Dear Valentin, In message <[email protected]> you wrote: > > > Could you please be a bit more specific which "advantage of the > > e500mc cores" you have in mind that would not be supportedby the > > generic-powerpc target of configuration of the ELDK? > > I was mostly thinking about all the mechanisms introduced by the PowerISA 2.06 > Instruction set. I was thinking that even if the e500mc core is compatible > with > the PowerISA 2.03, it would be better to produce code with PowerISA 2.06.
Which of these extensions seem relevant to your applications? I mean, even if Power ISA v.2.06 contains new vector-scalar FP instructions, I don't think that GCC will automatically generate these, nor can I assess that your code would actually benefit from it. Most of the extensions are actually about virtualisation and hypervisor zupport. Do you have any specific test cases and/or benchmarks that demonstrate this, and that are relevant to your application code? > I have mostly ARM experience and there every new core brings a new ISA that > requires a new target architecture to really take advantage of it. Maybe this > influenced a lot my expectations with this e500mc core and how to take > advantage > of it. >From what I've seen, a large amount of such talk is marketing babble. Yes, you can come up with synthetic benchmarks that will show improved performance - but how much does it mean in real life? Many of the performance related GCC patches deal with micro-optimizations, where it is difficult for me to balance the performance benefit for a few exotic corner-cases of code against the risk of introducing new bugs by little tested code. And how much can benchmarks be trusted? Even reputable organizations are known to come up with numbers that are primarily driven by marketing aspects, see for example [1]. Unless proven otherwise I doubt that a specific e500mc configuration of the ELDK would have measurable performance advantages in most application environments. [1] http://www.heise.de/open/meldung/Linaro-trickst-beim-Benchmarken-1616514.html Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [email protected] Plans break down. You cannot plan the future. Only presumptuous fools plan. The wise man _steers_. - Terry Pratchett, _Making_Money_ _______________________________________________ eldk mailing list [email protected] http://lists.denx.de/mailman/listinfo/eldk
