[PATCH] D101076: [SVE][LoopVectorize] Add support for scalable vectorization of first-order recurrences

[Paul Walker via Phabricator via llvm-commits]

paulwalker-arm added inline comments.


================
Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:4139-4143
+      auto *RuntimeVF = getRuntimeVF(Builder, IdxTy, VF);
+      auto *LastIdx = Builder.CreateBinOp(Instruction::Sub, RuntimeVF, One);
+      VectorInit = Builder.CreateInsertElement(
+          PoisonValue::get(VectorType::get(VectorInit->getType(), VF)),
+          VectorInit, LastIdx, "vector.recur.init");
----------------
Hi @kmclaughlin, sorry for the flyby comment but I just wanted to highlight this block looks equally applicable to fixed length vectors and thus ideally I'd prefer to not introduce split control flow unless absolutely necessary.

There's a couple of other changes below that also look like the "scalable" path can be used for all vector types.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D101076/new/

https://reviews.llvm.org/D101076