[all-commits] [llvm/llvm-project] e828dd: [ARM] Don't treat arguments as producesFalseLanesZero

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e828dd43027e1d2d096719e70d1e18d7bb9562c3
      https://github.com/llvm/llvm-project/commit/e828dd43027e1d2d096719e70d1e18d7bb9562c3
  Author: David Green <david.green at arm.com>
  Date:   2023-01-11 (Wed, 11 Jan 2023)

  Changed paths:
    M llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
    A llvm/test/CodeGen/Thumb2/LowOverheadLoops/mve-reduct-livein-arg.mir

  Log Message:
  -----------
  [ARM] Don't treat arguments as producesFalseLanesZero

Invalid tail predicated loops could be formed by treating function
arguments as FalseLanesZero due to getGlobalReachingDefs not returning
any values. Make sure we check that the list of Defs is empty and if so
treat it like a unknown value.

Differential Revision: https://reviews.llvm.org/D141399