On Thu, 15 Nov 2018 13:21:01 -0600, Paul Gilmartin wrote: >On Thu, 15 Nov 2018 12:38:05 -0600, Tom Marchant wrote: > >>On Thu, 15 Nov 2018 08:33:55 -0800, Charles Mills wrote: >> >>>LARL is also very cool. It is like LA without a base register. >> >>Agreed. One thing to be aware of with LARL. It uses a signed >>halfword that is added to the current PSW address. As a result >>it cannot be used to get the address of an odd address. ... >> >I believe the stumbling block is not the signedness but that the >displacement is multiplied by 2 in order to double the reach.
Right. The fact that it is signed allows references forward or backward. I neglected to say that the signed offset is in halfwords, and so it is multiplied by 2. Thanks for the correction. > >>... Nor can it be used to get an address in a DSECT, or in a CSECT that >>is not part of the same load module. >> >The requires using the result from STORAGE; the latter a V-constant. > >Is Binder nowadays savvy to RL displacements to honor RLD entries? I believe that you can have a relative branch to a symbol in another CSECT that is resolved at binder time. I'm not sure if that is what you mean. I haven't used it, so I'm not writing this from experience. >If the programmer is so rash as to define an ENTRY point with an odd >address, Bad Things can happen. I don't think that HLASM will allow you to do that. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
