https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113633
Radek Barton <radek.barton at microsoft dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |radek.barton at microsoft dot com --- Comment #2 from Radek Barton <radek.barton at microsoft dot com> --- When `__attribute__((__ms_struct__))` is present, the struct size should be compatible with MS ABI (which is 12). The relevant documentation for MS ABI is here https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions?view=msvc-170 Hope this helps.