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| author | Wouter van Oortmerssen <wvo@google.com> | 2016-08-10 10:09:39 -0700 |
|---|---|---|
| committer | Wouter van Oortmerssen <wvo@google.com> | 2016-08-10 10:49:17 -0700 |
| commit | be908939dae62d1dd128de6538b5492943315706 (patch) | |
| tree | 5abb3be2223ae5ea549a30514aec3ec9392d61cc | |
| parent | c96fc7fcef4b415f561d5e1b6434cb708cbeb592 (diff) | |
| download | flatbuffers-be908939dae62d1dd128de6538b5492943315706.tar.gz flatbuffers-be908939dae62d1dd128de6538b5492943315706.tar.bz2 flatbuffers-be908939dae62d1dd128de6538b5492943315706.zip | |
Fixed __builtin_bswap16 not being available on GCC <4.8
See e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52624
Change-Id: Idae99196c47e015a2ba2416aaf1526f77498ce5d
| -rw-r--r-- | include/flatbuffers/flatbuffers.h | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/include/flatbuffers/flatbuffers.h b/include/flatbuffers/flatbuffers.h index 1a690826..4644f9c6 100644 --- a/include/flatbuffers/flatbuffers.h +++ b/include/flatbuffers/flatbuffers.h @@ -153,32 +153,34 @@ inline void EndianCheck() { template<typename T> T EndianSwap(T t) { #if defined(_MSC_VER) - #pragma push_macro("__builtin_bswap16") - #pragma push_macro("__builtin_bswap32") - #pragma push_macro("__builtin_bswap64") - #define __builtin_bswap16 _byteswap_ushort - #define __builtin_bswap32 _byteswap_ulong - #define __builtin_bswap64 _byteswap_uint64 + #define FLATBUFFERS_BYTESWAP16 _byteswap_ushort + #define FLATBUFFERS_BYTESWAP32 _byteswap_ulong + #define FLATBUFFERS_BYTESWAP64 _byteswap_uint64 + #else + #if defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ < 408 + // __builtin_bswap16 was missing prior to GCC 4.8. + #define FLATBUFFERS_BYTESWAP16(x) \ + static_cast<uint16_t>(__builtin_bswap32(static_cast<uint32_t>(x) << 16)) + #else + #define FLATBUFFERS_BYTESWAP16 __builtin_bswap16 + #endif + #define FLATBUFFERS_BYTESWAP32 __builtin_bswap32 + #define FLATBUFFERS_BYTESWAP64 __builtin_bswap64 #endif if (sizeof(T) == 1) { // Compile-time if-then's. return t; } else if (sizeof(T) == 2) { - auto r = __builtin_bswap16(*reinterpret_cast<uint16_t *>(&t)); + auto r = FLATBUFFERS_BYTESWAP16(*reinterpret_cast<uint16_t *>(&t)); return *reinterpret_cast<T *>(&r); } else if (sizeof(T) == 4) { - auto r = __builtin_bswap32(*reinterpret_cast<uint32_t *>(&t)); + auto r = FLATBUFFERS_BYTESWAP32(*reinterpret_cast<uint32_t *>(&t)); return *reinterpret_cast<T *>(&r); } else if (sizeof(T) == 8) { - auto r = __builtin_bswap64(*reinterpret_cast<uint64_t *>(&t)); + auto r = FLATBUFFERS_BYTESWAP64(*reinterpret_cast<uint64_t *>(&t)); return *reinterpret_cast<T *>(&r); } else { assert(0); } - #if defined(_MSC_VER) - #pragma pop_macro("__builtin_bswap16") - #pragma pop_macro("__builtin_bswap32") - #pragma pop_macro("__builtin_bswap64") - #endif } template<typename T> T EndianScalar(T t) { |