[PATCH] D95645: [AArch64][GlobalISel] Add a combine to fold away truncate in: G_ICMP EQ/NE (G_TRUNC(v), 0)

[Amara Emerson via Phabricator via llvm-commits]

aemerson created this revision.
aemerson added reviewers: paquette, arsenm, foad.
aemerson added a project: LLVM.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls, rovka.
aemerson requested review of this revision.
Herald added a subscriber: wdng.

We try to do this optimization if we can determine that testing for the truncated bits with an eq/ne predicate results in the same thing as testing the lower bits.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95645

Files:
  llvm/lib/Target/AArch64/AArch64Combine.td
  llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp
  llvm/test/CodeGen/AArch64/GlobalISel/prelegalizercombiner-icmp-redundant-trunc.mir

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