Summary:
Implemented by Dejan Latinovic
See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=790735 for more more information

Reviewers: AndreyChurbanov, jlpeyton

Subscribers: openmp-commits, mgorny

Differential Revision: https://reviews.llvm.org/D26576

llvm-svn: 289032

Previous differencials D23305-D23310 changed task frame information management only for the kmp interface, but not for the whole gomp interface. This broke some testcases when building with gcc.
This patch fixes the broken task frame information for the gomp interface.

Patch by Joachim Protze!

Differential Revision: https://reviews.llvm.org/D24502

llvm-svn: 281468

In case, the current team is a serialized team (lwt), the frame information should be written to this data structure.
Before, nested serialized teams would overwrite the same task information.

Patch by Joachim Protze!

Differential Revision: https://reviews.llvm.org/D23310

llvm-svn: 281467

The latest OMPT spec changed the semantic of a tasks reenter frame to be the application frame, that will be entered, when the runtime frame drops.
Before it was the last frame in the runtime. This doesn't work for some gcc execution pathes or even clang generated code for :
Since there is no runtime frame between the executed task and the encountering task.

The test case compares exit and reenter addresses against addresses captured in application code

Patch by Joachim Protze!

Differential Revision: https://reviews.llvm.org/D23305

llvm-svn: 281464

llvm-svn: 273439

llvm-svn: 273438

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.

llvm-svn: 272687

The problem is the lack of dispatch buffers when thousands of loops with nowait,
about 10 iterations each, are executed by hundreds of threads. We only have
built-in 7 dispatch buffers, but there is a need in dozens or hundreds of
buffers.

The problem can be fixed by setting KMP_MAX_DISP_BUF to bigger value. In order
to give users same possibility I changed build-time control into run-time one,
adding API just in case.

This change adds an environment variable KMP_DISP_NUM_BUFFERS and a new API
function kmp_set_disp_num_buffers(int num_buffers).

The KMP_DISP_NUM_BUFFERS envirable works only before serial initialization,
because during the serial initialization we already allocate buffers for the hot
team, so it is too late to change the number of buffers later (or we need to
reallocate buffers for all teams which sounds too complicated). The
kmp_set_defaults() routine does not work for this envirable, because it calls
serial initialization before reading the parameter string. So a new routine,
kmp_set_disp_num_buffers(), is created so that it can set our internal global
variable before the library initialization. If both the envirable and API used
the envirable wins.

Differential Revision: http://reviews.llvm.org/D20697

llvm-svn: 271318

On Blue Gene/Q, having LIBOMP_USE_ITT_NOTIFY support compiled into a
statically-linked binary causes a failure at runtime because dlopen fails.
This patch changes LIBOMP_USE_ITT_NOTIFY to a cacheable configuration setting
that can be disabled.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D20517

llvm-svn: 270884

This patch doesn't affect D19878's context.  So D19878 still cleanly applies.

llvm-svn: 270252

KMP_USE_FUTEX preprocessor definition defined in kmp_lock.h is used
inconsequently throughout LLVM libomp code.

* some .c files that use this define do not include kmp_lock.h file,
  in effect guarded part of code are never compiled
* some places in code use architecture-depending preprocessor
  logic expressions which effectively disable use of Futex for
  AArch64 architecture, all these places should use
  '#if KMP_USE_FUTEX' instead to avoid any further confusions
* some places use KMP_HAS_FUTEX which is nowhere defined,
  KMP_USE_FUTEX should be used instead

Differential Revision: http://reviews.llvm.org/D19629

llvm-svn: 269642

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

llvm-svn: 268640

llvm-svn: 266760

This change adds back off logic in the test and set lock for better contended
lock performance. It uses a simple truncated binary exponential back off
function. The default back off parameters are tuned for x86.

The main back off logic has a two loop structure where each is controlled by a
user-level parameter:
max_backoff - limits the outer loop number of iterations.
    This parameter should be a power of 2.
min_ticks - the inner spin wait loop number of "ticks" which is system
    dependent and should be tuned for your system if you so choose.
    The "ticks" on x86 correspond to the time stamp counter,
    but on other architectures ticks is a timestamp derived
    from gettimeofday().

The user can modify these via the environment variable:
KMP_SPIN_BACKOFF_PARAMS=max_backoff[,min_ticks]
Currently, since the default user lock is a queuing lock,
one would have to also specify KMP_LOCK_KIND=tas to use the test-and-set locks.

Differential Revision: http://reviews.llvm.org/D19020

llvm-svn: 266329

The problem is that the definition of kmp_cpuinfo_t contains:

  char       name [3*sizeof (kmp_cpuid_t)]; // CPUID(0x80000002,0x80000003,0x80000004)

and kmp_cpuid_t is only defined when compiling for x86.

