[all-commits] [llvm/llvm-project] fa2daa: [2/2][RemoveRedundantDebugValues] Add a Pass that ...

[Djordje Todorovic via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fa2daaeff82e3eb26fe7008715024f5bc11f7f1a
      https://github.com/llvm/llvm-project/commit/fa2daaeff82e3eb26fe7008715024f5bc11f7f1a
  Author: Djordje Todorovic <djordje.todorovic at syrmia.com>
  Date:   2021-07-15 (Thu, 15 Jul 2021)

  Changed paths:
    M llvm/lib/CodeGen/RemoveRedundantDebugValues.cpp
    M llvm/test/CodeGen/PowerPC/non-debug-mi-search-frspxsrsp.ll
    M llvm/test/DebugInfo/MIR/X86/remove-redundant-dbg-vals.mir

  Log Message:
  -----------
  [2/2][RemoveRedundantDebugValues] Add a Pass that removes redundant DBG_VALUEs

This patch adds the forward scan for finding redundant DBG_VALUEs.

This analysis aims to remove redundant DBG_VALUEs by going forward
in the basic block by considering the first DBG_VALUE as a valid
until its first (location) operand is not clobbered/modified.
For example:

(1) DBG_VALUE $edi, !"var1", ...
(2) <block of code that does affect $edi>
(3) DBG_VALUE $edi, !"var1", ...
 ...
in this case, we can remove (3).

Differential Revision: https://reviews.llvm.org/D105280