sysdeps/hppa/fpu/feholdexcpt.c

   1 /* Store current floating-point environment and clear exceptions.
   2    Copyright (C) 2000-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by David Huggins-Daines <dhd@debian.org>, 2000
   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.h>
  21 #include <string.h>
  22
  23 int
  24 __feholdexcept (fenv_t *envp)
  25 {
  26   union { unsigned long long buf[4]; fenv_t env; } clear;
  27   unsigned long long *bufptr;
  28
  29   /* Store the environment.  */
  30   bufptr = clear.buf;
  31   __asm__ (
  32            "fstd %%fr0,0(%1)\n"
  33            : "=m" (clear) : "r" (bufptr) : "%r0");
  34   memcpy (envp, &clear.env, sizeof (fenv_t));
  35
  36   /* Clear exception queues */
  37   memset (clear.env.__exception, 0, sizeof (clear.env.__exception));
  38   /* And set all exceptions to non-stop.  */
  39   clear.env.__status_word &= ~FE_ALL_EXCEPT;
  40   /* Now clear all flags  */
  41   clear.env.__status_word &= ~(FE_ALL_EXCEPT << 27);
  42
  43   /* Load the new environment. Note: fr0 must load last to enable T-bit.  */
  44   __asm__ (
  45            "fldd 0(%0),%%fr0\n"
  46            : : "r" (bufptr), "m" (clear) : "%r0");
  47
  48   return 0;
  49 }
  50
  51 libm_hidden_def (__feholdexcept)
  52 weak_alias (__feholdexcept, feholdexcept)
  53 libm_hidden_weak (feholdexcept)