[all-commits] [llvm/llvm-project] e0e737: [AMDGPU] Keep skip branch for ds instructions

[Sebastian Neubauer via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e0e73714fbfeacad1a3adc0c6c8dbedcebc53ebc
      https://github.com/llvm/llvm-project/commit/e0e73714fbfeacad1a3adc0c6c8dbedcebc53ebc
  Author: Sebastian Neubauer <sebastian.neubauer at amd.com>
  Date:   2021-03-05 (Fri, 05 Mar 2021)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIRemoveShortExecBranches.cpp
    M llvm/test/CodeGen/AMDGPU/branch-condition-and.ll
    A llvm/test/CodeGen/AMDGPU/insert-skips-flat-vmem-ds.mir
    R llvm/test/CodeGen/AMDGPU/insert-skips-flat-vmem.mir
    M llvm/test/CodeGen/AMDGPU/ret_jump.ll
    M llvm/test/CodeGen/AMDGPU/si-lower-control-flow-unreachable-block.ll

  Log Message:
  -----------
  [AMDGPU] Keep skip branch for ds instructions

Same as other memory instructions, ds instructions add latency even if
exec is zero. Jumping over them if exec=0 is cheaper than executing
them.
With this change, the branch instruction that skips over a basic block
if exec=0 is not removed when the block contains a ds instruction.

Differential Revision: https://reviews.llvm.org/D97922