@copying
-Copyright @copyright{} 2006-2015 Free Software Foundation, Inc.
+Copyright @copyright{} 2006-2020 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
This manual documents the usage of libgomp, the GNU Offloading and
Multi Processing Runtime Library. This includes the GNU
-implementation of the @uref{http://www.openmp.org, OpenMP} Application
+implementation of the @uref{https://www.openmp.org, OpenMP} Application
Programming Interface (API) for multi-platform shared-memory parallel
programming in C/C++ and Fortran, and the GNU implementation of the
-@uref{http://www.openacc.org/, OpenACC} Application Programming
+@uref{https://www.openacc.org, OpenACC} Application Programming
Interface (API) for offloading of code to accelerator devices in C/C++
and Fortran.
@comment
@menu
* Enabling OpenMP:: How to enable OpenMP for your applications.
-* Runtime Library Routines:: The OpenMP runtime application programming
+* OpenMP Runtime Library Routines: Runtime Library Routines.
+ The OpenMP runtime application programming
interface.
-* Environment Variables:: Influencing runtime behavior with environment
- variables.
+* OpenMP Environment Variables: Environment Variables.
+ Influencing OpenMP runtime behavior with
+ environment variables.
+* Enabling OpenACC:: How to enable OpenACC for your
+ applications.
+* OpenACC Runtime Library Routines:: The OpenACC runtime application
+ programming interface.
+* OpenACC Environment Variables:: Influencing OpenACC runtime behavior with
+ environment variables.
+* CUDA Streams Usage:: Notes on the implementation of
+ asynchronous operations.
+* OpenACC Library Interoperability:: OpenACC library interoperability with the
+ NVIDIA CUBLAS library.
+* OpenACC Profiling Interface::
* The libgomp ABI:: Notes on the external ABI presented by libgomp.
* Reporting Bugs:: How to report bugs in the GNU Offloading and
Multi Processing Runtime Library.
(@ref{Runtime Library Routines}).
A complete description of all OpenMP directives accepted may be found in
-the @uref{http://www.openmp.org, OpenMP Application Program Interface} manual,
-version 4.0.
+the @uref{https://www.openmp.org, OpenMP Application Program Interface} manual,
+version 4.5.
@c ---------------------------------------------------------------------
-@c Runtime Library Routines
+@c OpenMP Runtime Library Routines
@c ---------------------------------------------------------------------
@node Runtime Library Routines
-@chapter Runtime Library Routines
+@chapter OpenMP Runtime Library Routines
The runtime routines described here are defined by Section 3 of the OpenMP
-specification in version 4.0. The routines are structured in following
+specification in version 4.5. The routines are structured in following
three parts:
@menu
@ref{omp_get_level}, @ref{omp_get_max_active_levels}, @ref{omp_set_max_active_levels}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.20.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.20.
@end table
@ref{omp_get_level}, @ref{omp_get_thread_num}, @ref{omp_get_team_size}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.18.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.18.
@end table
@ref{OMP_CANCELLATION}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.9.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.9.
@end table
@ref{OMP_DEFAULT_DEVICE}, @ref{omp_set_default_device}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.24.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.30.
@end table
@ref{omp_set_dynamic}, @ref{OMP_DYNAMIC}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.8.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.8.
@end table
@ref{omp_get_active_level}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.17.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.17.
@end table
@ref{omp_set_max_active_levels}, @ref{omp_get_active_level}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.16.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.16.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.29.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.29.
@end table
@ref{omp_set_num_threads}, @ref{omp_set_dynamic}, @ref{omp_get_thread_limit}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.3.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.3.
@end table
@ref{omp_set_nested}, @ref{OMP_NESTED}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.11.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.11.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.25.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.31.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.5.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.5.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.26.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.32.
@end table
@ref{omp_get_max_threads}, @ref{omp_set_num_threads}, @ref{OMP_NUM_THREADS}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.2.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.2.
@end table
@ref{OMP_PROC_BIND}, @ref{OMP_PLACES}, @ref{GOMP_CPU_AFFINITY},
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.22.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.22.
@end table
@ref{omp_set_schedule}, @ref{OMP_SCHEDULE}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.13.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.13.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.27.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.33.
@end table
@ref{omp_get_num_threads}, @ref{omp_get_level}, @ref{omp_get_ancestor_thread_num}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.19.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.19.
@end table
@ref{omp_get_max_threads}, @ref{OMP_THREAD_LIMIT}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.14.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.14.
@end table
@ref{omp_get_num_threads}, @ref{omp_get_ancestor_thread_num}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.4.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.4.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.6.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.6.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.21.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.21.
@end table
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.28.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.34.
@end table
@ref{OMP_DEFAULT_DEVICE}, @ref{omp_get_default_device}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.23.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.29.
@end table
@ref{OMP_DYNAMIC}, @ref{omp_get_dynamic}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.7.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.7.
@end table
@ref{omp_get_max_active_levels}, @ref{omp_get_active_level}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.15.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.15.
@end table
@ref{OMP_NESTED}, @ref{omp_get_nested}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.10.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.10.
@end table
@ref{OMP_NUM_THREADS}, @ref{omp_get_num_threads}, @ref{omp_get_max_threads}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.1.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.1.
@end table
@ref{OMP_SCHEDULE}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.2.12.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.2.12.
@end table
@ref{omp_destroy_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.1.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.1.
@end table
@ref{omp_init_lock}, @ref{omp_test_lock}, @ref{omp_unset_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.3.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.4.
@end table
@ref{omp_init_lock}, @ref{omp_set_lock}, @ref{omp_set_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.5.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.6.
@end table
@ref{omp_set_lock}, @ref{omp_test_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.4.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.5.
@end table
@ref{omp_init_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.2.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.3.
@end table
@ref{omp_destroy_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.1.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.1.
@end table
@ref{omp_init_nest_lock}, @ref{omp_unset_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.3.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.4.
@end table
@ref{omp_init_lock}, @ref{omp_set_lock}, @ref{omp_set_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.5.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.6.
@end table
@ref{omp_set_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.4.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.5.
@end table
@ref{omp_init_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.3.2.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.3.3.
@end table
@ref{omp_get_wtime}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.4.2.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.4.2.
@end table
@ref{omp_get_wtick}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 3.4.1.
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 3.4.1.
@end table
@c ---------------------------------------------------------------------
-@c Environment Variables
+@c OpenMP Environment Variables
@c ---------------------------------------------------------------------
@node Environment Variables
-@chapter Environment Variables
+@chapter OpenMP Environment Variables
The environment variables which beginning with @env{OMP_} are defined by
-section 4 of the OpenMP specification in version 4.0, while those
+section 4 of the OpenMP specification in version 4.5, while those
beginning with @env{GOMP_} are GNU extensions.
