[PATCH] D114799: [SLP]Improve vectorization of cmp instructions sequences.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/test/Transforms/SLPVectorizer/X86/reduction-logical.ll:111
+; SSE-NEXT:    [[S3:%.*]] = select i1 [[S2]], i1 [[TMP5]], i1 false
+; SSE-NEXT:    ret i1 [[S3]]
+;
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ABataev wrote:
> RKSimon wrote:
> > Any idea what happened here?
> The pair of `icmp slt` gets vectorized because the cost model decided that it is profitable. We can't handle these `select`s as reduction because `icmp` instructions have different predicates.
But the sgt didn't get swapped and from the TODO at line 9298 I take it we can't do an altopcode/perdicate to handle the ult?


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  https://reviews.llvm.org/D114799/new/

https://reviews.llvm.org/D114799