negu $v2,$s3
Translates into:
sub $v2,$0,$s3
The
mult
and the multu
instructions (which you have seen before)
put the result into MIPS registers hi and lo.
The results may be moved out of these registers
using mfhi
and
mflo
.
The three operand pseudoinstruction
mul d,s,t
uses those basic instructions.
It is used when the product of registers
$s
and $t
is
a value that fits into the 32 bits of lo.
mul d,s,t # d = s*t