[PATCH] D85848: [InlineCost] Skip scalable vectors in visitAlloca

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Analysis/InlineCost.cpp:857
+  if (isa<ScalableVectorType>(I.getAllocatedType()))
+    return false;
+
----------------
c-rhodes wrote:
> efriedma wrote:
> > This will refuse to inline any function with a scalable vector variable; that seems so conservative that it's likely to cause practical issues.  Please take the time to fix the code properly.
> > This will refuse to inline any function with a scalable vector variable; that seems so conservative that it's likely to cause practical issues. Please take the time to fix the code properly.
> 
> Is that not better than crashing? As far as I can tell either `getFixedSize` will be called causing a crash or it's a dynamic alloca that wont be inlined anyway.
> 
> I know we want to support scalable vectors here but unless I'm missing something this seems like a worthwhile improvement for the time being.
Reading the code, I think you could just replace the uses of getFixedSize() with getKnownMinSize() and get roughly the right behavior.

The reason I don't want to put this off is that inlining is very important for optimizations; if we add a hack now, we're inevitably going to have to look at it again very soon, so I'd rather just get it done now.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85848/new/

https://reviews.llvm.org/D85848