Faith Ekstrand
7bfb7a2b81
This breaks the dependency pass in two. The first pass builds a
dependency graph, including first-wait information for each barrier.
The second applies uses the newly constructed dependencies to place
barriers. This fixes at least two known bugs:
1. We were placing redundant write barriers. In the case where we did
a load, for example, we would add read barriers for the address and
write barriers for the result. In the fairly common case where the
result is used before someone tries to overwrite the address, we
don't actually need both barriers because a wait on the result
implies a wait on the sources.
2. There were a bunch of WaR cases which weren't being handled
correctly. In particular, when a variable-latency instruction read
a register and then a fixed fixed-latency instruction read it, the
fixed-latency read would replace the variable latency read. When we
then wrote that value with a fixed-latency instruction, we wouldn't
see the hazard. This commit fixes it by replacing the single last
use per reg with a Vec of uses in the case of reads.
This fixes all known 1.1 memory model fails.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26615>
`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.