a8ac0bd759
This is a less invasive alternative to the workaround documented in the hardware spec for GEN:BUG:1407528679, which doesn't involve disabling structured control flow (it's unlikely that switching to GOTO/JOIN would have actually fixed the problem anyway). Under some conditions Gen12 hardware can end up executing a BB with all channels disabled, which will lead to the execution of any NoMask instructions in it, even though any execution-masked instructions will be correctly shot down. This may break assumptions of some NoMask SEND messages whose descriptor depends on data generated by live invocations of the shader. This avoids the problem by predicating certain instructions on an ANY horizontal predicate that makes sure that their execution is omitted when all channels of the program are disabled. The shader-db impact of this patch seems to be minimal: total instructions in shared programs: 17169833 -> 17169913 (0.00%) instructions in affected programs: 30663 -> 30743 (0.26%) helped: 0 HURT: 42 total cycles in shared programs: 336966176 -> 336968568 (0.00%) cycles in affected programs: 2367290 -> 2369682 (0.10%) helped: 0 HURT: 13 Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com> Cc: 20.0 <mesa-stable@lists.freedesktop.org>
`Mesa <https://mesa3d.org>`_ - The 3D Graphics Library ====================================================== Source ------ This repository lives at https://gitlab.freedesktop.org/mesa/mesa. Other repositories are likely forks, and code found there is not supported. Build & install --------------- You can find more information in our documentation (`docs/install.html <https://mesa3d.org/install.html>`_), but the recommended way is to use Meson (`docs/meson.html <https://mesa3d.org/meson.html>`_): .. code-block:: sh $ mkdir build $ cd build $ meson .. $ sudo ninja install Support ------- Many Mesa devs hang on IRC; if you're not sure which channel is appropriate, you should ask your question on `Freenode's #dri-devel <irc://chat.freenode.net#dri-devel>`_, someone will redirect you if necessary. Remember that not everyone is in the same timezone as you, so it might take a while before someone qualified sees your question. To figure out who you're talking to, or which nick to ping for your question, check out `Who's Who on IRC <https://dri.freedesktop.org/wiki/WhosWho/>`_. The next best option is to ask your question in an email to the mailing lists: `mesa-dev\@lists.freedesktop.org <https://lists.freedesktop.org/mailman/listinfo/mesa-dev>`_ Bug reports ----------- If you think something isn't working properly, please file a bug report (`docs/bugs.html <https://mesa3d.org/bugs.html>`_). Contributing ------------ Contributions are welcome, and step-by-step instructions can be found in our documentation (`docs/submittingpatches.html <https://mesa3d.org/submittingpatches.html>`_). Note that Mesa uses gitlab for patches submission, review and discussions.