If A is a 32-bit address, typically an instruction sequence such as
lui $t0, A_upper
ori $t0, $t0, A_lower
lw $s0, 0($t0)
can be use to load the word at A into a register (in this case, $s0). Consider the following
alternative, which is more efficient:
lui $t0, A_upper_adjusted
lw $s0, A_lower($t0)

Describe how A_upper is adjusted to allow this simpler code to work. (Hint: A_upper needs to be adjusted because A_lower will be sign-extended.)