glibc/sysdeps/i386/setfpucw.c
H.J. Lu bf7730194f Check if SSE is available with HAS_CPU_FEATURE
Similar to other CPU feature checks, check if SSE is available with
HAS_CPU_FEATURE.

	* sysdeps/i386/fpu/fclrexcpt.c (__feclearexcept): Use
	HAS_CPU_FEATURE to check for SSE.
	* sysdeps/i386/fpu/fedisblxcpt.c (fedisableexcept): Likewise.
	* sysdeps/i386/fpu/feenablxcpt.c (feenableexcept): Likewise.
	* sysdeps/i386/fpu/fegetenv.c (__fegetenv): Likewise.
	* sysdeps/i386/fpu/fegetmode.c (fegetmode): Likewise.
	* sysdeps/i386/fpu/feholdexcpt.c (__feholdexcept): Likewise.
	* sysdeps/i386/fpu/fesetenv.c (__fesetenv): Likewise.
	* sysdeps/i386/fpu/fesetmode.c (fesetmode): Likewise.
	* sysdeps/i386/fpu/fesetround.c (__fesetround): Likewise.
	* sysdeps/i386/fpu/feupdateenv.c (__feupdateenv): Likewise.
	* sysdeps/i386/fpu/fgetexcptflg.c (__fegetexceptflag): Likewise.
	* sysdeps/i386/fpu/fsetexcptflg.c (__fesetexceptflag): Likewise.
	* sysdeps/i386/fpu/ftestexcept.c (fetestexcept): Likewise.
	* sysdeps/i386/setfpucw.c (__setfpucw): Likewise.
	* sysdeps/x86/cpu-features.h (bit_cpu_SSE): New.
	(index_cpu_SSE): Likewise.
	(reg_SSE): Likewise.
2017-04-07 07:44:59 -07:00

55 lines
1.7 KiB
C

/* Set the FPU control word for x86.
Copyright (C) 2003-2017 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 <math.h>
#include <fpu_control.h>
#include <fenv.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <dl-procinfo.h>
void
__setfpucw (fpu_control_t set)
{
fpu_control_t cw;
/* Fetch the current control word. */
__asm__ ("fnstcw %0" : "=m" (*&cw));
/* Preserve the reserved bits, and set the rest as the user
specified (or the default, if the user gave zero). */
cw &= _FPU_RESERVED;
cw |= set & ~_FPU_RESERVED;
__asm__ ("fldcw %0" : : "m" (*&cw));
/* If the CPU supports SSE, we set the MXCSR as well. */
if (HAS_CPU_FEATURE (SSE))
{
unsigned int xnew_exc;
/* Get the current MXCSR. */
__asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
xnew_exc &= ~((0xc00 << 3) | (FE_ALL_EXCEPT << 7));
xnew_exc |= ((set & 0xc00) << 3) | ((set & FE_ALL_EXCEPT) << 7);
__asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
}
}