[all-commits] [llvm/llvm-project] 99e7bf: [AVR] Optimize int16 shift operation for shift amo...

[Ben Shi via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 99e7bf46c9e34644a8c0033684798dcafc790200
      https://github.com/llvm/llvm-project/commit/99e7bf46c9e34644a8c0033684798dcafc790200
  Author: Ben Shi <ben.shi at streamcomputing.com>
  Date:   2022-01-04 (Tue, 04 Jan 2022)

  Changed paths:
    M llvm/lib/Target/AVR/AVRExpandPseudoInsts.cpp
    M llvm/lib/Target/AVR/AVRISelLowering.cpp
    M llvm/lib/Target/AVR/AVRISelLowering.h
    M llvm/lib/Target/AVR/AVRInstrInfo.td
    M llvm/test/CodeGen/AVR/shift.ll

  Log Message:
  -----------
  [AVR] Optimize int16 shift operation for shift amount greater than 8

Skip operation on the lower byte in int16 logical left shift when
shift amount is greater than 8.

Skip operation on the higher byte in int16 logical & arithmetic
right shift when shift amount is greater than 8.

Reviewed By: aykevl

Differential Revision: https://reviews.llvm.org/D115594