[all-commits] [llvm/llvm-project] af80a4: [ARM] Generate [SU]RHADD from (b - (~a)) >> 1

[Petre-Ionut Tudor via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: af80a4353e1462cefaa37d56eb76c8695a832ee2
      https://github.com/llvm/llvm-project/commit/af80a4353e1462cefaa37d56eb76c8695a832ee2
  Author: Petre-Ionut Tudor <petre-ionut.tudor at arm.com>
  Date:   2020-07-03 (Fri, 03 Jul 2020)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.h
    M llvm/lib/Target/AArch64/AArch64InstrInfo.td
    M llvm/test/CodeGen/AArch64/arm64-vhadd.ll

  Log Message:
  -----------
  [ARM] Generate [SU]RHADD from (b - (~a)) >> 1

Summary:
Teach LLVM to recognize the above pattern, which is usually a
transformation of (a + b + 1) >> 1, where the operands are either
signed or unsigned types.

Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82669