[all-commits] [llvm/llvm-project] 8181dc: [AMDGPU] WQM/WWM: Fix marking of partial definitions

[Carl Ritson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8181dcd30feeb7258685cafc35e0b01c894c6f3b
      https://github.com/llvm/llvm-project/commit/8181dcd30feeb7258685cafc35e0b01c894c6f3b
  Author: Carl Ritson <carl.ritson at amd.com>
  Date:   2021-02-19 (Fri, 19 Feb 2021)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp
    M llvm/test/CodeGen/AMDGPU/wqm.mir

  Log Message:
  -----------
  [AMDGPU] WQM/WWM: Fix marking of partial definitions

Track lanes when processing definitions for marking WQM/WWM.
If all lanes have been defined then marking can stop.
This prevents marking unnecessary instructions as WQM/WWM.

In particular this fixes a bug where values passing through
V_SET_INACTIVE would me marked as requiring WWM.

Reviewed By: piotr

Differential Revision: https://reviews.llvm.org/D95503