[all-commits] [llvm/llvm-project] d9beff: [RegisterCoalescer] Fix IMPLICIT_DEF init removal ...

[Valery via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: d9beff04a30877c117e15c7fbc4d4e5c87e413ab
      https://github.com/llvm/llvm-project/commit/d9beff04a30877c117e15c7fbc4d4e5c87e413ab
  Author: vpykhtin <valery.pykhtin at gmail.com>
  Date:   2020-09-24 (Thu, 24 Sep 2020)

  Changed paths:
    M llvm/lib/CodeGen/RegisterCoalescer.cpp
    A llvm/test/CodeGen/AMDGPU/coalescing_makes_lanes_undef.mir

  Log Message:
  -----------
  [RegisterCoalescer] Fix IMPLICIT_DEF init removal for a register on joining

This patch removes redundant IMPLICIT_DEF for subregs which was leading to
incorrect register initialization on joining in some cases.

Reviewed by: qcolombet

Differential revision: https://reviews.llvm.org/D82258