[all-commits] [llvm/llvm-project] 6a4714: [DebugInfo][DAG] Don't reuse debug location on COP...

[Tobias Bosch via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6a4714030e467293e839433a6754685ed3bdc108
      https://github.com/llvm/llvm-project/commit/6a4714030e467293e839433a6754685ed3bdc108
  Author: Tobias Bosch <tbosch at google.com>
  Date:   2020-05-29 (Fri, 29 May 2020)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    A llvm/test/DebugInfo/X86/dbg-value-funcarg3.ll

  Log Message:
  -----------
  [DebugInfo][DAG] Don't reuse debug location on COPY if width changes.

Summary:
This caused incorrect debug information for parameters:
Previously, after a COPY of a parameter that changes the width,
we would emit a DBG_VALUE that continues to be associated to that
parameter, even though it now used a different width.
This made the LiveDebugValues pass assume the parameter value
got clobbered and it stopped tracking the parameter entry
value, leading to incorrect debug information.

Fixes https://bugs.llvm.org/show_bug.cgi?id=39715

Subscribers: aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80819