sysdeps/arm/ieee754.h

   1 /* Copyright (C) 1992, 1995, 1996, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _IEEE754_H
  20
  21 #define _IEEE754_H 1
  22 #include <features.h>
  23
  24 #include <endian.h>
  25
  26 __BEGIN_DECLS
  27
  28 union ieee754_float
  29   {
  30     float f;
  31
  32     /* This is the IEEE 754 single-precision format.  */
  33     struct
  34       {
  35         unsigned int mantissa:23;
  36         unsigned int exponent:8;
  37         unsigned int negative:1;
  38       } ieee;
  39
  40     /* This format makes it easier to see if a NaN is a signalling NaN.  */
  41     struct
  42       {
  43         unsigned int mantissa:22;
  44         unsigned int quiet_nan:1;
  45         unsigned int exponent:8;
  46         unsigned int negative:1;
  47       } ieee_nan;
  48   };
  49
  50 #define IEEE754_FLOAT_BIAS      0x7f /* Added to exponent.  */
  51
  52
  53 union ieee754_double
  54   {
  55     double d;
  56
  57     /* This is the IEEE 754 double-precision format.  */
  58     struct
  59       {
  60         unsigned int mantissa0:20;
  61         unsigned int exponent:11;
  62         unsigned int negative:1;
  63         unsigned int mantissa1:32;
  64       } ieee;
  65
  66     /* This format makes it easier to see if a NaN is a signalling NaN.  */
  67     struct
  68       {
  69         unsigned int mantissa0:19;
  70         unsigned int quiet_nan:1;
  71         unsigned int exponent:11;
  72         unsigned int negative:1;
  73         unsigned int mantissa1:32;
  74       } ieee_nan;
  75   };
  76
  77 #define IEEE754_DOUBLE_BIAS     0x3ff /* Added to exponent.  */
  78
  79
  80 /* The following two structures are correct for `new' floating point systems but
  81    wrong for the old FPPC.  The only solution seems to be to avoid their use on
  82    old hardware.  */
  83
  84 union ieee854_long_double
  85   {
  86     long double d;
  87
  88     /* This is the IEEE 854 double-extended-precision format.  */
  89     struct
  90       {
  91         unsigned int exponent:15;
  92         unsigned int empty:16;
  93         unsigned int negative:1;
  94         unsigned int mantissa1:32;
  95         unsigned int mantissa0:32;
  96       } ieee;
  97
  98     /* This is for NaNs in the IEEE 854 double-extended-precision format.  */
  99     struct
 100       {
 101         unsigned int exponent:15;
 102         unsigned int empty:16;
 103         unsigned int negative:1;
 104         unsigned int mantissa1:32;
 105         unsigned int mantissa0:30;
 106         unsigned int quiet_nan:1;
 107         unsigned int one:1;
 108       } ieee_nan;
 109   };
 110
 111 #define IEEE854_LONG_DOUBLE_BIAS 0x3fff
 112
 113 __END_DECLS
 114
 115 #endif /* ieee754.h */