[all-commits] [llvm/llvm-project] 250de7: [llvm-reduce] Add reduction for special globals li...

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 250de7388b34500b1597d25af5c42f718ed28575
      https://github.com/llvm/llvm-project/commit/250de7388b34500b1597d25af5c42f718ed28575
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-11-11 (Wed, 11 Nov 2020)

  Changed paths:
    M llvm/test/Reduce/remove-alias.ll
    M llvm/tools/llvm-reduce/CMakeLists.txt
    M llvm/tools/llvm-reduce/DeltaManager.h
    A llvm/tools/llvm-reduce/deltas/ReduceSpecialGlobals.cpp
    A llvm/tools/llvm-reduce/deltas/ReduceSpecialGlobals.h

  Log Message:
  -----------
  [llvm-reduce] Add reduction for special globals like llvm.used.

This patch adds a reduction of 'special' globals that lead to further
reductions (e.g. alias or regular globals reduction) being less efficient
because there are special constraints on values referenced in those
special globals. For example, values in @llvm.used and
@llvm.compiler.used need to be named, so replacing all uses of an
alias/global with undef or a different unnamed constant results in
invalid IR.

More details:
https://llvm.org/docs/LangRef.html#intrinsic-global-variables

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D90302