sysdeps/m68k/m680x0/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, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef _MATH_H
  22 # error "Never use <bits/huge_val.h> directly; include <math.h> instead."
  23 #endif
  24
  25 #if __GNUC_PREREQ(3,3)
  26 # define HUGE_VALL      (__builtin_huge_vall ())
  27 #elif __GNUC_PREREQ(2,96)
  28 # define HUGE_VALL      (__extension__ 0x1.0p32767L)
  29 #elif defined__GNUC__
  30
  31 # define HUGE_VALL                                      \
  32   (__extension__                                        \
  33    ((union { unsigned long __l[3]; long double __ld; }) \
  34     { __l: { 0x7fff0000UL, 0x80000000UL, 0UL } }).__ld)
  35
  36 #else /* not GCC */
  37
  38 static union { unsigned char __c[12]; long double __ld; } __huge_vall =
  39   { { 0x7f, 0xff, 0, 0, 0x80, 0, 0, 0, 0, 0, 0, 0 } };
  40 # define HUGE_VALL      (__huge_vall.__ld)
  41
  42 #endif /* GCC 2.95.  */