[PATCH] D98422: [Alias] Add a ah-hoc pattern for aliasGEP

[JinGu Kang via Phabricator via llvm-commits]

jaykang10 added a comment.

In D98422#2623306 <https://reviews.llvm.org/D98422#2623306>, @reames wrote:

> If I'm reading the code right, this looks potentially expensive for compile time.  You're recursing on each phi operand individually.  Can we narrow the scope any without loosing your motivating example?
>
> I agree that this seems to make more sense in isKnownNonEqual than basic aa.  In that context, it would naturally follow to handle two phis with N-1 trivially different values (e.g. constants), and recurse through at most one input pair.  Would that handle your example?

@reames In order to check the recursive operand of PHI node, I thought it is enough to check backedge from PHI node's incoming block to the block with PHI node using dominance relation. I could be mis-understanding what you suggest . If I missed something, please let me know.


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https://reviews.llvm.org/D98422