汇编语言解疑

updlist (
        list    = "N410"
        stcode  = UPOV | DWOV
#
        cntdata (
                move    -p b0001 c4001/l
#
                cmp     -i 1 c4001/l              # オープン出納通番１
                jmpcc   0x0a $lab01
#
                add     -i 1 c0301/l c0301/l
#
                cmp     -i 1000000 c0301/l
                jmpcc   0x08 $lab20
#
                move    -i 0 c0301/l
#
                jmpcc   0x00 $lab20
#
        $lab01:
                cmp     -i 2 c4001/l              # オープン出納通番２
                jmpcc   0x0a $lab02
#
                add     -i 1 c0302/l c0302/l
#
                cmp     -i 1000000 c0302/l
                jmpcc   0x08 $lab20
#
                move    -i 0 c0302/l
#
                jmpcc   0x00 $lab20
#
        $lab02:
                cmp     -i 3 c4001/l              # オープン出納通番３
                jmpcc   0x0a $lab03
#
                add     -i 1 c0303/l c0303/l
#
                cmp     -i 1000000 c0303/l
                jmpcc   0x08 $lab20
#
                move    -i 0 c0303/l
#
                jmpcc   0x00 $lab20
#
        $lab03:
                cmp     -i 4 c4001/l              # オープン出納通番４
                jmpcc   0x0a $lab04
#
                add     -i 1 c0304/l c0304/l
#
                cmp     -i 1000000 c0304/l
                jmpcc   0x08 $lab20
#
                move    -i 0 c0304/l
#
                jmpcc   0x00 $lab20
#
        $lab04: