Multiplication, Division
Result of multiplying 2 32-bit numbers can be up to 64 bits
Instructions Semantics Type
mult  $rs, $rt
(HI, LO) = R[s] * R[t] signed R
multu $rs, $rt unsigned R
HI: high 32 bits
LO: low 32 bits
Note that $rd does not appear (set to 00000 in instruction)