Page MenuHomePhabricator

[WIP][TLI] SimplifyDemandedVectorElts(): for `OR`, don't demand elements that are known to be all-ones in another operand
Needs ReviewPublic

Authored by lebedev.ri on Sep 16 2021, 2:28 PM.

Details

Reviewers
RKSimon
Summary

This is a suggestion from https://reviews.llvm.org/D109726#3004107, although it does not work.

Diff Detail

Event Timeline

lebedev.ri created this revision.Sep 16 2021, 2:28 PM
lebedev.ri requested review of this revision.Sep 16 2021, 2:28 PM
Herald added a project: Restricted Project. · View Herald TranscriptSep 16 2021, 2:28 PM

@RKSimon i don't believe we can emulate what D109726 does when only looking at the OR,
i think we need to actually look at a blend (i.e. look past and and andn of operands),
and know what is being selected from what.