emms.h (1959B)
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_EMMS_H 20 #define AVUTIL_EMMS_H 21 22 #include "config.h" 23 #include "libavutil/attributes.h" 24 25 #if ARCH_X86 26 27 void avpriv_emms_asm(void); 28 29 #if HAVE_MMX_INLINE 30 #ifndef __MMX__ 31 #include "libavutil/cpu.h" 32 #endif 33 34 # define emms_c emms_c 35 /** 36 * Empty mmx state. 37 * this must be called between any dsp function and float/double code. 38 * for example sin(); dsp->idct_put(); emms_c(); cos() 39 * Note, *alloc() and *free() also use float code in some libc implementations 40 * thus this also applies to them or any function using them. 41 */ 42 static av_always_inline void emms_c(void) 43 { 44 /* Some inlined functions may also use mmx instructions regardless of 45 * runtime cpuflags. With that in mind, we unconditionally empty the 46 * mmx state if the target cpu chosen at configure time supports it. 47 */ 48 #if !defined(__MMX__) 49 if(av_get_cpu_flags() & AV_CPU_FLAG_MMX) 50 #endif 51 __asm__ volatile ("emms" ::: "memory"); 52 } 53 #elif HAVE_MMX && HAVE_MM_EMPTY 54 # include <mmintrin.h> 55 # define emms_c _mm_empty 56 #elif HAVE_MMX_EXTERNAL 57 # define emms_c avpriv_emms_asm 58 #endif /* HAVE_MMX_INLINE */ 59 60 #endif /* ARCH_X86 */ 61 62 #ifndef emms_c 63 # define emms_c() do {} while(0) 64 #endif 65 66 #endif /* AVUTIL_EMMS_H */