sysdeps/powerpc/fpu/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 1997-2013 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv_libc.h>
  20 #include <fpu_control.h>
  21 #include <bp-sym.h>
  22
  23 #define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM)
  24
  25 int
  26 __fesetenv (const fenv_t *envp)
  27 {
  28   fenv_union_t old, new;
  29
  30   /* get the currently set exceptions.  */
  31   new.fenv = *envp;
  32   old.fenv = fegetenv_register ();
  33
  34   /* If the old env has no enabled exceptions and the new env has any enabled
  35      exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits.  This will put the
  36      hardware into "precise mode" and may cause the FPU to run slower on some
  37      hardware.  */
  38   if ((old.l[1] & _FPU_MASK_ALL) == 0 && (new.l[1] & _FPU_MASK_ALL) != 0)
  39     (void)__fe_nomask_env ();
  40
  41   /* If the old env had any enabled exceptions and the new env has no enabled
  42      exceptions, then mask SIGFPE in the MSR FE0/FE1 bits.  This may allow the
  43      FPU to run faster because it always takes the default action and can not
  44      generate SIGFPE. */
  45   if ((old.l[1] & _FPU_MASK_ALL) != 0 && (new.l[1] & _FPU_MASK_ALL) == 0)
  46     (void)__fe_mask_env ();
  47
  48   fesetenv_register (*envp);
  49
  50   /* Success.  */
  51   return 0;
  52 }
  53
  54 #include <shlib-compat.h>
  55 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  56 strong_alias (__fesetenv, __old_fesetenv)
  57 compat_symbol (libm, BP_SYM (__old_fesetenv), BP_SYM (fesetenv), GLIBC_2_1);
  58 #endif
  59
  60 libm_hidden_ver (__fesetenv, fesetenv)
  61 versioned_symbol (libm, BP_SYM (__fesetenv), BP_SYM (fesetenv), GLIBC_2_2);