.. index::
    LLVM/Clang FPGA Phase options

.. _llvm_fpga_options:

LLVM/Clang FPGA Phase options
:::::::::::::::::::::::::::::

The following sections list and summarize the LLVM/Clang options from the FPGA Phase.

.. note::
   Do not forget the flag ``-fompss-2`` in both compilation and linking stages of your application. Otherwise, your application will not be compiled with parallel support or not linked to the tasking runtime library.

fompss-fpga-wrapper-code
------------------------

``[Available in release 2.0.0]``

Enables FPGA task extraction into independent HLS wrappers.

This option is mandatory when generating a bitstream.

.. code-block:: text

    clang -fompss-2 -fompss-fpga-wrapper-code \
      -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct" \
      src/dotproduct.c -o dotproduct

fompss-fpga-ait-flags
---------------------

``[Available in release 2.0.0]``

String of whitespace-separated list of AIT flags that will be passed to the tool. Also enables AIT on the linking stage.

This option is mandatory when generating a bitstream.

.. code-block:: text

    clang -fompss-2 -fompss-fpga-wrapper-code \
      -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct" \
      src/dotproduct.c -o dotproduct

.. _llvm_fpga_options_port_width:

fompss-fpga-memory-port-width
-----------------------------

``[Available in release 2.0.0]``

Enables wide-port feature of OmpSs\@FPGA.

Accelerator memory interfaces will be merged into a single wide-port of arbitrary power-of-2 size. Code inside the wrapper will be generated in order to pack and unpack local variables when reading and writing from memory.

.. code-block:: text
   :emphasize-lines: 3

    clang -fompss-2 -fompss-fpga-wrapper-code \
      -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct" \
      -fompss-fpga-memory-port-width 512 \
      src/dotproduct.c -o dotproduct

.. _llvm_fpga_options_check_limits:

fompss-fpga-check-limits-memory-port
------------------------------------

``[Available in release 2.0.0]``

By default the compiler assumes that all the data that has to be copied to and from memory is multiple of the wide-port size.

This option adds checks inside the pack/unpacking code to manage copies smaller than the wide-port size.

.. code-block:: text
   :emphasize-lines: 3

    clang -fompss-2 -fompss-fpga-wrapper-code \
      -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct" \
      -fompss-fpga-check-limits-memory-port \
      src/dotproduct.c -o dotproduct

fompss-fpga-instrumentation
---------------------------

``[Available in release 3.1.0]``

Enables HW instrumentation.

This option will add nanos6 FPGA instrumentation API function needed to trace dependency copies and kernel execution.

.. code-block:: text
   :emphasize-lines: 3

    clang -fompss-2 -fompss-fpga-wrapper-code \
      -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct" \
      -fompss-fpga-instrumentation \
      src/dotproduct.c -o dotproduct

..
  fompss-fpga
  -----------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-dump
  ----------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-dump \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-hls-tasks-dir
  -------------------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-hls-tasks-dir $(PWD) \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-mercurium
  ---------------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-mercurium /tmp/mcxx/bin/fpgacxx \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-mercurium-flags
  ---------------------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-mercurium-flags "" \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-ait
  ---------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-ait /tmp/ait/bin/ait \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"
  
  fompss-fpga-extract
  -------------------
  
  [Available in release 2.0.0]
  
  .. code:: bash
  
      clang++ -fompss-2 -fompss-fpga-extract \
        src/dotproduct.c -o dotproduct \
        -fompss-fpga-ait-flags "--board=alveo_u200 --name=dotproduct"