On Thu, 27 Jul 2006 15:54:00 +0000 "Jeffrey D. Smith" <[EMAIL PROTECTED]> wrote:
:>LM R2,R3,operand ; no check-point synch, no store. :>will concurrently load R2,R3. The values are fetched 8-bytes :>in parallel. If another CPU is concurrently storing 8-bytes, :>then your CPU will see the entire old 8-bytes or the entire :>new 8-bytes and never a mixture of old and new bytes. :>Note that if another CPU is storing with a narrower alignment, :>like a 4-byte store, then you will get inconsistent results :>with either CDS or LM/STM. In other words, if CPU1 is doing the LM of the doubleword while CPU2 is using PLO changing the two words via CSST (each separately on a word boundary), it is undefined whether CPU1 will get a consistent answer? I was thinking of using one word as a update-counter and the other a pointer to the chain. I was going to use PLO to do a compare/swap/store, with the compare/swap on the count and a store into the chain (possibly into the head pointer - thus both words in the doubleword would be accessed as single words). Obviously I would get bad results if the load of the chain header/count did not get a consistent result. Load word1 followed by PLO CL would obviously get consistent results. -- Binyamin Dissen <[EMAIL PROTECTED]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- 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