diff options
Diffstat (limited to 'sysdeps/i386/fpu/fesetenv.c')
-rw-r--r-- | sysdeps/i386/fpu/fesetenv.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/fesetenv.c b/sysdeps/i386/fpu/fesetenv.c new file mode 100644 index 0000000000..e7300ea1e6 --- /dev/null +++ b/sysdeps/i386/fpu/fesetenv.c @@ -0,0 +1,76 @@ +/* Install given floating-point environment. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <fenv.h> + +#include <assert.h> + + +void +fesetenv (const fenv_t *envp) +{ + fenv_t temp; + + /* The memory block used by fstenv/fldenv has a size of 28 bytes. */ + assert (sizeof (fenv_t) == 28); + + /* Install the environment specified by ENVP. But there are a few + values which we do not want to come from the saved environment. + Therefore, we get the current environment and replace the values + we want to use from the environment specified by the parameter. */ + __asm__ ("fnstenv %0" : "=m" (*&temp)); + + if (envp == FE_DFL_ENV) + { + temp.control_word |= FE_ALL_EXCEPT; + temp.control_word &= ~FE_TOWARDSZERO; + temp.status_word &= ~FE_ALL_EXCEPT; + temp.eip = 0; + temp.cs_selector = 0; + temp.opcode = 0; + temp.data_offset = 0; + temp.data_selector = 0; + } + else if (envp == FE_NOMASK_ENV) + { + temp.control_word &= ~(FE_ALL_EXCEPT | FE_TOWARDSZERO); + temp.status_word &= ~FE_ALL_EXCEPT; + temp.eip = 0; + temp.cs_selector = 0; + temp.opcode = 0; + temp.data_offset = 0; + temp.data_selector = 0; + } + else + { + temp.control_word &= ~(FE_ALL_EXCEPT | FE_TOWARDSZERO); + temp.control_word |= (envp->control_word + & (FE_ALL_EXCEPT | FE_TOWARDSZERO)); + temp.status_word &= ~FE_ALL_EXCEPT; + temp.status_word |= envp->status_word & FE_ALL_EXCEPT; + temp.eip = envp->eip; + temp.cs_selector = envp->cs_selector; + temp.opcode = envp->opcode; + temp.data_offset = envp->data_offset; + temp.data_selector = envp->data_selector; + } + + __asm__ ("fldenv %0" : : "m" (temp)); +} |