-FB_GEN( int64_t, bswap_64)
-FB_GEN(uint64_t, bswap_64)
-FB_GEN( int32_t, bswap_32)
-FB_GEN(uint32_t, bswap_32)
-FB_GEN( int16_t, bswap_16)
-FB_GEN(uint16_t, bswap_16)
+#ifdef _MSC_VER
+FB_GEN( int64_t, _byteswap_uint64)
+FB_GEN(uint64_t, _byteswap_uint64)
+FB_GEN( int32_t, _byteswap_ulong)
+FB_GEN(uint32_t, _byteswap_ulong)
+FB_GEN( int16_t, _byteswap_ushort)
+FB_GEN(uint16_t, _byteswap_ushort)
+#else
+FB_GEN( int64_t, __builtin_bswap64)
+FB_GEN(uint64_t, __builtin_bswap64)
+FB_GEN( int32_t, __builtin_bswap32)
+FB_GEN(uint32_t, __builtin_bswap32)
+FB_GEN( int16_t, our_bswap16)
+FB_GEN(uint16_t, our_bswap16)
+#endif