[LLVMdev] opt and bugs
baldrick at free.fr
Thu Nov 19 14:57:38 CST 2009
> My first question is: When we start running random combinations of
> passes using opt, which ones should we leave out, because you folks
> don't want to hear that they're wrong? For example, the other day I
> learned that ABCD is not yet ready for this sort of testing. A while
> ago someone on the list said something similar about predsimplify
> (though it looks like that pass has disappeared from the tree?).
check out include/llvm/Support/StandardPasses.h. All of the passes scheduled
there need to be solid because they are really being used.
> Also I'd appreciate some advice about probabilities for each pass. For
> example, it seems like a lot of passes will have little to do if Mem2Reg
> doesn't run, so perhaps that pass should get >0.5 probability of
> running. Does that make sense and do other examples come to mind?
You could start with the list of passes you get at -O3, then randomly
alter it, shifting the pass order, dropping passes and introducing more.
Each run might take too long though due to scheduling many passes.
> Frankly I don't expect a zillion bugs to come out of this but it is
> super easy and you asked for it :).
Well, we will soon know!
Thanks for doing this,
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