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ffmpeg / libavcodec / bswap.h @ 983e3246

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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
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inline static unsigned short ByteSwap16(unsigned short x)
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{
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  __asm("xchgb %b0,%h0"        :
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        "=q" (x)        :
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        "0" (x));
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    return x;
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}
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#define bswap_16(x) ByteSwap16(x)
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inline static unsigned int ByteSwap32(unsigned int 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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      "=q" (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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#define bswap_32(x) ByteSwap32(x)
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inline static unsigned long long int ByteSwap64(unsigned long long int x)
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{
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  register union { __extension__ uint64_t __ll;
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          uint32_t __l[2]; } __x;
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  asm("xchgl        %0,%1":
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      "=r"(__x.__l[0]),"=r"(__x.__l[1]):
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      "0"(bswap_32((unsigned long)x)),"1"(bswap_32((unsigned long)(x>>32))));
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  return __x.__ll;
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}
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#define bswap_64(x) ByteSwap64(x)
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#else
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#define bswap_16(x) (((x) & 0x00ff) << 8 | ((x) & 0xff00) >> 8)
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// code from bits/byteswap.h (C) 1997, 1998 Free Software Foundation, Inc.
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#define bswap_32(x) \
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     ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) | \
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      (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
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inline static uint64_t ByteSwap64(uint64_t x)
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{
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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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}
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#define bswap_64(x) ByteSwap64(x)
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#endif        /* !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__ */