search for: slsr

...a performance regression and noticed that LoopStrengthReduce hoists loop invariants (e.g., the initial formulae of indvars) in the reverse order of how they appear in the loop. This reverse order creates troubles for the StraightLineStrengthReduce pass I recently add. While I understand ultimately SLSR should be able to sort independent candidates in an optimal order, does it make sense to canonicalizing the order of LSR-hoisted loop invariants back to the "natural" order? IMO, the optimized code should in general resemble the original code unless intentionally changed otherwise. More...

...the initial formulae of > > indvars) in the reverse order of how they appear in the loop. > It has to to get maximized hoisting. > > > > > This reverse order creates troubles for the StraightLineStrengthReduce > pass > > I recently add. While I understand ultimately SLSR should be able to sort > > independent candidates in an optimal order, does it make sense to > > canonicalizing the order of LSR-hoisted loop invariants back to the > > "natural" order? IMO, the optimized code should in general resemble the > > original code unless...

Hi, As you may have noticed, since last year, we (Google's CUDA compiler team) have contributed quite a lot to the effort of optimizing LLVM for CUDA programs. I think it's worthwhile to write some docs to wrap them up for two reasons. 1) Whoever wants to understand or work on these optimizations has some detailed docs instead of just source code to refer to. 2) RFC on how to improve

...e=> on the > straight-line scalar optimizations. I will send out more docs on other > optimizations later. Please feel free to comment. > > Thanks, > Jingyue > > > Out of curiosity, is there any plan to make the NVPTX-originated passes > (separateconstantoffsetfromgep, slsr, naryreassociate) more generic? They > seem very specialized for the nVidia GPU addressing modes despite the > generic names, and in my tests tend to pessimize our target more often than > not for that reason. > > It’d be really nice to have something more generic, and I might look i...