libavutil/x86/bswap.h
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00001 /*
00002  * This file is part of FFmpeg.
00003  *
00004  * FFmpeg is free software; you can redistribute it and/or
00005  * modify it under the terms of the GNU Lesser General Public
00006  * License as published by the Free Software Foundation; either
00007  * version 2.1 of the License, or (at your option) any later version.
00008  *
00009  * FFmpeg is distributed in the hope that it will be useful,
00010  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012  * Lesser General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU Lesser General Public
00015  * License along with FFmpeg; if not, write to the Free Software
00016  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00017  */
00018 
00024 #ifndef AVUTIL_X86_BSWAP_H
00025 #define AVUTIL_X86_BSWAP_H
00026 
00027 #include <stdint.h>
00028 #include "config.h"
00029 #include "libavutil/attributes.h"
00030 
00031 #if !AV_GCC_VERSION_AT_LEAST(4,1)
00032 #define av_bswap16 av_bswap16
00033 static av_always_inline av_const unsigned av_bswap16(unsigned x)
00034 {
00035     __asm__("rorw $8, %w0" : "+r"(x));
00036     return x;
00037 }
00038 #endif /* !AV_GCC_VERSION_AT_LEAST(4,1) */
00039 
00040 #if !AV_GCC_VERSION_AT_LEAST(4,5)
00041 #define av_bswap32 av_bswap32
00042 static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
00043 {
00044     __asm__("bswap   %0" : "+r" (x));
00045     return x;
00046 }
00047 
00048 #if ARCH_X86_64
00049 #define av_bswap64 av_bswap64
00050 static inline uint64_t av_const av_bswap64(uint64_t x)
00051 {
00052     __asm__("bswap  %0": "=r" (x) : "0" (x));
00053     return x;
00054 }
00055 #endif
00056 #endif /* !AV_GCC_VERSION_AT_LEAST(4,5) */
00057 
00058 #endif /* AVUTIL_X86_BSWAP_H */