[all-commits] [llvm/llvm-project] b0922a: [LoopVectorize] Make VPWidenCanonicalIVRecipe::exe...

[david-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b0922a9dcd11710562f38cefc51872f835d50b0a
      https://github.com/llvm/llvm-project/commit/b0922a9dcd11710562f38cefc51872f835d50b0a
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2022-01-10 (Mon, 10 Jan 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/VPlan.cpp
    M llvm/test/Transforms/LoopVectorize/AArch64/sve-tail-folding.ll

  Log Message:
  -----------
  [LoopVectorize] Make VPWidenCanonicalIVRecipe::execute work for scalable vectors

The code in VPWidenCanonicalIVRecipe::execute only worked for fixed-width
vectors due to the way we generate the values per lane. This patch changes
the code to use a combination of vector splats and step vectors to get
the same result. This then works for both fixed-width and scalable vectors.

Tests that exercise this code path for scalable vectors have been added here:

  Transforms/LoopVectorize/AArch64/sve-tail-folding.ll

Differential Revision: https://reviews.llvm.org/D113180