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    SubjectRe: Pentium SSE prefetcht0 instruction... How do you make it work
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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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