Page MenuHomePhabricator

[X86] Add prefer-128-bit subtarget feature.
ClosedPublic

Authored by craig.topper on Fri, Sep 6, 9:35 PM.

Details

Summary

Similar to the previous prefer-256-bit flag. We might want to
enable this by default some CPUs. This just starts the initial
work to implement and prove that it effects TTI's vector width.

Diff Detail

Repository
rL LLVM

Event Timeline

craig.topper created this revision.Fri, Sep 6, 9:35 PM
Herald added a project: Restricted Project. · View Herald TranscriptFri, Sep 6, 9:35 PM
Herald added a subscriber: hiraditya. · View Herald Transcript
lebedev.ri added inline comments.
llvm/lib/Target/X86/X86.td
383 ↗(On Diff #219221)

Did you mean SSE?

craig.topper marked an inline comment as done.Sat, Sep 7, 12:30 AM
craig.topper added inline comments.
llvm/lib/Target/X86/X86.td
383 ↗(On Diff #219221)

We'll end up using 128-bit VEX encoded instructions which are part of AVX/AVX2

RKSimon accepted this revision.Sat, Sep 7, 4:45 AM

LGTM - this could be useful!

This revision is now accepted and ready to land.Sat, Sep 7, 4:45 AM
Closed by commit rL371319: [X86] Add prefer-128-bit subtarget feature. (authored by ctopper, committed by ). · Explain WhySat, Sep 7, 12:53 PM
This revision was automatically updated to reflect the committed changes.