[all-commits] [llvm/llvm-project] 2b3c13: [DebugInfo] Treat empty metadata operands the same...

[Orlando Cazalet-Hyams via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2b3c13b7166b479439ac05954b532c44aa3414fc
      https://github.com/llvm/llvm-project/commit/2b3c13b7166b479439ac05954b532c44aa3414fc
  Author: OCHyams <orlando.hyams at sony.com>
  Date:   2023-04-26 (Wed, 26 Apr 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
    M llvm/test/CodeGen/AMDGPU/llvm.dbg.value.ll
    A llvm/test/DebugInfo/X86/dbg-empty-metadata-lowering.ll

  Log Message:
  -----------
  [DebugInfo] Treat empty metadata operands the same as undef operands in SelectionDAG

Without this patch SelectionDAG silently drops dbg.values using `!{}` operands.

Related to https://discourse.llvm.org/t/auto-undef-debug-uses-of-a-deleted-value

Reviewed By: StephenTozer

Differential Revision: https://reviews.llvm.org/D140990