[all-commits] [llvm/llvm-project] 72e7e5: [MemorySSA] Always perform MemoryUses liveOnEntry ...

[aeubanks via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 72e7e5851f4aa1d7aef62d85338493ac34df5837
      https://github.com/llvm/llvm-project/commit/72e7e5851f4aa1d7aef62d85338493ac34df5837
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2023-07-06 (Thu, 06 Jul 2023)

  Changed paths:
    M llvm/include/llvm/Analysis/MemorySSA.h
    M llvm/lib/Analysis/MemorySSA.cpp
    M llvm/lib/Passes/PassBuilder.cpp
    M llvm/lib/Passes/PassRegistry.def
    A llvm/test/Analysis/MemorySSA/tbaa.ll

  Log Message:
  -----------
  [MemorySSA] Always perform MemoryUses liveOnEntry optimization on MSSA construction

Fixes invariant memory regressions in future DSE patches.

Also add a flag to print<memoryssa> to not ensure optimized uses to test this.

Noticeable compile time regression [1], but a future DSE change that depends on this more than makes up for it.

[1] https://llvm-compile-time-tracker.com/compare.php?from=9d5466849a770eeab222d5a5890376d3596e8ad6&to=95682dbe11d76a3342870437377216e96b167504&stat=instructions:u

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D152859


  Commit: 70503aeea73852402a9a858028544a942070fc88
      https://github.com/llvm/llvm-project/commit/70503aeea73852402a9a858028544a942070fc88
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2023-07-06 (Thu, 06 Jul 2023)

  Changed paths:
    M llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

  Log Message:
  -----------
  [DSE] Don't eagerly optimize MemorySSA uses

Compile time improvements:
https://llvm-compile-time-tracker.com/compare.php?from=a4a2b62495a63516a4f782acff1b19361906546b&to=a408521f71702a5c5fb65077adc23413d8631cfc&stat=instructions:u

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D152744


Compare: https://github.com/llvm/llvm-project/compare/897e69dd83de...70503aeea738