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Alyssa Rosenzweig 54d7907c27 nir: Propagate *2*16 conversions into vectors
If we have code like:

   ('f2f16', ('vec2', ('f2f32', 'a@16'), '#b@32'))

We would like to eliminate the conversions, but the existing rules can't
see into the the (heterogenous) vector. So instead of trying to
eliminate in one pass, we add opts to propagate the f2f16 into the
vector. Even if nothing further happens, this is often a win since then
the created vector is smaller (half2 instead of float2). Hence the above
gets transformed to

   ('vec2', ('f2f16', ('f2f32', 'a@16')), ('f2f16', '#b@32'))

Then the existing f2f16(f2f32) rule will kick in for the first component
and constant folding will for the second and we'll be left with

   ('vec2', 'a@16', '#b@16')

...eliminating all conversions.

v2: Predicate on !options->vectorize_vec2_16bit. As discussed, this
optimization helps greatly on true vector architectures (like Midgard)
but wreaks havoc on more modern SIMD-within-a-register architectures
(like Bifrost and modern AMD). So let's predicate on that.

v3: Extend for integers as well and add a comment explaining the
transforms.

Results on Midgard (unfortunately a true SIMD architecture):

total instructions in shared programs: 51359 -> 50963 (-0.77%)
instructions in affected programs: 4523 -> 4127 (-8.76%)
helped: 53
HURT: 0
helped stats (abs) min: 1 max: 86 x̄: 7.47 x̃: 6
helped stats (rel) min: 1.71% max: 28.00% x̄: 9.66% x̃: 7.34%
95% mean confidence interval for instructions value: -10.58 -4.36
95% mean confidence interval for instructions %-change: -11.45% -7.88%
Instructions are helped.

total bundles in shared programs: 25825 -> 25670 (-0.60%)
bundles in affected programs: 2057 -> 1902 (-7.54%)
helped: 53
HURT: 0
helped stats (abs) min: 1 max: 26 x̄: 2.92 x̃: 2
helped stats (rel) min: 2.86% max: 30.00% x̄: 8.64% x̃: 8.33%
95% mean confidence interval for bundles value: -3.93 -1.92
95% mean confidence interval for bundles %-change: -10.69% -6.59%
Bundles are helped.

total quadwords in shared programs: 41359 -> 41055 (-0.74%)
quadwords in affected programs: 3801 -> 3497 (-8.00%)
helped: 57
HURT: 0
helped stats (abs) min: 1 max: 57 x̄: 5.33 x̃: 4
helped stats (rel) min: 1.92% max: 21.05% x̄: 8.22% x̃: 6.67%
95% mean confidence interval for quadwords value: -7.35 -3.32
95% mean confidence interval for quadwords %-change: -9.54% -6.90%
Quadwords are helped.

total registers in shared programs: 3849 -> 3807 (-1.09%)
registers in affected programs: 167 -> 125 (-25.15%)
helped: 32
HURT: 1
helped stats (abs) min: 1 max: 3 x̄: 1.34 x̃: 1
helped stats (rel) min: 20.00% max: 50.00% x̄: 26.35% x̃: 20.00%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 16.67% max: 16.67% x̄: 16.67% x̃: 16.67%
95% mean confidence interval for registers value: -1.54 -1.00
95% mean confidence interval for registers %-change: -29.41% -20.69%
Registers are helped.

total threads in shared programs: 2471 -> 2520 (1.98%)
threads in affected programs: 49 -> 98 (100.00%)
helped: 25
HURT: 0
helped stats (abs) min: 1 max: 2 x̄: 1.96 x̃: 2
helped stats (rel) min: 100.00% max: 100.00% x̄: 100.00% x̃: 100.00%
95% mean confidence interval for threads value: 1.88 2.04
95% mean confidence interval for threads %-change: 100.00% 100.00%
Threads are [helped].

total spills in shared programs: 168 -> 168 (0.00%)
spills in affected programs: 0 -> 0
helped: 0
HURT: 0

total fills in shared programs: 186 -> 186 (0.00%)
fills in affected programs: 0 -> 0
helped: 0
HURT: 0

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4999>
2020-06-30 16:21:33 +00:00
.appveyor Appveyor: Quickly fix meson build. 2019-11-14 21:45:23 +00:00
.gitlab/issue_templates gitlab: Ask about reproduction rate in the issue template 2020-05-20 10:20:00 +00:00
.gitlab-ci CI: Re-enable Panfrost T860 jobs 2020-06-30 14:49:16 +01:00
bin bin/symbols-check: explain C++ symbols workaround 2020-06-23 11:05:39 +00:00
build-support configure: commit test files 2017-10-16 16:32:43 -07:00
docs radv: enable VK_AMD_shader_ballot on GFX6-7 with both compiler backends 2020-06-29 07:40:05 +00:00
doxygen doxygen: Plumb through gallium/ to automated documentation 2016-05-30 17:53:45 +01:00
include turnip: semaphore support. 2020-06-26 19:34:17 +00:00
scons scons/windows: Support build with LLVM 10. 2020-04-14 08:40:56 +00:00
src nir: Propagate *2*16 conversions into vectors 2020-06-30 16:21:33 +00:00
subprojects meson: use github URL for wraps instead of completely unreliable wrapdb 2020-01-16 23:06:43 +00:00
.dir-locals.el dir-locals.el: Adds White Space support 2016-11-14 19:17:49 +02:00
.editorconfig docs: fixup indentation 2020-01-18 11:39:32 +01:00
.gitignore intel/tools: Add unit tests for assembler 2019-05-07 14:33:48 -07:00
.gitlab-ci.yml CI: Re-enable the Windows VS2019 build job 2020-06-30 10:34:05 +01:00
.mailmap .mailmap: add an alias for Andres Gomez 2020-04-30 14:33:20 +03:00
.travis.yml travis: autodetect python version instead of hard-coding it 2019-12-21 20:23:08 +00:00
Android.common.mk tree-wide: fix deprecated GitLab URLs 2020-05-23 15:33:50 +00:00
Android.mk freedreno: android: fix build failure on android due to python version 2020-02-07 16:34:49 +00:00
appveyor.yml appveyor: Remove Meson job. 2020-04-01 01:13:21 +00:00
CleanSpec.mk CleanSpec.mk: Remove HOST_OUT_release 2018-08-02 15:42:40 -06:00
common.py scons: Print a deprecation warning about using scons on not windows 2019-10-24 18:33:50 +00:00
meson.build meson: Do not require shader cache for radv. 2020-06-28 01:10:45 +00:00
meson_options.txt meson: remove "empty array"/"array of an empty string" confusion 2020-06-02 19:36:12 +00:00
README.rst README: update references to internal docs 2020-06-13 10:42:01 +00:00
REVIEWERS REVIEWERS: add VMware reviewers 2019-10-18 16:42:40 +00:00
SConstruct tree-wide: fix deprecated GitLab URLs 2020-05-23 15:33:50 +00:00
VERSION cut 20.1 branch 2020-04-29 23:52:43 +00:00

`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.