[PATCH] D91415: [InstCombine] add multi-use demanded bits fold for add with low-bit mask

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp:838
+      // just return the add's variable operand.
+      if ((*C & LowMask).isNullValue())
+        return I->getOperand(0);
----------------
We could technically support non-uniform vectors here by matching m_Constant and using a similar ConstantExpr fold.


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Comment at: llvm/test/Transforms/InstCombine/and.ll:1052
 
+; Multi-use demanded bits - 'add' doesn't change 'and'
+
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Vector tests?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D91415/new/

https://reviews.llvm.org/D91415