@menu
@ref{omp_get_cancellation}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.11
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.11
@end table
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.12
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.12
@end table
@ref{omp_get_default_device}, @ref{omp_set_default_device},
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.11
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.13
@end table
@ref{omp_set_dynamic}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.3
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.3
@end table
@ref{omp_set_max_active_levels}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.9
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.9
@end table
@ref{omp_get_max_task_priority}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.14
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.14
@end table
@ref{omp_set_nested}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.6
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.6
@end table
@ref{omp_set_num_threads}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.2
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.2
@end table
@ref{OMP_PLACES}, @ref{GOMP_CPU_AFFINITY}, @ref{omp_get_proc_bind}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.4
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.4
@end table
@ref{OMP_DISPLAY_ENV}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.5
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.5
@end table
dependent.
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.7
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.7
@end table
@ref{omp_set_schedule}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Sections 2.7.1 and 4.1
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Sections 2.7.1.1 and 4.1
@end table
@ref{OMP_NUM_THREADS}, @ref{omp_get_thread_limit}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.10
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.10
@end table
@ref{GOMP_SPINCOUNT}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specification v4.0}, Section 4.8
+@uref{https://www.openmp.org, OpenMP specification v4.5}, Section 4.8
@end table
@ref{OMP_STACKSIZE}
@item @emph{Reference}:
-@uref{http://gcc.gnu.org/ml/gcc-patches/2006-06/msg00493.html,
+@uref{https://gcc.gnu.org/ml/gcc-patches/2006-06/msg00493.html,
GCC Patches Mailinglist},
-@uref{http://gcc.gnu.org/ml/gcc-patches/2006-06/msg00496.html,
+@uref{https://gcc.gnu.org/ml/gcc-patches/2006-06/msg00496.html,
GCC Patches Mailinglist}
@end table
+@c ---------------------------------------------------------------------
+@c Enabling OpenACC
+@c ---------------------------------------------------------------------
+
+@node Enabling OpenACC
+@chapter Enabling OpenACC
+
+To activate the OpenACC extensions for C/C++ and Fortran, the compile-time
+flag @option{-fopenacc} must be specified. This enables the OpenACC directive
+@code{#pragma acc} in C/C++ and @code{!$acc} directives in free form,
+@code{c$acc}, @code{*$acc} and @code{!$acc} directives in fixed form,
+@code{!$} conditional compilation sentinels in free form and @code{c$},
+@code{*$} and @code{!$} sentinels in fixed form, for Fortran. The flag also
+arranges for automatic linking of the OpenACC runtime library
+(@ref{OpenACC Runtime Library Routines}).
+
+See @uref{https://gcc.gnu.org/wiki/OpenACC} for more information.
+
+A complete description of all OpenACC directives accepted may be found in
+the @uref{https://www.openacc.org, OpenACC} Application Programming
+Interface manual, version 2.6.
+
+
+
+@c ---------------------------------------------------------------------
+@c OpenACC Runtime Library Routines
+@c ---------------------------------------------------------------------
+
+@node OpenACC Runtime Library Routines
+@chapter OpenACC Runtime Library Routines
+
+The runtime routines described here are defined by section 3 of the OpenACC
+specifications in version 2.6.
+They have C linkage, and do not throw exceptions.
+Generally, they are available only for the host, with the exception of
+@code{acc_on_device}, which is available for both the host and the
+acceleration device.
+
+@menu
+* acc_get_num_devices:: Get number of devices for the given device
+ type.
+* acc_set_device_type:: Set type of device accelerator to use.
+* acc_get_device_type:: Get type of device accelerator to be used.
+* acc_set_device_num:: Set device number to use.
+* acc_get_device_num:: Get device number to be used.
+* acc_get_property:: Get device property.
+* acc_async_test:: Tests for completion of a specific asynchronous
+ operation.
+* acc_async_test_all:: Tests for completion of all asynchronous
+ operations.
+* acc_wait:: Wait for completion of a specific asynchronous
+ operation.
+* acc_wait_all:: Waits for completion of all asynchronous
+ operations.
+* acc_wait_all_async:: Wait for completion of all asynchronous
+ operations.
+* acc_wait_async:: Wait for completion of asynchronous operations.
+* acc_init:: Initialize runtime for a specific device type.
+* acc_shutdown:: Shuts down the runtime for a specific device
+ type.
+* acc_on_device:: Whether executing on a particular device
+* acc_malloc:: Allocate device memory.
+* acc_free:: Free device memory.
+* acc_copyin:: Allocate device memory and copy host memory to
+ it.
+* acc_present_or_copyin:: If the data is not present on the device,
+ allocate device memory and copy from host
+ memory.
+* acc_create:: Allocate device memory and map it to host
+ memory.
+* acc_present_or_create:: If the data is not present on the device,
+ allocate device memory and map it to host
+ memory.
+* acc_copyout:: Copy device memory to host memory.
+* acc_delete:: Free device memory.
+* acc_update_device:: Update device memory from mapped host memory.
+* acc_update_self:: Update host memory from mapped device memory.
+* acc_map_data:: Map previously allocated device memory to host
+ memory.
+* acc_unmap_data:: Unmap device memory from host memory.
+* acc_deviceptr:: Get device pointer associated with specific
+ host address.
+* acc_hostptr:: Get host pointer associated with specific
+ device address.
+* acc_is_present:: Indicate whether host variable / array is
+ present on device.
+* acc_memcpy_to_device:: Copy host memory to device memory.
+* acc_memcpy_from_device:: Copy device memory to host memory.
+* acc_attach:: Let device pointer point to device-pointer target.
+* acc_detach:: Let device pointer point to host-pointer target.
+
+API routines for target platforms.
+
+* acc_get_current_cuda_device:: Get CUDA device handle.
+* acc_get_current_cuda_context::Get CUDA context handle.
+* acc_get_cuda_stream:: Get CUDA stream handle.
+* acc_set_cuda_stream:: Set CUDA stream handle.
+
+API routines for the OpenACC Profiling Interface.
+
+* acc_prof_register:: Register callbacks.
+* acc_prof_unregister:: Unregister callbacks.
+* acc_prof_lookup:: Obtain inquiry functions.
+* acc_register_library:: Library registration.
+@end menu
+
+
+
+@node acc_get_num_devices
+@section @code{acc_get_num_devices} -- Get number of devices for given device type
+@table @asis
+@item @emph{Description}
+This function returns a value indicating the number of devices available
+for the device type specified in @var{devicetype}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_get_num_devices(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function acc_get_num_devices(devicetype)}
+@item @tab @code{integer(kind=acc_device_kind) devicetype}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.1.
+@end table
+
+
+
+@node acc_set_device_type
+@section @code{acc_set_device_type} -- Set type of device accelerator to use.
+@table @asis
+@item @emph{Description}
+This function indicates to the runtime library which device type, specified
+in @var{devicetype}, to use when executing a parallel or kernels region.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_set_device_type(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_set_device_type(devicetype)}
+@item @tab @code{integer(kind=acc_device_kind) devicetype}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.2.
+@end table
+
+
+
+@node acc_get_device_type
+@section @code{acc_get_device_type} -- Get type of device accelerator to be used.
+@table @asis
+@item @emph{Description}
+This function returns what device type will be used when executing a
+parallel or kernels region.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_device_t acc_get_device_type(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_get_device_type(void)}
+@item @tab @code{integer(kind=acc_device_kind) acc_get_device_type}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.3.
