Find a file
Jason Ekstrand cd4ffb376f intel/fs: Account for live range lengths in spill costs
The current register allocator has a concept of "spill benefit" which is
based on the number of nodes with which a given node interferes.  The
idea is that you want to spill stuff with high interference because
those are the most likely registers to help when spilling.  However,
this fails to take into account the length of the live range so the
allocator frequently picks "cheap" (not many uses) registers which are
actually very short lived and so spilling them doesn't help with the
pressure situation.

This commit takes into account the length of the live range to make
long-lived registers more likely to get spilled than short-lived ones.
This encourages the spill chooser to choose slightly larger registers
which will affect a larger area of the program and hopefully we have to
spill fewer of them to get the same reduction in over-all register
pressure.

Shader-db results on Kaby Lake:

    total spills in shared programs: 23664 -> 12050 (-49.08%)
    spills in affected programs: 19243 -> 7629 (-60.35%)
    helped: 296
    HURT: 8

    total fills in shared programs: 32028 -> 25139 (-21.51%)
    fills in affected programs: 20378 -> 13489 (-33.81%)
    helped: 295
    HURT: 16

Of course, most of that is in Deus Ex...

Shader-db results on Kaby Lake (without Deus Ex):

    total spills in shared programs: 6479 -> 5834 (-9.96%)
    spills in affected programs: 3231 -> 2586 (-19.96%)
    helped: 40
    HURT: 4

    total fills in shared programs: 17165 -> 17099 (-0.38%)
    fills in affected programs: 6951 -> 6885 (-0.95%)
    helped: 40
    HURT: 7

Even without Deus Ex, the spill help is pretty respectable.  The worst
hurt shaders were one compute shader in Aztec Ruins and one fragment
shader in KSP that were each hurt by around 13% fill 9% spill.

VkPipeline-db results on Kaby Lake:

    total spills in shared programs: 9149 -> 8069 (-11.80%)
    spills in affected programs: 5197 -> 4117 (-20.78%)
    helped: 27
    HURT: 16

    total fills in shared programs: 26390 -> 25477 (-3.46%)
    fills in affected programs: 12662 -> 11749 (-7.21%)
    helped: 24
    HURT: 22

The Vulkan results were decidedly more mixed but we don't have nearly as
many apps in that database yet.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2019-04-18 23:04:45 +00:00
.gitlab-ci gitlab-ci: Use LLVM 3.4 from Debian jessie for scons-llvm job 2019-04-16 10:57:55 +02:00
bin meson: remove meson-created megadrivers symlinks 2019-04-11 12:40:16 +00:00
build-support configure: commit test files 2017-10-16 16:32:43 -07:00
docs doc/features: Add a few extensions to the feature matrix 2019-04-16 08:01:13 +00:00
doxygen doxygen: Plumb through gallium/ to automated documentation 2016-05-30 17:53:45 +01:00
include vulkan: Update the XML and headers to 1.1.106 2019-04-15 13:25:43 +00:00
scons scons: Compatibility with Scons development version string 2019-03-12 14:22:34 +00:00
scripts appveyor: Revert commits adding Cygwin support. 2019-01-25 14:13:26 +00:00
src intel/fs: Account for live range lengths in spill costs 2019-04-18 23:04:45 +00:00
.dir-locals.el dir-locals.el: Adds White Space support 2016-11-14 19:17:49 +02:00
.editorconfig editorconfig: Add max_line_length property 2019-01-10 15:50:34 +02:00
.gitattributes Disable autocrlf for Visual Studio project files. 2008-02-28 12:34:01 +09:00
.gitignore .gitignore: Remove autotool artifacts 2019-04-18 14:12:43 -07:00
.gitlab-ci.yml gitlab-ci: Use LLVM 3.4 from Debian jessie for scons-llvm job 2019-04-16 10:57:55 +02:00
.mailmap .mailmap: Add a few more alises for myself 2019-02-13 12:03:41 -08:00
.travis.yml ci: Delete autotools build jobs 2019-04-15 13:44:41 -07:00
Android.common.mk android: fix missing backspace for line continuation 2019-03-08 21:14:24 +00:00
Android.mk android: fix LLVM version string related building errors 2019-04-13 18:56:14 +02:00
appveyor.yml appveyor: Revert commits adding Cygwin support. 2019-01-25 14:13:26 +00:00
CleanSpec.mk CleanSpec.mk: Remove HOST_OUT_release 2018-08-02 15:42:40 -06:00
common.py scons/svga: remove opt from the list of valid build types 2018-10-26 12:09:00 -06:00
meson.build kmsro: Add lima renderonly support 2019-04-11 09:57:53 +08:00
meson_options.txt intel/common: Add unit tests for gen_mi_builder 2019-04-11 18:04:09 +00:00
README.rst README: Drop the badges from the readme 2019-02-07 12:46:17 -06:00
REVIEWERS docs: drop most autoconf references 2019-04-15 13:44:34 -07:00
SConstruct scons: Require python 2.7 2018-08-16 13:52:56 -07:00
VERSION bump version for 19.0 branch 2019-01-29 15:30:25 -08:00

`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.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.