[PATCH] D113209: [LV] Use VScaleForTuning to fine-tune the cost per lane.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen created this revision.
Herald added a subscriber: hiraditya.
sdesmalen requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

When targeting a specific CPU with scalable vectorization, the knowledge
of that particular CPU's vscale value can be used to tune the cost-model
and make the cost per lane less pessimistic.

If the target implements 'TTI.getVScaleForTuning()', the cost-per-lane
is calculated as:

  Cost / (VScaleForTuning * VF.KnownMinLanes)

Otherwise, it assumes a value of 1 meaning that the behavior
is unchanged and calculated as:

  Cost / VF.KnownMinLanes


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113209

Files:
  llvm/include/llvm/Analysis/TargetTransformInfo.h
  llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
  llvm/include/llvm/CodeGen/BasicTTIImpl.h
  llvm/lib/Analysis/TargetTransformInfo.cpp
  llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/AArch64/scalable-vectorization-cost-tuning.ll
  llvm/test/Transforms/LoopVectorize/AArch64/scalable-vectorization.ll
  llvm/test/Transforms/LoopVectorize/AArch64/scalable-vf-hint.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D113209.384822.patch
Type: text/x-patch
Size: 12224 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20211104/feeb33f0/attachment.bin>