added constants/macros to help maintain endian changes

Source/Project64/N64 System/Mips/Memory Virtual Mem.h

@@ -30,7 +30,25 @@
 #define Eip     Rip
 #endif
 
-extern unsigned long swap32by8(unsigned long word);
+/*
+ * This will help us gradually be able to port Project64 for big-endian CPUs
+ * later.  Currently it is written to assume 32-bit little-endian, like so:
+ *
+ * 0xAABBCCDD EEFFGGHH --> 0xDDCCBBAA HHGGFFEE
+ *   GPR bits[63..0]         b1b2b3b4 b5b6b7b8
+ */
+#define BYTE_SWAP_MASK          3u
+#define HALF_SWAP_MASK          ((BYTE_SWAP_MASK) & ~1u)
+#define WORD_SWAP_MASK          ((BYTE_SWAP_MASK) & ~3u)
+
+// Convert MIPS server-native byte order to client-native endian.
+#define BES(offset)             ((offset) ^ (BYTE_SWAP_MASK))
+
+// Convert MIPS server-native halfword order to client-native int16_t order.
+#define HES(offset)             ((offset) ^ (HALF_SWAP_MASK))
+
+// Convert MIPS server-native word order to client-native int32_t order.
+#define WES(offset)             ((offset) ^ (WORD_SWAP_MASK))
 
 class CMipsMemoryVM :
 	public CMipsMemory,