Commit Graph
48 Commits
Author SHA1 Message Date
Joachim Protze ff9d3f5109 Update implementation of OMPT to the specification OpenMP 5.0 Preview 1 (TR4).
The code is tested to work with latest clang, GNU and Intel compiler. The implementation
is optimized for low overhead when no tool is attached shifting the cost to execution with
tool attached.

This patch does not implement OMPT for libomptarget.

Patch by Simon Convent and Joachim Protze

Differential Revision: https://reviews.llvm.org/D38185

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@317085 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-01 10:08:30 +00:00
Jonathan Peyton be524d6135 Apply formatting changes
.clang-format's comments are removed and a (hopefully) final
set of formatting changes are applied.

Differential Revision: https://reviews.llvm.org/D38837
Differential Revision: https://reviews.llvm.org/D38920


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@316227 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-20 19:30:57 +00:00
Jonathan Peyton 31535f3451 Read blocktime value set by kmp_set_blocktime() before reading from KMP_BLOCKTIME
Patch by Hansang Bae

Differential Revision: https://reviews.llvm.org/D37403


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@312539 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-05 15:45:48 +00:00
Andrey Churbanov b88a01f4ef OpenMP RTL cleanup: eliminated warnings with -Wcast-qual, patch 2.
Changes are: got all atomics to accept volatile pointers that allowed
to simplify many type conversions. Windows specific code fixed correspondingly.

Differential Revision: https://reviews.llvm.org/D35417


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@308164 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-17 09:03:14 +00:00
Ed Maste 06426cf363 remove deprecated register storage class specifier
While importing libomp into the FreeBSD base system we encountered
Clang warnings that "'register' storage class specifier is deprecated
and incompatible with C++1z [-Wdeprecated-register]".

Differential Revision:	https://reviews.llvm.org/D35124


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@307441 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-07 21:06:05 +00:00
Andrey Churbanov 1c31fdada0 OpenMP RTL cleanup: eliminated warnings with -Wcast-qual.
Changes are: replaced C-style casts with cons_cast and reinterpret_cast;
type of several counters changed to signed; type of parameters of 32-bit and
64-bit AND and OR intrinsics changes to unsigned; changed files formatted
using clang-format version 3.8.1.

Differential Revision: https://reviews.llvm.org/D34759


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@307020 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-03 11:24:08 +00:00
Jonathan Peyton fcec73a508 Fix minor formatting issues
Some code was restructured to move it under KMP_DEBUG.  The rest is
formatting changes to fix some things broken by clang-format

Patch by Terry Wilmarth

Differential Revision: https://reviews.llvm.org/D33744


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@304438 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-01 16:46:36 +00:00
Jonathan Peyton e703e783e7 Clang-format and whitespace cleanup of source code
This patch contains the clang-format and cleanup of the entire code base. Some
of clang-formats changes made the code look worse in places. A best effort was
made to resolve the bulk of these problems, but many remain. Most of the
problems were mangling line-breaks and tabbing of comments.

Patch by Terry Wilmarth

Differential Revision: https://reviews.llvm.org/D32659


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@302929 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-12 18:01:32 +00:00
Olga Malysheva b8b75f9476 Reset cancellation status for 'parallel', 'sections' and 'for' constracts.
Without this fix cancellation status for parallel, sections and for persists 
across construct boundaries.

Differential Revision: https://reviews.llvm.org/D31419

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@299434 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-04 13:56:50 +00:00
Jonas Hahnfeld 4726583580 [OpenMP] New Tsan annotations to remove false positive on reduction and barriers
Added new ThreadSanitizer annotations to remove false positives with OpenMP reduction.
Cleaned up Tsan annotations header file from unused annotations.

Patch by Simone Atzeni!

Differential Revision: https://reviews.llvm.org/D29202

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@295158 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-15 08:14:22 +00:00
Jonathan Peyton c0cfee9024 Fix performance issue incurred by removing monitor thread.
When the monitor thread is used, most threads in the team directly go to
sleep if the copy of bt_intervals/bt_set is not available in the cache,
and this happens at least once per thread in the wait function, making the
overall performance slightly better.
This change tries to mimic this behavior by using the bt_intervals cache,
which simply keeps the blocktime interval in terms of the platform-dependent
ticks or nanoseconds.

