[LLVMdev] LSR is Unbearably Slow

David Greene dag at cray.com
Wed Aug 11 16:13:52 PDT 2010

On Wednesday 11 August 2010 17:05:17 Jan Voung wrote:
> I also noticed LSR spending a lot of time in GenerateAllReuseFormulae, just
> to have some cases pruned in NarrowSearchSpaceUsingHeuristics. I'm not
> familiar enough with the code to comment on how this affects the quality of
> LSR results, but a hack is to "EstimateSearchSpaceComplexity" inside the
> loops of GenerateAllReuseFormulae and cut out early.

I assume you mean NarrowSearchSpaceUsingHeuristics inside the loops.

I tried this and it helped a bit but nowhere near enough to overcome
the algorithmic complexity.  Looks like we need another solution.

[copied this to the bug to keep track of it]


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