[all-commits] [llvm/llvm-project] 3755ea: [AMDGPU] Fix scan of atomicFSub in AtomicOptimizer...

[Pravin Jagtap via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 3755ea93b4f7d7a637db307d1e56256a16f4459a
      https://github.com/llvm/llvm-project/commit/3755ea93b4f7d7a637db307d1e56256a16f4459a
  Author: Pravin Jagtap <prjagtap at amd.com>
  Date:   2023-09-13 (Wed, 13 Sep 2023)

  Changed paths:
    M llvm/lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp
    M llvm/test/CodeGen/AMDGPU/global_atomic_optimizer_fp_rtn.ll
    M llvm/test/CodeGen/AMDGPU/global_atomics_iterative_scan_fp.ll
    M llvm/test/CodeGen/AMDGPU/global_atomics_optimizer_fp_no_rtn.ll
    M llvm/test/CodeGen/AMDGPU/global_atomics_scan_fsub.ll

  Log Message:
  -----------
  [AMDGPU] Fix scan of atomicFSub in AtomicOptimizer. (#66082)

[D156301](https://reviews.llvm.org/D156301) introduced atomic
optimizations for FAdd/FSub. For FSub, reduction/scan needs to be
performed using add operation (`not sub`) and memory location will be
updated by reduced value using atomic sub later by only one lane.

---------

Authored-by: Pravin Jagtap <Pravin.Jagtap at amd.com>