Patch by Hansang Bae

Differential Revision: https://reviews.llvm.org/D28906


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@293312 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-27 17:54:31 +00:00
Jonathan Peyton 0859e6a24e Update stats-gathering code
Have developer timers use partitioning scheme which also required that some
redundant developer timers be removed in favor of the already existing normal
timers. Move per thread stats initialization to just after global thread id
assignment which is as early as possible. Also put all global stats
initialization code in __kmp_stats_init() and all global stats destruction code
in __kmp_stats_fini().

Differential Revision: https://reviews.llvm.org/D26361


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@286892 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-14 21:13:44 +00:00
Jonas Hahnfeld 3fd0cf124f [OpenMP] Enable ThreadSanitizer to check OpenMP programs
This patch allows ThreadSanitizer (Tsan) to verify OpenMP programs.
It means that no false positive will be reported by Tsan when
verifying an OpenMP programs.
This patch introduces annotations within the OpenMP runtime module to
provide information about thread synchronization to the Tsan runtime.

In order to enable the Tsan support when building the runtime, you must
enable the TSAN_SUPPORT option with the following environment variable:

-DLIBOMP_TSAN_SUPPORT=TRUE

The annotations will be enabled in the main shared library
(same mechanism of OMPT).

Patch by Simone Atzeni and Joachim Protze!

Differential Revision: https://reviews.llvm.org/D13072

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@286115 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-07 15:58:36 +00:00
Jonathan Peyton 88b2b1cf48 Code cleanup for the runtime without monitor thread
This change removes/disables unnecessary code when monitor thread is not used.

Patch by Hansang Bae

Differential Revision: https://reviews.llvm.org/D25102


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@283577 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-07 18:12:19 +00:00
Jonathan Peyton 171ddd1f23 Renaming change: 41 -> 45 and 4.1 -> 4.5
OpenMP 4.1 is now OpenMP 4.5.  Any mention of 41 or 4.1 is replaced with
45 or 4.5.  Also, if the CMake option LIBOMP_OMP_VERSION is 41, CMake warns that
41 is deprecated and to use 45 instead.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@272687 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-14 17:57:47 +00:00
Jonathan Peyton 561ebb5943 Remove trailing whitespace in src/ directory
This patch doesn't affect D19878's context.  So D19878 still cleanly applies.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@270252 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-20 19:03:38 +00:00
Jonathan Peyton 039c3ab59a [STATS] Use partitioned timer scheme
This change removes the current timers with ones that partition time properly.
The current timers are nested, so that if a new timer, B, starts when the
current timer, A, is already timing, A's time will include B's. To eliminate
this problem, the partitioned timers are designed to stop the current timer (A),
let the new timer run (B), and when the new timer is finished, restart the
previously running timer (A). With this partitioning of time, a threads' timers
all sum up to the OMP_worker_thread_life time and can now easily show the
percentage of time a thread is spending in different parts of the runtime or
user code.

There is also a new state variable associated with each thread which tells where
it is executing a task. This corresponds with the timers: OMP_task_*, e.g., if
time is spent in OMP_task_taskwait, then that thread executed tasks inside a
#pragma omp taskwait construct.

The changes are mostly changing the MACROs to use the new PARITIONED_* macros,
the new partitionedTimers class and its methods, and new state logic.

Differential Revision: http://reviews.llvm.org/D19229


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@268640 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-05 16:15:57 +00:00
Jonathan Peyton 3fb06fd2fe [ITTNOTIFY] Correct barrier imbalance time in case of tasks
ittnotify fix for barrier imbalance time in case tasks exist. In the current
implementation, task execution time is included into aggregated time on a
barrier. This fix calculates task execution time and corrects the arrive time
by subtracting the task execution time.

Since __kmp_invoke_task() can not only be called on a barrier, the field
th.th_bar_arrive_time is used to check if the function was called at the
barrier (th.th_bar_arrive_time != 0). So for this check, th_bar_arrive_time
is set to zero right after the value is used on the barrier.

Differential Revision: http://reviews.llvm.org/D19030


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@266332 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-14 16:06:49 +00:00
Jonathan Peyton fa6b30f80a Fixing comments.
Removing references to non-existent functions, fixing typos.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@258985 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-27 20:57:32 +00:00
Jonathan Peyton 22361cf975 Add debug trace message for hierarchical barrier
Trace when thread is waiting at join phase for oncore children.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@252954 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 21:40:39 +00:00
Jonathan Peyton 6e98151883 Fixes and improvements to tasking in barriers
1) When the number of threads in a team increases, new threads need to have all
   their barrier struct fields initialized. We were missing the parent_bar and
   team fields.
2) For non-forkjoin barriers, we now do the __kmp_task_team_setup before the
   gather. The setup now sets up the task_team that all the threads will switch
   to after the barrier, but it needs to be done before other threads do the
   switch.
3) Remove an unneeded assignment of tt_found_tasks in task team free function.