+@end table
+
+
+
+@node acc_set_device_num
+@section @code{acc_set_device_num} -- Set device number to use.
+@table @asis
+@item @emph{Description}
+This function will indicate to the runtime which device number,
+specified by @var{devicenum}, associated with the specified device
+type @var{devicetype}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_set_device_num(int devicenum, acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_set_device_num(devicenum, devicetype)}
+@item @tab @code{integer devicenum}
+@item @tab @code{integer(kind=acc_device_kind) devicetype}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.4.
+@end table
+
+
+
+@node acc_get_device_num
+@section @code{acc_get_device_num} -- Get device number to be used.
+@table @asis
+@item @emph{Description}
+This function returns which device number associated with the specified device
+type @var{devicetype}, will be used when executing a parallel or kernels
+region.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_get_device_num(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_get_device_num(devicetype)}
+@item @tab @code{integer(kind=acc_device_kind) devicetype}
+@item @tab @code{integer acc_get_device_num}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.5.
+@end table
+
+
+
+@node acc_get_property
+@section @code{acc_get_property} -- Get device property.
+@cindex acc_get_property
+@cindex acc_get_property_string
+@table @asis
+@item @emph{Description}
+These routines return the value of the specified @var{property} for the
+device being queried according to @var{devicenum} and @var{devicetype}.
+Integer-valued and string-valued properties are returned by
+@code{acc_get_property} and @code{acc_get_property_string} respectively.
+The Fortran @code{acc_get_property_string} subroutine returns the string
+retrieved in its fourth argument while the remaining entry points are
+functions, which pass the return value as their result.
+
+Note for Fortran, only: the OpenACC technical committee corrected and, hence,
+modified the interface introduced in OpenACC 2.6. The kind-value parameter
+@code{acc_device_property} has been renamed to @code{acc_device_property_kind}
+for consistency and the return type of the @code{acc_get_property} function is
+now a @code{c_size_t} integer instead of a @code{acc_device_property} integer.
+The parameter @code{acc_device_property} will continue to be provided,
+but might be removed in a future version of GCC.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{size_t acc_get_property(int devicenum, acc_device_t devicetype, acc_device_property_t property);}
+@item @emph{Prototype}: @tab @code{const char *acc_get_property_string(int devicenum, acc_device_t devicetype, acc_device_property_t property);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_get_property(devicenum, devicetype, property)}
+@item @emph{Interface}: @tab @code{subroutine acc_get_property_string(devicenum, devicetype, property, string)}
+@item @tab @code{use ISO_C_Binding, only: c_size_t}
+@item @tab @code{integer devicenum}
+@item @tab @code{integer(kind=acc_device_kind) devicetype}
+@item @tab @code{integer(kind=acc_device_property_kind) property}
+@item @tab @code{integer(kind=c_size_t) acc_get_property}
+@item @tab @code{character(*) string}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.6.
+@end table
+
+
+
+@node acc_async_test
+@section @code{acc_async_test} -- Test for completion of a specific asynchronous operation.
+@table @asis
+@item @emph{Description}
+This function tests for completion of the asynchronous operation specified
+in @var{arg}. In C/C++, a non-zero value will be returned to indicate
+the specified asynchronous operation has completed. While Fortran will return
+a @code{true}. If the asynchronous operation has not completed, C/C++ returns
+a zero and Fortran returns a @code{false}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_async_test(int arg);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_async_test(arg)}
+@item @tab @code{integer(kind=acc_handle_kind) arg}
+@item @tab @code{logical acc_async_test}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.9.
+@end table
+
+
+
+@node acc_async_test_all
+@section @code{acc_async_test_all} -- Tests for completion of all asynchronous operations.
+@table @asis
+@item @emph{Description}
+This function tests for completion of all asynchronous operations.
+In C/C++, a non-zero value will be returned to indicate all asynchronous
+operations have completed. While Fortran will return a @code{true}. If
+any asynchronous operation has not completed, C/C++ returns a zero and
+Fortran returns a @code{false}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_async_test_all(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_async_test()}
+@item @tab @code{logical acc_get_device_num}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.10.
+@end table
+
+
+
+@node acc_wait
+@section @code{acc_wait} -- Wait for completion of a specific asynchronous operation.
+@table @asis
+@item @emph{Description}
+This function waits for completion of the asynchronous operation
+specified in @var{arg}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_wait(arg);}
+@item @emph{Prototype (OpenACC 1.0 compatibility)}: @tab @code{acc_async_wait(arg);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_wait(arg)}
+@item @tab @code{integer(acc_handle_kind) arg}
+@item @emph{Interface (OpenACC 1.0 compatibility)}: @tab @code{subroutine acc_async_wait(arg)}
+@item @tab @code{integer(acc_handle_kind) arg}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.11.
+@end table
+
+
+
+@node acc_wait_all
+@section @code{acc_wait_all} -- Waits for completion of all asynchronous operations.
+@table @asis
+@item @emph{Description}
+This function waits for the completion of all asynchronous operations.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_wait_all(void);}
+@item @emph{Prototype (OpenACC 1.0 compatibility)}: @tab @code{acc_async_wait_all(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_wait_all()}
+@item @emph{Interface (OpenACC 1.0 compatibility)}: @tab @code{subroutine acc_async_wait_all()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.13.
+@end table
+
+
+
+@node acc_wait_all_async
+@section @code{acc_wait_all_async} -- Wait for completion of all asynchronous operations.
+@table @asis
+@item @emph{Description}
+This function enqueues a wait operation on the queue @var{async} for any
+and all asynchronous operations that have been previously enqueued on
+any queue.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_wait_all_async(int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_wait_all_async(async)}
+@item @tab @code{integer(acc_handle_kind) async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.14.
+@end table
+
+
+
+@node acc_wait_async
+@section @code{acc_wait_async} -- Wait for completion of asynchronous operations.
+@table @asis
+@item @emph{Description}
+This function enqueues a wait operation on queue @var{async} for any and all
+asynchronous operations enqueued on queue @var{arg}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_wait_async(int arg, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_wait_async(arg, async)}
+@item @tab @code{integer(acc_handle_kind) arg, async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.12.
+@end table
+
+
+
+@node acc_init
+@section @code{acc_init} -- Initialize runtime for a specific device type.
+@table @asis
+@item @emph{Description}
+This function initializes the runtime for the device type specified in
+@var{devicetype}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_init(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_init(devicetype)}
+@item @tab @code{integer(acc_device_kind) devicetype}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.7.
+@end table
+
+
+
+@node acc_shutdown
+@section @code{acc_shutdown} -- Shuts down the runtime for a specific device type.
+@table @asis
+@item @emph{Description}
+This function shuts down the runtime for the device type specified in
+@var{devicetype}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_shutdown(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_shutdown(devicetype)}
+@item @tab @code{integer(acc_device_kind) devicetype}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.8.
+@end table
+
+
+
+@node acc_on_device
+@section @code{acc_on_device} -- Whether executing on a particular device
+@table @asis
+@item @emph{Description}:
+This function returns whether the program is executing on a particular
+device specified in @var{devicetype}. In C/C++ a non-zero value is
+returned to indicate the device is executing on the specified device type.
