p7zip

Correction to previous message.

I used stdcall in past. But now fastсall is default for all functions in all files in 7-Zip. But C++ classes in MSVC still use stdcall (ECX).

So you can try to do same with GCC (fastcall for all files).

MYFASTCALL is not so important now in 7-zip. But It allows to disable global fastcall switch keeping asm-crc code still to use fastcall.