[all-commits] [llvm/llvm-project] b2020f: [DbgHistoryCalculator] Improve debug messages

[Felipe de Azevedo Piovezan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b2020fe3aab0d9e867d38847de38201a50cf983e
      https://github.com/llvm/llvm-project/commit/b2020fe3aab0d9e867d38847de38201a50cf983e
  Author: Felipe de Azevedo Piovezan <fpiovezan at apple.com>
  Date:   2023-04-11 (Tue, 11 Apr 2023)

  Changed paths:
    M llvm/include/llvm/CodeGen/DbgEntityHistoryCalculator.h
    M llvm/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
    M llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp

  Log Message:
  -----------
  [DbgHistoryCalculator] Improve debug messages

I've found that a frequent source of debug information loss in optimized
code is due to DEBUG_VALUE intrinsics in a position of the instruction
stream that is outside the scope of the variable it describes.

Tracking these is pretty difficult with the existing debug messages of
the history calculator; this patch addresses the issue by making it
obvious when this event happens.

Differential Revision: https://reviews.llvm.org/D147718