+In Fortran, @code{true} will be returned. If the program is not executing
+on the specified device type C/C++ will return a zero, while Fortran will
+return @code{false}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_on_device(acc_device_t devicetype);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_on_device(devicetype)}
+@item @tab @code{integer(acc_device_kind) devicetype}
+@item @tab @code{logical acc_on_device}
+@end multitable
+
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.17.
+@end table
+
+
+
+@node acc_malloc
+@section @code{acc_malloc} -- Allocate device memory.
+@table @asis
+@item @emph{Description}
+This function allocates @var{len} bytes of device memory. It returns
+the device address of the allocated memory.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{d_void* acc_malloc(size_t len);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.18.
+@end table
+
+
+
+@node acc_free
+@section @code{acc_free} -- Free device memory.
+@table @asis
+@item @emph{Description}
+Free previously allocated device memory at the device address @code{a}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_free(d_void *a);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.19.
+@end table
+
+
+
+@node acc_copyin
+@section @code{acc_copyin} -- Allocate device memory and copy host memory to it.
+@table @asis
+@item @emph{Description}
+In C/C++, this function allocates @var{len} bytes of device memory
+and maps it to the specified host address in @var{a}. The device
+address of the newly allocated device memory is returned.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a
+variable or array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_copyin(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{void *acc_copyin_async(h_void *a, size_t len, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_copyin(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_copyin(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_copyin_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_copyin_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.20.
+@end table
+
+
+
+@node acc_present_or_copyin
+@section @code{acc_present_or_copyin} -- If the data is not present on the device, allocate device memory and copy from host memory.
+@table @asis
+@item @emph{Description}
+This function tests if the host data specified by @var{a} and of length
+@var{len} is present or not. If it is not present, then device memory
+will be allocated and the host memory copied. The device address of
+the newly allocated device memory is returned.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+Note that @code{acc_present_or_copyin} and @code{acc_pcopyin} exist for
+backward compatibility with OpenACC 2.0; use @ref{acc_copyin} instead.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_present_or_copyin(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{void *acc_pcopyin(h_void *a, size_t len);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_present_or_copyin(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_present_or_copyin(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_pcopyin(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_pcopyin(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.20.
+@end table
+
+
+
+@node acc_create
+@section @code{acc_create} -- Allocate device memory and map it to host memory.
+@table @asis
+@item @emph{Description}
+This function allocates device memory and maps it to host memory specified
+by the host address @var{a} with a length of @var{len} bytes. In C/C++,
+the function returns the device address of the allocated device memory.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_create(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{void *acc_create_async(h_void *a, size_t len, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_create(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_create(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_create_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_create_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.21.
+@end table
+
+
+
+@node acc_present_or_create
+@section @code{acc_present_or_create} -- If the data is not present on the device, allocate device memory and map it to host memory.
+@table @asis
+@item @emph{Description}
+This function tests if the host data specified by @var{a} and of length
+@var{len} is present or not. If it is not present, then device memory
+will be allocated and mapped to host memory. In C/C++, the device address
+of the newly allocated device memory is returned.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+Note that @code{acc_present_or_create} and @code{acc_pcreate} exist for
+backward compatibility with OpenACC 2.0; use @ref{acc_create} instead.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_present_or_create(h_void *a, size_t len)}
+@item @emph{Prototype}: @tab @code{void *acc_pcreate(h_void *a, size_t len)}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_present_or_create(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_present_or_create(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_pcreate(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_pcreate(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.21.
+@end table
+
+
+
+@node acc_copyout
+@section @code{acc_copyout} -- Copy device memory to host memory.
+@table @asis
+@item @emph{Description}
+This function copies mapped device memory to host memory which is specified
+by host address @var{a} for a length @var{len} bytes in C/C++.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_copyout(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_copyout_async(h_void *a, size_t len, int async);}
+@item @emph{Prototype}: @tab @code{acc_copyout_finalize(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_copyout_finalize_async(h_void *a, size_t len, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_copyout(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_finalize(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_finalize(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_finalize_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_copyout_finalize_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.22.
+@end table
+
+
+
+@node acc_delete
+@section @code{acc_delete} -- Free device memory.
+@table @asis
+@item @emph{Description}
+This function frees previously allocated device memory specified by
+the device address @var{a} and the length of @var{len} bytes.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_delete(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_delete_async(h_void *a, size_t len, int async);}
+@item @emph{Prototype}: @tab @code{acc_delete_finalize(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_delete_finalize_async(h_void *a, size_t len, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_delete(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_delete(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_finalize(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_finalize(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_async_finalize(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_delete_async_finalize(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.23.
+@end table
+
+
+
+@node acc_update_device
+@section @code{acc_update_device} -- Update device memory from mapped host memory.
+@table @asis
+@item @emph{Description}
+This function updates the device copy from the previously mapped host memory.
+The host memory is specified with the host address @var{a} and a length of
+@var{len} bytes.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_update_device(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_update_device(h_void *a, size_t len, async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_update_device(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_update_device(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_update_device_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_update_device_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.24.
+@end table
+
+
+
+@node acc_update_self
+@section @code{acc_update_self} -- Update host memory from mapped device memory.
+@table @asis
+@item @emph{Description}
+This function updates the host copy from the previously mapped device memory.
+The host memory is specified with the host address @var{a} and a length of
+@var{len} bytes.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_update_self(h_void *a, size_t len);}
+@item @emph{Prototype}: @tab @code{acc_update_self_async(h_void *a, size_t len, int async);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_update_self(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @emph{Interface}: @tab @code{subroutine acc_update_self(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @emph{Interface}: @tab @code{subroutine acc_update_self_async(a, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@item @emph{Interface}: @tab @code{subroutine acc_update_self_async(a, len, async)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{integer(acc_handle_kind) :: async}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.25.
+@end table
+
+
+
+@node acc_map_data
+@section @code{acc_map_data} -- Map previously allocated device memory to host memory.
+@table @asis
+@item @emph{Description}
+This function maps previously allocated device and host memory. The device
+memory is specified with the device address @var{d}. The host memory is
+specified with the host address @var{h} and a length of @var{len}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_map_data(h_void *h, d_void *d, size_t len);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.26.
+@end table
+
+
+
+@node acc_unmap_data
+@section @code{acc_unmap_data} -- Unmap device memory from host memory.
+@table @asis
+@item @emph{Description}
+This function unmaps previously mapped device and host memory. The latter
+specified by @var{h}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_unmap_data(h_void *h);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.27.
+@end table
+
+
+
+@node acc_deviceptr
+@section @code{acc_deviceptr} -- Get device pointer associated with specific host address.
+@table @asis
+@item @emph{Description}
+This function returns the device address that has been mapped to the
+host address specified by @var{h}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_deviceptr(h_void *h);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.28.
+@end table
+
+
+
+@node acc_hostptr
+@section @code{acc_hostptr} -- Get host pointer associated with specific device address.
+@table @asis
+@item @emph{Description}
+This function returns the host address that has been mapped to the
+device address specified by @var{d}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_hostptr(d_void *d);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.29.
+@end table
+
+
+
+@node acc_is_present
+@section @code{acc_is_present} -- Indicate whether host variable / array is present on device.
