[all-commits] [llvm/llvm-project] 790c75: [AMDGPU] Add SI_EARLY_TERMINATE_SCC0 for early ter...

[Carl Ritson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 790c75c16373d37846c8433a69efd9b0d5e4ad12
      https://github.com/llvm/llvm-project/commit/790c75c16373d37846c8433a69efd9b0d5e4ad12
  Author: Carl Ritson <carl.ritson at amd.com>
  Date:   2021-01-13 (Wed, 13 Jan 2021)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIInsertSkips.cpp
    M llvm/lib/Target/AMDGPU/SIInstructions.td
    A llvm/test/CodeGen/AMDGPU/early-term.mir

  Log Message:
  -----------
  [AMDGPU] Add SI_EARLY_TERMINATE_SCC0 for early terminating shader

Add pseudo instruction to allow early termination of pixel shader
anywhere based on the value of SCC.  The intention is to use this
when a mask of live lanes is updated, e.g. live lanes in WQM pass.
This facilitates early termination of shaders even when EXEC is
incomplete, e.g. in non-uniform control flow.

Reviewed By: foad

Differential Revision: https://reviews.llvm.org/D88777