fpu-glibc.h

gcc-fortran,linux使用fortran的编译软件。很好用的。

/* FPU-related code for systems with GNU libc.
   Copyright 2005 Free Software Foundation, Inc.
   Contributed by Francois-Xavier Coudert <[e-mail]>

This file is part of the GNU Fortran 95 runtime library (libgfortran).

Libgfortran is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

Libgfortran is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public
License along with libgfortran; see the file COPYING.  If not,
write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */


/* FPU-related code for systems with the GNU libc, providing the
   feenableexcept function in fenv.h to set individual exceptions
   (there's nothing to do that in C99).  */

#ifdef HAVE_FENV_H
#include <fenv.h>
#endif

void set_fpu (void)
{
  if (FE_ALL_EXCEPT != 0)
    fedisableexcept (FE_ALL_EXCEPT);

  if (options.fpe & GFC_FPE_INVALID)
#ifdef FE_INVALID
    feenableexcept (FE_INVALID);
#else
    st_printf ("Fortran runtime warning: IEEE 'invalid operation' "
	       "exception not supported.\n");
#endif

/* glibc does never have a FE_DENORMAL.  */
  if (options.fpe & GFC_FPE_DENORMAL)
#ifdef FE_DENORMAL
    feenableexcept (FE_DENORMAL);
#else
    st_printf ("Fortran runtime warning: IEEE 'denormal number' "
	       "exception not supported.\n");
#endif

  if (options.fpe & GFC_FPE_ZERO)
#ifdef FE_DIVBYZERO
    feenableexcept (FE_DIVBYZERO);
#else
    st_printf ("Fortran runtime warning: IEEE 'division by zero' "
	       "exception not supported.\n");
#endif

  if (options.fpe & GFC_FPE_OVERFLOW)
#ifdef FE_OVERFLOW
    feenableexcept (FE_OVERFLOW);
#else
    st_printf ("Fortran runtime warning: IEEE 'overflow' "
	       "exception not supported.\n");
#endif

  if (options.fpe & GFC_FPE_UNDERFLOW)
#ifdef FE_UNDERFLOW
    feenableexcept (FE_UNDERFLOW);
#else
    st_printf ("Fortran runtime warning: IEEE 'underflow' "
	       "exception not supported.\n");
#endif

  if (options.fpe & GFC_FPE_PRECISION)
#ifdef FE_INEXACT
    feenableexcept (FE_INEXACT);
#else
    st_printf ("Fortran runtime warning: IEEE 'loss of precision' "
	       "exception not supported.\n");
#endif
}