[PATCH] D78210: [LV] Mark first-order recurrences as allowed exit

[Florian Hahn via Phabricator via llvm-commits]

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

LGTM, thanks!



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Comment at: llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp:671
                                                          SinkAfter, DT)) {
+          AllowedExit.insert(Phi);
           FirstOrderRecurrences.insert(Phi);
----------------
nit: it seems a bit counter-intuitive to add to something called `AllowedExit` to reject loops with users of Phi outside the loop. There might be potential for re-naming/refactoring to make it clearer in future. In the meantime it might make sense to add a comment.


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Comment at: llvm/test/Transforms/LoopVectorize/optsize.ll:129
+; CHECK-LABEL: @pr45526
+; CHECK-NOT: <
+;
----------------
This seems like a very subtle way to check vectorization is not happening. Given that the function is small, it might be better to check the IR for the whole function (or just the control-flow)


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