sysdeps/i386/huge_val.h

   1 /* `HUGE_VAL' constants for ix86 (where it is infinity).
   2    Used by <stdlib.h> and <math.h> functions for overflow.
   3    Copyright (C) 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef    _HUGE_VAL_H
  22 #define    _HUGE_VAL_H  1
  23
  24 #include <features.h>
  25 #include <sys/cdefs.h>
  26
  27 /* IEEE positive infinity (-HUGE_VAL is negative infinity).  */
  28
  29 #define __HUGE_VAL_bytes        { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }
  30
  31 #define __huge_val_t    union { unsigned char __c[8]; double __d; }
  32 #ifdef  __GNUC__
  33 #define HUGE_VAL        (__extension__ \
  34                          ((__huge_val_t) { __c: __HUGE_VAL_bytes }).__d)
  35 #else   /* Not GCC.  */
  36 static __huge_val_t __huge_val = { __HUGE_VAL_bytes };
  37 #define HUGE_VAL        (__huge_val.__d)
  38 #endif  /* GCC.  */
  39
  40
  41 /* ISO C 9X extensions: (float) HUGE_VALF and (long double) HUGE_VALL.  */
  42
  43 #ifdef __USE_ISOC9X
  44
  45 #define __HUGE_VALF_bytes       { 0, 0, 0x80, 0x7f }
  46
  47 #define __huge_valf_t   union { unsigned char __c[4]; float __f; }
  48 #ifdef  __GNUC__
  49 #define HUGE_VALF       (__extension__ \
  50                          ((__huge_valf_t) { __c: __HUGE_VALF_bytes }).__f)
  51 #else   /* Not GCC.  */
  52 static __huge_valf_t __huge_valf = { __HUGE_VALF_bytes };
  53 #define HUGE_VALF       (__huge_valf.__f)
  54 #endif  /* GCC.  */
  55
  56
  57 #define __HUGE_VALL_bytes       { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0x7f, 0, 0 }
  58
  59 #define __huge_vall_t   union { unsigned char __c[12]; long double __ld; }
  60 #ifdef  __GNUC__
  61 #define HUGE_VALL       (__extension__ \
  62                          ((__huge_vall_t) { __c: __HUGE_VALL_bytes }).__ld)
  63 #else   /* Not GCC.  */
  64 static __huge_vall_t __huge_vall = { __HUGE_VALL_bytes };
  65 #define HUGE_VALL       (__huge_vall.__ld)
  66 #endif  /* GCC.  */
  67
  68 #endif  /* __USE_ISOC9X.  */
  69
  70 #endif     /* huge_val.h */