Solving a multiplication problem in mips without using MUL command

Question

What I want to do?

Translate this code without using mul command but only the other possible commands like add, subtruct and logical shift commands.

.text
.globl main
main:              # execution starts here
    li $t0,19057        
    li $t1,123               # input data in $t1
    sll $t0,$t0,27
    srl $t0,$t0,26
    mul $t2,$t1,$t0
    li $v0,10   
    syscall 

The program created must have the same exit as the initial one in $t2 register without using the mul command. With what commands should I replace the mul command in order to have the same output?

Note: $t1 register can take any number from 1 to 10.000.000.

Answer 1

I solved it by using a loop that simulates how the MUL command works. It then stores the final result in the register $t2.

.text
.globl main

main:              # execution starts here
li $t0,19057        
li $t1,123               # input data in $t1

# shift left by 27 bits
sll $t0,$t0,27

# shift right by 26 bits
srl $t0,$t0,26

# initialize result to 0
li $t2, 0

# loop until the multiplier is 0
loop:
beq $t0, $0, end

# add the multiplicand to the result
add $t2, $t2, $t1

# decrement the multiplier
addi $t0, $t0, -1

# jump to the beginning of the loop
j loop

# end of the multiplication
end:

li $v0,10   
syscall