@copying
-Copyright @copyright{} 2006, 2007, 2008, 2010 Free Software Foundation, Inc.
+Copyright @copyright{} 2006-2017 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
@ifinfo
@dircategory GNU Libraries
@direntry
-* libgomp: (libgomp). GNU OpenMP runtime library
+* libgomp: (libgomp). GNU Offloading and Multi Processing Runtime Library.
@end direntry
-This manual documents the GNU implementation of the OpenMP API for
-multi-platform shared-memory parallel programming in C/C++ and Fortran.
+This manual documents libgomp, the GNU Offloading and Multi Processing
+Runtime library. This is the GNU implementation of the OpenMP and
+OpenACC APIs for parallel and accelerator programming in C/C++ and
+Fortran.
Published by the Free Software Foundation
51 Franklin Street, Fifth Floor
@setchapternewpage odd
@titlepage
-@title The GNU OpenMP Implementation
+@title GNU Offloading and Multi Processing Runtime Library
+@subtitle The GNU OpenMP and OpenACC Implementation
@page
@vskip 0pt plus 1filll
@comment For the @value{version-GCC} Version*
@top Introduction
@cindex Introduction
-This manual documents the usage of libgomp, the GNU implementation of the
-@uref{http://www.openmp.org, OpenMP} Application Programming Interface (API)
-for multi-platform shared-memory parallel programming in C/C++ and Fortran.
+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
+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
+Interface (API) for offloading of code to accelerator devices in C/C++
+and Fortran.
+
+Originally, libgomp implemented the GNU OpenMP Runtime Library. Based
+on this, support for OpenACC and offloading (both OpenACC and OpenMP
+4's target construct) has been added later on, and the library's name
+changed to GNU Offloading and Multi Processing Runtime Library.
interface.
* Environment Variables:: Influencing 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.
* The libgomp ABI:: Notes on the external ABI presented by libgomp.
-* Reporting Bugs:: How to report bugs in GNU OpenMP.
+* Reporting Bugs:: How to report bugs in the GNU Offloading and
+ Multi Processing Runtime Library.
* Copying:: GNU general public license says
how you can copy and share libgomp.
* GNU Free Documentation License::
How you can copy and share this manual.
* Funding:: How to help assure continued work for free
software.
-* Index:: Index of this documentation.
+* Library Index:: Index of this documentation.
@end menu
@chapter Enabling OpenMP
To activate the OpenMP extensions for C/C++ and Fortran, the compile-time
-flag @command{-fopenmp} must be specified. This enables the OpenMP directive
+flag @command{-fopenmp} must be specified. This enables the OpenMP directive
@code{#pragma omp} in C/C++ and @code{!$omp} directives in free form,
@code{c$omp}, @code{*$omp} and @code{!$omp} 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
+@code{*$} and @code{!$} sentinels in fixed form, for Fortran. The flag also
arranges for automatic linking of the OpenMP 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 3.0.
+version 4.5.
@c ---------------------------------------------------------------------
@node Runtime Library Routines
@chapter Runtime Library Routines
-The runtime routines described here are defined by section 3 of the OpenMP
-specifications in version 3.0. The routines are structured in following
+The runtime routines described here are defined by Section 3 of the OpenMP
+specification in version 4.5. The routines are structured in following
three parts:
-Control threads, processors and the parallel environment.
-
@menu
+Control threads, processors and the parallel environment. They have C
+linkage, and do not throw exceptions.
+
* omp_get_active_level:: Number of active parallel regions
* omp_get_ancestor_thread_num:: Ancestor thread ID
+* omp_get_cancellation:: Whether cancellation support is enabled
+* omp_get_default_device:: Get the default device for target regions
* omp_get_dynamic:: Dynamic teams setting
* omp_get_level:: Number of parallel regions
* omp_get_max_active_levels:: Maximum number of active regions
+* omp_get_max_task_priority:: Maximum task priority value that can be set
* omp_get_max_threads:: Maximum number of threads of parallel region
* omp_get_nested:: Nested parallel regions
+* omp_get_num_devices:: Number of target devices
* omp_get_num_procs:: Number of processors online
+* omp_get_num_teams:: Number of teams
* omp_get_num_threads:: Size of the active team
+* omp_get_proc_bind:: Whether theads may be moved between CPUs
* omp_get_schedule:: Obtain the runtime scheduling method
+* omp_get_team_num:: Get team number
* omp_get_team_size:: Number of threads in a team
* omp_get_thread_limit:: Maximum number of threads
* omp_get_thread_num:: Current thread ID
* omp_in_parallel:: Whether a parallel region is active
+* omp_in_final:: Whether in final or included task region
+* omp_is_initial_device:: Whether executing on the host device
+* omp_set_default_device:: Set the default device for target regions
* omp_set_dynamic:: Enable/disable dynamic teams
* omp_set_max_active_levels:: Limits the number of active parallel regions
* omp_set_nested:: Enable/disable nested parallel regions
* omp_set_num_threads:: Set upper team size limit
* omp_set_schedule:: Set the runtime scheduling method
-@end menu
Initialize, set, test, unset and destroy simple and nested locks.
-@menu
* omp_init_lock:: Initialize simple lock
* omp_set_lock:: Wait for and set simple lock
* omp_test_lock:: Test and set simple lock if available
* omp_test_nest_lock:: Test and set nested lock if available
* omp_unset_nest_lock:: Unset nested lock
* omp_destroy_nest_lock:: Destroy nested lock
-@end menu
Portable, thread-based, wall clock timer.
-@menu
* omp_get_wtick:: Get timer precision.
* omp_get_wtime:: Elapsed wall clock time.
@end 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 specifications v3.0}, section 3.2.19.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.20.
@end table
@table @asis
@item @emph{Description}:
This function returns the thread identification number for the given
-nesting level of the current thread. For values of @var{level} outside
+nesting level of the current thread. For values of @var{level} outside
zero to @code{omp_get_level} -1 is returned; if @var{level} is
@code{omp_get_level} the result is identical to @code{omp_get_thread_num}.
@ref{omp_get_level}, @ref{omp_get_thread_num}, @ref{omp_get_team_size}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.17.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.18.
+@end table
+
+
+
+@node omp_get_cancellation
+@section @code{omp_get_cancellation} -- Whether cancellation support is enabled
+@table @asis
+@item @emph{Description}:
+This function returns @code{true} if cancellation is activated, @code{false}
+otherwise. Here, @code{true} and @code{false} represent their language-specific
+counterparts. Unless @env{OMP_CANCELLATION} is set true, cancellations are
+deactivated.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_cancellation(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{logical function omp_get_cancellation()}
+@end multitable
+
+@item @emph{See also}:
+@ref{OMP_CANCELLATION}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.9.
+@end table
+
+
+
+@node omp_get_default_device
+@section @code{omp_get_default_device} -- Get the default device for target regions
+@table @asis
+@item @emph{Description}:
+Get the default device for target regions without device clause.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_default_device(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function omp_get_default_device()}
+@end multitable
+
+@item @emph{See also}:
+@ref{OMP_DEFAULT_DEVICE}, @ref{omp_set_default_device}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.30.
