[all-commits] [llvm/llvm-project] 138e6c: [AArch64][TTI] Improve `LegalVF` when gather loads...

[Antonio Frighetto via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 138e6c1c86e8050781cb626598c380651d31206c
      https://github.com/llvm/llvm-project/commit/138e6c1c86e8050781cb626598c380651d31206c
  Author: Antonio Frighetto <me at antoniofrighetto.com>
  Date:   2023-10-27 (Fri, 27 Oct 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/test/Analysis/CostModel/AArch64/sve-gather.ll
    A llvm/test/Transforms/SLPVectorizer/AArch64/gather-load-128.ll

  Log Message:
  -----------
  [AArch64][TTI] Improve `LegalVF` when gather loads are scalarized

After determining the cost of loads that could not be coalesced into
`VectorizedLoads` in SLP, computing the cost of a gather-vectorized
load is carried out. Favour a potentially high valid cost when the
type of a group of loads, whose type is a vector of size dependent
upon `VF`, may be legalized into a scalar value.

Fixes: https://github.com/llvm/llvm-project/issues/68953.