The assembler translates these instructions to one or more MIPS instructions.

These instructions exist for convenience and can add clarity to programs.

You may notice while running qtspim that Pseudo-instructions such as li, la and move (and many more) get translated to something else.

Implementation of pseudo-instructions:

What you write           Machine code produced
---------------------    ---------------------
move   $t5, $t4          addu  $t5, $0, $t4

li   $t5, const          ori  $t5, $0, const

la   $t3, label          lui  $at, &label[31..16]
                         ori  $t3, $at, &label[15..0]