我用一个循环来模拟MUL命令的工作方式，然后将最终结果存储在寄存器$t2中。

.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