ffmpeg/libavutil/x86/emms.h

56 lines
1.8 KiB
C

/*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_X86_EMMS_H
#define AVUTIL_X86_EMMS_H
#include "config.h"
#include "libavutil/attributes.h"
#include "libavutil/cpu.h"
void avpriv_emms_asm(void);
#if HAVE_MMX_INLINE
# define emms_c emms_c
/**
* Empty mmx state.
* this must be called between any dsp function and float/double code.
* for example sin(); dsp->idct_put(); emms_c(); cos()
* Note, *alloc() and *free() also use float code in some libc implementations
* thus this also applies to them or any function using them.
*/
static av_always_inline void emms_c(void)
{
/* Some inlined functions may also use mmx instructions regardless of
* runtime cpuflags. With that in mind, we unconditionally empty the
* mmx state if the target cpu chosen at configure time supports it.
*/
#if !defined(__MMX__)
if(av_get_cpu_flags() & AV_CPU_FLAG_MMX)
#endif
__asm__ volatile ("emms" ::: "memory");
}
#elif HAVE_MMX && HAVE_MM_EMPTY
# include <mmintrin.h>
# define emms_c _mm_empty
#elif HAVE_MMX_EXTERNAL
# define emms_c avpriv_emms_asm
#endif /* HAVE_MMX_INLINE */
#endif /* AVUTIL_X86_EMMS_H */