newlib/libc/stdio/vfieeefp.h

   1 /****************************************************************
   2  *
   3  * The author of this software is David M. Gay.
   4  *
   5  * Copyright (c) 1991 by AT&T.
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose without fee is hereby granted, provided that this entire notice
   9  * is included in all copies of any software which is or includes a copy
  10  * or modification of this software and in all copies of the supporting
  11  * documentation for such software.
  12  *
  13  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
  14  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY
  15  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
  16  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
  17  *
  18  ***************************************************************/
  19
  20 /* Please send bug reports to
  21         David M. Gay
  22         AT&T Bell Laboratories, Room 2C-463
  23         600 Mountain Avenue
  24         Murray Hill, NJ 07974-2070
  25         U.S.A.
  26         dmg@research.att.com or research!dmg
  27  */
  28
  29 /* This header file is a modification of mprec.h that only contains floating
  30    point union code. */
  31
  32 #include <newlib.h>
  33 #include <ieeefp.h>
  34 #include <math.h>
  35 #include <float.h>
  36 #include <errno.h>
  37 #include <sys/config.h>
  38 #include <sys/cdefs.h>
  39
  40 #ifdef __IEEE_LITTLE_ENDIAN
  41 #define IEEE_8087
  42 #endif
  43
  44 #ifdef __IEEE_BIG_ENDIAN
  45 #define IEEE_MC68k
  46 #endif
  47
  48 #ifdef __Z8000__
  49 #define Just_16
  50 #endif
  51
  52 #ifdef Unsigned_Shifts
  53 #define Sign_Extend(a,b) if (b < 0) a |= (__uint32_t)0xffff0000;
  54 #else
  55 #define Sign_Extend(a,b) /*no-op*/
  56 #endif
  57
  58 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
  59 Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
  60 #endif
  61
  62 #ifdef _WANT_IO_LONG_DOUBLE
  63 /* If we are going to examine or modify specific bits in a long double using
  64    the lword0 or lwordx macros, then we must wrap the long double inside
  65    a union.  This is necessary to avoid undefined behavior according to
  66    the ANSI C spec.  */
  67
  68 #ifdef IEEE_8087
  69 #if LDBL_MANT_DIG == 24
  70 struct ldieee
  71 {
  72   unsigned manh:23;
  73   unsigned exp:8;
  74   unsigned sign:1;
  75 } __packed;
  76 #elif LDBL_MANT_DIG == 53
  77 struct ldieee
  78 {
  79   unsigned manl:20;
  80   unsigned manh:32;
  81   unsigned exp:11;
  82   unsigned sign:1;
  83 } __packed;
  84 #elif LDBL_MANT_DIG == 64
  85 struct ldieee
  86 {
  87   unsigned manl:32;
  88   unsigned manh:32;
  89   unsigned exp:15;
  90   unsigned sign:1;
  91 } __packed;
  92 #elif LDBL_MANT_DIG > 64
  93 struct ldieee
  94 {
  95   unsigned manl3:16;
  96   unsigned manl2:32;
  97   unsigned manl:32;
  98   unsigned manh:32;
  99   unsigned exp:15;
 100   unsigned sign:1;
 101 } __packed;
 102 #endif /* LDBL_MANT_DIG */
 103 #else  /* !IEEE_8087 */
 104 #if LDBL_MANT_DIG == 24
 105 struct ldieee
 106 {
 107   unsigned sign:1;
 108   unsigned exp:8;
 109   unsigned manh:23;
 110 } __packed;
 111 #elif LDBL_MANT_DIG == 53
 112 struct ldieee
 113 {
 114   unsigned sign:1;
 115   unsigned exp:11;
 116   unsigned manh:32;
 117   unsigned manl:20;
 118 } __packed;
 119 #elif LDBL_MANT_DIG == 64
 120 struct ldieee
 121 {
 122   unsigned sign:1;
 123   unsigned exp:15;
 124   unsigned manh:32;
 125   unsigned manl:32;
 126 } __packed;
 127 #elif LDBL_MANT_DIG > 64
 128 struct ldieee
 129 {
 130   unsigned sign:1;
 131   unsigned exp:15;
 132   unsigned manh:32;
 133   unsigned manl:32;
 134   unsigned manl2:32;
 135   unsigned manl3:16;
 136 } __packed;
 137 #endif /* LDBL_MANT_DIG */
 138 #endif /* !IEEE_8087 */
 139 #endif /* _WANT_IO_LONG_DOUBLE */
 140
 141 /* If we are going to examine or modify specific bits in a double using
 142    the word0 and/or word1 macros, then we must wrap the double inside
 143    a union.  This is necessary to avoid undefined behavior according to
 144    the ANSI C spec.  */
 145 union double_union
 146 {
 147   double d;
 148   __uint32_t i[2];
 149 };
 150
 151 #ifdef IEEE_8087
 152 #define word0(x) (x.i[1])
 153 #define word1(x) (x.i[0])
 154 #else