@end table
counterparts.
The dynamic team setting may be initialized at startup by the
-@code{OMP_DYNAMIC} environment variable or at runtime using
-@code{omp_set_dynamic}. If undefined, dynamic adjustment is
+@env{OMP_DYNAMIC} environment variable or at runtime using
+@code{omp_set_dynamic}. If undefined, dynamic adjustment is
disabled by default.
@item @emph{C/C++}:
@ref{omp_set_dynamic}, @ref{OMP_DYNAMIC}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.8.
+@uref{http://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 specifications v3.0}, section 3.2.16.
+@uref{http://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 specifications v3.0}, section 3.2.14.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.16.
@end table
+@node omp_get_max_task_priority
+@section @code{omp_get_max_task_priority} -- Maximum priority value
+that can be set for tasks.
+@table @asis
+@item @emph{Description}:
+This function obtains the maximum allowed priority number for tasks.
+
+@item @emph{C/C++}
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_max_task_priority(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function omp_get_max_task_priority()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.29.
+@end table
+
@node omp_get_max_threads
@section @code{omp_get_max_threads} -- Maximum number of threads of parallel region
@ref{omp_set_num_threads}, @ref{omp_set_dynamic}, @ref{omp_get_thread_limit}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.3.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.3.
@end table
@table @asis
@item @emph{Description}:
This function returns @code{true} if nested parallel regions are
-enabled, @code{false} otherwise. Here, @code{true} and @code{false}
+enabled, @code{false} otherwise. Here, @code{true} and @code{false}
represent their language-specific counterparts.
Nested parallel regions may be initialized at startup by the
-@code{OMP_NESTED} environment variable or at runtime using
-@code{omp_set_nested}. If undefined, nested parallel regions are
+@env{OMP_NESTED} environment variable or at runtime using
+@code{omp_set_nested}. If undefined, nested parallel regions are
disabled by default.
@item @emph{C/C++}:
@ref{omp_set_nested}, @ref{OMP_NESTED}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.10.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.11.
+@end table
+
+
+
+@node omp_get_num_devices
+@section @code{omp_get_num_devices} -- Number of target devices
+@table @asis
+@item @emph{Description}:
+Returns the number of target devices.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_num_devices(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function omp_get_num_devices()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.31.
@end table
@section @code{omp_get_num_procs} -- Number of processors online
@table @asis
@item @emph{Description}:
-Returns the number of processors online.
+Returns the number of processors online on that device.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.5.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.5.
+@end table
+
+
+
+@node omp_get_num_teams
+@section @code{omp_get_num_teams} -- Number of teams
+@table @asis
+@item @emph{Description}:
+Returns the number of teams in the current team region.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_num_teams(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function omp_get_num_teams()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.32.
@end table
@section @code{omp_get_num_threads} -- Size of the active team
@table @asis
@item @emph{Description}:
-Returns the number of threads in the current team. In a sequential section of
+Returns the number of threads in the current team. In a sequential section of
the program @code{omp_get_num_threads} returns 1.
The default team size may be initialized at startup by the
-@code{OMP_NUM_THREADS} environment variable. At runtime, the size
+@env{OMP_NUM_THREADS} environment variable. At runtime, the size
of the current team may be set either by the @code{NUM_THREADS}
-clause or by @code{omp_set_num_threads}. If none of the above were
-used to define a specific value and @code{OMP_DYNAMIC} is disabled,
+clause or by @code{omp_set_num_threads}. If none of the above were
+used to define a specific value and @env{OMP_DYNAMIC} is disabled,
one thread per CPU online is used.
@item @emph{C/C++}:
@ref{omp_get_max_threads}, @ref{omp_set_num_threads}, @ref{OMP_NUM_THREADS}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.2.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.2.
+@end table
+
+
+
+@node omp_get_proc_bind
+@section @code{omp_get_proc_bind} -- Whether theads may be moved between CPUs
+@table @asis
+@item @emph{Description}:
+This functions returns the currently active thread affinity policy, which is
+set via @env{OMP_PROC_BIND}. Possible values are @code{omp_proc_bind_false},
+@code{omp_proc_bind_true}, @code{omp_proc_bind_master},
+@code{omp_proc_bind_close} and @code{omp_proc_bind_spread}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{omp_proc_bind_t omp_get_proc_bind(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer(kind=omp_proc_bind_kind) function omp_get_proc_bind()}
+@end multitable
+
+@item @emph{See also}:
+@ref{OMP_PROC_BIND}, @ref{OMP_PLACES}, @ref{GOMP_CPU_AFFINITY},
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.22.
@end table
@section @code{omp_get_schedule} -- Obtain the runtime scheduling method
@table @asis
@item @emph{Description}:
-Obtain the runtime scheduling method. The @var{kind} argument will be
+Obtain the runtime scheduling method. The @var{kind} argument will be
set to the value @code{omp_sched_static}, @code{omp_sched_dynamic},
-@code{omp_sched_guided} or @code{omp_sched_auto}. The second argument,
-@var{modifier}, is set to the chunk size.
+@code{omp_sched_guided} or @code{omp_sched_auto}. The second argument,
+@var{chunk_size}, is set to the chunk size.
@item @emph{C/C++}
@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{omp_schedule(omp_sched_t *kind, int *modifier);}
+@item @emph{Prototype}: @tab @code{void omp_get_schedule(omp_sched_t *kind, int *chunk_size);}
@end multitable
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_schedule(kind, modifier)}
+@item @emph{Interface}: @tab @code{subroutine omp_get_schedule(kind, chunk_size)}
@item @tab @code{integer(kind=omp_sched_kind) kind}
-@item @tab @code{integer modifier}
+@item @tab @code{integer chunk_size}
@end multitable
@item @emph{See also}:
@ref{omp_set_schedule}, @ref{OMP_SCHEDULE}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.12.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.13.
+@end table
+
+
+
+@node omp_get_team_num
+@section @code{omp_get_team_num} -- Get team number
+@table @asis
+@item @emph{Description}:
+Returns the team number of the calling thread.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_get_team_num(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{integer function omp_get_team_num()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.33.
@end table
@table @asis
@item @emph{Description}:
This function returns the number of threads in a thread team to which
-either the current thread or its ancestor belongs. For values of @var{level}
+either the current thread or its ancestor belongs. For values of @var{level}
outside zero to @code{omp_get_level}, -1 is returned; if @var{level} is zero,
1 is returned, and for @code{omp_get_level}, the result is identical
to @code{omp_get_num_threads}.
@ref{omp_get_num_threads}, @ref{omp_get_level}, @ref{omp_get_ancestor_thread_num}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.18.
+@uref{http://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 specifications v3.0}, section 3.2.13.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.14.
@end table
-@node omp_get_thread_num
+@node omp_get_thread_num
@section @code{omp_get_thread_num} -- Current thread ID
@table @asis
@item @emph{Description}:
Returns a unique thread identification number within the current team.
