Key differences in compiled Virtual Method Tables when reversing MSVC vs Clang:

1. Multiple Inheritance: MSVC creates separate VTable thunks ([thunk]:MyClass::Func with sub rcx, delta) to adjust the this pointer for secondary base classes.
2. RTTI Descriptors: MSVC places CompleteObjectLocator pointer at offset -0x8 above the VTable. Clang/GCC Itanium ABI places TypeInfo pointer at -0x8 and offset-to-top at -0x10.
3. Destructors: MSVC generates both a scalar deleting destructor and non-deleting destructor in the VTable slots.

Understanding offset-to-top in Clang VTables is essential when reversing cross-platform games on Linux/SteamOS.

Great comparison of ABI specifications.