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[DAGCombiner] Teach scalarizeBinOpOfSplats handle scalable splat.
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Authored by jacquesguan on Mar 31 2022, 2:15 AM.

Details

Summary

This revision supports to scalarize a binary operation of two scalable
splat vectors.

Diff Detail

Event Timeline

jacquesguan created this revision.Mar 31 2022, 2:15 AM
Herald added a project: Restricted Project. · View Herald TranscriptMar 31 2022, 2:15 AM
jacquesguan requested review of this revision.Mar 31 2022, 2:15 AM

precommit the new tests and rebase so the patch shows the diff?

rebase the precommit test.

craig.topper added inline comments.Jun 14 2022, 9:49 PM
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
23506

Not sure we should be creating SPLAT_VECTOR on targets that don't support SPLAT_VECTOR. At the very least it's a waste of compile time to convert it back to a BUILD_VECTOR.

RKSimon added inline comments.Jun 15 2022, 4:31 AM
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
23476

Use DAG.isSplatValue instead?

23506

+1 at the very least we need a hasOperation() check for the getSplatVector path and getBuildVector fallback

Address comment.

Fix test case.

jacquesguan added inline comments.Jul 10 2022, 7:27 PM
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
23476

I tried to use DAG.isSplatValue, but this way would affect many no splat cases of X86 target, some of them are negative.

23506

Done, I only build splat_vector when is scalable now.

RKSimon accepted this revision.Jul 18 2022, 1:53 AM

LGTM with one minor

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
23476

OK - please can you add a TODO comment? It sounds like something that needs revisiting in the future.

This revision is now accepted and ready to land.Jul 18 2022, 1:53 AM

Address comment.

This revision was landed with ongoing or failed builds.Jul 18 2022, 8:23 PM
This revision was automatically updated to reflect the committed changes.
jacquesguan reopened this revision.Jul 19 2022, 1:24 AM
This revision is now accepted and ready to land.Jul 19 2022, 1:24 AM

rebase main