[PATCH] D59174: [DAGCombine][AArch64] Fold (x & ~y) | y patterns

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

In D59174#1423934 <https://reviews.llvm.org/D59174#1423934>, @RKSimon wrote:

> These seem to be managing special cases of the bit select pattern OR(AND(X,Y),AND(Z,~Y)) - would we benefit from adding a helper function to detect these, similar to what we have for isBitwiseNot ? Although in this case we'd have to generate the -1 constant.


Don't think a helper would be useful here, as this is specifically looking for degenerate forms of the bit select pattern where one of the ands has been folded away.


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