sysdeps/powerpc/powerpc32/e500/nofpu/atomic-feclearexcept.c

   1 /* Clear floating-point exceptions for atomic compound assignment.
   2    e500 version.
   3    Copyright (C) 2004-2015 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <fenv_libc.h>
  21 #include <stdlib.h>
  22 #include <sysdep.h>
  23 #include <sys/prctl.h>
  24
  25 void
  26 __atomic_feclearexcept (void)
  27 {
  28   unsigned int fpescr, old_fpescr;
  29
  30   /* Get the current state.  */
  31   old_fpescr = fpescr = fegetenv_register ();
  32
  33   /* Clear the relevant bits.  */
  34   fpescr &= ~SPEFSCR_ALL_EXCEPT;
  35
  36   /* Put the new state in effect.  */
  37   fesetenv_register (fpescr);
  38
  39   /* Let the kernel know if the "invalid" or "underflow" bit was
  40      cleared.  */
  41   if (old_fpescr & (SPEFSCR_FINVS | SPEFSCR_FUNFS))
  42     {
  43       int pflags __attribute__ ((__unused__)), r;
  44       INTERNAL_SYSCALL_DECL (err);
  45
  46       r = INTERNAL_SYSCALL (prctl, err, 2, PR_GET_FPEXC, &pflags);
  47       if (INTERNAL_SYSCALL_ERROR_P (r, err))
  48         abort ();
  49     }
  50 }