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Ian Romanick 5fb386c48d Revert "nir/algebraic: Convert some f2u to f2i"
Per https://gitlab.freedesktop.org/mesa/mesa/-/issues/5178#note_1019666,
the assumption fundamental to this optimization is false.  Section
2.4.1 (Float to Integer) of Ivy Bridge PRMs describes the situation.
The wording of the section is somewhat confusing (because it doesn't
clearly delineate between signed and unsigned integers), but the last
two rows of the table make it clear that F->UD conversion clamps
negative float values to 0.

All other hardware mentioned in that thread seems to behave the same
way.

The real problem is that, with hardware that behaves in this ways,
converting f2u(2147483648.0) to f2i(2147483648.0) changes the bit pattern
that would be produced from 0x80000000 to 0x7fffffff.

This reverts commit ad05920258.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12297>
(cherry picked from commit 84d2e53789)
2021-08-12 10:06:57 -07:00
.gitlab/issue_templates issue_templates/Bug Report: Rename master branch to main 2021-05-05 12:20:11 -07:00
.gitlab-ci ci: actually run piglit tests with virgl 2021-07-21 11:53:48 -07:00
android android: Restore android/Android.mk 2021-07-09 13:54:45 +00:00
bin pick-ui: show commit date 2021-08-12 10:06:57 -07:00
build-support configure: commit test files 2017-10-16 16:32:43 -07:00
docs docs: Add sha256 sum for 21.2.0 2021-08-04 12:07:28 -07:00
include crocus: Make the driver loader use PCI IDs for crocus 2021-07-03 06:34:33 +02:00
src Revert "nir/algebraic: Convert some f2u to f2i" 2021-08-12 10:06:57 -07:00
subprojects util: Perfetto SDK v15.0 2021-05-07 13:41:38 +00:00
.dir-locals.el dir-locals.el: Adds White Space support 2016-11-14 19:17:49 +02:00
.editorconfig editorconfig: Use 3-space tabs for .rst 2021-06-22 17:37:55 +00:00
.gitignore intel/tools: Add unit tests for assembler 2019-05-07 14:33:48 -07:00
.gitlab-ci.yml ci: Drop "success" job 2021-08-05 09:25:17 -07:00
.mailmap mailmap: Add two more lines for Alyssa Rosenzweig 2021-07-12 23:45:34 +00:00
.pick_status.json Revert "nir/algebraic: Convert some f2u to f2i" 2021-08-12 10:06:57 -07:00
.travis.yml travis: Download XQuartz from GitHub. 2021-05-29 10:25:16 +00:00
meson.build meson: dont use missing dumpbin path 2021-08-02 13:30:04 -07:00
meson_options.txt meson: allow egl_native_platform to be specified 2021-07-26 12:01:54 -07:00
README.rst docs: promote #dri-devel on oftc over freenode 2021-05-24 09:21:48 +00:00
REVIEWERS Fix up leftover "state_trackers" references to "frontends" 2021-07-02 07:35:05 +00:00
VERSION VERSION: bump for 21.2.0 release 2021-08-04 11:47:36 -07:00

`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 `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.