MZIXCO - create compound division index

A compound division index permits to indicate several divisions of the same store in one single word, as used with MZWIPE for example.

MZIXCO joins up to four division indices into a compound:

MZIXCOIXCO = MZIXCO (IX1,IX2,IX3,IX4)

If less than 4 indices are to be joined trailing zeros should be given. If more than 4 indices are to be joined this is done by repeated calls.

Any input parameter IXn may take any one of the three possible forms of a division index:

  a) specific division index, as returned by MZDIV

  b) generic division index, [ IXSTOR + ] n, where

        n = 21:  all user short range divisions
            22:  all user long  range divisions
            23:  all package divisions
            24:  the system division

  c) compound division index, created by a previous call to MZIXCO.

Examples:

for the primary store one has:

  1) Compound to give divisions 1 and 2:

                   IXCO = MZIXCO (1,2,0,0)

  2) Compound to give divisions 1, 2, and IXHITS:

                   IXCO = MZIXCO (1,2,IXHITS,0)

  3) Compound to give all short-range divisions and IXCUMU:

                   IXCO = MZIXCO (21,IXCUMU,0,0)

[ 4) Compound to give all user divisions of the store
     whose index is IXSTOR:

                   IXCO = MZIXCO (IXSTOR+21,IXSTOR+22,0,0) ]

Format of the division index

      bits 25, 26, 32    non-zero is illegal

      bit 31  zero:     simple index
              one:     compound index

      bits 27-30 :     the number of the store,
                         zero for the primary store

Division JDIV is selected if

     simple index:      the value of bits 1-24 is JDIV
   compound index:      bit JDIV is present

JDIV may be 1 to 20 for that particular division,
         or it may be generic with:

          JDIV = 21:  user's short range divisions
                 22:  user's  long range divisions
                 23:  package divisions
                 24:  system division