+@table @asis
+@item @emph{Description}
+This function indicates whether the specified host address in @var{a} and a
+length of @var{len} bytes is present on the device. In C/C++, a non-zero
+value is returned to indicate the presence of the mapped memory on the
+device. A zero is returned to indicate the memory is not mapped on the
+device.
+
+In Fortran, two (2) forms are supported. In the first form, @var{a} specifies
+a contiguous array section. The second form @var{a} specifies a variable or
+array element and @var{len} specifies the length in bytes. If the host
+memory is mapped to device memory, then a @code{true} is returned. Otherwise,
+a @code{false} is return to indicate the mapped memory is not present.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_is_present(h_void *a, size_t len);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{function acc_is_present(a)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{logical acc_is_present}
+@item @emph{Interface}: @tab @code{function acc_is_present(a, len)}
+@item @tab @code{type, dimension(:[,:]...) :: a}
+@item @tab @code{integer len}
+@item @tab @code{logical acc_is_present}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.30.
+@end table
+
+
+
+@node acc_memcpy_to_device
+@section @code{acc_memcpy_to_device} -- Copy host memory to device memory.
+@table @asis
+@item @emph{Description}
+This function copies host memory specified by host address of @var{src} to
+device memory specified by the device address @var{dest} for a length of
+@var{bytes} bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_memcpy_to_device(d_void *dest, h_void *src, size_t bytes);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.31.
+@end table
+
+
+
+@node acc_memcpy_from_device
+@section @code{acc_memcpy_from_device} -- Copy device memory to host memory.
+@table @asis
+@item @emph{Description}
+This function copies host memory specified by host address of @var{src} from
+device memory specified by the device address @var{dest} for a length of
+@var{bytes} bytes.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_memcpy_from_device(d_void *dest, h_void *src, size_t bytes);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.32.
+@end table
+
+
+
+@node acc_attach
+@section @code{acc_attach} -- Let device pointer point to device-pointer target.
+@table @asis
+@item @emph{Description}
+This function updates a pointer on the device from pointing to a host-pointer
+address to pointing to the corresponding device data.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_attach(h_void **ptr);}
+@item @emph{Prototype}: @tab @code{acc_attach_async(h_void **ptr, int async);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.34.
+@end table
+
+
+
+@node acc_detach
+@section @code{acc_detach} -- Let device pointer point to host-pointer target.
+@table @asis
+@item @emph{Description}
+This function updates a pointer on the device from pointing to a device-pointer
+address to pointing to the corresponding host data.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_detach(h_void **ptr);}
+@item @emph{Prototype}: @tab @code{acc_detach_async(h_void **ptr, int async);}
+@item @emph{Prototype}: @tab @code{acc_detach_finalize(h_void **ptr);}
+@item @emph{Prototype}: @tab @code{acc_detach_finalize_async(h_void **ptr, int async);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+3.2.35.
+@end table
+
+
+
+@node acc_get_current_cuda_device
+@section @code{acc_get_current_cuda_device} -- Get CUDA device handle.
+@table @asis
+@item @emph{Description}
+This function returns the CUDA device handle. This handle is the same
+as used by the CUDA Runtime or Driver API's.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_get_current_cuda_device(void);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+A.2.1.1.
+@end table
+
+
+
+@node acc_get_current_cuda_context
+@section @code{acc_get_current_cuda_context} -- Get CUDA context handle.
+@table @asis
+@item @emph{Description}
+This function returns the CUDA context handle. This handle is the same
+as used by the CUDA Runtime or Driver API's.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_get_current_cuda_context(void);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+A.2.1.2.
+@end table
+
+
+
+@node acc_get_cuda_stream
+@section @code{acc_get_cuda_stream} -- Get CUDA stream handle.
+@table @asis
+@item @emph{Description}
+This function returns the CUDA stream handle for the queue @var{async}.
+This handle is the same as used by the CUDA Runtime or Driver API's.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void *acc_get_cuda_stream(int async);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+A.2.1.3.
+@end table
+
+
+
+@node acc_set_cuda_stream
+@section @code{acc_set_cuda_stream} -- Set CUDA stream handle.
+@table @asis
+@item @emph{Description}
+This function associates the stream handle specified by @var{stream} with
+the queue @var{async}.
+
+This cannot be used to change the stream handle associated with
+@code{acc_async_sync}.
+
+The return value is not specified.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int acc_set_cuda_stream(int async, void *stream);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+A.2.1.4.
+@end table
+
+
+
+@node acc_prof_register
+@section @code{acc_prof_register} -- Register callbacks.
+@table @asis
+@item @emph{Description}:
+This function registers callbacks.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void acc_prof_register (acc_event_t, acc_prof_callback, acc_register_t);}
+@end multitable
+
+@item @emph{See also}:
+@ref{OpenACC Profiling Interface}
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+5.3.
+@end table
+
+
+
+@node acc_prof_unregister
+@section @code{acc_prof_unregister} -- Unregister callbacks.
+@table @asis
+@item @emph{Description}:
+This function unregisters callbacks.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void acc_prof_unregister (acc_event_t, acc_prof_callback, acc_register_t);}
+@end multitable
+
+@item @emph{See also}:
+@ref{OpenACC Profiling Interface}
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+5.3.
+@end table
+
+
+
+@node acc_prof_lookup
+@section @code{acc_prof_lookup} -- Obtain inquiry functions.
+@table @asis
+@item @emph{Description}:
+Function to obtain inquiry functions.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_query_fn acc_prof_lookup (const char *);}
+@end multitable
+
+@item @emph{See also}:
+@ref{OpenACC Profiling Interface}
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+5.3.
+@end table
+
+
+
+@node acc_register_library
+@section @code{acc_register_library} -- Library registration.
+@table @asis
+@item @emph{Description}:
+Function for library registration.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void acc_register_library (acc_prof_reg, acc_prof_reg, acc_prof_lookup_func);}
+@end multitable
+
+@item @emph{See also}:
+@ref{OpenACC Profiling Interface}, @ref{ACC_PROFLIB}
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+5.3.
+@end table
+
+
+
+@c ---------------------------------------------------------------------
+@c OpenACC Environment Variables
+@c ---------------------------------------------------------------------
+
+@node OpenACC Environment Variables
+@chapter OpenACC Environment Variables
+
+The variables @env{ACC_DEVICE_TYPE} and @env{ACC_DEVICE_NUM}
+are defined by section 4 of the OpenACC specification in version 2.0.
+The variable @env{ACC_PROFLIB}
+is defined by section 4 of the OpenACC specification in version 2.6.
+The variable @env{GCC_ACC_NOTIFY} is used for diagnostic purposes.
+
+@menu
+* ACC_DEVICE_TYPE::
+* ACC_DEVICE_NUM::
+* ACC_PROFLIB::
+* GCC_ACC_NOTIFY::
+@end menu
+
+
+
+@node ACC_DEVICE_TYPE
+@section @code{ACC_DEVICE_TYPE}
+@table @asis
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+4.1.
