Windows x86 C++ Calling Conventions Cheat Sheet
Jan 25, 2026
Noodling with reverse engineering Windows applications needs me to know these things but they refuse to stick in my brain, so I have put them in one place.
All stack parameters are passed in right-to-left order.
| Name | Stack cleaned by | Parameters |
|---|---|---|
thiscall |
Callee | this in ECX, params on stack |
fastcall |
Callee | First in ECX, second in EDX, rest on stack |
cdecl |
Caller | Stack |
stdcall |
Callee | Stack |