This problem is adapted from an earlier edition of P&H.

Consider the following code used to implement the instruction:

foo $s0,$s1,$s2

mask: .word 0xFFFFF83F

start: la $t0,mask

lw $t0,0($t0)

la $s0,shftr

lw $s0,0($s0)

and $s0,$s0,$t0

andi $s2,$s2,0x1f

sll $s2,$s2,6

or $s0,$s0,$s2

la $t5,shftr

sw $s0,0($t5)

shftr: sll $s0,$s1,0

Add meaningful comments to the code and write a paragraph describing how it works. Why do you suppose that writing self-modifying code such as this is a bad idea (and often times not actually allowed)?

Please clearly explain it. thank you.