In a sequential parts of the program, @code{omp_get_thread_num}
-always returns 0. In parallel regions the return value varies
-from 0 to @code{omp_get_num_threads}-1 inclusive. The return
+always returns 0. In parallel regions the return value varies
+from 0 to @code{omp_get_num_threads}-1 inclusive. The return
value of the master thread of a team is always 0.
@item @emph{C/C++}:
@ref{omp_get_num_threads}, @ref{omp_get_ancestor_thread_num}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.4.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.4.
@end table
@section @code{omp_in_parallel} -- Whether a parallel region is active
@table @asis
@item @emph{Description}:
-This function returns @code{true} if currently running in parallel,
-@code{false} otherwise. Here, @code{true} and @code{false} represent
+This function returns @code{true} if currently running in parallel,
+@code{false} otherwise. Here, @code{true} and @code{false} represent
their language-specific counterparts.
@item @emph{C/C++}:
@end multitable
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.6.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.6.
+@end table
+
+
+@node omp_in_final
+@section @code{omp_in_final} -- Whether in final or included task region
+@table @asis
+@item @emph{Description}:
+This function returns @code{true} if currently running in a final
+or included task region, @code{false} otherwise. Here, @code{true}
+and @code{false} represent their language-specific counterparts.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_in_final(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{logical function omp_in_final()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.21.
+@end table
+
+
+
+@node omp_is_initial_device
+@section @code{omp_is_initial_device} -- Whether executing on the host device
+@table @asis
+@item @emph{Description}:
+This function returns @code{true} if currently running on the host device,
+@code{false} otherwise. Here, @code{true} and @code{false} represent
+their language-specific counterparts.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{int omp_is_initial_device(void);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{logical function omp_is_initial_device()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.34.
+@end table
+
+
+
+@node omp_set_default_device
+@section @code{omp_set_default_device} -- Set the default device for target regions
+@table @asis
+@item @emph{Description}:
+Set the default device for target regions without device clause. The argument
+shall be a nonnegative device number.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{void omp_set_default_device(int device_num);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine omp_set_default_device(device_num)}
+@item @tab @code{integer device_num}
+@end multitable
+
+@item @emph{See also}:
+@ref{OMP_DEFAULT_DEVICE}, @ref{omp_get_default_device}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.29.
@end table
+
@node omp_set_dynamic
@section @code{omp_set_dynamic} -- Enable/disable dynamic teams
@table @asis
@item @emph{Description}:
Enable or disable the dynamic adjustment of the number of threads
-within a team. The function takes the language-specific equivalent
+within a team. The function takes the language-specific equivalent
of @code{true} and @code{false}, where @code{true} enables dynamic
adjustment of team sizes and @code{false} disables it.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{void omp_set_dynamic(int set);}
+@item @emph{Prototype}: @tab @code{void omp_set_dynamic(int dynamic_threads);}
@end multitable
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_dynamic(set)}
-@item @tab @code{logical, intent(in) :: set}
+@item @emph{Interface}: @tab @code{subroutine omp_set_dynamic(dynamic_threads)}
+@item @tab @code{logical, intent(in) :: dynamic_threads}
@end multitable
@item @emph{See also}:
@ref{OMP_DYNAMIC}, @ref{omp_get_dynamic}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.7.
+@uref{http://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 specifications v3.0}, section 3.2.14.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.15.
@end table
@table @asis
@item @emph{Description}:
Enable or disable nested parallel regions, i.e., whether team members
-are allowed to create new teams. The function takes the language-specific
+are allowed to create new teams. The function takes the language-specific
equivalent of @code{true} and @code{false}, where @code{true} enables
dynamic adjustment of team sizes and @code{false} disables it.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{void omp_set_nested(int set);}
+@item @emph{Prototype}: @tab @code{void omp_set_nested(int nested);}
@end multitable
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_nested(set)}
-@item @tab @code{logical, intent(in) :: set}
+@item @emph{Interface}: @tab @code{subroutine omp_set_nested(nested)}
+@item @tab @code{logical, intent(in) :: nested}
@end multitable
@item @emph{See also}:
@ref{OMP_NESTED}, @ref{omp_get_nested}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.9.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.10.
@end table
@table @asis
@item @emph{Description}:
Specifies the number of threads used by default in subsequent parallel
-sections, if those do not specify a @code{num_threads} clause. The
-argument of @code{omp_set_num_threads} shall be a positive integer.
+sections, if those do not specify a @code{num_threads} clause. The
+argument of @code{omp_set_num_threads} shall be a positive integer.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{void omp_set_num_threads(int n);}
+@item @emph{Prototype}: @tab @code{void omp_set_num_threads(int num_threads);}
@end multitable
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_num_threads(n)}
-@item @tab @code{integer, intent(in) :: n}
+@item @emph{Interface}: @tab @code{subroutine omp_set_num_threads(num_threads)}
+@item @tab @code{integer, intent(in) :: num_threads}
@end multitable
@item @emph{See also}:
@ref{OMP_NUM_THREADS}, @ref{omp_get_num_threads}, @ref{omp_get_max_threads}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.1.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.1.
@end table
@section @code{omp_set_schedule} -- Set the runtime scheduling method
@table @asis
@item @emph{Description}:
-Sets the runtime scheduling method. The @var{kind} argument can have the
+Sets the runtime scheduling method. The @var{kind} argument can have the
value @code{omp_sched_static}, @code{omp_sched_dynamic},
-@code{omp_sched_guided} or @code{omp_sched_auto}. Except for
+@code{omp_sched_guided} or @code{omp_sched_auto}. Except for
@code{omp_sched_auto}, the chunk size is set to the value of
-@var{modifier} if positive, or to the default value if zero or negative.
-For @code{omp_sched_auto} the @var{modifier} argument is ignored.
+@var{chunk_size} if positive, or to the default value if zero or negative.
+For @code{omp_sched_auto} the @var{chunk_size} argument is ignored.
@item @emph{C/C++}
@multitable @columnfractions .20 .80
-@item @emph{Prototype}: @tab @code{int omp_set_schedule(omp_sched_t *kind, int *modifier);}
+@item @emph{Prototype}: @tab @code{void omp_set_schedule(omp_sched_t kind, int chunk_size);}
@end multitable
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_schedule(kind, modifier)}
+@item @emph{Interface}: @tab @code{subroutine omp_set_schedule(kind, chunk_size)}
@item @tab @code{integer(kind=omp_sched_kind) kind}
-@item @tab @code{integer modifier}
+@item @tab @code{integer chunk_size}
@end multitable
@item @emph{See also}:
@ref{OMP_SCHEDULE}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.2.11.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.2.12.
@end table
@section @code{omp_init_lock} -- Initialize simple lock
@table @asis
@item @emph{Description}:
-Initialize a simple lock. After initialization, the lock is in
+Initialize a simple lock. After initialization, the lock is in
an unlocked state.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_init_lock(lock)}
-@item @tab @code{integer(omp_lock_kind), intent(out) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_init_lock(svar)}
+@item @tab @code{integer(omp_lock_kind), intent(out) :: svar}
@end multitable
@item @emph{See also}:
@ref{omp_destroy_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.1.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.1.
