sysdeps/powerpc/powerpc32/e500/nofpu/feholdexcpt.c

   1 /* Store current floating-point environment and clear exceptions.
   2    e500 version.
   3    Copyright (C) 2004-2014 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 <sysdep.h>
  22 #include <sys/prctl.h>
  23
  24 int
  25 feholdexcept (fenv_t *envp)
  26 {
  27   fenv_union_t u;
  28   INTERNAL_SYSCALL_DECL (err);
  29   int r;
  30
  31   /* Get the current state.  */
  32   r = INTERNAL_SYSCALL (prctl, err, 2, PR_GET_FPEXC, &u.l[0]);
  33   if (INTERNAL_SYSCALL_ERROR_P (r, err))
  34     return -1;
  35
  36   u.l[1] = fegetenv_register ();
  37   *envp = u.fenv;
  38
  39   /* Clear everything except for the rounding mode and trapping to the
  40      kernel.  */
  41   u.l[0] &= ~(PR_FP_EXC_DIV
  42               | PR_FP_EXC_OVF
  43               | PR_FP_EXC_UND
  44               | PR_FP_EXC_RES
  45               | PR_FP_EXC_INV);
  46   u.l[1] &= SPEFSCR_FRMC | (SPEFSCR_ALL_EXCEPT_ENABLE & ~SPEFSCR_FINXE);
  47
  48   /* Put the new state in effect.  */
  49   fesetenv_register (u.l[1]);
  50   r = INTERNAL_SYSCALL (prctl, err, 2, PR_SET_FPEXC,
  51                         u.l[0] | PR_FP_EXC_SW_ENABLE);
  52   if (INTERNAL_SYSCALL_ERROR_P (r, err))
  53     return -1;
  54
  55   return 0;
  56 }
  57 libm_hidden_def (feholdexcept)