---
tags: 大二筆記
---

# 計算機組織MIPS
https://blog.xuite.net/tzeng015/twblog/113272086-MIPS+%E6%8C%87%E4%BB%A4%E9%9B%86

## Factorial


fact:
    addi $sp, $sp, -8         # allocate 8 bytes to this stack
    sw $ra, 0($sp)            # save return address in stack
    sw $a0, 4($sp)            # save argument value in stack

    slti $t0, $a0, 1          # if n < 1 then $t0 = 1, else $t0 = 0
    beq $t0, $zero, L1        # if $t0 == 0 then jump to branch L1
    addi $v0, $zero, 1        # let $v0 be 1
    addi $sp, $sp, 8          # let $sp point to upper stack
    jr $ra                    # jump to the next line of the line calling fib

L1:
    addi $a0, $a0, -1         # n = n - 1
    jal fact                  # jump fact again, like as returning F(n - 1)
    lw $a0, 4($sp)            # recover the value of argument
    lw $ra, 0($sp)            # recover return address
    mul $v0, $a0, $v0         # $v0 *= $a0, like as F(n) = n * F(n - 1)
    addi, $sp, $sp, 8         # let $sp point to upper stack
    jr $ra                    # jump to the next line of the line calling L1

exit:

## Fibonacci


fib:
    addi $sp, $sp, -12        # allocate 12 bytes to stack
    sw $ra, 0($sp)            # save return address in stack
    sw $a0, 4($sp)            # save argument value in stack
    sw $s0, 8($sp)

    slti $t0, $a0, 2          # if n < 2 then $t0 = 1, else $t0 = 0
    beq $t0, $zero, L1        # if $t0 == 0 then jump to branch L1
    add $v0, $a0,$zero        # f(n)=n
    addi $sp, $sp, 12         # let $sp point to upper stack
    jr $ra                    # jump to the next line of the line calling fib

L1:
    addi $a0, $a0, -1         # n = n - 1
    jal fib                   # return f(n - 1)
    add $s0,$v0,$zero         # let $s0=f(n - 1)
    addi $a0, $a0, -1         # n = n - 1
    jal fib                   # return f(n - 2)
    add $v0,$v0,$s0           # f(n - 2)+f(n - 1)
    lw $t0, 8($sp)
    lw $a0, 4($sp)            # recover the value of argument
    lw $ra, 0($sp)            # recover return address
    addi, $sp, $sp, 12        # let $sp point to upper stack
    jr $ra                    # jump to the next line of the line calling L1
exit:

## Swap
<br>

## Bubble sort
<br>