sysdeps/m68k/bits/huge_vall.h

   1 /* `HUGE_VALL' constant 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, 2004
   4    Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #ifndef _MATH_H
  23 # error "Never use <bits/huge_val.h> directly; include <math.h> instead."
  24 #endif
  25
  26 #if __GNUC_PREREQ(3,3)
  27 # define HUGE_VALL      (__builtin_huge_vall ())
  28 #elif __GNUC_PREREQ(2,96)
  29 # define HUGE_VALL      (__extension__ 0x1.0p32767L)
  30 #elif defined__GNUC__
  31
  32 # define HUGE_VALL                                      \
  33   (__extension__                                        \
  34    ((union { unsigned long __l[3]; long double __ld; }) \
  35     { __l: { 0x7fff0000UL, 0x80000000UL, 0UL } }).__ld)
  36
  37 #else /* not GCC */
  38
  39 static union { unsigned char __c[12]; long double __ld; } __huge_vall =
  40   { { 0x7f, 0xff, 0, 0, 0x80, 0, 0, 0, 0, 0, 0, 0 } };
  41 # define HUGE_VALL      (__huge_vall.__ld)
  42
  43 #endif /* GCC 2.95.  */