[PATCH] D131894: [SLP]Try to vectorize single store operands.

Tue Aug 16 05:32:14 PDT 2022

RKSimon accepted this revision.
RKSimon added a comment.
This revision is now accepted and ready to land.

LGTM with one minor

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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:12245
+        // Try to vectorize chain in store, if this is the only store to the
+        // address in the block.
+        if ((I == Stores.end() || I->second.size() == 1) &&
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ABataev wrote:
> RKSimon wrote:
> > This comment suggests we're checking for aliasing of the pointer as well? But I thought this was supposed to be purely about the stored value having one use?
> I tried to reduce compile time effect with this change, so added another check that we have only single store in the basic block for the provided base pointer.
> The alternative solution is just enable `ShouldStartVectorizeHorAtStore` by default but it requires some extra work with side effect and compile time analysis. 
OK - please can you make it clear in the comment that this is purely to reduce compile time and that ShouldStartVectorizeHorAtStore could one day be switched on by default.

Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131894/new/

https://reviews.llvm.org/D131894