_BitScanReverse was introduced in Microsoft Visual Studio 2005

include/SDL3/SDL_bits.h

@@ -78,7 +78,7 @@ SDL_FORCE_INLINE int SDL_MostSignificantBitIndex32(Uint32 x)
         return -1;
     }
     return _SDL_bsr_watcom(x);
-#elif defined(_MSC_VER)
+#elif defined(_MSC_VER) && _MSC_VER >= 1400
     unsigned long index;
     if (_BitScanReverse(&index, x)) {
         return (int)index;