d81a6e5f1d
The current policy is to always favor accumulators if possible, however, this is not always optimal. Particularly, accumulators play a crucial role in enabling QPU instruction merges, since these are limited to both the ADD and the ALU instructions addressing at most 2 physical registers. For 2-src instructions, this means that to be able to merge we need them to address at least 2 accumulators. While favoring accumulators does help the case for instruction merges in general, it is risky to assign accumulators to variables that have long life spans. Doing so will make the accumulator unavailable for any other instructions during that life span, and since we only have a few accumulators, we can quickly run out and losing our capacity to merge instructions for large parts of the qpu program. On the other hand, we also want to avoid the extreme case were we keep allocating physical registers to the point we run out, even if we have accumulators available, since accumulators have additional restrictions and may not be suitable for everything. This change continues the policy of favoring accumulators, but it only does so if the life span of the temps is short, to ensure that we can recycle accumulators often across instructions and avoid running out for sections of the QPU code, unless we are already running out of physical registers. total instructions in shared programs: 13654647 -> 13336921 (-2.33%) instructions in affected programs: 11015919 -> 10698193 (-2.88%) helped: 39758 HURT: 17325 Instructions are helped. total threads in shared programs: 412046 -> 412038 (<.01%) threads in affected programs: 16 -> 8 (-50.00%) helped: 0 HURT: 4 Threads are HURT. total uniforms in shared programs: 3745726 -> 3746003 (<.01%) uniforms in affected programs: 17296 -> 17573 (1.60%) helped: 76 HURT: 99 Uniforms are HURT. total max-temps in shared programs: 2364430 -> 2359942 (-0.19%) max-temps in affected programs: 109117 -> 104629 (-4.11%) helped: 2893 HURT: 772 Max-temps are helped. total spills in shared programs: 5727 -> 5746 (0.33%) spills in affected programs: 221 -> 240 (8.60%) helped: 1 HURT: 2 total fills in shared programs: 13121 -> 13139 (0.14%) fills in affected programs: 466 -> 484 (3.86%) helped: 1 HURT: 2 total sfu-stalls in shared programs: 33432 -> 34491 (3.17%) sfu-stalls in affected programs: 18219 -> 19278 (5.81%) helped: 4459 HURT: 5087 Inconclusive result total inst-and-stalls in shared programs: 13688079 -> 13371412 (-2.31%) inst-and-stalls in affected programs: 11030017 -> 10713350 (-2.87%) helped: 39630 HURT: 17429 Inst-and-stalls are helped. total nops in shared programs: 335753 -> 333708 (-0.61%) nops in affected programs: 112659 -> 110614 (-1.82%) helped: 8726 HURT: 7383 Inconclusive result Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10686>
`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.rst <https://mesa3d.org/install.html>`_), but the recommended way is to use Meson (`docs/meson.rst <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.rst <https://mesa3d.org/bugs.html>`_). Contributing ------------ Contributions are welcome, and step-by-step instructions can be found in our documentation (`docs/submittingpatches.rst <https://mesa3d.org/submittingpatches.html>`_). Note that Mesa uses gitlab for patches submission, review and discussions.