[PATCH] D87464: [TargetLowering] Improve SimplifyDemandedBits for AND and OR

Simon Pilgrim via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 10 09:40:18 PDT 2020


RKSimon added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:1220
+      return true;
+    assert(!Known.hasConflict() && "Bits known to be one AND zero?");
+
----------------
If we're worried about the cost of the extra SimplifyDemandedBits, we might be able to just create Op0DemandedBits/Op1DemandedBits from the knowbits and only use these on the SimplifyMultipleUseDemandedBits cases below? The calls currently only use the original DemandedBits.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87464/new/

https://reviews.llvm.org/D87464



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