Messages in this thread |  | | Subject | Re: Pentium SSE prefetcht0 instruction... How do you make it work | From | Robert Love <> | Date | 27 Sep 2001 15:55:35 -0400 |
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On Thu, 2001-09-27 at 14:43, Tony Hagale wrote: > Intel's p3/4 prefetch instructions are hints only. They are only executed > asynchronously, and depend heavily on the other load on the processor at > the time. They are not required to prefetch, *and* they are not required > to be executed when you think they should in the flow of the program. You > can serialize them by using an MFENCE instruction, but they still aren't > guaranteed to run. > > Check the p4 manuals. In fact, I'm not sure prefetch was implemented in > p3. I could be wrong, check the manual.
prefetch is in P3 and P4.
there are prefetcht0, prefetcht1, prefetcht2, and prefetchnta instructions, Intel's programming docs have references on these all online.
-- Robert M. Love rml at ufl.edu rml at tech9.net
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