sysdeps/powerpc/fpu/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 1997,99,2000,01,02,07 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <fenv_libc.h>
  21 #include <bp-sym.h>
  22
  23 int
  24 __fesetenv (const fenv_t *envp)
  25 {
  26   fenv_union_t old, new;
  27
  28   /* get the currently set exceptions.  */
  29   new.fenv = *envp;
  30   old.fenv = fegetenv_register ();
  31
  32   /* If the old env has no eabled exceptions and the new env has any enabled
  33      exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits.  This will put
  34      the hardware into "precise mode" and may cause the FPU to run slower on
  35      some hardware.  */
  36   if ((old.l[1] & 0x000000F8) == 0 && (new.l[1] & 0x000000F8) != 0)
  37     (void)__fe_nomask_env ();
  38
  39   /* If the old env had any eabled exceptions and the new env has no enabled
  40      exceptions, then mask SIGFPE in the MSR FE0/FE1 bits.  This may allow the
  41      FPU to run faster because it always takes the default action and can not
  42      generate SIGFPE. */
  43   if ((old.l[1] & 0x000000F8) != 0 && (new.l[1] & 0x000000F8) == 0)
  44     (void)__fe_mask_env ();
  45
  46   fesetenv_register (*envp);
  47
  48   /* Success.  */
  49   return 0;
  50 }
  51
  52 #include <shlib-compat.h>
  53 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  54 strong_alias (__fesetenv, __old_fesetenv)
  55 compat_symbol (libm, BP_SYM (__old_fesetenv), BP_SYM (fesetenv), GLIBC_2_1);
  56 #endif
  57
  58 libm_hidden_ver (__fesetenv, fesetenv)
  59 versioned_symbol (libm, BP_SYM (__fesetenv), BP_SYM (fesetenv), GLIBC_2_2);