Differential Revision: http://reviews.llvm.org/D14456


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@252486 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 16:28:32 +00:00
Jonathan Peyton b9e8048db1 Refactor of task_team code.
This is a refactoring of the task_team code that more elegantly handles the two
task_team case. Two task_teams per team are kept in use for the lifetime of the
team. Thus no reference counting is needed.

Differential Revision: http://reviews.llvm.org/D13993


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@252082 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 21:37:48 +00:00
Jonathan Peyton d76e1838f1 Formatting/Whitespace/Comment changes associated with wait/release improvements.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@249725 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-08 19:44:16 +00:00
Jonathan Peyton fd69bc2810 OpenMP Wait/release improvements.
These changes improve the wait/release mechanism for threads spinning in 
barriers that are handling tasks while spinnin by providing feedback to the 
barriers about any task stealing that occurs.

Differential Revision: http://reviews.llvm.org/D13353


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@249711 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-08 18:23:38 +00:00
Jonathan Peyton f56794a06c [OMPT] Simplify control variable logic for OMPT
Prior to this change, OMPT had a status flag ompt_status, which could take
several values. This was due to an earlier OMPT design that had several levels
of enablement (ready, disabled, tracking state, tracking callbacks). The
current OMPT design has OMPT support either on or off.
This revision replaces ompt_status with a boolean flag ompt_enabled, which 
simplifies the runtime logic for OMPT.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D12999


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@248189 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-21 18:11:22 +00:00
Jonathan Peyton 9a904471e9 Fix the OpenMP 3.0 build
This change adds guards to the code in places where they are missing to enable
the OpenMP 3.0 build.

Patch by Diego Caballero and Johnny Peyton

Mailing List: http://lists.llvm.org/pipermail/openmp-dev/2015-September/000935.html


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@248178 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-21 17:24:46 +00:00
Jonathan Peyton 5c72f9ce80 [OMPT] Correct an incorrect OMPT ifdef
An ifdef for OMPT_TRACE needs to be OMPT_BLAME so that both instances of a
callback are controlled by the same ifdef.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D12911


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@248001 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-18 16:24:46 +00:00
Jonathan Peyton ccc39aacca Fix hanging barriers if number of parallel regions exceeds UINT_MAX
The fix is to make b_arrived flag 64 bit in both structures - kmp_balign_team_t
and kmp_balign_t. Otherwise when flag in kmp_balign_team_t wrapped over
UINT_MAX the library hangs.

Differential Revision: http://reviews.llvm.org/D12563


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@247320 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-10 18:44:30 +00:00
Jonathan Peyton d78ef70561 Replace variables with definitions inside KMP_DEBUG_ASSERT statements
This change just removes the variables created solely for KMP_DEBUG_ASSERT statements
and puts the definition of the removed variables inside the KMP_DEBUG_ASSERT
statements.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@246065 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-26 19:58:48 +00:00
Jonathan Peyton 7bd6023443 One line fix for hierarchical barrier
There was a missing implicit task init for the ICV PUSH case in hierarchical barrier.


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@244807 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-12 20:59:48 +00:00
Jonathan Peyton 9d7a4861d7 Tidy statistics collection
This removes some statistics counters and timers which were not used,
adds new counters and timers for some language features that were not
monitored previously and separates the counters and timers into those
which are of interest for investigating user code and those which are
only of interest to the developer of the runtime itself.
The runtime developer statistics are now ony collected if the
additional #define KMP_DEVELOPER_STATS is set.

Additional user statistics which are now collected include:
* Count of nested parallelism (omp parallel inside a parallel region)
* Count of omp distribute occurrences
* Count of omp teams occurrences
* Counts of task related statistics (taskyield, task execution, task
  cancellation, task steal)
* Values passed to omp_set_numtheads
* Time spent in omp single and omp master

None of this affects code compiled without stats gathering enabled,
which is the normal library build mode.

This also fixes the CMake build by linking to the standard c++ library
when building the stats library as it is a requirement.  The normal library
does not have this requirement and its link phase is left alone.

