[PATCH] D54790: [ARM] Prevent parallel macs for unsigned values

Wed Nov 21 05:22:01 PST 2018

samparker created this revision.
samparker added a reviewer: SjoerdMeijer.
Herald added subscribers: chrib, kristof.beyls, javed.absar.

Both zext and sext are currently allowed during the search for narrow sequences and sexts operands are later added to the mac candidates. But operands of muls are also added, without checking whether they're sext or zext, which means we can generate a signed smlad when we shouldn't.

https://reviews.llvm.org/D54790

Files:
  lib/Target/ARM/ARMParallelDSP.cpp
  test/CodeGen/ARM/smlad0.ll
  test/CodeGen/ARM/smlald0.ll
  test/CodeGen/ARM/smlald2.ll

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