mul $v2,$s3,$t0

Translates into:

mult $s3, $t0 mflo $v2

The
`mul`

pseudoinstruction makes it look as if MIPS has a
32-bit multiply instruction that places its 32-bit
result:

mul d,s,t # multiply $s by $t. put the # result in $d # (pseudoinstruction)

There is no overflow checking.
The bits of **hi** are not examined nor saved.
There are several other pseudoinstructions that examine
**hi** and perform various actions on overflow.
We won't use them.

There is a similar instruction for division.
The basic instructions
`div s,t`

and
`divu s,t`

put their results in MIPS registers
**hi** and **lo**.
The 32-bit quotient goes in **lo**
and the 32-bit remainder goes in **hi**.
To move the quotient into a register,
`mflo`

is used.