Skip to content

Clarify corner case behavior of --device option #2779

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 5 commits into from
Oct 18, 2024
Merged

Clarify corner case behavior of --device option #2779

Changes from 2 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
01ddb1b
Clarify corner case behavior of --device option
petergrossmann21 Oct 17, 2024
307f0c8
Merge branch 'master' into update_device_option_documentation
AlexandreSinger Oct 17, 2024
76c3ab0
Incorporate PR feedback
petergrossmann21 Oct 18, 2024
4332584
Merge branch 'master' into update_device_option_documentation
petergrossmann21 Oct 18, 2024
ffd0079
Merge branch 'update_device_option_documentation' of https://github.c…
petergrossmann21 Oct 18, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 11 additions & 4 deletions doc/src/vpr/command_line_usage.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -200,12 +200,19 @@ General Options

.. option:: --device <string>

Specifies which device layout/floorplan to use from the architecture file.
Specifies which device layout/floorplan to use from the architecture file. Valid values are:

``auto`` uses the smallest device satisfying the circuit's resource requirements.
Other values are assumed to be the names of device layouts defined in the :ref:`arch_grid_layout` section of the architecture file.
* ``auto`` VPR uses the smallest device satisfying the circuit's resource requirements, with device layout specified using the ``auto_layout`` section of the architecture file.
* Any string matching ``name`` attribute of a device layout defined with a ``fixed_layout`` tag in the :ref:`arch_grid_layout` section of the architecture file.

.. note:: If the architecture contains both ``<auto_layout>`` and ``<fixed_layout>`` specifications, specifying an ``auto`` device will use the ``<auto_layout>``.
If the value specified is neither ``auto`` nor matches the ``name`` attribute value of a ``<fixed_layout>`` tag, VPR issues an error.

In the event that no ``<auto_layout>`` tag is present in the architecture file, this option has the following behaviour:
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would delete thse 3 lines as now they are covered by the introduction of --auto above.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@vaughnbetz I kept the line documenting how VPR does error handling here, but deleted the bullet points below the highlights; I believe this better captures the desired elimination of redundancy. Let me know if additional changes are desired.


* ``auto`` VPR uses the smallest device amongst all ``fixed_layout`` specifications into which the design can be packed.
* Otherwise, the value of the ``fixed_layout`` attribute ``name`` is matched as when an ``<auto_layout>`` tag is present.

.. note:: If the only layout in the architecture file is a single device specified using ``<fixed_layout>``, it is recommended to always specify the ``--device`` option; this prevents the value ``--device auto`` from interfering with operations supported only for ``<fixed_layout>`` grids.

**Default:** ``auto``

Expand Down