+@end table
+
+
+
+@node ACC_DEVICE_NUM
+@section @code{ACC_DEVICE_NUM}
+@table @asis
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+4.2.
+@end table
+
+
+
+@node ACC_PROFLIB
+@section @code{ACC_PROFLIB}
+@table @asis
+@item @emph{See also}:
+@ref{acc_register_library}, @ref{OpenACC Profiling Interface}
+
+@item @emph{Reference}:
+@uref{https://www.openacc.org, OpenACC specification v2.6}, section
+4.3.
+@end table
+
+
+
+@node GCC_ACC_NOTIFY
+@section @code{GCC_ACC_NOTIFY}
+@table @asis
+@item @emph{Description}:
+Print debug information pertaining to the accelerator.
+@end table
+
+
+
+@c ---------------------------------------------------------------------
+@c CUDA Streams Usage
+@c ---------------------------------------------------------------------
+
+@node CUDA Streams Usage
+@chapter CUDA Streams Usage
+
+This applies to the @code{nvptx} plugin only.
+
+The library provides elements that perform asynchronous movement of
+data and asynchronous operation of computing constructs. This
+asynchronous functionality is implemented by making use of CUDA
+streams@footnote{See "Stream Management" in "CUDA Driver API",
+TRM-06703-001, Version 5.5, for additional information}.
+
+The primary means by that the asynchronous functionality is accessed
+is through the use of those OpenACC directives which make use of the
+@code{async} and @code{wait} clauses. When the @code{async} clause is
+first used with a directive, it creates a CUDA stream. If an
+@code{async-argument} is used with the @code{async} clause, then the
+stream is associated with the specified @code{async-argument}.
+
+Following the creation of an association between a CUDA stream and the
+@code{async-argument} of an @code{async} clause, both the @code{wait}
+clause and the @code{wait} directive can be used. When either the
+clause or directive is used after stream creation, it creates a
+rendezvous point whereby execution waits until all operations
+associated with the @code{async-argument}, that is, stream, have
+completed.
+
+Normally, the management of the streams that are created as a result of
+using the @code{async} clause, is done without any intervention by the
+caller. This implies the association between the @code{async-argument}
+and the CUDA stream will be maintained for the lifetime of the program.
+However, this association can be changed through the use of the library
+function @code{acc_set_cuda_stream}. When the function
+@code{acc_set_cuda_stream} is called, the CUDA stream that was
+originally associated with the @code{async} clause will be destroyed.
+Caution should be taken when changing the association as subsequent
+references to the @code{async-argument} refer to a different
+CUDA stream.
+
+
+
+@c ---------------------------------------------------------------------
+@c OpenACC Library Interoperability
+@c ---------------------------------------------------------------------
+
+@node OpenACC Library Interoperability
+@chapter OpenACC Library Interoperability
+
+@section Introduction
+
+The OpenACC library uses the CUDA Driver API, and may interact with
+programs that use the Runtime library directly, or another library
+based on the Runtime library, e.g., CUBLAS@footnote{See section 2.26,
+"Interactions with the CUDA Driver API" in
+"CUDA Runtime API", Version 5.5, and section 2.27, "VDPAU
+Interoperability", in "CUDA Driver API", TRM-06703-001, Version 5.5,
+for additional information on library interoperability.}.
+This chapter describes the use cases and what changes are
+required in order to use both the OpenACC library and the CUBLAS and Runtime
+libraries within a program.
+
+@section First invocation: NVIDIA CUBLAS library API
+
+In this first use case (see below), a function in the CUBLAS library is called
+prior to any of the functions in the OpenACC library. More specifically, the
+function @code{cublasCreate()}.
+
+When invoked, the function initializes the library and allocates the
+hardware resources on the host and the device on behalf of the caller. Once
+the initialization and allocation has completed, a handle is returned to the
+caller. The OpenACC library also requires initialization and allocation of
+hardware resources. Since the CUBLAS library has already allocated the
+hardware resources for the device, all that is left to do is to initialize
+the OpenACC library and acquire the hardware resources on the host.
+
+Prior to calling the OpenACC function that initializes the library and
+allocate the host hardware resources, you need to acquire the device number
+that was allocated during the call to @code{cublasCreate()}. The invoking of the
+runtime library function @code{cudaGetDevice()} accomplishes this. Once
+acquired, the device number is passed along with the device type as
+parameters to the OpenACC library function @code{acc_set_device_num()}.
+
+Once the call to @code{acc_set_device_num()} has completed, the OpenACC
+library uses the context that was created during the call to
+@code{cublasCreate()}. In other words, both libraries will be sharing the
+same context.
+
+@smallexample
+ /* Create the handle */
+ s = cublasCreate(&h);
+ if (s != CUBLAS_STATUS_SUCCESS)
+ @{
+ fprintf(stderr, "cublasCreate failed %d\n", s);
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Get the device number */
+ e = cudaGetDevice(&dev);
+ if (e != cudaSuccess)
+ @{
+ fprintf(stderr, "cudaGetDevice failed %d\n", e);
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Initialize OpenACC library and use device 'dev' */
+ acc_set_device_num(dev, acc_device_nvidia);
+
+@end smallexample
+@center Use Case 1
+
+@section First invocation: OpenACC library API
+
+In this second use case (see below), a function in the OpenACC library is
+called prior to any of the functions in the CUBLAS library. More specificially,
+the function @code{acc_set_device_num()}.
+
+In the use case presented here, the function @code{acc_set_device_num()}
+is used to both initialize the OpenACC library and allocate the hardware
+resources on the host and the device. In the call to the function, the
+call parameters specify which device to use and what device
+type to use, i.e., @code{acc_device_nvidia}. It should be noted that this
+is but one method to initialize the OpenACC library and allocate the
+appropriate hardware resources. Other methods are available through the
+use of environment variables and these will be discussed in the next section.
+
+Once the call to @code{acc_set_device_num()} has completed, other OpenACC
+functions can be called as seen with multiple calls being made to
+@code{acc_copyin()}. In addition, calls can be made to functions in the
+CUBLAS library. In the use case a call to @code{cublasCreate()} is made
+subsequent to the calls to @code{acc_copyin()}.
+As seen in the previous use case, a call to @code{cublasCreate()}
+initializes the CUBLAS library and allocates the hardware resources on the
+host and the device. However, since the device has already been allocated,
+@code{cublasCreate()} will only initialize the CUBLAS library and allocate
+the appropriate hardware resources on the host. The context that was created
+as part of the OpenACC initialization is shared with the CUBLAS library,
+similarly to the first use case.
