Jason Ekstrand
4386c06770
Version 4.4 of the GLSL spec changed the definition of noise*() to always return zero and earlier versions of the spec allowed zero as a valid implementation. All drivers, as far as I can tell, unconditionally call lower_noise() today which turns ir_unop_noise into zero. We've got a 10-year-old comment in there saying "In the future, ir_unop_noise may be replaced by a call to a function that implements noise." Well, it's the future now and we've not yet gotten around to that. In the mean time, the GLSL spec has made doing so illegal. To make things worse, we then pretend to handle the opcode in glsl_to_nir, ir_to_mesa, and st_glsl_to_tgsi even though it should never get there given the lowering. The lowering in st_glsl_to_tgsi defines noise*() to be 0.5 which is an illegal implementation of the noise functions according to pre-4.4 specs. We also have opcodes for this in NIR which are never used because, again, we always call lower_noise(). Let's just kill the whole opcode and make builtin_builder.cpp build a bunch of functions that just return zero. Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> Reviewed-by: Eric Anholt <eric@anholt.net> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4624>
`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.