[PATCH] D72423: [DemandedBits] Improve accuracy of Add propagator

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added reviewers: regehr, nikic.
RKSimon added a subscriber: regehr.
RKSimon added a comment.

Adding @regehr and @nikic as they might have some thoughts on this

If possible I'd like to see some tests in InstCombine/InstSimplify that demonstrates the benefit of this.

Does anyone have comments about the exhaustive tests? 4 bits shouldn't take very long to complete but I'm not sure about general policy on this approach.



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Comment at: llvm/include/llvm/Analysis/DemandedBits.h:76
+                                           const KnownBits &LHS,
+                                           const KnownBits &RHS);
+
----------------
Would it make sense to move this into KnownBits so DAG/GlobalIsel can reuse it more easily?


Repository:
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  https://reviews.llvm.org/D72423/new/

https://reviews.llvm.org/D72423