/*
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/*
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* Copyright (C) 2005 Free Software Foundation, Inc.
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* Copyright (C) 2005 Free Software Foundation, Inc.
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*
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*
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* This file is free software; you can redistribute it and/or modify it
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* This file is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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* later version.
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*
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*
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* In addition to the permissions in the GNU General Public License, the
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* In addition to the permissions in the GNU General Public License, the
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* Free Software Foundation gives you unlimited permission to link the
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* Free Software Foundation gives you unlimited permission to link the
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* compiled version of this file with other programs, and to distribute
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* compiled version of this file with other programs, and to distribute
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* those programs without any restriction coming from the use of this
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* those programs without any restriction coming from the use of this
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* file. (The General Public License restrictions do apply in other
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* file. (The General Public License restrictions do apply in other
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* respects; for example, they cover modification of the file, and
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* respects; for example, they cover modification of the file, and
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* distribution when not linked into another program.)
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* distribution when not linked into another program.)
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*
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*
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* This file is distributed in the hope that it will be useful, but
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* This file is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* General Public License for more details.
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*
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*
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* You should have received a copy of the GNU General Public License
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 51 Franklin Street, Fifth Floor,
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* the Free Software Foundation, 51 Franklin Street, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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* Boston, MA 02110-1301, USA.
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*
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*
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* As a special exception, if you link this library with files
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* As a special exception, if you link this library with files
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* compiled with GCC to produce an executable, this does not cause
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* compiled with GCC to produce an executable, this does not cause
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* the resulting executable to be covered by the GNU General Public License.
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* the resulting executable to be covered by the GNU General Public License.
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* This exception does not however invalidate any other reasons why
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* This exception does not however invalidate any other reasons why
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* the executable file might be covered by the GNU General Public License.
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* the executable file might be covered by the GNU General Public License.
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*/
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*/
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#define MXCSR_DAZ (1 << 6) /* Enable denormals are zero mode */
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#define MXCSR_DAZ (1 << 6) /* Enable denormals are zero mode */
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#define MXCSR_FTZ (1 << 15) /* Enable flush to zero mode */
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#define MXCSR_FTZ (1 << 15) /* Enable flush to zero mode */
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#define FXSAVE (1 << 24)
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#define FXSAVE (1 << 24)
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#define SSE (1 << 25)
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#define SSE (1 << 25)
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static void __attribute__((constructor))
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static void __attribute__((constructor))
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#ifndef __x86_64__
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#ifndef __x86_64__
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/* The i386 ABI only requires 4-byte stack alignment, so this is necessary
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/* The i386 ABI only requires 4-byte stack alignment, so this is necessary
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to make sure the fxsave struct gets correct alignment.
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to make sure the fxsave struct gets correct alignment.
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See PR27537 and PR28621. */
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See PR27537 and PR28621. */
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__attribute__ ((force_align_arg_pointer))
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__attribute__ ((force_align_arg_pointer))
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#endif
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#endif
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set_fast_math (void)
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set_fast_math (void)
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{
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{
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#ifndef __x86_64__
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#ifndef __x86_64__
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/* All 64-bit targets have SSE and DAZ; only check them explicitly
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/* All 64-bit targets have SSE and DAZ; only check them explicitly
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for 32-bit ones. */
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for 32-bit ones. */
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unsigned int eax, ebx, ecx, edx;
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unsigned int eax, ebx, ecx, edx;
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/* See if we can use cpuid. */
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/* See if we can use cpuid. */
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asm volatile ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;"
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asm volatile ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;"
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"pushl %0; popfl; pushfl; popl %0; popfl"
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"pushl %0; popfl; pushfl; popl %0; popfl"
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: "=&r" (eax), "=&r" (ebx)
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: "=&r" (eax), "=&r" (ebx)
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: "i" (0x00200000));
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: "i" (0x00200000));
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if (((eax ^ ebx) & 0x00200000) == 0)
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if (((eax ^ ebx) & 0x00200000) == 0)
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return;
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return;
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/* Check the highest input value for eax. */
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/* Check the highest input value for eax. */
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asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
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asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
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: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
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: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
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: "0" (0));
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: "0" (0));
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if (eax == 0)
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if (eax == 0)
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return;
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return;
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asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
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asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
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: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
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: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
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: "0" (1));
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: "0" (1));
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if (edx & SSE)
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if (edx & SSE)
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{
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{
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unsigned int mxcsr = __builtin_ia32_stmxcsr ();
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unsigned int mxcsr = __builtin_ia32_stmxcsr ();
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mxcsr |= MXCSR_FTZ;
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mxcsr |= MXCSR_FTZ;
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if (edx & FXSAVE)
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if (edx & FXSAVE)
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{
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{
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/* Check if DAZ is available. */
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/* Check if DAZ is available. */
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struct
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struct
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{
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{
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unsigned short int cwd;
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unsigned short int cwd;
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unsigned short int swd;
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unsigned short int swd;
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unsigned short int twd;
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unsigned short int twd;
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unsigned short int fop;
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unsigned short int fop;
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long int fip;
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long int fip;
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long int fcs;
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long int fcs;
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long int foo;
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long int foo;
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long int fos;
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long int fos;
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long int mxcsr;
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long int mxcsr;
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long int mxcsr_mask;
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long int mxcsr_mask;
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long int st_space[32];
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long int st_space[32];
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long int xmm_space[32];
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long int xmm_space[32];
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long int padding[56];
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long int padding[56];
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} __attribute__ ((aligned (16))) fxsave;
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} __attribute__ ((aligned (16))) fxsave;
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__builtin_memset (&fxsave, 0, sizeof (fxsave));
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__builtin_memset (&fxsave, 0, sizeof (fxsave));
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asm volatile ("fxsave %0" : "=m" (fxsave) : "m" (fxsave));
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asm volatile ("fxsave %0" : "=m" (fxsave) : "m" (fxsave));
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if (fxsave.mxcsr_mask & MXCSR_DAZ)
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if (fxsave.mxcsr_mask & MXCSR_DAZ)
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mxcsr |= MXCSR_DAZ;
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mxcsr |= MXCSR_DAZ;
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}
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}
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__builtin_ia32_ldmxcsr (mxcsr);
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__builtin_ia32_ldmxcsr (mxcsr);
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}
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}
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#else
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#else
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unsigned int mxcsr = __builtin_ia32_stmxcsr ();
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unsigned int mxcsr = __builtin_ia32_stmxcsr ();
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mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
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mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
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__builtin_ia32_ldmxcsr (mxcsr);
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__builtin_ia32_ldmxcsr (mxcsr);
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#endif
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#endif
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}
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}
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