fegetenv.c

Glibc 2.3.2源代码(解压后有100多M)

/* Store current floating-point environment.
   Copyright (C) 1997,99,2000,01 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson <[e-mail]>, 1997

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <fenv_libc.h>

int
__fegetenv (fenv_t *envp)
{
  unsigned long int fpcr;
  unsigned long int swcr;

  /* Get status from software and hardware.  Note that we don't need an
     excb because the callsys is an implied trap barrier.  */
  swcr = __ieee_get_fp_control ();
  __asm__ __volatile__ ("mf_fpcr %0" : "=f" (fpcr));

  /* Merge the two bits of information.  */
  *envp = ((fpcr & FPCR_ROUND_MASK) | (swcr & SWCR_ALL_MASK));

  /* Success.  */
  return 0;
}

#include <shlib-compat.h>
#if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
strong_alias (__fegetenv, __old_fegetenv)
compat_symbol (libm, __old_fegetenv, fegetenv, GLIBC_2_1);
#endif

versioned_symbol (libm, __fegetenv, fegetenv, GLIBC_2_2);