A conditional branch tests a condition then changes the PC if the condition is true, for example:

beq $t1,$t2,label

Branch Equal to Zero

The extended assembler implements several conditional branch instructions beyond the basic ones. For example:

beqz     s,label          # branch to label if register  s == 0
                          # (pseudoinstruction)

The hardware does not have a machine instruction for this operation. It does, however, have a zero register and the beq instruction (branch equal).

Fill in the blanks so the branch is taken if $s1 is zero.

   $s1,,label   # branch to label if register $s1 == 0