search for: looptransform

Hi, As I now have a working LLVM installation I would like to start experimenting with loop transformations. Special loop unrollings, mergers etc. I just wanted to check if there are any special things that one should take into account ? I just figured I'd ask on the list before I start digging since there might be some tips out there. Anyway, back to the code. Thanks. /Fred

...upport such extended loop transformations. First, the transformations must be represented in the IR metadata. Second, a pass must carry-out all transformations. Regarding the first part, I suggest storing the loop transformations in a metadata node of the parent function, e.g.: define func() !looptransform !3 [...] br i1 %cond, label %loopheader, ... !loop !1 !1 = distinct !{ !4, !2 } ; LoopID !2 = {"llvm.loop.id", "myloop"} ; Loop name Only the loop id remains a property of the loop. The transformations are stored in the !looptransform metadata node: !3...

On 2/5/20 6:13 PM, Chris Lattner via llvm-dev wrote: > > >> On Feb 2, 2020, at 10:35 PM, Michael Kruse via llvm-dev >> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >>> >>> That's actually not how I read it. Red/green trees was *one* of the >>> nine items you mentioned in your list and this didn't

...s not mean we cannot learn from each other's experience. 3) On the technical point design of red/green trees, my personal opinion is > that this isn’t solving the important part of the problem. Red/green trees > (as far as I’m aware > <https://llvm.org/devmtg/2018-10/slides/Kruse-LoopTransforms.pdf>) are a > memory saving optimization. > Not entirely, there would also be a run-time cost if we had to copy the complete IR before for creating a new "red" representation. If this was necessary, I think it would be a barrier to speculatively apply transformations. >...