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Diffstat (limited to 'Build/source/libs/icu/icu-50.1/layout/LESwaps.h')
-rw-r--r-- | Build/source/libs/icu/icu-50.1/layout/LESwaps.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/Build/source/libs/icu/icu-50.1/layout/LESwaps.h b/Build/source/libs/icu/icu-50.1/layout/LESwaps.h new file mode 100644 index 00000000000..b9b133f4f72 --- /dev/null +++ b/Build/source/libs/icu/icu-50.1/layout/LESwaps.h @@ -0,0 +1,100 @@ +/* + * + * (C) Copyright IBM Corp. 1998-2011 - All Rights Reserved + * + */ + +#ifndef __LESWAPS_H +#define __LESWAPS_H + +#include "LETypes.h" + +/** + * \file + * \brief C++ API: Endian independent access to data for LayoutEngine + */ + +U_NAMESPACE_BEGIN + +/** + * A convenience macro which invokes the swapWord member function + * from a concise call. + * + * @stable ICU 2.8 + */ +#define SWAPW(value) LESwaps::swapWord((le_uint16)(value)) + +/** + * A convenience macro which invokes the swapLong member function + * from a concise call. + * + * @stable ICU 2.8 + */ +#define SWAPL(value) LESwaps::swapLong((le_uint32)(value)) + +/** + * This class is used to access data which stored in big endian order + * regardless of the conventions of the platform. + * + * All methods are static and inline in an attempt to induce the compiler + * to do most of the calculations at compile time. + * + * @stable ICU 2.8 + */ +class U_LAYOUT_API LESwaps /* not : public UObject because all methods are static */ { +public: + + /** + * Reads a big-endian 16-bit word and returns a native-endian value. + * No-op on a big-endian platform, byte-swaps on a little-endian platform. + * + * @param value - the word to be byte swapped + * + * @return the byte swapped word + * + * @stable ICU 2.8 + */ + static le_uint16 swapWord(le_uint16 value) + { +#if (defined(U_IS_BIG_ENDIAN) && U_IS_BIG_ENDIAN) || \ + (defined(BYTE_ORDER) && defined(BIG_ENDIAN) && (BYTE_ORDER == BIG_ENDIAN)) || \ + defined(__BIG_ENDIAN__) + // Fastpath when we know that the platform is big-endian. + return value; +#else + // Reads a big-endian value on any platform. + const le_uint8 *p = reinterpret_cast<const le_uint8 *>(&value); + return (le_uint16)((p[0] << 8) | p[1]); +#endif + }; + + /** + * Reads a big-endian 32-bit word and returns a native-endian value. + * No-op on a big-endian platform, byte-swaps on a little-endian platform. + * + * @param value - the long to be byte swapped + * + * @return the byte swapped long + * + * @stable ICU 2.8 + */ + static le_uint32 swapLong(le_uint32 value) + { +#if (defined(U_IS_BIG_ENDIAN) && U_IS_BIG_ENDIAN) || \ + (defined(BYTE_ORDER) && defined(BIG_ENDIAN) && (BYTE_ORDER == BIG_ENDIAN)) || \ + defined(__BIG_ENDIAN__) + // Fastpath when we know that the platform is big-endian. + return value; +#else + // Reads a big-endian value on any platform. + const le_uint8 *p = reinterpret_cast<const le_uint8 *>(&value); + return (le_uint32)((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]); +#endif + }; + +private: + LESwaps() {} // private - forbid instantiation +}; + +U_NAMESPACE_END +#endif |