> For the complete documentation index, see [llms.txt](https://www.ctfrecipes.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.ctfrecipes.com/pwn/architectures/mips64/calling-convention.md).

# Calling convention

The MIPS architecture supports several different calling conventions, which define how functions are called and how arguments are passed between functions in a program. Some of the most commonly used calling conventions on the MIPS architecture include:

* **O32**: This is the default calling convention for the MIPS architecture. It is used for functions written in C or C++. In this convention, arguments are passed to the function in registers, and any additional arguments are passed on the stack. The return value is stored in the $v0 and $v1 registers.
* **N32**: This calling convention is similar to the O32 convention, but it is used for functions that return values that are larger than 64 bits up to 128 bits. In this convention, the return value is stored in a pair of registers, $f0 and $f1.
* **N64**: This calling convention is used for functions that are compiled for the MIPS64 instruction set. It is similar to the N32 convention for return values larger than 128 bits. It supports 64-bit integers and pointers.

Overall, the MIPS architecture supports a number of different calling conventions, which allows it to be used in a variety of programming languages and environments. The specific calling convention that is used can affect the performance of a program, as well as the compatibility of functions with different compilers and libraries.


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