+
+@smallexample
+ dev = 0;
+
+ acc_set_device_num(dev, acc_device_nvidia);
+
+ /* Copy the first set to the device */
+ d_X = acc_copyin(&h_X[0], N * sizeof (float));
+ if (d_X == NULL)
+ @{
+ fprintf(stderr, "copyin error h_X\n");
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Copy the second set to the device */
+ d_Y = acc_copyin(&h_Y1[0], N * sizeof (float));
+ if (d_Y == NULL)
+ @{
+ fprintf(stderr, "copyin error h_Y1\n");
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Create the handle */
+ s = cublasCreate(&h);
+ if (s != CUBLAS_STATUS_SUCCESS)
+ @{
+ fprintf(stderr, "cublasCreate failed %d\n", s);
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Perform saxpy using CUBLAS library function */
+ s = cublasSaxpy(h, N, &alpha, d_X, 1, d_Y, 1);
+ if (s != CUBLAS_STATUS_SUCCESS)
+ @{
+ fprintf(stderr, "cublasSaxpy failed %d\n", s);
+ exit(EXIT_FAILURE);
+ @}
+
+ /* Copy the results from the device */
+ acc_memcpy_from_device(&h_Y1[0], d_Y, N * sizeof (float));
+
+@end smallexample
+@center Use Case 2
+
+@section OpenACC library and environment variables
+
+There are two environment variables associated with the OpenACC library
+that may be used to control the device type and device number:
+@env{ACC_DEVICE_TYPE} and @env{ACC_DEVICE_NUM}, respectively. These two
+environment variables can be used as an alternative to calling
+@code{acc_set_device_num()}. As seen in the second use case, the device
+type and device number were specified using @code{acc_set_device_num()}.
+If however, the aforementioned environment variables were set, then the
+call to @code{acc_set_device_num()} would not be required.
+
+
+The use of the environment variables is only relevant when an OpenACC function
+is called prior to a call to @code{cudaCreate()}. If @code{cudaCreate()}
+is called prior to a call to an OpenACC function, then you must call
+@code{acc_set_device_num()}@footnote{More complete information
+about @env{ACC_DEVICE_TYPE} and @env{ACC_DEVICE_NUM} can be found in
+sections 4.1 and 4.2 of the @uref{https://www.openacc.org, OpenACC}
+Application Programming Interfaceā€¯, Version 2.6.}
+
+
+
+@c ---------------------------------------------------------------------
+@c OpenACC Profiling Interface
+@c ---------------------------------------------------------------------
+
+@node OpenACC Profiling Interface
+@chapter OpenACC Profiling Interface
+
+@section Implementation Status and Implementation-Defined Behavior
+
+We're implementing the OpenACC Profiling Interface as defined by the
+OpenACC 2.6 specification. We're clarifying some aspects here as
+@emph{implementation-defined behavior}, while they're still under
+discussion within the OpenACC Technical Committee.
+
+This implementation is tuned to keep the performance impact as low as
+possible for the (very common) case that the Profiling Interface is
+not enabled. This is relevant, as the Profiling Interface affects all
+the @emph{hot} code paths (in the target code, not in the offloaded
+code). Users of the OpenACC Profiling Interface can be expected to
+understand that performance will be impacted to some degree once the
+Profiling Interface has gotten enabled: for example, because of the
+@emph{runtime} (libgomp) calling into a third-party @emph{library} for
+every event that has been registered.
+
+We're not yet accounting for the fact that @cite{OpenACC events may
+occur during event processing}.
+
+We're not yet implementing initialization via a
+@code{acc_register_library} function that is either statically linked
+in, or dynamically via @env{LD_PRELOAD}.
+Initialization via @code{acc_register_library} functions dynamically
+loaded via the @env{ACC_PROFLIB} environment variable does work, as
+does directly calling @code{acc_prof_register},
+@code{acc_prof_unregister}, @code{acc_prof_lookup}.
+
+As currently there are no inquiry functions defined, calls to
+@code{acc_prof_lookup} will always return @code{NULL}.
+
+There aren't separate @emph{start}, @emph{stop} events defined for the
+event types @code{acc_ev_create}, @code{acc_ev_delete},
+@code{acc_ev_alloc}, @code{acc_ev_free}. It's not clear if these
+should be triggered before or after the actual device-specific call is
+made. We trigger them after.
+
+Remarks about data provided to callbacks:
+
+@table @asis
+
+@item @code{acc_prof_info.event_type}
+It's not clear if for @emph{nested} event callbacks (for example,
+@code{acc_ev_enqueue_launch_start} as part of a parent compute
+construct), this should be set for the nested event
+(@code{acc_ev_enqueue_launch_start}), or if the value of the parent
+construct should remain (@code{acc_ev_compute_construct_start}). In
+this implementation, the value will generally correspond to the
+innermost nested event type.
+
+@item @code{acc_prof_info.device_type}
+@itemize
+
+@item
+For @code{acc_ev_compute_construct_start}, and in presence of an
+@code{if} clause with @emph{false} argument, this will still refer to
+the offloading device type.
+It's not clear if that's the expected behavior.
+
+@item
+Complementary to the item before, for
+@code{acc_ev_compute_construct_end}, this is set to
+@code{acc_device_host} in presence of an @code{if} clause with
+@emph{false} argument.
+It's not clear if that's the expected behavior.
+
+@end itemize
+
+@item @code{acc_prof_info.thread_id}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_prof_info.async}
+@itemize
+
+@item
+Not yet implemented correctly for
+@code{acc_ev_compute_construct_start}.
+
+@item
+In a compute construct, for host-fallback
+execution/@code{acc_device_host} it will always be
+@code{acc_async_sync}.
+It's not clear if that's the expected behavior.
+
+@item
+For @code{acc_ev_device_init_start} and @code{acc_ev_device_init_end},
+it will always be @code{acc_async_sync}.
+It's not clear if that's the expected behavior.
+
+@end itemize
+
+@item @code{acc_prof_info.async_queue}
+There is no @cite{limited number of asynchronous queues} in libgomp.
+This will always have the same value as @code{acc_prof_info.async}.
+
+@item @code{acc_prof_info.src_file}
+Always @code{NULL}; not yet implemented.
+
+@item @code{acc_prof_info.func_name}
+Always @code{NULL}; not yet implemented.
+
+@item @code{acc_prof_info.line_no}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_prof_info.end_line_no}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_prof_info.func_line_no}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_prof_info.func_end_line_no}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_event_info.event_type}, @code{acc_event_info.*.event_type}
+Relating to @code{acc_prof_info.event_type} discussed above, in this
+implementation, this will always be the same value as
+@code{acc_prof_info.event_type}.
+
+@item @code{acc_event_info.*.parent_construct}
+@itemize
+
+@item
+Will be @code{acc_construct_parallel} for all OpenACC compute
+constructs as well as many OpenACC Runtime API calls; should be the
+one matching the actual construct, or
+@code{acc_construct_runtime_api}, respectively.
+
+@item
+Will be @code{acc_construct_enter_data} or
+@code{acc_construct_exit_data} when processing variable mappings
+specified in OpenACC @emph{declare} directives; should be
+@code{acc_construct_declare}.
+
+@item
+For implicit @code{acc_ev_device_init_start},
+@code{acc_ev_device_init_end}, and explicit as well as implicit
+@code{acc_ev_alloc}, @code{acc_ev_free},
+@code{acc_ev_enqueue_upload_start}, @code{acc_ev_enqueue_upload_end},
+@code{acc_ev_enqueue_download_start}, and
+@code{acc_ev_enqueue_download_end}, will be
+@code{acc_construct_parallel}; should reflect the real parent
+construct.
