Question

2.9 5 $2.2, 2.3> Translate the following C code to MIPS. Assume that the variables f, g, h, i, and j are assigned to registers $s0, $s1, $s2, $s3, and $s4, respectively. Assume that the base address of the arrays A and B are in registers $s6 and $s7, respectively. Assume that the elements of the arrays A and B are 4-byte words: fAlBg

Answer 1

# f = A[B[g]+1]
# f -> $s0, g -> $s1, A -> $s6, B -> $s7

sll $s1, 2       # making g an index
add $t0, $s1, $s7   # $t0 = &(B[g])
lw $t0, 0($t0)       # $t0 = B[g]
addi $t0, $t0, 1   # $t0 = B[g]+1
sll $t0, $t0, 2       # making $t0 an index
add $t0, $t0, $s6   # $t0 = &(A[B[g]+1)
lw $s0, 0($t0)       # $s0 = f = A[B[g]+1]