51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
|
/* Install given floating-point control modes. x86_64 version.
|
||
|
|
Copyright (C) 2016-2022 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
|
||
|
|
<https://www.gnu.org/licenses/>. */
|
||
|
|
|
||
|
|
#include <fenv.h>
|
||
|
|
#include <fpu_control.h>
|
||
|
|
|
||
|
|
/* All exceptions, including the x86-specific "denormal operand"
|
||
|
|
exception. */
|
||
|
|
#define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM)
|
||
|
|
|
||
|
|
int
|
||
|
|
fesetmode (const femode_t *modep)
|
||
|
|
{
|
||
|
|
fpu_control_t cw;
|
||
|
|
unsigned int mxcsr;
|
||
|
|
__asm__ ("stmxcsr %0" : "=m" (mxcsr));
|
||
|
|
/* Preserve SSE exception flags but restore other state in
|
||
|
|
MXCSR. */
|
||
|
|
mxcsr &= FE_ALL_EXCEPT_X86;
|
||
|
|
if (modep == FE_DFL_MODE)
|
||
|
|
{
|
||
|
|
cw = _FPU_DEFAULT;
|
||
|
|
/* Default MXCSR state has all bits zero except for those
|
||
|
|
masking exceptions. */
|
||
|
|
mxcsr |= FE_ALL_EXCEPT_X86 << 7;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
cw = modep->__control_word;
|
||
|
|
mxcsr |= modep->__mxcsr & ~FE_ALL_EXCEPT_X86;
|
||
|
|
}
|
||
|
|
_FPU_SETCW (cw);
|
||
|
|
__asm__ ("ldmxcsr %0" : : "m" (mxcsr));
|
||
|
|
return 0;
|
||
|
|
}
|