Power8 branch conversion

By: SHK (no.delete@this.mail.com), July 6, 2015 12:41 pm
Room: Moderated Discussions
Maynard Handley (name99.delete@this.name99.org) on July 6, 2015 10:25 am wrote:

>
> The IBM branch over one instruction is neat, but, like you said
> for forming immediates, it reflects a hole in the iSA.

Power has a conditional move (isel) since v2.06 so a programmer/compiler should choose it over branches if it's just to skip 1-2 instructions.

Maybe that kind of hardware optimization is there for old non-recompiled code?
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          Benefit of dynamic hammock predicationsomeotherdude2015/07/06 05:12 PM
            Benefit of dynamic hammock predicationMichael S2015/07/07 01:19 AM
          Benefit of dynamic hammock predicationPatrick Chase2015/07/06 10:20 PM
            SIMD predication is also helpful, of course (NT)Paul A. Clayton2015/07/07 07:45 AM
        Power8 branch conversionGabriele Svelto2015/07/07 02:50 AM
          isel works for storesPaul A. Clayton2015/07/07 07:43 AM
            isel works for storesPatrick Chase2015/07/07 11:08 AM
            isel DOES NOT work for storessomeotherdude2015/07/07 04:01 PM
              isel DOES NOT work for storesWilco2015/07/07 04:40 PM
              Yes it doesPatrick Chase2015/07/07 11:14 PM
                Yes it doesvvid2015/07/08 09:51 AM
            You don't need isel eitherGabriele Svelto2015/07/08 02:01 AM
              You don't need isel eitherPaul A. Clayton2015/07/08 04:46 AM
                You don't need isel eitherGabriele Svelto2015/07/08 05:22 AM
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