[PATCH] D83440: [InstSimplify] Re-enable select ?, undef, X -> X transform when X is provably not poison

[Nuno Lopes via Phabricator via llvm-commits]

nlopes added inline comments.


================
Comment at: llvm/lib/Analysis/InstructionSimplify.cpp:4124
+  // select ?, undef, X -> X
+  if (isa<UndefValue>(TrueVal) && isGuaranteedNotToBeUndefOrPoison(FalseVal))
+    return FalseVal;
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craig.topper wrote:
> Should I be passing CxtI and DT here? I based this off the code in SimplifyInsertElementInst, but maybe i should have based it off of SimplifyFreezeInst?
Yes, you can; it's correct to do so.
The only issue is that `SimplifySelectInst()` doesn't seem to receive the select instruction as argument to be passed as CxtI.


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  https://reviews.llvm.org/D83440/new/

https://reviews.llvm.org/D83440