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/*
* Copyright (C) 2005-2017 Free Software Foundation, Inc.
*
* This file is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 3, or (at your option) any
* later version.
*
* This file 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
* General Public License for more details.
*
* Under Section 7 of GPL version 3, you are granted additional
* permissions described in the GCC Runtime Library Exception, version
* 3.1, as published by the Free Software Foundation.
*
* You should have received a copy of the GNU General Public License and
* a copy of the GCC Runtime Library Exception along with this program;
* see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
* <http://www.gnu.org/licenses/>.
*/
#ifndef _SOFT_FLOAT
#define MXCSR_DAZ (1 << 6) /* Enable denormals are zero mode */
#define MXCSR_FTZ (1 << 15) /* Enable flush to zero mode */
#ifndef __x86_64__
/* All 64-bit targets have SSE and DAZ;
only check them explicitly for 32-bit ones. */
#include "cpuid.h"
__attribute__ ((target("fxsr,sse")))
static void
/* The i386 ABI only requires 4-byte stack alignment, so this is necessary
to make sure the fxsave struct gets correct alignment.
See PR27537 and PR28621. */
__attribute__ ((force_align_arg_pointer))
set_fast_math_sse (unsigned int edx)
{
unsigned int mxcsr;
if (edx & bit_FXSAVE)
{
/* Check if DAZ is available. */
struct
{
unsigned short cwd;
unsigned short swd;
unsigned short twd;
unsigned short fop;
unsigned int fip;
unsigned int fcs;
unsigned int foo;
unsigned int fos;
unsigned int mxcsr;
unsigned int mxcsr_mask;
unsigned int st_space[32];
unsigned int xmm_space[32];
unsigned int padding[56];
} __attribute__ ((aligned (16))) fxsave;
/* This is necessary since some implementations of FXSAVE
do not modify reserved areas within the image. */
fxsave.mxcsr_mask = 0;
__builtin_ia32_fxsave (&fxsave);
mxcsr = fxsave.mxcsr;
if (fxsave.mxcsr_mask & MXCSR_DAZ)
mxcsr |= MXCSR_DAZ;
}
else
mxcsr = __builtin_ia32_stmxcsr ();
mxcsr |= MXCSR_FTZ;
__builtin_ia32_ldmxcsr (mxcsr);
}
#endif
static void __attribute__((constructor))
set_fast_math (void)
{
#ifndef __x86_64__
unsigned int eax, ebx, ecx, edx;
if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx))
return;
if (edx & bit_SSE)
set_fast_math_sse (edx);
#else
unsigned int mxcsr = __builtin_ia32_stmxcsr ();
mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
__builtin_ia32_ldmxcsr (mxcsr);
#endif
}
#endif
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