[all-commits] [llvm/llvm-project] cdac44: [SplitKit] Cope with no live subranges in defFromP...

[Jay Foad via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cdac4492b4a523a888a013d42ea0a968f684ed59
      https://github.com/llvm/llvm-project/commit/cdac4492b4a523a888a013d42ea0a968f684ed59
  Author: Jay Foad <jay.foad at amd.com>
  Date:   2020-09-30 (Wed, 30 Sep 2020)

  Changed paths:
    M llvm/lib/CodeGen/SplitKit.cpp
    A llvm/test/CodeGen/AMDGPU/splitkit-nolivesubranges.mir

  Log Message:
  -----------
  [SplitKit] Cope with no live subranges in defFromParent

Following on from D87757 "[SplitKit] Only copy live lanes", it is
possible to split a live range at a point when none of its subranges
are live. This patch handles that case by inserting an implicit def
of the superreg.

Patch by Quentin Colombet!

Differential Revision: https://reviews.llvm.org/D88397