Differential Revision: http://reviews.llvm.org/D11759


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@244677 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-11 21:36:41 +00:00
Jonathan Peyton 7f88ff4ca8 Follow up to safe API patch
A while back, we made an initial change where dangerous C API functions were
replaced with macros that translated the dangerous API function calls to safer
function calls e.g., sprintf() replaced with KMP_SPRINTF() which translates to 
sprintf_s() on Windows. Currently, the only operating system where this is 
applicable is Windows. Unix-like systems are still using the dangerous API 
e.g., KMP_SPRINTF() translates to sprintf().  Our own testing showed no
performance differences.

Differential Revision: http://reviews.llvm.org/D9918


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@241833 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 18:20:51 +00:00
Jonathan Peyton c0d8cfddb6 Enable debugger support
These changes enable external debuggers to conveniently interface with 
the LLVM OpenMP Library.  Structures are added which describe the important
internal structures of the OpenMP Library e.g., teams, threads, etc.
This feature is turned on by default (CMake variable LIBOMP_USE_DEBUGGER)
and can be turned off with -DLIBOMP_USE_DEBUGGER=off.

Differential Revision: http://reviews.llvm.org/D10038


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@241832 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 18:16:58 +00:00
Jonathan Peyton 219c0242d9 Fix OMPT event_barrer_end
The OMPT status is never equal to ompt_status_track. ompt_status_track = 0x2 
and ompt_status_track_callback = 0x6 just share a bit, so that we can check 
for traceing and callbacks with the same status.

Patch by Tim Cramer

Differential Revision: http://reviews.llvm.org/D10863


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@241167 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-01 15:16:04 +00:00
Jonathan Peyton 0746d6010e Fix OMPT state maintenance for barriers and missing init of implicit task id.
Fix OMPT support for barriers so that state changes occur even if OMPT_TRACE turned off. 
These state changes are needed by performance tools that use callbacks for either 
ompt_event_wait_barrier_begin or ompt_event_wait_barrier_end.  Change ifdef flag to OMPT_BLAME 
for callbacks ompt_event_wait_barrier_begin or ompt_event_wait_barrier_end rather than 
OMPT_TRACE -- they were misclassified.  Without this patch, when the runtime is compiled with 
LIBOMP_OMPT_SUPPORT=true, LIBOMP_OMPT_BLAME=true, and LIBOMP_OMPT_TRACE=false, and a callback 
is registered for either ompt_event_wait_barrier_begin or ompt_event_wait_barrier_end, then an 
assertion will trip.  Fix the scoping of one OMPT_TRACE ifdef, which should not have surrounded 
an update of an OMPT state.  Add a missing initialization of an OMPT task id for an implicit task.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D10759


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@240970 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-29 17:28:57 +00:00
Jonathan Peyton 5174723912 Remove unused variable warnings by moving variables.
As an ongoing effort to sanitize the openmp code, these changes move
variables under already existing macro guards.

Patch by Jack Howarth


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@239331 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-08 19:39:07 +00:00
Jonathan Peyton 4c6ccfea87 Remove unused variable warnings by fooling compiler.
Some variables are convenient to keep around even if they aren't
really used in a release build.  This is often seen in DEBUG guarded code where the variable
is only used in a DEBUG build.

Patch by Jack Howarth


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@239326 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-08 18:56:33 +00:00
Andrey Churbanov 4af0f3a6a7 D9306 omp 4.1 async offload support (partial): code changes
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@236753 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 17:41:51 +00:00
Andrey Churbanov efb6bb2106 D9302.partial2: cleanup of ittnotify checks, that eliminats redundant notifications in case of nested regions.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@236631 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 19:22:36 +00:00
Andrey Churbanov 730074da8d D9302.partial: bug fix for ittnotify: added missed timing on hierarchical barrier.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@236623 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 18:34:15 +00:00
Andrey Churbanov 98270aa879 These are the actual changes in the runtime to issue OMPT-related functions. All of them are surrounded by #if OMPT_SUPPORT and can be disabled (which is the default).
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@236122 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:42:24 +00:00
Andrey Churbanov 890e8fd276 proc_bind_disabled enum value removed, its usage replased with proc_bind_false
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@231776 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 09:19:47 +00:00
Andrey Churbanov 2ce31a0c3a The usage of tt_state flag is replaced by an array of two task_team pointers.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@228718 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 18:37:43 +00:00
Andrey Churbanov 9236d9713a Comments only: removing the Revision and Date svn variables from the top of all the source files.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@227207 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-27 17:13:53 +00:00
Andrey Churbanov 0a2bac028a Fixed implementation of the teams construct in case it contains parallel regions with different number of threads.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@227198 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-27 16:50:31 +00:00
Andrey Churbanov 9dd2dbbb70 This patch enables the use of KMP_AFFINITY=balanced on non-MIC Architectures. The restriction for using balanced affinity on non-MIC architectures is it only works for one-package machines.
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@225794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 14:54:00 +00:00
Andrey Churbanov cc78b24209 small fixes to the hierarchical barrier
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@225793 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 14:47:02 +00:00
Jim Cownie f12a6547f0 I apologise in advance for the size of this check-in. At Intel we do
understand that this is not friendly, and are working to change our
internal code-development to make it easier to make development
features available more frequently and in finer (more functional)
chunks. Unfortunately we haven't got that in place yet, and unpicking
this into multiple separate check-ins would be non-trivial, so please
bear with me on this one. We should be better in the future.

