[PATCH] D88209: [ARM] Check for LSTP side-effects.

[Sam Parker via Phabricator via llvm-commits]

samparker created this revision.
samparker added reviewers: SjoerdMeijer, dmgreen, samtebbs.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls.
Herald added a project: LLVM.
samparker requested review of this revision.

If the LSTP instruction is inserted with an element count low enough to immediately predicate some lanes as false, this can have some unintended effects on any proceeding MVE instructions in the preheader.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D88209

Files:
  llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
  llvm/test/CodeGen/Thumb2/LowOverheadLoops/iv-two-vcmp.mir
  llvm/test/CodeGen/Thumb2/LowOverheadLoops/lstp-insertion-position.mir
  llvm/test/CodeGen/Thumb2/LowOverheadLoops/mov-after-dlstp.mir
  llvm/test/CodeGen/Thumb2/mve-gather-scatter-tailpred.ll

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