[llvm-commits] [llvm] r84038 - in /llvm/trunk: lib/Analysis/BasicAliasAnalysis.cpp test/Analysis/BasicAA/phi-aa.ll
clattner at apple.com
Tue Oct 13 23:00:34 PDT 2009
On Oct 13, 2009, at 6:31 PM, Evan Cheng wrote:
>> Did you look at the compile time impact of this on something like
>> GVN on 403.gcc?
> I am not seeing any compile time impact.
>> Because you only have one 'VisitedPHIs' set, you are conflating
>> PHIs walked on the LHS with phis walked on the RHS. I guess it
>> probably doesn't matter because if the same phi shows up on both
>> sides, they definitely alias. This is worth mentioning in a
>> comment somewhere.
> The analysis stops asap it hits a phi source which is itself a phi.
> So the worst possible case if both LHS and RHS are phis. In that
> case, its m x n.
Yep, makes sense, please add a comment somewhere to this effect.
Thanks for working on this, improving AA is a great thing to do.
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