FFmpeg
emms.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_X86_EMMS_H
20 #define AVUTIL_X86_EMMS_H
21 
22 #include "config.h"
23 #include "libavutil/attributes.h"
24 #include "libavutil/cpu.h"
25 
26 void avpriv_emms_asm(void);
27 
28 #if HAVE_MMX_INLINE
29 # define emms_c emms_c
30 /**
31  * Empty mmx state.
32  * this must be called between any dsp function and float/double code.
33  * for example sin(); dsp->idct_put(); emms_c(); cos()
34  * Note, *alloc() and *free() also use float code in some libc implementations
35  * thus this also applies to them or any function using them.
36  */
37 static av_always_inline void emms_c(void)
38 {
39 /* Some inlined functions may also use mmx instructions regardless of
40  * runtime cpuflags. With that in mind, we unconditionally empty the
41  * mmx state if the target cpu chosen at configure time supports it.
42  */
43 #if !defined(__MMX__)
45 #endif
46  __asm__ volatile ("emms" ::: "memory");
47 }
48 #elif HAVE_MMX && HAVE_MM_EMPTY
49 # include <mmintrin.h>
50 # define emms_c _mm_empty
51 #elif HAVE_MMX_EXTERNAL
52 # define emms_c avpriv_emms_asm
53 #endif /* HAVE_MMX_INLINE */
54 
55 #endif /* AVUTIL_X86_EMMS_H */
avpriv_emms_asm
void avpriv_emms_asm(void)
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:96
cpu.h
attributes.h
av_always_inline
#define av_always_inline
Definition: attributes.h:49
__asm__
__asm__(".macro parse_r var r\n\t" "\\var = -1\n\t" _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) ".iflt \\var\n\t" ".error \"Unable to parse register name \\r\"\n\t" ".endif\n\t" ".endm")
AV_CPU_FLAG_MMX
#define AV_CPU_FLAG_MMX
standard MMX
Definition: cpu.h:29