the functions (procedures) in MIPS

mips procedures examples
jal mips
mips nested functions
mips instructions
mips registers
function prologue mips
jr mips
jal mips example

I'm new in MIPS language and I don't understand how the functions (procedures) in the MIPS assembly language work. Here are but I will specify my problem :

  1. What does:

    • jal
    • jr
    • $ra

    mean in mips language and the important thing

  2. How can we use them when we want to create a function or (procedure)?

Firstly, you might want to check this quick MIPS reference. It really helped me.

Secondly, to explain jal, jr and $ra. What jal <label> does is jump to the label label and store the program counter (think of it as the address of the current instruction) in the $ra register. Now, when you want to return from label to where you initially were, you just use jr $ra.

Here's an example:

li $t0, 1
jal procedure # call procedure
li $v0, 10

li $t0, 3
jr $ra # return

You will notice when running this in a SPIM emulator that the value left in $t0 is 3, the one loaded in the so-called procedure.

Hope this helps.

the functions (procedures) in MIPS, Firstly, you might want to check this quick MIPS reference. It really helped me. Secondly, to explain jal , jr and $ra . What jal <label> does is� CS 61C L09 MIPS Procedures (9) A Carle, Summer 2006 © UCB Instruction Support for Functions (4/6) •Single instruction to jump and save return address: jump and

Subroutines/Functions in MIPS, This is why recursive function calls work. Each recursive call has its own copy of local variables and parameters (unless the parameters are passed by reference).  MIPS uses the jump-and-link instruction jal to call functions. —The jal saves the return address (the address of the nextinstruction) in the dedicated register $ra, before jumping to the function. —jal is the only MIPS instruction that can access the value of the program counter, so it can store the return address PC+4 in $ra.

You will want to read the System V Application Binary Interface, MIPS RISC Processor Supplement. This describes the conventions used for calling functions, in particular how the stack is managed and parameters are exchanged (there is no hardware stack in MIPS, everything is a matter of software conventions, and the ABI defines those conventions).

The document above assumes some basic knowledge of what MIPS instructions do, so you will also need the MIPS32 Architecture for Programmers, in particular volume II (instruction set), which describes the detailed effect of each instruction. But, do yourself a favor, download and read volume I (introduction) first.

The jal instruction is the "jump and link" opcode. It jumps at the target address (which is the address of the first opcode of the called procedure) while saving the current instruction pointer into the link register, which is register 31 (to be precise, it saves in register 31 the value x+8, where x is the address of the jal opcode itself).

MIPS Tutorial 15 Introduction to Functions, Learn how to create and call procedures (functions) in MIPS Assembly language!Duration: 9:52 Posted: Dec 26, 2014 By making the smallest possible incision, hair follicles are left intact around the abutment, providing a discreet result. Minimised post-op complications. MIPS leaves the soft tissue around the abutment with a full blood supply and the microcirculation and nerves intact. This is required for healthy skin.

MIPS Tutorial 16 Function Arguments and Return Values, Learn how to pass arguments to procedures, and learn how to return value from procedures in Duration: 6:36 Posted: Dec 26, 2014 Learn how to pass arguments to procedures, and learn how to return value from procedures in MIPS Assembly language!

[PDF] MIPS Procedure Calls, MIPS Function Calls. • Transfer control to function. ◇ jal label. ▫ Jumps to label's instruction. ▫ Stores return address in $ra (PC+4). • Return control to caller. mips procedure calls USING THE STACK IN PCSPIM SYSTEM CALLS in MIPS: System call is used to communicate with the system for reading from keyboard or writing to the screen.

[PDF] Functions (and procedures), A ”procedure” is just a “function” that doesn't return a value. When we write a MIPS function, we label the first instruction with the name that� Subroutines/Functions in MIPS. Subroutines/Functions in MIPS. Introduction. Functions are perhaps the most fundamental unit of programmingused in all of programming languages. It gives us the simplestform of program abstraction. It provides an interface (i.e., theprototype) and allows us to use the function without knowing howit is implemented.