@end table
@table @asis
@item @emph{Description}:
Before setting a simple lock, the lock variable must be initialized by
-@code{omp_init_lock}. The calling thread is blocked until the lock
-is available. If the lock is already held by the current thread,
+@code{omp_init_lock}. The calling thread is blocked until the lock
+is available. If the lock is already held by the current thread,
a deadlock occurs.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_lock(lock)}
-@item @tab @code{integer(omp_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_set_lock(svar)}
+@item @tab @code{integer(omp_lock_kind), intent(inout) :: svar}
@end multitable
@item @emph{See also}:
@ref{omp_init_lock}, @ref{omp_test_lock}, @ref{omp_unset_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.3.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.4.
@end table
@table @asis
@item @emph{Description}:
Before setting a simple lock, the lock variable must be initialized by
-@code{omp_init_lock}. Contrary to @code{omp_set_lock}, @code{omp_test_lock}
-does not block if the lock is not available. This function returns
-@code{true} upon success, @code{false} otherwise. Here, @code{true} and
+@code{omp_init_lock}. Contrary to @code{omp_set_lock}, @code{omp_test_lock}
+does not block if the lock is not available. This function returns
+@code{true} upon success, @code{false} otherwise. Here, @code{true} and
@code{false} represent their language-specific counterparts.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_test_lock(lock)}
-@item @tab @code{logical(omp_logical_kind) :: omp_test_lock}
-@item @tab @code{integer(omp_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{logical function omp_test_lock(svar)}
+@item @tab @code{integer(omp_lock_kind), intent(inout) :: svar}
@end multitable
@item @emph{See also}:
@ref{omp_init_lock}, @ref{omp_set_lock}, @ref{omp_set_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.5.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.6.
@end table
@table @asis
@item @emph{Description}:
A simple lock about to be unset must have been locked by @code{omp_set_lock}
-or @code{omp_test_lock} before. In addition, the lock must be held by the
-thread calling @code{omp_unset_lock}. Then, the lock becomes unlocked. If one
-or more threads attempted to set the lock before, one of them is chosen to,
-again, set the lock for itself.
+or @code{omp_test_lock} before. In addition, the lock must be held by the
+thread calling @code{omp_unset_lock}. Then, the lock becomes unlocked. If one
+or more threads attempted to set the lock before, one of them is chosen to,
+again, set the lock to itself.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_unset_lock(lock)}
-@item @tab @code{integer(omp_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_unset_lock(svar)}
+@item @tab @code{integer(omp_lock_kind), intent(inout) :: svar}
@end multitable
@item @emph{See also}:
@ref{omp_set_lock}, @ref{omp_test_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.4.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.5.
@end table
@section @code{omp_destroy_lock} -- Destroy simple lock
@table @asis
@item @emph{Description}:
-Destroy a simple lock. In order to be destroyed, a simple lock must be
+Destroy a simple lock. In order to be destroyed, a simple lock must be
in the unlocked state.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_destroy_lock(lock)}
-@item @tab @code{integer(omp_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_destroy_lock(svar)}
+@item @tab @code{integer(omp_lock_kind), intent(inout) :: svar}
@end multitable
@item @emph{See also}:
@ref{omp_init_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.2.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.3.
@end table
@section @code{omp_init_nest_lock} -- Initialize nested lock
@table @asis
@item @emph{Description}:
-Initialize a nested lock. After initialization, the lock is in
+Initialize a nested lock. After initialization, the lock is in
an unlocked state and the nesting count is set to zero.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_init_nest_lock(lock)}
-@item @tab @code{integer(omp_nest_lock_kind), intent(out) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_init_nest_lock(nvar)}
+@item @tab @code{integer(omp_nest_lock_kind), intent(out) :: nvar}
@end multitable
@item @emph{See also}:
@ref{omp_destroy_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.1.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.1.
@end table
@table @asis
@item @emph{Description}:
Before setting a nested lock, the lock variable must be initialized by
-@code{omp_init_nest_lock}. The calling thread is blocked until the lock
-is available. If the lock is already held by the current thread, the
-nesting count for the lock in incremented.
+@code{omp_init_nest_lock}. The calling thread is blocked until the lock
+is available. If the lock is already held by the current thread, the
+nesting count for the lock is incremented.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_set_nest_lock(lock)}
-@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_set_nest_lock(nvar)}
+@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: nvar}
@end multitable
@item @emph{See also}:
@ref{omp_init_nest_lock}, @ref{omp_unset_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.3.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.4.
@end table
@table @asis
@item @emph{Description}:
Before setting a nested lock, the lock variable must be initialized by
-@code{omp_init_nest_lock}. Contrary to @code{omp_set_nest_lock},
+@code{omp_init_nest_lock}. Contrary to @code{omp_set_nest_lock},
@code{omp_test_nest_lock} does not block if the lock is not available.
If the lock is already held by the current thread, the new nesting count
-is returned. Otherwise, the return value equals zero.
+is returned. Otherwise, the return value equals zero.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{integer function omp_test_nest_lock(lock)}
-@item @tab @code{integer(omp_integer_kind) :: omp_test_nest_lock}
-@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{logical function omp_test_nest_lock(nvar)}
+@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: nvar}
@end multitable
@ref{omp_init_lock}, @ref{omp_set_lock}, @ref{omp_set_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.5.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.6.
@end table
@table @asis
@item @emph{Description}:
A nested lock about to be unset must have been locked by @code{omp_set_nested_lock}
-or @code{omp_test_nested_lock} before. In addition, the lock must be held by the
-thread calling @code{omp_unset_nested_lock}. If the nesting count drops to zero, the
-lock becomes unlocked. If one ore more threads attempted to set the lock before,
-one of them is chosen to, again, set the lock for itself.
+or @code{omp_test_nested_lock} before. In addition, the lock must be held by the
+thread calling @code{omp_unset_nested_lock}. If the nesting count drops to zero, the
+lock becomes unlocked. If one ore more threads attempted to set the lock before,
+one of them is chosen to, again, set the lock to itself.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_unset_nest_lock(lock)}
-@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_unset_nest_lock(nvar)}
+@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: nvar}
@end multitable
@item @emph{See also}:
@ref{omp_set_nest_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.4.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.3.5.
@end table
@section @code{omp_destroy_nest_lock} -- Destroy nested lock
@table @asis
@item @emph{Description}:
-Destroy a nested lock. In order to be destroyed, a nested lock must be
+Destroy a nested lock. In order to be destroyed, a nested lock must be
in the unlocked state and its nesting count must equal zero.
