[PATCH] D151660: [InstCombine] (icmp eq A, -1) & (icmp eq B, -1) --> (icmp eq (A&B), -1)

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:2952
+  // (icmp eq A, -1) & (icmp eq B, -1) --> (icmp eq (A&B), -1)
+  // TODO: Remove this when foldLogOpOfMaskedICmps can handle undefs.
+  if (!IsLogical && PredL == (IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE) &&
----------------
Is there why this patch adds this new functionality and doesn't juist update `foldLogOpOfMaskedICmps` to handle undefs? Is it alot of work?


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:2958
+    return Builder.CreateICmp(PredL, NewAnd,
+                              ConstantInt::get(LHS0->getType(), -1));
+  }
----------------
`ConstantInt::get(LHS0->getType(), -1)` -> `Constant::getAllOnesValue(LHS0->getType())`


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D151660/new/

https://reviews.llvm.org/D151660