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/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <wtf/Compiler.h>
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
namespace WTF {
inline bool needToFlipBytesIfLittleEndian(bool littleEndian)
{
#if CPU(BIG_ENDIAN)
return littleEndian;
#else
return !littleEndian;
#endif
}
inline uint16_t flipBytes(uint16_t value)
{
return ((value & 0x00ff) << 8)
| ((value & 0xff00) >> 8);
}
inline uint32_t flipBytes(uint32_t value)
{
return ((value & 0x000000ff) << 24)
| ((value & 0x0000ff00) << 8)
| ((value & 0x00ff0000) >> 8)
| ((value & 0xff000000) >> 24);
}
inline uint64_t flipBytes(uint64_t value)
{
return ((value & 0x00000000000000ffull) << 56)
| ((value & 0x000000000000ff00ull) << 40)
| ((value & 0x0000000000ff0000ull) << 24)
| ((value & 0x00000000ff000000ull) << 8)
| ((value & 0x000000ff00000000ull) >> 8)
| ((value & 0x0000ff0000000000ull) >> 24)
| ((value & 0x00ff000000000000ull) >> 40)
| ((value & 0xff00000000000000ull) >> 56);
}
template<typename T>
inline T flipBytes(T value)
{
if (sizeof(value) == 1)
return value;
if (sizeof(value) == 2) {
union {
T original;
uint16_t word;
} u;
u.original = value;
u.word = flipBytes(u.word);
return u.original;
}
if (sizeof(value) == 4) {
union {
T original;
uint32_t word;
} u;
u.original = value;
u.word = flipBytes(u.word);
return u.original;
}
if (sizeof(value) == 8) {
union {
T original;
uint64_t word;
} u;
u.original = value;
u.word = flipBytes(u.word);
return u.original;
}
if (sizeof(value) == 16) {
union {
T original;
uint64_t words[2];
} u, v;
v.original = value;
u.words[0] = flipBytes(v.words[1]);
u.words[1] = flipBytes(v.words[0]);
return u.original;
}
RELEASE_ASSERT_NOT_REACHED();
return T();
}
template<typename T>
inline T flipBytesIfLittleEndian(T value, bool littleEndian)
{
if (needToFlipBytesIfLittleEndian(littleEndian))
return flipBytes(value);
return value;
}
} // namespace WTF
using WTF::needToFlipBytesIfLittleEndian;
using WTF::flipBytes;
using WTF::flipBytesIfLittleEndian;
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
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