[PATCH] D126939: [SLP] Avoid converting undef to poison when gathering.

[Alexey Bataev via Phabricator via llvm-commits]

ABataev added inline comments.


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:7559
         NumValues = VF;
+      } else if (UniqueValues.size() == 1 && NumValues == 1) {
+        NumValues = VF;
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vporpo wrote:
> @ABataev I am not sure this is the right fix for it, please take a look.
I think you need to drop `&& NumValues == 1` check, otherwise we may miss something like `undef, 0, under, undef`


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126939/new/

https://reviews.llvm.org/D126939