[PATCH] D66608: [InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, null

[Philip Reames via Phabricator via llvm-commits]

reames planned changes to this revision.
reames added a comment.

In D66608#1641754 <https://reviews.llvm.org/D66608#1641754>, @nikic wrote:

> As mentioned on the previous review, do we need to handle `getelementptr inbounds {}, {}* %p, i32 %idx`? That is, an inbounds GEP on a zero-sized type, which may be null for a non-zero index. It looks like this case is not handled in the existing code either though, so possibly this construction isn't legal (though I don't see anything to that effect in langref)?


I'm happy to add another bailout.  To be honest, the exact semantics of unsized types are not all clear to me.


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