- The order in which atomic (scalar) parameters, or individual parts of a complex parameter, are allocated
- How parameters are passed
	- Pushed on the stack, placed in registers, or a mix of both
- Which registers the called function must preserve for the caller
	- Also known as: callee-saved registers or non-volatile registers
- How the task of preparing the stack for, and restoring after, a function call is divided between the caller and the callee

Subtle differences between [[compilers]], can be difficult to interface codes from different [[compilers]]

Calling conventions, type representations, and name mangling are all part of what is known as an [application binary interface](https://en.wikipedia.org/wiki/Application_binary_interface) ([[ABI]])

# cdecl
C declaration

- Originally from Microsoft's C [[compilers|compiler]]
	- Used by many C [[compilers]] for x86
- Subroutine arguments passed on the stack
- Function arguments pushed right-to-left
	- Last pushed first
- Caller cleans stack after function call returns

# stdcall

- Variation on Pascal calling convention
- Callee cleans stack
- Params pushed onto stack right-to-left
	- Same as _cdecl_
- Standard for Microsoft Win32 API