[all-commits] [llvm/llvm-project] 61888d: [AArch64] Basic demand elements for some intrinsics

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 61888d97f67d98afafc224620ee1f9ecc7d062d0
      https://github.com/llvm/llvm-project/commit/61888d97f67d98afafc224620ee1f9ecc7d062d0
  Author: David Green <david.green at arm.com>
  Date:   2022-01-13 (Thu, 13 Jan 2022)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
    M llvm/test/Transforms/InstCombine/AArch64/demandelts.ll

  Log Message:
  -----------
  [AArch64] Basic demand elements for some intrinsics

A lot of neon intrinsics work lane-wise, meaning that non-demanded
elements in and not demanded out. This teaches that to
AArch64TTIImpl::simplifyDemandedVectorEltsIntrinsic for some simple
single-input truncate intrinsics, which can help remove unnecessary
instructions.

Differential Revision: https://reviews.llvm.org/D117097