Well, I should have double checked the PoPS. Even if everybody thought this was an excellent idea (which they don't), all the current Control Registers 0-15 are in use. So there isn't one available to hold the "Register Stack" value. So it would require a special purpose instruction, like SET PREFIX, to set the stack pointer.
I was warned about using BAKR/PC in a CICS assembler routine if there was any chance of a program check. There is. But why is is not relevant to this discussion, and I don't want a us to veer off course like we do on IBM-MAIN quite often. Suffice it to say that it would be too difficult for something will too little return at this late date. On Thu, Jun 27, 2013 at 12:00 PM, Chris Craddock <[email protected]>wrote: > Not to take issue with JG on this but stacking operations definitely store > a lot more machine state than normal program linkage would require and so > even on the most current machines they take a lot longer. > > It would be a bad idea to do wholesale replacement of traditional > entry/exit linkage with BAKR/PR. > > But we're talking in terms of microseconds per instruction. The stacking > instructions are enormously valuable in situations where the alternative > would require you to obtain storage. They will ALWAYS outperform OS storage > obtain/release by many orders of magnitude. > > So use them appropriately for your situation and there's no real down > side. At this point I would usually feel compelled to throw in a remark > about interactions with recovery. But I am on a phone, so I won't. > > CC > > On Jun 27, 2013, at 9:37 AM, "John Gilmore" <[email protected]> wrote: > > > I wish I had some definitive timing results to provide. I do not. > > > > I can, however, report that timings for otherwise identical blocks of > > SRB code within which BAKR/PR and alternatives to them are used do not > > at all support the notion that BAKR/PR is slower than they. > > > > John Gilmore, Ashland, MA 01721 - USA > -- This is a test of the Emergency Broadcast System. If this had been an actual emergency, do you really think we'd stick around to tell you? Maranatha! <>< John McKown
