[MSDN Library June 1998] __fastcall (100%)
MSDN Library Visual Studio 6.0 > Visual C++ Documentation > Using Visual C++ > Visual C++ Programmer's Guide > Adding Program Functionality > Details > Calling Conventions Topics > Argument Passing and Naming Conventions
[MSDN Library September 1992] __fastcall (44.7727272727273%)
Product Documentation > C/C++ 7.0 > C++ Language Reference > Appendix B Microsoft-Specific Modifiers > B.2 Calling and Naming Convention Modifiers