@item @emph{C/C++}:
@item @emph{Fortran}:
@multitable @columnfractions .20 .80
-@item @emph{Interface}: @tab @code{subroutine omp_destroy_nest_lock(lock)}
-@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: lock}
+@item @emph{Interface}: @tab @code{subroutine omp_destroy_nest_lock(nvar)}
+@item @tab @code{integer(omp_nest_lock_kind), intent(inout) :: nvar}
@end multitable
@item @emph{See also}:
@ref{omp_init_lock}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.3.2.
+@uref{http://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 specifications v3.0}, section 3.4.2.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.4.2.
@end table
@section @code{omp_get_wtime} -- Elapsed wall clock time
@table @asis
@item @emph{Description}:
-Elapsed wall clock time in seconds. The time is measured per thread, no
+Elapsed wall clock time in seconds. The time is measured per thread, no
guarantee can be made that two distinct threads measure the same time.
-Time is measured from some "time in the past". On POSIX compliant systems
-the seconds since the Epoch (00:00:00 UTC, January 1, 1970) are returned.
+Time is measured from some "time in the past", which is an arbitrary time
+guaranteed not to change during the execution of the program.
@item @emph{C/C++}:
@multitable @columnfractions .20 .80
@ref{omp_get_wtick}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 3.4.1.
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 3.4.1.
@end table
@node Environment Variables
@chapter Environment Variables
-The variables @env{OMP_DYNAMIC}, @env{OMP_MAX_ACTIVE_LEVELS},
-@env{OMP_NESTED}, @env{OMP_NUM_THREADS}, @env{OMP_SCHEDULE},
-@env{OMP_STACKSIZE},@env{OMP_THREAD_LIMIT} and @env{OMP_WAIT_POLICY}
-are defined by section 4 of the OpenMP specifications in version 3.0,
-while @env{GOMP_CPU_AFFINITY} and @env{GOMP_STACKSIZE} are GNU
-extensions.
+The environment variables which beginning with @env{OMP_} are defined by
+section 4 of the OpenMP specification in version 4.5, while those
+beginning with @env{GOMP_} are GNU extensions.
@menu
-* OMP_DYNAMIC:: Dynamic adjustment of threads
-* OMP_MAX_ACTIVE_LEVELS:: Set the maximum number of nested parallel regions
-* OMP_NESTED:: Nested parallel regions
-* OMP_NUM_THREADS:: Specifies the number of threads to use
-* OMP_STACKSIZE:: Set default thread stack size
-* OMP_SCHEDULE:: How threads are scheduled
-* OMP_THREAD_LIMIT:: Set the maximum number of threads
-* OMP_WAIT_POLICY:: How waiting threads are handled
-* GOMP_CPU_AFFINITY:: Bind threads to specific CPUs
-* GOMP_STACKSIZE:: Set default thread stack size
+* OMP_CANCELLATION:: Set whether cancellation is activated
+* OMP_DISPLAY_ENV:: Show OpenMP version and environment variables
+* OMP_DEFAULT_DEVICE:: Set the device used in target regions
+* OMP_DYNAMIC:: Dynamic adjustment of threads
+* OMP_MAX_ACTIVE_LEVELS:: Set the maximum number of nested parallel regions
+* OMP_MAX_TASK_PRIORITY:: Set the maximum task priority value
+* OMP_NESTED:: Nested parallel regions
+* OMP_NUM_THREADS:: Specifies the number of threads to use
+* OMP_PROC_BIND:: Whether theads may be moved between CPUs
+* OMP_PLACES:: Specifies on which CPUs the theads should be placed
+* OMP_STACKSIZE:: Set default thread stack size
+* OMP_SCHEDULE:: How threads are scheduled
+* OMP_THREAD_LIMIT:: Set the maximum number of threads
+* OMP_WAIT_POLICY:: How waiting threads are handled
+* GOMP_CPU_AFFINITY:: Bind threads to specific CPUs
+* GOMP_DEBUG:: Enable debugging output
+* GOMP_STACKSIZE:: Set default thread stack size
+* GOMP_SPINCOUNT:: Set the busy-wait spin count
+* GOMP_RTEMS_THREAD_POOLS:: Set the RTEMS specific thread pools
@end menu
+@node OMP_CANCELLATION
+@section @env{OMP_CANCELLATION} -- Set whether cancellation is activated
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+If set to @code{TRUE}, the cancellation is activated. If set to @code{FALSE} or
+if unset, cancellation is disabled and the @code{cancel} construct is ignored.
+
+@item @emph{See also}:
+@ref{omp_get_cancellation}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.11
+@end table
+
+
+
+@node OMP_DISPLAY_ENV
+@section @env{OMP_DISPLAY_ENV} -- Show OpenMP version and environment variables
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+If set to @code{TRUE}, the OpenMP version number and the values
+associated with the OpenMP environment variables are printed to @code{stderr}.
+If set to @code{VERBOSE}, it additionally shows the value of the environment
+variables which are GNU extensions. If undefined or set to @code{FALSE},
+this information will not be shown.
+
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.12
+@end table
+
+
+
+@node OMP_DEFAULT_DEVICE
+@section @env{OMP_DEFAULT_DEVICE} -- Set the device used in target regions
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+Set to choose the device which is used in a @code{target} region, unless the
+value is overridden by @code{omp_set_default_device} or by a @code{device}
+clause. The value shall be the nonnegative device number. If no device with
+the given device number exists, the code is executed on the host. If unset,
+device number 0 will be used.
+
+
+@item @emph{See also}:
+@ref{omp_get_default_device}, @ref{omp_set_default_device},
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.13
+@end table
+
+
+
@node OMP_DYNAMIC
@section @env{OMP_DYNAMIC} -- Dynamic adjustment of threads
@cindex Environment Variable
@table @asis
@item @emph{Description}:
Enable or disable the dynamic adjustment of the number of threads
-within a team. The value of this environment variable shall be
-@code{TRUE} or @code{FALSE}. If undefined, dynamic adjustment is
+within a team. The value of this environment variable shall be
+@code{TRUE} or @code{FALSE}. If undefined, dynamic adjustment is
disabled by default.
@item @emph{See also}:
@ref{omp_set_dynamic}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 4.3
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.3
@end table
@table @asis
@item @emph{Description}:
Specifies the initial value for the maximum number of nested parallel
-regions. The value of this variable shall be positive integer.
+regions. The value of this variable shall be a positive integer.
If undefined, the number of active levels is unlimited.
@item @emph{See also}:
@ref{omp_set_max_active_levels}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 4.7
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.9
+@end table
+
+
+
+@node OMP_MAX_TASK_PRIORITY
+@section @env{OMP_MAX_TASK_PRIORITY} -- Set the maximum priority
+number that can be set for a task.
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+Specifies the initial value for the maximum priority value that can be
+set for a task. The value of this variable shall be a non-negative
+integer, and zero is allowed. If undefined, the default priority is
+0.
+
+@item @emph{See also}:
+@ref{omp_get_max_task_priority}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.14
@end table
@table @asis
@item @emph{Description}:
Enable or disable nested parallel regions, i.e., whether team members
-are allowed to create new teams. The value of this environment variable
-shall be @code{TRUE} or @code{FALSE}. If undefined, nested parallel
+are allowed to create new teams. The value of this environment variable
+shall be @code{TRUE} or @code{FALSE}. If undefined, nested parallel
regions are disabled by default.
