========================================= -----Original Message----- From: "Thompson, Steve (SCI TW)" <[EMAIL PROTECTED]> Sent: 7/27/2006 11:46 AM To: "IBM-MAIN@BAMA.UA.EDU" <IBM-MAIN@BAMA.UA.EDU> Subject: Re: Doing a LM of two words on a double word bounday - is it serialized?
Binyamin: Are you trying to ensure that all CPUs will see the "new" values once you are done? Because that is what I assumed you were really after when I attempted to answered the question. In order to do that, you must do an update that forces the other CPUs to "flush" or store the affected cache line(e) in their local cache before your update is started. In another life (Amdahl 5990 MDF development) we assisted this using a "pipe-cleaner" instruction (BR 0) Something like: BR 0 CSD x,y,zz BR 0 BR 0 /snip/ Steve Thompson ========================================= I think CSD should be CDS. If you read the PoPs, you'll see the CS/CDS/CSG/CDSG all perform check-point synchronization before and after the operation. The "BR 0" is not needed. There were instruction sequences in Amdahl 5990/5995 MDF that used "NOPR 0" to fill the instruction pipeline to compensate for some processing that may contaminate the pipeline. I can't recall those weird situations at the moment. Jeffrey D. Smith Farsight Systems Corporation 24 BURLINGTON DR LONGMONT, CO 80501 303-774-9381 direct 303-709-8153 cell 303-484-6170 fax ---------------------------------------------------------------------- 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
