mima-tools/examples/README.md

Example MiMa programs

This folder contains a few example programs, both as .mimasm and as assembled .mima files.

• Basic programs
• Advanced programs

Basic programs

subtract.mimasm

This is a very simple program that just subtracts a value from another and stores the result in memory. It is meant as a starting point for working with this repo's tools.

call_ret.mimasm

This program demonstrates how the CALL and RET instructions behave. It doesn't use any sort of stack, so the call depth is limited and recursion is not easily possible.

call_ret_stack.mimasm

This program works similar to call_ret.mimasm, but uses the SP register for a stack. This way, it can have nested CALLs by storing the content of the RA register on the stack.

jmp_to_address_in_acc.mimasm

This program demonstrates two different techniques for jumping to an address that is currently stored in the ACC register.

Advanced programs

stack.mimasm

This program demonstrates the use of stack frames for calling a function and passing parameters. To call a function, it creates a shared stack frame containing the function's input parameters and enough space for its return values.

fib.mimasm

This program calculates the first few fibonacci numbers and stores them in consecutive memory locations. It uses a stack with stack frames and recursive calls according to the following pattern:

int fib(int n) {
    if (n == 0) return 0;
    if (n == 1) return 1;
    return fib(n - 1) + fib(n - 2);
}

This recursive solution for calculating fibonacci numbers is by far not the most efficient, but it demonstrates recursion and stack usage quite well.

bench.mimasm

This program is fib.miamsm, but it calculates the first 24 fibonacci numbers instead of the first 10. It is meant as a benchmark for MiMa emulators and takes 11877318 steps to execute (not counting the HALT instruction).

sort.mimasm

This program sorts an array of numbers that starts at memory address 0. It demonstrates a few more advanced assembler directives, including flags, as well as a bit of non-trivial, non-stack-management logic. It is based on an exercise that defined areas for the array, temporary variables and code, as well as a field containg the address of the array's last element.