Noooooo!!!! That was what I was trying to say: you can no longer say "instruction X takes n cycles." You just cannot. That is why IBM no longer publishes such a thing. At best case an LR or an L take "no time at all" -- read what I wrote earlier. Worst case an LR takes a little while and an L takes a really long time. (How's that for technical precision?)
Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Brian Chapman Sent: Tuesday, August 13, 2019 7:52 AM To: [email protected] Subject: Re: Instruction speeds Thanks Giliad. This is what I was searching for. I understand that the timings in this document are very old and probably wildly inaccurate for today's Z systems, but would it be on a relative scale? Would a LR be twice the speed of a L? Thank you, Brian Chapman On Tue, Aug 13, 2019 at 10:28 AM Giliad Wilf < [email protected]> wrote: > On Mon, 12 Aug 2019 20:48:18 -0400, Brian Chapman <[email protected]> > wrote: > > >Hi everyone, > > > >I did some searching, but I didn't find anything that really discussed > this > >on the topic that I'm interested. Is there anything published that > compares > >the cycle times of the most used instructions? > > > >For example; moving an address between areas of storage. I would assume > >that executing a LOAD and STORE would be much quicker than executing a > MVC. > > > >Or executing a LOAD ADDRESS to increment a register instead of ADD HALF > >WORD. > > > >Or does this really matter as much as ordering the instructions so they > are > >optimized for the pipeline? > > > > There used to be, with every new IBM System/360 machine, a "Functional > Characteristics" publication stating "Instruction Times" in microseconds. > Here is one for the IBM System/360 Model 85: > > > http://www.bitsavers.org/pdf/ibm/360/funcChar/A22-6916-1_360-85_funcChar_Jun68.pdf > > See page 27. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
