<h2>Edit File: pycore_byteswap.h</h2><form method="post"><textarea name="content" rows="20" cols="80">/* Bytes swap functions, reverse order of bytes:

   - _Py_bswap16(uint16_t)
   - _Py_bswap32(uint32_t)
   - _Py_bswap64(uint64_t)
*/

#ifndef Py_INTERNAL_BSWAP_H
#define Py_INTERNAL_BSWAP_H
#ifdef __cplusplus
extern &quot;C&quot; {
#endif

#ifndef Py_BUILD_CORE
#  error &quot;this header requires Py_BUILD_CORE define&quot;
#endif

#if defined(__GNUC__) \
      &amp;&amp; ((__GNUC__ &gt;= 5) || (__GNUC__ == 4) &amp;&amp; (__GNUC_MINOR__ &gt;= 8))
   /* __builtin_bswap16() is available since GCC 4.8,
      __builtin_bswap32() is available since GCC 4.3,
      __builtin_bswap64() is available since GCC 4.3. */
#  define _PY_HAVE_BUILTIN_BSWAP
#endif

#ifdef _MSC_VER
   /* Get _byteswap_ushort(), _byteswap_ulong(), _byteswap_uint64() */
#  include &lt;intrin.h&gt;
#endif

static inline uint16_t
_Py_bswap16(uint16_t word)
{
#if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap16)
    return __builtin_bswap16(word);
#elif defined(_MSC_VER)
    Py_BUILD_ASSERT(sizeof(word) == sizeof(unsigned short));
    return _byteswap_ushort(word);
#else
    // Portable implementation which doesn&#039;t rely on circular bit shift
    return ( ((word &amp; UINT16_C(0x00FF)) &lt;&lt; 8)
           | ((word &amp; UINT16_C(0xFF00)) &gt;&gt; 8));
#endif
}

static inline uint32_t
_Py_bswap32(uint32_t word)
{
#if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap32)
    return __builtin_bswap32(word);
#elif defined(_MSC_VER)
    Py_BUILD_ASSERT(sizeof(word) == sizeof(unsigned long));
    return _byteswap_ulong(word);
#else
    // Portable implementation which doesn&#039;t rely on circular bit shift
    return ( ((word &amp; UINT32_C(0x000000FF)) &lt;&lt; 24)
           | ((word &amp; UINT32_C(0x0000FF00)) &lt;&lt;  8)
           | ((word &amp; UINT32_C(0x00FF0000)) &gt;&gt;  8)
           | ((word &amp; UINT32_C(0xFF000000)) &gt;&gt; 24));
#endif
}

static inline uint64_t
_Py_bswap64(uint64_t word)
{
#if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap64)
    return __builtin_bswap64(word);
#elif defined(_MSC_VER)
    return _byteswap_uint64(word);
#else
    // Portable implementation which doesn&#039;t rely on circular bit shift
    return ( ((word &amp; UINT64_C(0x00000000000000FF)) &lt;&lt; 56)
           | ((word &amp; UINT64_C(0x000000000000FF00)) &lt;&lt; 40)
           | ((word &amp; UINT64_C(0x0000000000FF0000)) &lt;&lt; 24)
           | ((word &amp; UINT64_C(0x00000000FF000000)) &lt;&lt;  8)
           | ((word &amp; UINT64_C(0x000000FF00000000)) &gt;&gt;  8)
           | ((word &amp; UINT64_C(0x0000FF0000000000)) &gt;&gt; 24)
           | ((word &amp; UINT64_C(0x00FF000000000000)) &gt;&gt; 40)
           | ((word &amp; UINT64_C(0xFF00000000000000)) &gt;&gt; 56));
#endif
}


#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_BSWAP_H */

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