Re: S/390 (was Market pressures for more reliable software)

["Shmuel (Seymour J.) Metz" <spamtrap@library.lspace.org.invalid>]

In <rWO_6.10272$e5.30402@newsfeeds.bigpond.com>, on 06/28/2001
   at 11:17 PM, robin <robin_v@bigpond.nospam.com> said:

>But when the second address is zero, it does not branch, and the
>address of the next instruction is placed in the nominated register. 
>(e.g., BALR 3,0)

>This value (contents) is then used as the base for addressing
>purposes.

And that is the standard way to establish addressability when there
isn't a register known to contain a suitable base. 

ObBadCode. SVC 18 used to contain a sequence something like

         BALR  R3,0
         BALR  R3,0
         BALR  R3,0
         USING *,R3

which contains two extraneous instructions.


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