[PATCH] D30472: [DAGCombine] Simplify ISD::AND in GetDemandedBits.

Simon Pilgrim via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Feb 28 14:55:35 PST 2017


RKSimon added inline comments.


================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:7441
+    APInt KnownZero, KnownOne;
+    DAG.computeKnownBits(V.getOperand(0), KnownZero, KnownOne);
+    if ((KnownOne & Mask) == Mask)
----------------
How often are cases from each operand occurring? Since we canonicalize constants to the RHS would it be performant to test that first?


Repository:
  rL LLVM

https://reviews.llvm.org/D30472





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