S390: Optimize wmemset.
[glibc.git] / sysdeps / powerpc / fpu / feupdateenv.c
blob1e0db9e3c10135c884d31ed77fb4b5d9296e1d83
1 /* Install given floating-point environment and raise exceptions.
2 Copyright (C) 1997-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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.
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.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
20 #include <fenv_libc.h>
21 #include <fpu_control.h>
23 #define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM)
25 int
26 __feupdateenv (const fenv_t *envp)
28 fenv_union_t old, new;
30 /* Save the currently set exceptions. */
31 new.fenv = *envp;
32 old.fenv = fegetenv_register ();
34 /* Restore rounding mode and exception enable from *envp and merge
35 exceptions. Leave fraction rounded/inexact and FP result/CC bits
36 unchanged. */
37 new.l = (old.l & 0xffffffff1fffff00LL) | (new.l & 0x1ff80fff);
39 /* If the old env has no enabled exceptions and the new env has any enabled
40 exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits. This will put
41 the hardware into "precise mode" and may cause the FPU to run slower on
42 some hardware. */
43 if ((old.l & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0)
44 (void) __fe_nomask_env_priv ();
46 /* If the old env had any enabled exceptions and the new env has no enabled
47 exceptions, then mask SIGFPE in the MSR FE0/FE1 bits. This may allow the
48 FPU to run faster because it always takes the default action and can not
49 generate SIGFPE. */
50 if ((old.l & _FPU_MASK_ALL) != 0 && (new.l & _FPU_MASK_ALL) == 0)
51 (void)__fe_mask_env ();
53 /* Atomically enable and raise (if appropriate) exceptions set in `new'. */
54 fesetenv_register (new.fenv);
56 /* Success. */
57 return 0;
60 #include <shlib-compat.h>
61 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
62 strong_alias (__feupdateenv, __old_feupdateenv)
63 compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1);
64 #endif
66 libm_hidden_def (__feupdateenv)
67 libm_hidden_ver (__feupdateenv, feupdateenv)
68 versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);