sysdeps/hppa/fpu/feholdexcpt.c

   1 /* Store current floating-point environment and clear exceptions.
   2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20 #include <string.h>
  21
  22 int
  23 __feholdexcept (fenv_t *envp)
  24 {
  25   union { unsigned long long buf[4]; fenv_t env; } clear;
  26   unsigned long long *bufptr;
  27
  28   /* Store the environment.  */
  29   bufptr = clear.buf;
  30   __asm__ (
  31            "fstd %%fr0,0(%1)\n"
  32            : "=m" (clear) : "r" (bufptr) : "%r0");
  33   memcpy (envp, &clear.env, sizeof (fenv_t));
  34
  35   /* Clear exception queues */
  36   memset (clear.env.__exception, 0, sizeof (clear.env.__exception));
  37   /* And set all exceptions to non-stop.  */
  38   clear.env.__status_word &= ~FE_ALL_EXCEPT;
  39   /* Now clear all flags  */
  40   clear.env.__status_word &= ~(FE_ALL_EXCEPT << 27);
  41
  42   /* Load the new environment. Note: fr0 must load last to enable T-bit.  */
  43   __asm__ (
  44            "fldd 0(%0),%%fr0\n"
  45            : : "r" (bufptr), "m" (clear) : "%r0");
  46
  47   return 0;
  48 }
  49
  50 libm_hidden_def (__feholdexcept)
  51 weak_alias (__feholdexcept, feholdexcept)
  52 libm_hidden_weak (feholdexcept)