+
+@end itemize
+
+@item @code{acc_event_info.*.implicit}
+For @code{acc_ev_alloc}, @code{acc_ev_free},
+@code{acc_ev_enqueue_upload_start}, @code{acc_ev_enqueue_upload_end},
+@code{acc_ev_enqueue_download_start}, and
+@code{acc_ev_enqueue_download_end}, this currently will be @code{1}
+also for explicit usage.
+
+@item @code{acc_event_info.data_event.var_name}
+Always @code{NULL}; not yet implemented.
+
+@item @code{acc_event_info.data_event.host_ptr}
+For @code{acc_ev_alloc}, and @code{acc_ev_free}, this is always
+@code{NULL}.
+
+@item @code{typedef union acc_api_info}
+@dots{} as printed in @cite{5.2.3. Third Argument: API-Specific
+Information}. This should obviously be @code{typedef @emph{struct}
+acc_api_info}.
+
+@item @code{acc_api_info.device_api}
+Possibly not yet implemented correctly for
+@code{acc_ev_compute_construct_start},
+@code{acc_ev_device_init_start}, @code{acc_ev_device_init_end}:
+will always be @code{acc_device_api_none} for these event types.
+For @code{acc_ev_enter_data_start}, it will be
+@code{acc_device_api_none} in some cases.
+
+@item @code{acc_api_info.device_type}
+Always the same as @code{acc_prof_info.device_type}.
+
+@item @code{acc_api_info.vendor}
+Always @code{-1}; not yet implemented.
+
+@item @code{acc_api_info.device_handle}
+Always @code{NULL}; not yet implemented.
+
+@item @code{acc_api_info.context_handle}
+Always @code{NULL}; not yet implemented.
+
+@item @code{acc_api_info.async_handle}
+Always @code{NULL}; not yet implemented.
+
+@end table
+
+Remarks about certain event types:
+
+@table @asis
+
+@item @code{acc_ev_device_init_start}, @code{acc_ev_device_init_end}
+@itemize
+
+@item
+@c See 'DEVICE_INIT_INSIDE_COMPUTE_CONSTRUCT' in
+@c 'libgomp.oacc-c-c++-common/acc_prof-kernels-1.c',
+@c 'libgomp.oacc-c-c++-common/acc_prof-parallel-1.c'.
+Whan a compute construct triggers implicit
+@code{acc_ev_device_init_start} and @code{acc_ev_device_init_end}
+events, they currently aren't @emph{nested within} the corresponding
+@code{acc_ev_compute_construct_start} and
+@code{acc_ev_compute_construct_end}, but they're currently observed
+@emph{before} @code{acc_ev_compute_construct_start}.
+It's not clear what to do: the standard asks us provide a lot of
+details to the @code{acc_ev_compute_construct_start} callback, without
+(implicitly) initializing a device before?
+
+@item
+Callbacks for these event types will not be invoked for calls to the
+@code{acc_set_device_type} and @code{acc_set_device_num} functions.
+It's not clear if they should be.
+
+@end itemize
+
+@item @code{acc_ev_enter_data_start}, @code{acc_ev_enter_data_end}, @code{acc_ev_exit_data_start}, @code{acc_ev_exit_data_end}
+@itemize
+
+@item
+Callbacks for these event types will also be invoked for OpenACC
+@emph{host_data} constructs.
+It's not clear if they should be.
+
+@item
+Callbacks for these event types will also be invoked when processing
+variable mappings specified in OpenACC @emph{declare} directives.
+It's not clear if they should be.
+
+@end itemize
+
+@end table
+
+Callbacks for the following event types will be invoked, but dispatch
+and information provided therein has not yet been thoroughly reviewed:
+
+@itemize
+@item @code{acc_ev_alloc}
+@item @code{acc_ev_free}
+@item @code{acc_ev_update_start}, @code{acc_ev_update_end}
+@item @code{acc_ev_enqueue_upload_start}, @code{acc_ev_enqueue_upload_end}
+@item @code{acc_ev_enqueue_download_start}, @code{acc_ev_enqueue_download_end}
+@end itemize
+
+During device initialization, and finalization, respectively,
+callbacks for the following event types will not yet be invoked:
+
+@itemize
+@item @code{acc_ev_alloc}
+@item @code{acc_ev_free}
+@end itemize
+
+Callbacks for the following event types have not yet been implemented,
+so currently won't be invoked:
+
+@itemize
+@item @code{acc_ev_device_shutdown_start}, @code{acc_ev_device_shutdown_end}
+@item @code{acc_ev_runtime_shutdown}
+@item @code{acc_ev_create}, @code{acc_ev_delete}
+@item @code{acc_ev_wait_start}, @code{acc_ev_wait_end}
+@end itemize
+
+For the following runtime library functions, not all expected
+callbacks will be invoked (mostly concerning implicit device
+initialization):
+
+@itemize
+@item @code{acc_get_num_devices}
+@item @code{acc_set_device_type}
+@item @code{acc_get_device_type}
+@item @code{acc_set_device_num}
+@item @code{acc_get_device_num}
+@item @code{acc_init}
+@item @code{acc_shutdown}
+@end itemize
+
+Aside from implicit device initialization, for the following runtime
+library functions, no callbacks will be invoked for shared-memory
+offloading devices (it's not clear if they should be):
+
+@itemize
+@item @code{acc_malloc}
+@item @code{acc_free}
+@item @code{acc_copyin}, @code{acc_present_or_copyin}, @code{acc_copyin_async}
+@item @code{acc_create}, @code{acc_present_or_create}, @code{acc_create_async}
+@item @code{acc_copyout}, @code{acc_copyout_async}, @code{acc_copyout_finalize}, @code{acc_copyout_finalize_async}
+@item @code{acc_delete}, @code{acc_delete_async}, @code{acc_delete_finalize}, @code{acc_delete_finalize_async}
+@item @code{acc_update_device}, @code{acc_update_device_async}
+@item @code{acc_update_self}, @code{acc_update_self_async}
+@item @code{acc_map_data}, @code{acc_unmap_data}
+@item @code{acc_memcpy_to_device}, @code{acc_memcpy_to_device_async}
+@item @code{acc_memcpy_from_device}, @code{acc_memcpy_from_device_async}
+@end itemize
+
+
+
@c ---------------------------------------------------------------------
@c The libgomp ABI
@c ---------------------------------------------------------------------
* Implementing ORDERED construct::
* Implementing SECTIONS construct::
* Implementing SINGLE construct::
+* Implementing OpenACC's PARALLEL construct::
@end menu
+@node Implementing OpenACC's PARALLEL construct
+@section Implementing OpenACC's PARALLEL construct
+
+@smallexample
+ void GOACC_parallel ()
+@end smallexample
+
+
+
@c ---------------------------------------------------------------------
@c Reporting Bugs
@c ---------------------------------------------------------------------
@chapter Reporting Bugs
Bugs in the GNU Offloading and Multi Processing Runtime Library should
-be reported via @uref{http://gcc.gnu.org/bugzilla/, Bugzilla}. Please add
+be reported via @uref{https://gcc.gnu.org/bugzilla/, Bugzilla}. Please add
"openacc", or "openmp", or both to the keywords field in the bug
report, as appropriate.