Simply always use an unsigned long long for ltc_mp_digit on 64-bit besides when using MSVC.
@@ -219,7 +219,7 @@ LTC_EXPORT int LTC_CALL XSTRCMP(const char *s1, const char *s2);
#endif
-#if defined(ENDIAN_64BITWORD) && (defined(__ILP32__) || defined(_ILP32))
+#if defined(ENDIAN_64BITWORD) && !defined(_MSC_VER)
typedef unsigned long long ltc_mp_digit;
#else
typedef unsigned long ltc_mp_digit;