[all-commits] [llvm/llvm-project] 9a98ab: [AArch64][SVE2] Change the cost of extends with S/...

[kmclaughlin-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9a98ab589a4fe17012b6af4fd14c0166d2d58d2b
      https://github.com/llvm/llvm-project/commit/9a98ab589a4fe17012b6af4fd14c0166d2d58d2b
  Author: Kerry McLaughlin <kerry.mclaughlin at arm.com>
  Date:   2023-08-29 (Tue, 29 Aug 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
    A llvm/test/Analysis/CostModel/AArch64/ext-rhadd.ll

  Log Message:
  -----------
  [AArch64][SVE2] Change the cost of extends with S/URHADD to 0

When SVE2 is enabled, we can combine an add of 1, add & shift right by 1
to a single s/urhadd instruction. If the operands to the adds are extended,
these extends will fold into the s/urhadd and their costs should be 0.

Reviewed By: david-arm, dtemirbulatov

Differential Revision: https://reviews.llvm.org/D157628