3. Calling Conventions

• By default, Assembly programs use STDCALL calling convention for passing parameters.

• When dealing with high-level languages, programmer needs to be aware of the calling convention used by that particular language.

• Types of return values:

  • In Assembly language, everything is simple: the value is returned in the EAX register with two possibilities:

    • the value is either a number, or

    • a pointer to some variable or structure.

  • If the return value has the WORD data type, it is passed in the least significant word of the EAX register, namely, AX.

    • (When dealing with the C programming language, type casting of return value must be also considered.)