This is an archive of the discontinued LLVM Phabricator instance.

AMDGPU: add +xnack feature
ClosedPublic

Authored by nhaehnle on Jan 4 2016, 1:38 PM.

Details

Summary

Enabling this feature will account for the two SGPRs used by the hardware
to store the XNACK_MASK physically.

The hardware only requires this reservation when the XNACK feature is
explicitly enabled. At some point, HSA will probably want to do that, but
it does increase SGPR register pressure, so leave it disabled by default
for now (but do add a small test).

Diff Detail

Event Timeline

nhaehnle updated this revision to Diff 43918.Jan 4 2016, 1:38 PM
nhaehnle retitled this revision from to AMDGPU: add +xnack feature.
nhaehnle updated this object.
nhaehnle added reviewers: arsenm, tstellarAMD.
nhaehnle added a subscriber: llvm-commits.
arsenm accepted this revision.Jan 4 2016, 2:31 PM
arsenm edited edge metadata.

LGTM.

Is there some bit that should be set if it is enabled in the binary?

This revision is now accepted and ready to land.Jan 4 2016, 2:31 PM
This revision was automatically updated to reflect the committed changes.

I've added a hunk that sets the code_properties bit so it does not get forgotten. According to Tom, this enum isn't uptodate anyway.