..
  Copyright 1988-2021 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the GPL license file

  .. _omp_target_offload:

OMP_TARGET_OFFLOAD -- Controls offloading behaviour
***************************************************

.. index:: Environment Variable

.. index:: Implementation specific setting

:samp:`{Description}:`
  Specifies the behaviour with regard to offloading code to a device.  This
  variable can be set to one of three values - ``MANDATORY``, ``DISABLED``
  or ``DEFAULT``.

  If set to ``MANDATORY``, the program will terminate with an error if
  the offload device is not present or is not supported.  If set to
  ``DISABLED``, then offloading is disabled and all code will run on the
  host. If set to ``DEFAULT``, the program will try offloading to the
  device first, then fall back to running code on the host if it cannot.

  If undefined, then the program will behave as if ``DEFAULT`` was set.

:samp:`{Reference}:`
  `OpenMP specification v5.0 <https://www.openmp.org>`_, Section 6.17