> -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Binyamin Dissen > Sent: Thursday, April 23, 2009 10:45 AM > To: [email protected] > Subject: Re: Effective pipeline programming [was:RE: METAL C: CodeGen > defeciency?] > > On Thu, 23 Apr 2009 09:58:18 -0400 "Farley, Peter x23353" > <[email protected]> wrote: <Snipped> > :>In the notes under the Branch on Condition instruction in Chapter 7: > > :>"4. Execution of BCR 15,0 (that is, an instruction > :>with a value of 07F0 hex) may result in significant > :>performance degradation. To ensure optimum > :>performance, the program should avoid use of > :>BCR 15,0 except in cases when the serialization > :>or checkpoint-synchronization function is actually > :>required." > > As there is no reason to code a BCR 15,0 this provides little value. > CNOP/NOPR generate BCR 0,0.
Agreed, but this was just an example of pipeline-related information provided in the z/Arch PoOP. Not useful per se, I agree, but I'm sure there are many more such notes that I haven't read about that might indeed be useful to know. Hence my request for a collected source of such information. Peter This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
