3cb091f8b4
The value-range tracking pass that is coming is not clever enough to know that the result of the ffma must be non-negative. Making it that smart will require quite a bit of work. It might be possible to add a special case that detects that a whole tree of fadd(fmul(fsat(a), fneg(fsat(a))), 1.0) cannot be negative. For cases when the comparison is used in the domain guard for a square-root (see nir/algebraic: Simplify fsqrt domain guard), the compare may be converted to a fmax. This patch also handles that case. All of the affected cases are in DiRT: Showdown. All Gen7+ platforms had similar results. (Ice Lake shown) total instructions in shared programs: 17225365 -> 17225303 (<.01%) instructions in affected programs: 40051 -> 39989 (-0.15%) helped: 62 HURT: 0 helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1 helped stats (rel) min: 0.07% max: 0.66% x̄: 0.27% x̃: 0.26% 95% mean confidence interval for instructions value: -1.00 -1.00 95% mean confidence interval for instructions %-change: -0.31% -0.22% Instructions are helped. total cycles in shared programs: 360842788 -> 360842595 (<.01%) cycles in affected programs: 1818081 -> 1817888 (-0.01%) helped: 29 HURT: 22 helped stats (abs) min: 1 max: 206 x̄: 20.66 x̃: 14 helped stats (rel) min: <.01% max: 9.55% x̄: 0.87% x̃: 0.42% HURT stats (abs) min: 1 max: 108 x̄: 18.45 x̃: 7 HURT stats (rel) min: <.01% max: 4.48% x̄: 0.56% x̃: 0.19% 95% mean confidence interval for cycles value: -14.48 6.91 95% mean confidence interval for cycles %-change: -0.71% 0.21% Inconclusive result (value mean confidence interval includes 0). No changes on any other Intel platform. Reviewed-by: Matt Turner <mattst88@gmail.com> Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
`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 email mailing-lists for patches submission, review and discussions.