@item @emph{See also}:
@ref{omp_set_nested}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 4.4
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.6
@end table
@cindex Implementation specific setting
@table @asis
@item @emph{Description}:
-Specifies the default number of threads to use in parallel regions. The
-value of this variable shall be a positive integer. If undefined one thread
-per CPU is used.
+Specifies the default number of threads to use in parallel regions. The
+value of this variable shall be a comma-separated list of positive integers;
+the value specified the number of threads to use for the corresponding nested
+level. If undefined one thread per CPU is used.
@item @emph{See also}:
@ref{omp_set_num_threads}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 4.2
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.2
@end table
-@node OMP_SCHEDULE
-@section @env{OMP_SCHEDULE} -- How threads are scheduled
+@node OMP_PROC_BIND
+@section @env{OMP_PROC_BIND} -- Whether theads may be moved between CPUs
@cindex Environment Variable
-@cindex Implementation specific setting
@table @asis
@item @emph{Description}:
-Allows to specify @code{schedule type} and @code{chunk size}.
-The value of the variable shall have the form: @code{type[,chunk]} where
-@code{type} is one of @code{static}, @code{dynamic}, @code{guided} or @code{auto}
-The optional @code{chunk} size shall be a positive integer. If undefined,
-dynamic scheduling and a chunk size of 1 is used.
+Specifies whether threads may be moved between processors. If set to
+@code{TRUE}, OpenMP theads should not be moved; if set to @code{FALSE}
+they may be moved. Alternatively, a comma separated list with the
+values @code{MASTER}, @code{CLOSE} and @code{SPREAD} can be used to specify
+the thread affinity policy for the corresponding nesting level. With
+@code{MASTER} the worker threads are in the same place partition as the
+master thread. With @code{CLOSE} those are kept close to the master thread
+in contiguous place partitions. And with @code{SPREAD} a sparse distribution
+across the place partitions is used.
+
+When undefined, @env{OMP_PROC_BIND} defaults to @code{TRUE} when
+@env{OMP_PLACES} or @env{GOMP_CPU_AFFINITY} is set and @code{FALSE} otherwise.
@item @emph{See also}:
-@ref{omp_set_schedule}
+@ref{OMP_PLACES}, @ref{GOMP_CPU_AFFINITY}, @ref{omp_get_proc_bind}
-@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, sections 2.5.1 and 4.1
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.4
+@end table
+
+
+
+@node OMP_PLACES
+@section @env{OMP_PLACES} -- Specifies on which CPUs the theads should be placed
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+The thread placement can be either specified using an abstract name or by an
+explicit list of the places. The abstract names @code{threads}, @code{cores}
+and @code{sockets} can be optionally followed by a positive number in
+parentheses, which denotes the how many places shall be created. With
+@code{threads} each place corresponds to a single hardware thread; @code{cores}
+to a single core with the corresponding number of hardware threads; and with
+@code{sockets} the place corresponds to a single socket. The resulting
+placement can be shown by setting the @env{OMP_DISPLAY_ENV} environment
+variable.
+
+Alternatively, the placement can be specified explicitly as comma-separated
+list of places. A place is specified by set of nonnegative numbers in curly
+braces, denoting the denoting the hardware threads. The hardware threads
+belonging to a place can either be specified as comma-separated list of
+nonnegative thread numbers or using an interval. Multiple places can also be
+either specified by a comma-separated list of places or by an interval. To
+specify an interval, a colon followed by the count is placed after after
+the hardware thread number or the place. Optionally, the length can be
+followed by a colon and the stride number -- otherwise a unit stride is
+assumed. For instance, the following specifies the same places list:
+@code{"@{0,1,2@}, @{3,4,6@}, @{7,8,9@}, @{10,11,12@}"};
+@code{"@{0:3@}, @{3:3@}, @{7:3@}, @{10:3@}"}; and @code{"@{0:2@}:4:3"}.
+
+If @env{OMP_PLACES} and @env{GOMP_CPU_AFFINITY} are unset and
+@env{OMP_PROC_BIND} is either unset or @code{false}, threads may be moved
+between CPUs following no placement policy.
+
+@item @emph{See also}:
+@ref{OMP_PROC_BIND}, @ref{GOMP_CPU_AFFINITY}, @ref{omp_get_proc_bind},
+@ref{OMP_DISPLAY_ENV}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.5
@end table
Set the default thread stack size in kilobytes, unless the number
is suffixed by @code{B}, @code{K}, @code{M} or @code{G}, in which
case the size is, respectively, in bytes, kilobytes, megabytes
-or gigabytes. This is different from @code{pthread_attr_setstacksize}
-which gets the number of bytes as an argument. If the stacksize cannot
+or gigabytes. This is different from @code{pthread_attr_setstacksize}
+which gets the number of bytes as an argument. If the stack size cannot
be set due to system constraints, an error is reported and the initial
-stacksize is left unchanged. If undefined, the stack size is system
+stack size is left unchanged. If undefined, the stack size is system
dependent.
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, sections 4.5
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.7
@end table
-@node OMP_THREAD_LIMIT
-@section @env{OMP_THREAD_LIMIT} -- Set the maximum number of threads
+@node OMP_SCHEDULE
+@section @env{OMP_SCHEDULE} -- How threads are scheduled
@cindex Environment Variable
+@cindex Implementation specific setting
@table @asis
@item @emph{Description}:
-Specifies the number of threads to use for the whole program. The
-value of this variable shall be a positive integer. If undefined,
-the number of threads is not limited.
+Allows to specify @code{schedule type} and @code{chunk size}.
+The value of the variable shall have the form: @code{type[,chunk]} where
+@code{type} is one of @code{static}, @code{dynamic}, @code{guided} or @code{auto}
+The optional @code{chunk} size shall be a positive integer. If undefined,
+dynamic scheduling and a chunk size of 1 is used.
@item @emph{See also}:
-@ref{OMP_NUM_THREADS}
-@ref{omp_get_thread_limit}
+@ref{omp_set_schedule}
@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, section 4.8
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Sections 2.7.1.1 and 4.1
@end table
-@node OMP_WAIT_POLICY
-@section @env{OMP_WAIT_POLICY} -- How waiting threads are handled
+@node OMP_THREAD_LIMIT
+@section @env{OMP_THREAD_LIMIT} -- Set the maximum number of threads
@cindex Environment Variable
@table @asis
@item @emph{Description}:
-Specifies whether waiting threads should be active or passive. If
-the value is @code{PASSIVE}, waiting threads should not consume CPU
-power while waiting; while the value is @code{ACTIVE} specifies that
-they should.
+Specifies the number of threads to use for the whole program. The
+value of this variable shall be a positive integer. If undefined,
+the number of threads is not limited.
