[PATCH] D70068: [SLP] Enhance SLPVectorizer to vectorize vector aggregate

[Anton Afanasyev via Phabricator via llvm-commits]

anton-afanasyev marked 2 inline comments as done.
anton-afanasyev added inline comments.


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Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:2879-2880
+  if (auto *VT = dyn_cast<VectorType>(EltTy)) {
+    if (VT->isScalable())
+      return 0;
+    EltTy = VT->getElementType();
----------------
ABataev wrote:
> anton-afanasyev wrote:
> > ABataev wrote:
> > > ABataev wrote:
> > > > Why do we have this check?
> > > Also, would be good to have a test for this if we don't have it yet.
> > Hmm, you're right, I'm just to delete this check. I haven't faced any issue concerning scalability, but decided to check it just in case (`{ <vscale x 2 x float>, <vscale x 2 x float> }` is not isomorphic to `<4 x float>`?). But I see no similar check across `SLPVectorizer.cpp`, so I'm to delete this check.
> My question was different. I just wanted some explanation what's the problem with the scalable vectors? If the check is required we must have it. Also, still, would be good to have a test for this situation.
I wasn't familiar with `vscale` property, but learned it now. That check was actually unnecessary: `{ <vscale x N x Ty>, <vscale x N x Ty> }` maps to `<vscale x 2N x Ty>`,  so we can deal with this scalability set to true.


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  https://reviews.llvm.org/D70068/new/

https://reviews.llvm.org/D70068