[all-commits] [llvm/llvm-project] bb5069: [SystemZ] Improvement of emitMemMemWrapper()

[Jonas Paulsson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bb506938be820df8c7992b7c567fa93afaab2bc4
      https://github.com/llvm/llvm-project/commit/bb506938be820df8c7992b7c567fa93afaab2bc4
  Author: Jonas Paulsson <paulsson at linux.vnet.ibm.com>
  Date:   2021-10-26 (Tue, 26 Oct 2021)

  Changed paths:
    M llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
    M llvm/test/CodeGen/SystemZ/memset-05.ll

  Log Message:
  -----------
  [SystemZ] Improvement of emitMemMemWrapper()

It was discovered that an extra register COPY remained when expanding a
(variable length) memory operation with a loop and there was another use of
the involved address register(s) afterwards.

A simple fix for this is to COPY the address registers before the loop and
use that new vreg instead.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D112065