[all-commits] [llvm/llvm-project] 38641d: [VPlan] Do not sink uniform recipes in sinkScalarO...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 38641ddf3e5630db6ecb167b2d1b520b22e56405
      https://github.com/llvm/llvm-project/commit/38641ddf3e5630db6ecb167b2d1b520b22e56405
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2021-05-27 (Thu, 27 May 2021)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
    M llvm/test/Transforms/LoopVectorize/vplan-sink-scalars-and-merge-vf1.ll
    M llvm/test/Transforms/LoopVectorize/vplan-sink-scalars-and-merge.ll

  Log Message:
  -----------
  [VPlan] Do not sink uniform recipes in sinkScalarOperands.

For uniform ReplicateRecipes, only the first lane should be used, so
sinking them would mean we have to compute the value of the first lane
multiple times. Also, at the moment, sinking them causes a crash because
the value of the first lane is re-used by all users.

Reported post-commit for D100258.