glibc/sysdeps/powerpc/fpu/fsetexcptflg.c
Adhemerval Zanella 18f2945ae9 PowerPC: Suppress unnecessary FPSCR write
This patch optimizes the FPSCR update on exception and rounding change
functions by just updating its value if new value if different from
current one.  It also optimizes fedisableexcept and feenableexcept by
removing an unecessary FPSCR read.
2014-04-29 07:05:39 -05:00

60 lines
1.9 KiB
C

/* Set floating-point environment exception handling.
Copyright (C) 1997-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <fenv_libc.h>
int
__fesetexceptflag (const fexcept_t *flagp, int excepts)
{
fenv_union_t u, n;
fexcept_t flag;
/* Get the current state. */
u.fenv = fegetenv_register ();
/* Ignore exceptions not listed in 'excepts'. */
flag = *flagp & excepts;
/* Replace the exception status */
n.l = ((u.l & ~(FPSCR_STICKY_BITS & excepts))
| (flag & FPSCR_STICKY_BITS)
| (flag >> ((31 - FPSCR_VX) - (31 - FPSCR_VXSOFT))
& FE_INVALID_SOFTWARE));
/* Store the new status word (along with the rest of the environment).
This may cause floating-point exceptions if the restored state
requests it. */
if (n.l != u.l)
fesetenv_register (u.fenv);
/* Deal with FE_INVALID_SOFTWARE not being implemented on some chips. */
if (flag & FE_INVALID)
feraiseexcept(FE_INVALID);
/* Success. */
return 0;
}
#include <shlib-compat.h>
#if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
strong_alias (__fesetexceptflag, __old_fesetexceptflag)
compat_symbol (libm, __old_fesetexceptflag, fesetexceptflag, GLIBC_2_1);
#endif
versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);