-#define SWAP16(s) ((U16) ((U8*)&s)[0] | ((U16) ((U8*)&s)[1] << 8))
-#define SWAP32(s) ((U32) ((U8*)&s)[0] | ((U32) ((U8*)&s)[1] << 8) | ((U32) ((U8*)&s)[2] << 16) | ((U32) ((U8*)&s)[3] << 24))
+#define SWAP16(s) ((((s)>>8)&0x00ff)|(((s)<<8)&0xff00))
+#define SWAP32(s) (SWAP16(((s)>>16)&0x0000ffff)|((SWAP16(s)<<16)&0xffff0000))
+#define REVERSESWAP16(x) (x)
+#define REVERSESWAP32(x) (x)