+
+@item @emph{See also}:
+@ref{OMP_NUM_THREADS}, @ref{omp_get_thread_limit}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.10
+@end table
+
+
+
+@node OMP_WAIT_POLICY
+@section @env{OMP_WAIT_POLICY} -- How waiting threads are handled
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+Specifies whether waiting threads should be active or passive. If
+the value is @code{PASSIVE}, waiting threads should not consume CPU
+power while waiting; while the value is @code{ACTIVE} specifies that
+they should. If undefined, threads wait actively for a short time
+before waiting passively.
+
+@item @emph{See also}:
+@ref{GOMP_SPINCOUNT}
+
+@item @emph{Reference}:
+@uref{http://www.openmp.org/, OpenMP specification v4.5}, Section 4.8
+@end table
+
+
+
+@node GOMP_CPU_AFFINITY
+@section @env{GOMP_CPU_AFFINITY} -- Bind threads to specific CPUs
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+Binds threads to specific CPUs. The variable should contain a space-separated
+or comma-separated list of CPUs. This list may contain different kinds of
+entries: either single CPU numbers in any order, a range of CPUs (M-N)
+or a range with some stride (M-N:S). CPU numbers are zero based. For example,
+@code{GOMP_CPU_AFFINITY="0 3 1-2 4-15:2"} will bind the initial thread
+to CPU 0, the second to CPU 3, the third to CPU 1, the fourth to
+CPU 2, the fifth to CPU 4, the sixth through tenth to CPUs 6, 8, 10, 12,
+and 14 respectively and then start assigning back from the beginning of
+the list. @code{GOMP_CPU_AFFINITY=0} binds all threads to CPU 0.
+
+There is no libgomp library routine to determine whether a CPU affinity
+specification is in effect. As a workaround, language-specific library
+functions, e.g., @code{getenv} in C or @code{GET_ENVIRONMENT_VARIABLE} in
+Fortran, may be used to query the setting of the @code{GOMP_CPU_AFFINITY}
+environment variable. A defined CPU affinity on startup cannot be changed
+or disabled during the runtime of the application.
+
+If both @env{GOMP_CPU_AFFINITY} and @env{OMP_PROC_BIND} are set,
+@env{OMP_PROC_BIND} has a higher precedence. If neither has been set and
+@env{OMP_PROC_BIND} is unset, or when @env{OMP_PROC_BIND} is set to
+@code{FALSE}, the host system will handle the assignment of threads to CPUs.
+
+@item @emph{See also}:
+@ref{OMP_PLACES}, @ref{OMP_PROC_BIND}
+@end table
+
+
+
+@node GOMP_DEBUG
+@section @env{GOMP_DEBUG} -- Enable debugging output
+@cindex Environment Variable
+@table @asis
+@item @emph{Description}:
+Enable debugging output. The variable should be set to @code{0}
+(disabled, also the default if not set), or @code{1} (enabled).
+
+If enabled, some debugging output will be printed during execution.
+This is currently not specified in more detail, and subject to change.
+@end table
+
+
+
+@node GOMP_STACKSIZE
+@section @env{GOMP_STACKSIZE} -- Set default thread stack size
+@cindex Environment Variable
+@cindex Implementation specific setting
+@table @asis
+@item @emph{Description}:
+Set the default thread stack size in kilobytes. This is different from
+@code{pthread_attr_setstacksize} which gets the number of bytes as an
+argument. If the stack size cannot be set due to system constraints, an
+error is reported and the initial stack size is left unchanged. If undefined,
+the stack size is system dependent.
+
+@item @emph{See also}:
+@ref{OMP_STACKSIZE}
+
+@item @emph{Reference}:
+@uref{http://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,
+GCC Patches Mailinglist}
+@end table
+
+
+
+@node GOMP_SPINCOUNT
+@section @env{GOMP_SPINCOUNT} -- Set the busy-wait spin count
+@cindex Environment Variable
+@cindex Implementation specific setting
+@table @asis
+@item @emph{Description}:
+Determines how long a threads waits actively with consuming CPU power
+before waiting passively without consuming CPU power. The value may be
+either @code{INFINITE}, @code{INFINITY} to always wait actively or an
+integer which gives the number of spins of the busy-wait loop. The
+integer may optionally be followed by the following suffixes acting
+as multiplication factors: @code{k} (kilo, thousand), @code{M} (mega,
+million), @code{G} (giga, billion), or @code{T} (tera, trillion).
+If undefined, 0 is used when @env{OMP_WAIT_POLICY} is @code{PASSIVE},
+300,000 is used when @env{OMP_WAIT_POLICY} is undefined and
+30 billion is used when @env{OMP_WAIT_POLICY} is @code{ACTIVE}.
+If there are more OpenMP threads than available CPUs, 1000 and 100
+spins are used for @env{OMP_WAIT_POLICY} being @code{ACTIVE} or
+undefined, respectively; unless the @env{GOMP_SPINCOUNT} is lower
+or @env{OMP_WAIT_POLICY} is @code{PASSIVE}.
+
+@item @emph{See also}:
+@ref{OMP_WAIT_POLICY}
+@end table
+
+
+
+@node GOMP_RTEMS_THREAD_POOLS
+@section @env{GOMP_RTEMS_THREAD_POOLS} -- Set the RTEMS specific thread pools
+@cindex Environment Variable
+@cindex Implementation specific setting
+@table @asis
+@item @emph{Description}:
+This environment variable is only used on the RTEMS real-time operating system.
+It determines the scheduler instance specific thread pools. The format for
+@env{GOMP_RTEMS_THREAD_POOLS} is a list of optional
+@code{<thread-pool-count>[$<priority>]@@<scheduler-name>} configurations
+separated by @code{:} where:
+@itemize @bullet
+@item @code{<thread-pool-count>} is the thread pool count for this scheduler
+instance.
+@item @code{$<priority>} is an optional priority for the worker threads of a
+thread pool according to @code{pthread_setschedparam}. In case a priority
+value is omitted, then a worker thread will inherit the priority of the OpenMP
+master thread that created it. The priority of the worker thread is not
+changed after creation, even if a new OpenMP master thread using the worker has
+a different priority.
+@item @code{@@<scheduler-name>} is the scheduler instance name according to the
+RTEMS application configuration.
+@end itemize
+In case no thread pool configuration is specified for a scheduler instance,
+then each OpenMP master thread of this scheduler instance will use its own
+dynamically allocated thread pool. To limit the worker thread count of the
+thread pools, each OpenMP master thread must call @code{omp_set_num_threads}.
+@item @emph{Example}:
+Lets suppose we have three scheduler instances @code{IO}, @code{WRK0}, and
+@code{WRK1} with @env{GOMP_RTEMS_THREAD_POOLS} set to
+@code{"1@@WRK0:3$4@@WRK1"}. Then there are no thread pool restrictions for
+scheduler instance @code{IO}. In the scheduler instance @code{WRK0} there is
+one thread pool available. Since no priority is specified for this scheduler
+instance, the worker thread inherits the priority of the OpenMP master thread
+that created it. In the scheduler instance @code{WRK1} there are three thread
+pools available and their worker threads run at priority four.
