if (Ldef)
 182       fprintf(f, "#define Long int\n#define Intcast (int)(long)\n");
 183     if (dalign)
 184       fprintf(f, "#define Double_Align\n");
 185     if (sizeof(char*) == 8)
 186       fprintf(f, "#define X64_bit_pointers\n");
 187 #ifndef NO_LONG_LONG
 188     if (sizeof(long long) < 8)
 189 #endif
 190       fprintf(f, "#define NO_LONG_LONG\n");
 191     if (a->kind <= 2 && fzcheck())
 192       fprintf(f, "#define Sudden_Underflow\n");
 193     return 0;
 194     }
 195   fprintf(f, "/* Unknown arithmetic */\n");
 196   return 1;
 197   }