Apologies over, what do we have here?

GGC 4.9 compatibility
--------------------
* We have implemented the new entrypoints used by code compiled by GCC
4.9 to implement the same functionality in gcc 4.8. Therefore code
compiled with gcc 4.9 that used to work will continue to do so.
However, there are some other new entrypoints (associated with task
cancellation) which are not implemented. Therefore user code compiled
by gcc 4.9 that uses these new features will not link against the LLVM
runtime. (It remains unclear how to handle those entrypoints, since
the GCC interface has potentially unpleasant performance implications
for join barriers even when cancellation is not used)

--- new parallel entry points ---
new entry points that aren't OpenMP 4.0 related
These are implemented fully :-
      GOMP_parallel_loop_dynamic()
      GOMP_parallel_loop_guided()
      GOMP_parallel_loop_runtime()
      GOMP_parallel_loop_static()
      GOMP_parallel_sections()
      GOMP_parallel()

--- cancellation entry points ---
Currently, these only give a runtime error if OMP_CANCELLATION is true
because our plain barriers don't check for cancellation while waiting
        GOMP_barrier_cancel()
        GOMP_cancel()
        GOMP_cancellation_point()
        GOMP_loop_end_cancel()
        GOMP_sections_end_cancel()

--- taskgroup entry points ---
These are implemented fully.
      GOMP_taskgroup_start()
      GOMP_taskgroup_end()

--- target entry points ---
These are empty (as they are in libgomp)
     GOMP_target()
     GOMP_target_data()
     GOMP_target_end_data()
     GOMP_target_update()
     GOMP_teams()

Improvements in Barriers and Fork/Join
--------------------------------------
* Barrier and fork/join code is now in its own file (which makes it
easier to understand and modify).
* Wait/release code is now templated and in its own file; suspend/resume code is also templated
* There's a new, hierarchical, barrier, which exploits the
cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve
fork/join and barrier performance.

***BEWARE*** the new source files have *not* been added to the legacy
Cmake build system. If you want to use that fixes wil be required.

Statistics Collection Code
--------------------------
* New code has been added to collect application statistics (if this
is enabled at library compile time; by default it is not). The
statistics code itself is generally useful, the lightweight timing
code uses the X86 rdtsc instruction, so will require changes for other
architectures.
The intent of this code is not for users to tune their codes but
rather 
1) For timing code-paths inside the runtime
2) For gathering general properties of OpenMP codes to focus attention
on which OpenMP features are most used. 

Nested Hot Teams
----------------
* The runtime now maintains more state to reduce the overhead of
creating and destroying inner parallel teams. This improves the
performance of code that repeatedly uses nested parallelism with the
same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL
envirable to a depth to enable this (and, of course, OMP_NESTED=true
to enable nested parallelism at all).

Improved Intel(r) VTune(Tm) Amplifier support
---------------------------------------------
* The runtime provides additional information to Vtune via the
itt_notify interface to allow it to display better OpenMP specific
analyses of load-imbalance.

Support for OpenMP Composite Statements
---------------------------------------
* Implement new entrypoints required by some of the OpenMP 4.1
composite statements.

Improved ifdefs
---------------
* More separation of concepts ("Does this platform do X?") from
platforms ("Are we compiling for platform Y?"), which should simplify
future porting.


ScaleMP* contribution
---------------------
Stack padding to improve the performance in their environment where
cross-node coherency is managed at the page level.

Redesign of wait and release code
---------------------------------
The code is simplified and performance improved.

Bug Fixes
---------
    *Fixes for Windows multiple processor groups.
    *Fix Fortran module build on Linux: offload attribute added.
    *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen.
    *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable.



git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@219214 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 16:25:50 +00:00