1 /* $NetBSD: arithchk.c,v 1.3 2010/01/17 23:06:31 wiz Exp $ */ 2 3 /**************************************************************** 4 Copyright (C) 1997, 1998 Lucent Technologies 5 All Rights Reserved 6 7 Permission to use, copy, modify, and distribute this software and 8 its documentation for any purpose and without fee is hereby 9 granted, provided that the above copyright notice appear in all 10 copies and that both that the copyright notice and this 11 permission notice and warranty disclaimer appear in supporting 12 documentation, and that the name of Lucent or any of its entities 13 not be used in advertising or publicity pertaining to 14 distribution of the software without specific, written prior 15 permission. 16 17 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 18 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 19 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 20 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 21 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 22 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 23 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 24 THIS SOFTWARE. 25 ****************************************************************/ 26 27 /* Try to deduce arith.h from arithmetic properties. */ 28 29 #include <stdio.h> 30 31 static int dalign; 32 typedef struct 33 Akind { 34 char *name; 35 int kind; 36 } Akind; 37 38 static Akind 39 IEEE_LITTLE_ENDIAN = { "IEEE_LITTLE_ENDIAN", 1 }, 40 IEEE_BIG_ENDIAN = { "IEEE_BIG_ENDIAN", 2 }, 41 IBM = { "IBM", 3 }, 42 VAX = { "VAX", 4 }, 43 CRAY = { "CRAY", 5}; 44 45 static Akind * 46 Lcheck() 47 { 48 union { 49 double d; 50 long L[2]; 51 } u; 52 struct { 53 double d; 54 long L; 55 } x[2]; 56 57 if (sizeof(x) > 2*(sizeof(double) + sizeof(long))) 58 dalign = 1; 59 u.L[0] = u.L[1] = 0; 60 u.d = 1e13; 61 if (u.L[0] == 1117925532 && u.L[1] == -448790528) 62 return &IEEE_BIG_ENDIAN; 63 if (u.L[1] == 1117925532 && u.L[0] == -448790528) 64 return &IEEE_LITTLE_ENDIAN; 65 if (u.L[0] == -2065213935 && u.L[1] == 10752) 66 return &VAX; 67 if (u.L[0] == 1267827943 && u.L[1] == 704643072) 68 return &IBM; 69 return 0; 70 } 71 72 static Akind * 73 icheck() 74 { 75 union { 76 double d; 77 int L[2]; 78 } u; 79 struct { 80 double d; 81 int L; 82 } x[2]; 83 84 if (sizeof(x) > 2*(sizeof(double) + sizeof(int))) 85 dalign = 1; 86 u.L[0] = u.L[1] = 0; 87 u.d = 1e13; 88 if (u.L[0] == 1117925532 && u.L[1] == -448790528) 89 return &IEEE_BIG_ENDIAN; 90 if (u.L[1] == 1117925532 && u.L[0] == -448790528) 91 return &IEEE_LITTLE_ENDIAN; 92 if (u.L[0] == -2065213935 && u.L[1] == 10752) 93 return &VAX; 94 if (u.L[0] == 1267827943 && u.L[1] == 704643072) 95 return &IBM; 96 return 0; 97 } 98 99 char *emptyfmt = ""; /* avoid possible warning message with printf("") */ 100 101 static Akind * 102 ccheck() 103 { 104 union { 105 double d; 106 long L; 107 } u; 108 long Cray1; 109 110 /* Cray1 = 4617762693716115456 -- without overflow on non-Crays */ 111 Cray1 = printf(emptyfmt) < 0 ? 0 : 4617762; 112 if (printf(emptyfmt, Cray1) >= 0) 113 Cray1 = 1000000*Cray1 + 693716; 114 if (printf(emptyfmt, Cray1) >= 0) 115 Cray1 = 1000000*Cray1 + 115456; 116 u.d = 1e13; 117 if (u.L == Cray1) 118 return &CRAY; 119 return 0; 120 } 121 122 static int 123 fzcheck() 124 { 125 double a, b; 126 int i; 127 128 a = 1.; 129 b = .1; 130 for(i = 155;; b *= b, i >>= 1) { 131 if (i & 1) { 132 a *= b; 133 if (i == 1) 134 break; 135 } 136 } 137 b = a * a; 138 return b == 0.; 139 } 140 141 int 142 main() 143 { 144 Akind *a = 0; 145 int Ldef = 0; 146 FILE *f; 147 148 #ifdef WRITE_ARITH_H /* for Symantec's buggy "make" */ 149 f = fopen("arith.h", "w"); 150 if (!f) { 151 printf("Cannot open arith.h\n"); 152 return 1; 153 } 154 #else 155 f = stdout; 156 #endif 157 158 if (sizeof(double) == 2*sizeof(long)) 159 a = Lcheck(); 160 else if (sizeof(double) == 2*sizeof(int)) { 161 Ldef = 1; 162 a = icheck(); 163 } 164 else if (sizeof(double) == sizeof(long)) 165 a = ccheck(); 166 if (a) { 167 fprintf(f, "#define %s\n#define Arith_Kind_ASL %d\n", 168 a->name, a->kind); 169 if (Ldef) 170 fprintf(f, "#define Long int\n#define Intcast (int)(long)\n"); 171 if (dalign) 172 fprintf(f, "#define Double_Align\n"); 173 if (sizeof(char*) == 8) 174 fprintf(f, "#define X64_bit_pointers\n"); 175 #ifndef NO_LONG_LONG 176 if (sizeof(long long) < 8) 177 #endif 178 fprintf(f, "#define NO_LONG_LONG\n"); 179 if (a->kind <= 2 && fzcheck()) 180 fprintf(f, "#define Sudden_Underflow\n"); 181 #ifdef WRITE_ARITH_H 182 fclose(f); 183 #endif 184 return 0; 185 } 186 fprintf(f, "/* Unknown arithmetic */\n"); 187 #ifdef WRITE_ARITH_H 188 fclose(f); 189 #endif 190 return 1; 191 } 192