sysdeps/powerpc/fpu/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 1997, 1999, 2000, 2001, 2007, 2008
   3    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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <fenv_libc.h>
  22 #include <fpu_control.h>
  23 #include <bp-sym.h>
  24
  25 #define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM)
  26
  27 int
  28 __fesetenv (const fenv_t *envp)
  29 {
  30   fenv_union_t old, new;
  31
  32   /* get the currently set exceptions.  */
  33   new.fenv = *envp;
  34   old.fenv = fegetenv_register ();
  35
  36   /* If the old env has no enabled exceptions and the new env has any enabled
  37      exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits.  This will put the
  38      hardware into "precise mode" and may cause the FPU to run slower on some
  39      hardware.  */
  40   if ((old.l[1] & _FPU_MASK_ALL) == 0 && (new.l[1] & _FPU_MASK_ALL) != 0)
  41     (void)__fe_nomask_env ();
  42
  43   /* If the old env had any enabled exceptions and the new env has no enabled
  44      exceptions, then mask SIGFPE in the MSR FE0/FE1 bits.  This may allow the
  45      FPU to run faster because it always takes the default action and can not
  46      generate SIGFPE. */
  47   if ((old.l[1] & _FPU_MASK_ALL) != 0 && (new.l[1] & _FPU_MASK_ALL) == 0)
  48     (void)__fe_mask_env ();
  49
  50   fesetenv_register (*envp);
  51
  52   /* Success.  */
  53   return 0;
  54 }
  55
  56 #include <shlib-compat.h>
  57 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  58 strong_alias (__fesetenv, __old_fesetenv)
  59 compat_symbol (libm, BP_SYM (__old_fesetenv), BP_SYM (fesetenv), GLIBC_2_1);
  60 #endif
  61
  62 libm_hidden_ver (__fesetenv, fesetenv)
  63 versioned_symbol (libm, BP_SYM (__fesetenv), BP_SYM (fesetenv), GLIBC_2_2);