[PATCH] D32422: LoopVectorizer: let target prefer scalar addressing computations (+ minor improvements in SystemZTTI)

[Renato Golin via Phabricator via llvm-commits]

rengolin added a comment.

Hi Jonas,

I understand your problem and the SystemZ part is probably fine (I can't review that myself), but I fear introducing such a call-back will not help the underlying cause.

What we really need to to know if the shuffle costs will be higher than the savings, and that should be done by asking the shuffle costs directly.

I'd assume that targets without scatter/gather support would return higher costs for those operations (probably a magnitude higher), so maybe there's a problem in the load/store cost analysis that could considerably simplify this.

cheers,
--renato



================
Comment at: include/llvm/Analysis/TargetTransformInfo.h:394
+  /// Return true if target doesn't mind addresses in vectors.
+  bool prefersVectorizedAddressing() const;
+
----------------
Can't you check for scatter/gather support directly?


https://reviews.llvm.org/D32422