[PATCH] D148963: [X86] Support `X86ISD::PCMPEQ` and `X86ISD::PCMPGT` in ComputeKnownBits

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

In D148963#4304551 <https://reviews.llvm.org/D148963#4304551>, @nikic wrote:

> Shouldn't this be a DAGCombine instead? It seems pointless to make computeKnownBits() recurse past an instruction that can only return either unknown or constant. If it returns constant, we want to just replace the instruction, and otherwise we get zero information.

At least part of this is only matching cases because it has access to the DemandedElts mask


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  https://reviews.llvm.org/D148963/new/

https://reviews.llvm.org/D148963