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ffmpeg / libavutil / bswap.h @ 80a289b9

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/*
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 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but 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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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file bswap.h
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 * byte swap.
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 */
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#ifndef __BSWAP_H__
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#define __BSWAP_H__
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#ifdef HAVE_BYTESWAP_H
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#include <byteswap.h>
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#else
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#ifdef ARCH_X86_64
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#  define LEGACY_REGS "=Q"
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#else
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#  define LEGACY_REGS "=q"
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#endif
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#if defined(ARCH_X86)
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static av_always_inline uint16_t bswap_16(uint16_t x)
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{
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  __asm("rorw $8, %0"   :
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        LEGACY_REGS (x) :
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        "0" (x));
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    return x;
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}
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static av_always_inline uint32_t bswap_32(uint32_t x)
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{
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#if __CPU__ != 386
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 __asm("bswap   %0":
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      "=r" (x)     :
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#else
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 __asm("xchgb   %b0,%h0\n"
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      "         rorl    $16,%0\n"
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      "         xchgb   %b0,%h0":
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      LEGACY_REGS (x)                :
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#endif
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      "0" (x));
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  return x;
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}
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static inline uint64_t bswap_64(uint64_t x)
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{
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#ifdef ARCH_X86_64
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  __asm("bswap  %0":
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        "=r" (x)   :
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        "0" (x));
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  return x;
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#else
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    union {
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        uint64_t ll;
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        struct {
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           uint32_t l,h;
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        } l;
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    } r;
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    r.l.l = bswap_32 (x);
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    r.l.h = bswap_32 (x>>32);
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    return r.ll;
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#endif
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}
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#elif defined(ARCH_SH4)
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static av_always_inline uint16_t bswap_16(uint16_t x) {
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        __asm__("swap.b %0,%0":"=r"(x):"0"(x));
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        return x;
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}
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static av_always_inline uint32_t bswap_32(uint32_t x) {
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        __asm__(
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        "swap.b %0,%0\n"
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        "swap.w %0,%0\n"
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        "swap.b %0,%0\n"
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        :"=r"(x):"0"(x));
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        return x;
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}
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static inline uint64_t bswap_64(uint64_t x)
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{
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    union {
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        uint64_t ll;
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        struct {
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           uint32_t l,h;
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        } l;
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    } r;
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    r.l.l = bswap_32 (x);
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    r.l.h = bswap_32 (x>>32);
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    return r.ll;
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}
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#else
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static av_always_inline uint16_t bswap_16(uint16_t x){
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    return (x>>8) | (x<<8);
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}
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#ifdef ARCH_ARM
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static av_always_inline uint32_t bswap_32(uint32_t x){
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    uint32_t t;
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    __asm__ (
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      "eor %1, %0, %0, ror #16 \n\t"
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      "bic %1, %1, #0xFF0000   \n\t"
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      "mov %0, %0, ror #8      \n\t"
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      "eor %0, %0, %1, lsr #8  \n\t"
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      : "+r"(x), "+r"(t));
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    return x;
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}
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#else
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static av_always_inline uint32_t bswap_32(uint32_t x){
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    x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
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    return (x>>16) | (x<<16);
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}
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#endif
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static inline uint64_t bswap_64(uint64_t x)
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{
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#if 0
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    x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
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    x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
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    return (x>>32) | (x<<32);
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#else
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    union {
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        uint64_t ll;
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        uint32_t l[2];
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    } w, r;
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    w.ll = x;
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    r.l[0] = bswap_32 (w.l[1]);
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    r.l[1] = bswap_32 (w.l[0]);
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    return r.ll;
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#endif
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}
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#endif  /* defined(ARCH_X86) */
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#endif  /* !HAVE_BYTESWAP_H */
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// be2me ... BigEndian to MachineEndian
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// le2me ... LittleEndian to MachineEndian
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#ifdef WORDS_BIGENDIAN
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#define be2me_16(x) (x)
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#define be2me_32(x) (x)
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#define be2me_64(x) (x)
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#define le2me_16(x) bswap_16(x)
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#define le2me_32(x) bswap_32(x)
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#define le2me_64(x) bswap_64(x)
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#else
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#define be2me_16(x) bswap_16(x)
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#define be2me_32(x) bswap_32(x)
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#define be2me_64(x) bswap_64(x)
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#define le2me_16(x) (x)
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#define le2me_32(x) (x)
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#define le2me_64(x) (x)
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#endif
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#endif /* __BSWAP_H__ */