sysdeps/m68k/bits/huge_val.h

   1 /* `HUGE_VAL' constants for m68k (where it is infinity).
   2    Used by <stdlib.h> and <math.h> functions for overflow.
   3    Copyright (C) 1992, 1995, 1996, 1997, 1999, 2000 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 Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the 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    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _MATH_H
  22 # error "Never use <bits/huge_val.h> directly; include <math.h> instead."
  23 #endif
  24
  25
  26 #include <features.h>
  27 #include <sys/cdefs.h>
  28
  29 /* IEEE positive infinity (-HUGE_VAL is negative infinity).  */
  30
  31 #ifdef  __GNUC__
  32
  33 # if __GNUC_PREREQ(2,96)
  34
  35 #  define HUGE_VAL (__extension__ 0x1.0p2047)
  36
  37 # else
  38
  39 #  define HUGE_VAL                                      \
  40   (__extension__                                        \
  41    ((union { unsigned long long __l; double __d; })     \
  42     { __l: 0x7ff0000000000000ULL }).__d)
  43
  44 # endif
  45
  46 #else /* not GCC */
  47
  48 static union { unsigned char __c[8]; double __d; } __huge_val =
  49   { { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 } };
  50 # define HUGE_VAL       (__huge_val.__d)
  51
  52 #endif  /* GCC.  */
  53
  54
  55 /* ISO C 99 extensions: (float) HUGE_VALF and (long double) HUGE_VALL.  */
  56
  57 #ifdef __USE_ISOC99
  58
  59 # if __GNUC_PREREQ(2,96)
  60
  61 #  define HUGE_VALF (__extension__ 0x1.0p255f)
  62 #  define HUGE_VALL (__extension__ 0x1.0p32767L)
  63
  64 # else
  65
  66 #  ifdef __GNUC__
  67
  68 #   define HUGE_VALF                                    \
  69   (__extension__                                        \
  70    ((union { unsigned long __l; float __f; })           \
  71     { __l: 0x7f800000UL }).__f)
  72
  73 #   define HUGE_VALL                                    \
  74   (__extension__                                        \
  75    ((union { unsigned long __l[3]; long double __ld; }) \
  76     { __l: { 0x7fff0000UL, 0x80000000UL, 0UL } }).__ld)
  77
  78 #  else /* not GCC */
  79
  80 static union { unsigned char __c[4]; float __f; } __huge_valf =
  81   { { 0x7f, 0x80, 0, 0 } };
  82 #   define HUGE_VALF    (__huge_valf.__f)
  83
  84 static union { unsigned char __c[12]; long double __ld; } __huge_vall =
  85   { { 0x7f, 0xff, 0, 0, 0x80, 0, 0, 0, 0, 0, 0, 0 } };
  86 #   define HUGE_VALL    (__huge_vall.__ld)
  87
  88 #  endif /* GCC.  */
  89
  90 # endif /* GCC 2.95.  */
  91
  92 #endif  /* __USE_ISOC99.  */