[all-commits] [llvm/llvm-project] 453dc4: [OPT-DBG] Teach DbgEntityHistoryCalculator about m...

[Tom Weaver via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 453dc4d7ec5a3c3d8f54fc358bc5673834516d48
      https://github.com/llvm/llvm-project/commit/453dc4d7ec5a3c3d8f54fc358bc5673834516d48
  Author: Tom Weaver <Tom.Weaver at Sony.com>
  Date:   2019-12-20 (Fri, 20 Dec 2019)

  Changed paths:
    M llvm/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
    M llvm/test/DebugInfo/COFF/pieces.ll
    A llvm/test/DebugInfo/X86/dbg_entity_calc_ignores_KILL_instruction_at_return.mir
    A llvm/test/DebugInfo/X86/dbg_entity_calc_ignores_KILL_instruction_still_clobbers.mir
    M llvm/test/DebugInfo/X86/pieces-3.ll

  Log Message:
  -----------
  [OPT-DBG] Teach DbgEntityHistoryCalculator about meta-instructions.

The calculator was considering instructions such as KILLs as clobbers
of a physical address. This is wrong as meta instructions such as KILLs
produce no output in the final program and thus don't clobber or change
any physical location's value. As a result they're safe to ignore whilst
calculating location list ranges.

reviewers: aprantl, vsk

diff revision: https://reviews.llvm.org/D70497

fixes: https://bugs.llvm.org/show_bug.cgi?id=38753