 155 #define word0(x) (x.i[0])
 156 #define word1(x) (x.i[1])
 157 #endif
 158
 159 /* #define P DBL_MANT_DIG */
 160 /* Ten_pmax = floor(P*log(2)/log(5)) */
 161 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
 162 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
 163 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
 164
 165 #if defined(IEEE_8087) + defined(IEEE_MC68k)
 166 #if defined (_DOUBLE_IS_32BITS)
 167 #define Exp_shift   23
 168 #define Exp_shift1  23
 169 #define Exp_msk1    ((__uint32_t)0x00800000L)
 170 #define Exp_msk11   ((__uint32_t)0x00800000L)
 171 #define Exp_mask    ((__uint32_t)0x7f800000L)
 172 #define P           24
 173 #define Bias        127
 174 #define IEEE_Arith
 175 #define Emin        (-126)
 176 #define Exp_1       ((__uint32_t)0x3f800000L)
 177 #define Exp_11      ((__uint32_t)0x3f800000L)
 178 #define Ebits       8
 179 #define Frac_mask   ((__uint32_t)0x007fffffL)
 180 #define Frac_mask1  ((__uint32_t)0x007fffffL)
 181 #define Ten_pmax    10
 182 #define Sign_bit    ((__uint32_t)0x80000000L)
 183 #define Ten_pmax    10
 184 #define Bletch      2
 185 #define Bndry_mask  ((__uint32_t)0x007fffffL)
 186 #define Bndry_mask1 ((__uint32_t)0x007fffffL)
 187 #define LSB 1
 188 #define Sign_bit    ((__uint32_t)0x80000000L)
 189 #define Log2P       1
 190 #define Tiny0       0
 191 #define Tiny1       1
 192 #define Quick_max   5
 193 #define Int_max     6
 194 #define Infinite(x) (word0(x) == ((__uint32_t)0x7f800000L))
 195 #undef word0
 196 #undef word1
 197
 198 #define word0(x) (x.i[0])
 199 #define word1(x) 0
 200 #else
 201
 202 #define Exp_shift  20
 203 #define Exp_shift1 20
 204 #define Exp_msk1    ((__uint32_t)0x100000L)
 205 #define Exp_msk11   ((__uint32_t)0x100000L)
 206 #define Exp_mask  ((__uint32_t)0x7ff00000L)
 207 #define P 53
 208 #define Bias 1023
 209 #define IEEE_Arith
 210 #define Emin (-1022)
 211 #define Exp_1  ((__uint32_t)0x3ff00000L)
 212 #define Exp_11 ((__uint32_t)0x3ff00000L)
 213 #define Ebits 11
 214 #define Frac_mask  ((__uint32_t)0xfffffL)
 215 #define Frac_mask1 ((__uint32_t)0xfffffL)
 216 #define Ten_pmax 22
 217 #define Bletch 0x10
 218 #define Bndry_mask  ((__uint32_t)0xfffffL)
 219 #define Bndry_mask1 ((__uint32_t)0xfffffL)
 220 #define LSB 1
 221 #define Sign_bit ((__uint32_t)0x80000000L)
 222 #define Log2P 1
 223 #define Tiny0 0
 224 #define Tiny1 1
 225 #define Quick_max 14
 226 #define Int_max 14
 227 #define Infinite(x) (word0(x) == ((__uint32_t)0x7ff00000L)) /* sufficient test for here */
 228 #endif
 229
 230 #else
 231 #undef  Sudden_Underflow
 232 #define Sudden_Underflow
 233 #ifdef IBM
 234 #define Exp_shift  24
 235 #define Exp_shift1 24
 236 #define Exp_msk1   ((__uint32_t)0x1000000L)
 237 #define Exp_msk11  ((__uint32_t)0x1000000L)
 238 #define Exp_mask  ((__uint32_t)0x7f000000L)
 239 #define P 14
 240 #define Bias 65
 241 #define Exp_1  ((__uint32_t)0x41000000L)
 242 #define Exp_11 ((__uint32_t)0x41000000L)
 243 #define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
 244 #define Frac_mask  ((__uint32_t)0xffffffL)
 245 #define Frac_mask1 ((__uint32_t)0xffffffL)
 246 #define Bletch 4
 247 #define Ten_pmax 22
 248 #define Bndry_mask  ((__uint32_t)0xefffffL)
 249 #define Bndry_mask1 ((__uint32_t)0xffffffL)
 250 #define LSB 1
 251 #define Sign_bit ((__uint32_t)0x80000000L)
 252 #define Log2P 4
 253 #define Tiny0 ((__uint32_t)0x100000L)
 254 #define Tiny1 0
 255 #define Quick_max 14
 256 #define Int_max 15
 257 #else /* VAX */
 258 #define Exp_shift  23
 259 #define Exp_shift1 7
 260 #define Exp_msk1    0x80
 261 #define Exp_msk11   ((__uint32_t)0x800000L)
 262 #define Exp_mask  ((__uint32_t)0x7f80L)
 263 #define P 56
 264 #define Bias 129
 265 #define Exp_1  ((__uint32_t)0x40800000L)
 266 #define Exp_11 ((__uint32_t)0x4080L)
 267 #define Ebits 8
 268 #define Frac_mask  ((__uint32_t)0x7fffffL)
 269 #define Frac_mask1 ((__uint32_t)0xffff007fL)
 270 #define Ten_pmax 24
 271 #define Bletch 2
 272 #define Bndry_mask  ((__uint32_t)0xffff007fL)
 273 #define Bndry_mask1 ((__uint32_t)0xffff007fL)
 274 #define LSB ((__uint32_t)0x10000L)
 275 #define Sign_bit ((__uint32_t)0x8000L)
 276 #define Log2P 1
 277 #define Tiny0 0x80
 278 #define Tiny1 0
 279 #define Quick_max 15
 280 #define Int_max 15
 281 #endif
 282 #endif
 283
 284