mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 00:31:08 +00:00
115 lines
3.8 KiB
C
115 lines
3.8 KiB
C
/* Install given floating-point environment.
|
|
Copyright (C) 2001-2016 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.h>
|
|
#include <fpu_control.h>
|
|
#include <assert.h>
|
|
|
|
|
|
/* All exceptions, including the x86-specific "denormal operand"
|
|
exception. */
|
|
#define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM)
|
|
|
|
|
|
int
|
|
__fesetenv (const fenv_t *envp)
|
|
{
|
|
fenv_t temp;
|
|
|
|
/* 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\n"
|
|
"stmxcsr %1" : "=m" (*&temp), "=m" (*&temp.__mxcsr));
|
|
|
|
if (envp == FE_DFL_ENV)
|
|
{
|
|
temp.__control_word |= FE_ALL_EXCEPT_X86;
|
|
temp.__control_word &= ~FE_TOWARDZERO;
|
|
temp.__control_word |= _FPU_EXTENDED;
|
|
temp.__status_word &= ~FE_ALL_EXCEPT_X86;
|
|
temp.__eip = 0;
|
|
temp.__cs_selector = 0;
|
|
temp.__opcode = 0;
|
|
temp.__data_offset = 0;
|
|
temp.__data_selector = 0;
|
|
/* Clear SSE exceptions. */
|
|
temp.__mxcsr &= ~FE_ALL_EXCEPT_X86;
|
|
/* Set mask for SSE MXCSR. */
|
|
temp.__mxcsr |= (FE_ALL_EXCEPT_X86 << 7);
|
|
/* Set rounding to FE_TONEAREST. */
|
|
temp.__mxcsr &= ~ 0x6000;
|
|
temp.__mxcsr |= (FE_TONEAREST << 3);
|
|
/* Clear the FZ and DAZ bits. */
|
|
temp.__mxcsr &= ~0x8040;
|
|
}
|
|
else if (envp == FE_NOMASK_ENV)
|
|
{
|
|
temp.__control_word &= ~(FE_ALL_EXCEPT | FE_TOWARDZERO);
|
|
/* Keep the "denormal operand" exception masked. */
|
|
temp.__control_word |= __FE_DENORM;
|
|
temp.__control_word |= _FPU_EXTENDED;
|
|
temp.__status_word &= ~FE_ALL_EXCEPT_X86;
|
|
temp.__eip = 0;
|
|
temp.__cs_selector = 0;
|
|
temp.__opcode = 0;
|
|
temp.__data_offset = 0;
|
|
temp.__data_selector = 0;
|
|
/* Clear SSE exceptions. */
|
|
temp.__mxcsr &= ~FE_ALL_EXCEPT_X86;
|
|
/* Set mask for SSE MXCSR. */
|
|
/* Set rounding to FE_TONEAREST. */
|
|
temp.__mxcsr &= ~ 0x6000;
|
|
temp.__mxcsr |= (FE_TONEAREST << 3);
|
|
/* Do not mask exceptions. */
|
|
temp.__mxcsr &= ~(FE_ALL_EXCEPT << 7);
|
|
/* Keep the "denormal operand" exception masked. */
|
|
temp.__mxcsr |= (__FE_DENORM << 7);
|
|
/* Clear the FZ and DAZ bits. */
|
|
temp.__mxcsr &= ~0x8040;
|
|
}
|
|
else
|
|
{
|
|
temp.__control_word &= ~(FE_ALL_EXCEPT_X86
|
|
| FE_TOWARDZERO
|
|
| _FPU_EXTENDED);
|
|
temp.__control_word |= (envp->__control_word
|
|
& (FE_ALL_EXCEPT_X86
|
|
| FE_TOWARDZERO
|
|
| _FPU_EXTENDED));
|
|
temp.__status_word &= ~FE_ALL_EXCEPT_X86;
|
|
temp.__status_word |= envp->__status_word & FE_ALL_EXCEPT_X86;
|
|
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;
|
|
temp.__mxcsr = envp->__mxcsr;
|
|
}
|
|
|
|
__asm__ ("fldenv %0\n"
|
|
"ldmxcsr %1" : : "m" (temp), "m" (temp.__mxcsr));
|
|
|
|
/* Success. */
|
|
return 0;
|
|
}
|
|
libm_hidden_def (__fesetenv)
|
|
weak_alias (__fesetenv, fesetenv)
|
|
libm_hidden_weak (fesetenv)
|