Vasily Khoruzhick
3b15fb3575
Mali4x0 supports writing depth and stencil from fragment shader and we've been using it quite a while for depth/stencil buffer reload. The missing part was specifying output register for depth/stencil. To figure it out, I changed reload shader to use register $4 as output and poked RSW bits (or rather consecutive 4 bit groups) until tests that rely on reload started to pass again. It turns out that register number for gl_FragDepth/gl_FragStencil is in rsw->depth_test and register number for gl_FragColor is in rsw->multi_sample and it's repeated 4 times for some reason (likely for MSAA?) With this knowledge we now can modify ppir compiler to support multiple store_output intrinsics. To do that just add destination SSA for store_output to the registers list for regalloc and mark them explicitly as output. Since it's never read in shader we have to take care about it in liveness analysis - basically just mark it alive from the time when it's written to the end of the block. If it's live only in the last instruction, mark it as live_internal, so regalloc doesn't clobber it. Then just let regalloc do its job, and then copy register number to the shader state and program it in RSW. The tricky part is gl_FragStencil, since it resides in the same register as gl_FragDepth and with the current design of the compiler it's hard to merge them. However gl_FragStencil doesn't seem to be part of GL2 or GLES2, so we can just leave it not implemented. Also we need to take care of stop bit for instructions - now we can't just set it in every instruction that stores output, since there may be several outputs. So if there's any store_output instructions in the block just mark that block has a stop, and set stop bit in the last instruction in the block. The only exception is discard - we always need to set stop bit in discard instruction. Reviewed-by: Andreas Baierl <ichgeh@imkreisrum.de> Reviewed-by: Erico Nunes <nunes.erico@gmail.com> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13830>
`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 `OFTC's #dri-devel <irc://irc.oftc.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.