Anna Sophia Welker via llvm-dev
2020-Nov-04 14:00 UTC
[llvm-dev] Fwd: Re: [RFC] Goals for VPlan-based cost modelling
+ llvm-dev, which got accidentally dropped - sorry for any duplication -------- Forwarded Message -------- Hi Sjoerd,> There was a VPlan round-table at the US LLVM dev conference just a few > weeks ago, and I have linked in the people who were involved in this > as cost-modeling was one of the topics that was discussed. You may > have seen this already, but Dave started doing some work in this area > recently: > > https://reviews.llvm.org/D89322 > https://reviews.llvm.org/D89323That's good to know, thanks for linking the experts!> Just some first high-level remarks on your proposal: I think work in > this area would be very valuable and solve a real problem that we > currently have. If you plan to choose this as a subject for a master's > thesis, you probably need to think about how big of a task this is and > having some motivating examples would be good too (but you mentioned > some already). To me it sounds like a big task that needs a lot of > plumbing in VPlan, but that's why having this discussion here is > interesting and hopefully people with more VPlan experience can > provide insights.You are right and I am fully aware that building a fully functional cost model for VPlan might be a very big task, well beyond the scope of a master thesis. But right now there isn't even clear documentation of how exactly such a cost model should look like, and I think it is an interesting and important topic to explore. If I end up with a good idea , a thesis that discusses the topic so there finally is some documentation, and a proof-of-concept implementation, I hope that would already be of some value and interest to the community. But yes, good examples are needed - that's one reason for this RFC, as of course my experience in the matter is very localised to a specific kind of instructions, and I am sure many members of the community have met other issues that could help painting a better picture of what should be done. Best, Anna -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20201104/c796752e/attachment.html>