[PATCH] D127680: [BasicTTI] Allow generic handling of scalable vector fshr/fshl

[Philip Reames via Phabricator via llvm-commits]

reames added inline comments.


================
Comment at: llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp:425
+  case Intrinsic::fshr:
+    // Match legacy behavior - this is probably not the right costing here
+    if (isa<ScalableVectorType>(RetTy))
----------------
dmgreen wrote:
> craig.topper wrote:
> > Seems like this should be a FIXME?
> I don't think this needs to be added. Just updating the costs in the test files to whatever is now produced will likely be more accurate, and more in-line with the scalar and fixed length vector costs. We can then update them more accurately in the future.
I don't work on SVE, don't have any sense for what "reasonable" costs are for the target, and don't particularly want to be on the blame list for a potential performance swing investigation.  If you think the costs are likely reasonable, I'd ask that you remove the bailout in a separate following change.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127680/new/

https://reviews.llvm.org/D127680