+@end table
+
+
+
+@c ---------------------------------------------------------------------
+@c Enabling OpenACC
+@c ---------------------------------------------------------------------
+
+@node Enabling OpenACC
+@chapter Enabling OpenACC
+
+To activate the OpenACC extensions for C/C++ and Fortran, the compile-time
+flag @option{-fopenacc} must be specified. This enables the OpenACC directive
+@code{#pragma acc} in C/C++ and @code{!$accp} 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}).
+
+A complete description of all OpenACC directives accepted may be found in
+the @uref{http://www.openacc.org/, OpenACC} Application Programming
+Interface manual, version 2.0.
+
+Note that this is an experimental feature and subject to
+change in future versions of GCC. See
+@uref{https://gcc.gnu.org/wiki/OpenACC} for more information.
+
+
+
+@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 2.0.
+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_async_test:: Tests for completion of a specific asynchronous
+ operation.
+* acc_async_test_all:: Tests for completion of all asychronous
+ operations.
+* acc_wait:: Wait for completion of a specific asynchronous
+ operation.
+* acc_wait_all:: Waits for completion of all asyncrhonous
+ 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:: Indiciate 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.
+
+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.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, 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 typr, 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{http://www.openacc.org/, OpenACC specification v2.0}, 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{http://www.openacc.org/, OpenACC specification v2.0}, 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{num}, associated with the specifed device
+type @var{devicetype}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_set_device_num(int num, 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{http://www.openacc.org/, OpenACC specification v2.0}, 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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.5.
+@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 asynchrounous 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 asynchrounous 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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.6.
+@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 asynchrounous 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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.7.
+@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);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.8.
+@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);}
+@end multitable
+
+@item @emph{Fortran}:
+@multitable @columnfractions .20 .80
+@item @emph{Interface}: @tab @code{subroutine acc_wait_async()}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.10.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.11.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.9.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.12.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.13.
+@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 execiting 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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.14.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.15.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.16.
+@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);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.17.
+@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 specifed 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.
+
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.18.
+@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);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.19.
+@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 specifed 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.
+
+
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.20.
+@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);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.21.
+@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.
-@item @emph{Reference}:
-@uref{http://www.openmp.org/, OpenMP specifications v3.0}, sections 4.6
+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);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.22.
@end table
-@node GOMP_CPU_AFFINITY
-@section @env{GOMP_CPU_AFFINITY} -- Bind threads to specific CPUs
-@cindex Environment Variable
+@node acc_update_device
+@section @code{acc_update_device} -- Update device memory from mapped host memory.
@table @asis
-@item @emph{Description}:
-Binds threads to specific CPUs. The variable should contain a space-separated
-or comma-separated list of CPUs. This list may contain different kinds of
-entries: either single CPU numbers in any order, a range of CPUs (M-N)
-or a range with some stride (M-N:S). CPU numbers are zero based. For example,
-@code{GOMP_CPU_AFFINITY="0 3 1-2 4-15:2"} will bind the initial thread
-to CPU 0, the second to CPU 3, the third to CPU 1, the fourth to
-CPU 2, the fifth to CPU 4, the sixth through tenth to CPUs 6, 8, 10, 12,
-and 14 respectively and then start assigning back from the beginning of
-the list. @code{GOMP_CPU_AFFINITY=0} binds all threads to CPU 0.
+@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.
-There is no GNU OpenMP library routine to determine whether a CPU affinity
-specification is in effect. As a workaround, language-specific library
-functions, e.g., @code{getenv} in C or @code{GET_ENVIRONMENT_VARIABLE} in
-Fortran, may be used to query the setting of the @code{GOMP_CPU_AFFINITY}
-environment variable. A defined CPU affinity on startup cannot be changed
-or disabled during the runtime of the application.
+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);}
+@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}
+@end multitable
-If this environment variable is omitted, the host system will handle the
-assignment of threads to CPUs.
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.23.
@end table
-@node GOMP_STACKSIZE
-@section @env{GOMP_STACKSIZE} -- Set default thread stack size
-@cindex Environment Variable
-@cindex Implementation specific setting
+@node acc_update_self
+@section @code{acc_update_self} -- Update host memory from mapped device memory.
@table @asis
-@item @emph{Description}:
-Set the default thread stack size in kilobytes. This is different from
-@code{pthread_attr_setstacksize} which gets the number of bytes as an
-argument. If the stacksize cannot be set due to system constraints, an
-error is reported and the initial stacksize is left unchanged. If undefined,
-the stack size is system dependent.
+@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.
-@item @emph{See also}:
-@ref{GOMP_STACKSIZE}
+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{Reference}:
-@uref{http://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,
-GCC Patches Mailinglist}
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_update_self(h_void *a, size_t len);}
+@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}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.24.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.25.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.26.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.27.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.28.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.29.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.30.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, section
+3.2.31.
+@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{http://www.openacc.org/, OpenACC specification v2.0}, 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{acc_get_current_cuda_context(void);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, 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. 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{acc_get_cuda_stream(void);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, 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 asynchronous value specified by @var{async}.
+
+@item @emph{C/C++}:
+@multitable @columnfractions .20 .80
+@item @emph{Prototype}: @tab @code{acc_set_cuda_stream(int async void *stream);}
+@end multitable
+
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+A.2.1.4.
+@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{GCC_ACC_NOTIFY} is used for diagnostic purposes.
+
+@menu
+* ACC_DEVICE_TYPE::
+* ACC_DEVICE_NUM::
+* GCC_ACC_NOTIFY::
+@end menu
+
+
+
+@node ACC_DEVICE_TYPE
+@section @code{ACC_DEVICE_TYPE}
+@table @asis
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+4.1.
+@end table
+
+
+
+@node ACC_DEVICE_NUM
+@section @code{ACC_DEVICE_NUM}
+@table @asis
+@item @emph{Reference}:
+@uref{http://www.openacc.org/, OpenACC specification v2.0}, section
+4.2.
+@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 asychronous 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}, respecively. These two
+environement 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{http://www.openacc.org/, OpenACC}
+Application Programming Interface”, Version 2.0.}
+
+
+
@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
+@c Reporting Bugs
@c ---------------------------------------------------------------------
@node Reporting Bugs
@chapter Reporting Bugs
-Bugs in the GNU OpenMP implementation should be reported via
-@uref{http://gcc.gnu.org/bugzilla/, bugzilla}. For all cases, please add
-"openmp" to the keywords field in the bug report.
+Bugs in the GNU Offloading and Multi Processing Runtime Library should
+be reported via @uref{http://gcc.gnu.org/bugzilla/, Bugzilla}. Please add
+"openacc", or "openmp", or both to the keywords field in the bug
+report, as appropriate.
@c GNU General Public License
@c ---------------------------------------------------------------------
-@include gpl.texi
+@include gpl_v3.texi
@c Index
@c ---------------------------------------------------------------------
-@node Index
-@unnumbered Index
+@node Library Index
+@unnumbered Library Index
@printindex cp
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