Differential Revision: http://reviews.llvm.org/D18245

llvm-svn: 264535

For serialized parallel regions, wrong ids were reported. Now the same code is
used as in kmp_dispatch.cpp which emits the correct ids.

Differential Revision: http://reviews.llvm.org/D18348

llvm-svn: 264266

Have Visual Studio use MemoryBarrier() instead of _mm_mfence() and remove
__declspec align attribute from function parameters in kmp_atomic.h

llvm-svn: 264166

OMP_critical - time spent in critical section
OMP_critical_wait - time spent waiting to enter a critical section

llvm-svn: 263967

Only the thread which executes the single/master section will update its statistics.

llvm-svn: 262656

From the standard: A doacross loop nest is a loop nest that has cross-iteration
dependence. An iteration is dependent on one or more lexicographically earlier
iterations. The ordered clause parameter on a loop directive identifies the
loop(s) associated with the doacross loop nest.

The init/fini routines allocate/free doacross buffer(s) for each loop for each
thread.  The wait routine waits for a flag designated by the dependence vector.
The post routine sets the flag designated by current iteration vector.  We use
a similar technique of shared buffer indices that covers up to 7 nowait loops
executed simultaneously by different threads (number 7 has no real meaning,
just heuristic value).  Also, the size of structures are kept intact via
reducing dummy arrays.

This needs to be put into the OpenMP runtime library in order for the compiler
team to develop the compiler side of the implementation.

Differential Revision: http://reviews.llvm.org/D17399

llvm-svn: 262532

Recent changes to support dynamic locks didn't consider the code compiled when
OMPT_SUPPORT=true. As a result, the OMPT support was broken by recent changes
to nested locks to support dynamic locks. For OMPT to work with dynamic locks,
they need to provide a return code indicating whether a nested lock acquisition
was the first or not.

This patch moves the OMPT support for nested locks into the #else case when
DYNAMIC locks were not used. New support is needed for dynamic locks. This patch
fixes the build and leaves a placeholder where the missing OMPT callbacks can be
added either the author of the OMPT support for locks, or the dynamic
locking support.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D15656

llvm-svn: 256314

This change set includes all changes to make the code conform to the OMP 4.5 specification:

* Removed hint / hinted_init definitions from include/40 files
* Hint values are powers of 2 to enable composition (4.5 spec)
* Hinted lock initialization functions were renamed (4.5 spec)
  kmp_init_lock_hinted -> omp_init_lock_with_hint
  kmp_init_nest_lock_hinted -> omp_init_nest_lock_with_hint
* __kmpc_critical_section_with_hint was added to support a critical section with
  a hint (4.5 spec)
* __kmp_map_hint_to_lock was added to convert a hint (possibly a composite) to
  an internal lock type
* kmpc_init_lock_with_hint and kmpc_init_nest_lock_with_hint were added as
  internal entries for the hinted lock initializers. The preivous internal
  functions (__kmp_init*) were moved to kmp_csupport.c and reused in multiple
  places
* Added the two init functions to dllexports
* KMP_USE_DYNAMIC_LOCK is turned on if OMP_41_ENABLED is turned on

Differential Revision: http://reviews.llvm.org/D15205

llvm-svn: 255376

* Added a new user TSX lock implementation, RTM, This implementation is a
  light-weight version of the adaptive lock implementation, omitting the
  back-off logic for deciding when to specualte (or not). The fall-back lock is
  still the queuing lock.
* Changed indirect lock table management. The data for indirect lock management
  was encapsulated in the "kmp_indirect_lock_table_t" type. Also, the lock table
  dimension was changed to 2D (was linear), and each entry is a
  kmp_indirect_lock_t object now (was a pointer to an object).
* Some clean up in the critical section code
* Removed the limits of the tuning parameters read from KMP_ADAPTIVE_LOCK_PROPS
* KMP_USE_DYNAMIC_LOCK=1 also turns on these two switches:
  KMP_USE_TSX, KMP_USE_ADAPTIVE_LOCKS

Differential Revision: http://reviews.llvm.org/D15204

llvm-svn: 255375

There are going to be two more patches which bring this feature up to date and in line with OpenMP 4.5.

* Renamed jump tables for the lock functions (and some clean up).
* Renamed some macros to be in KMP_ namespace.
* Return type of unset functions changed from void to int.
* Enabled use of _xebgin() et al. intrinsics for accessing TSX instructions.

Differential Revision: http://reviews.llvm.org/D15199

llvm-svn: 255373

llvm-svn: 254637

This fix implements the following OMPT events for the API locking routines:
* ompt_event_acquired_lock
* ompt_event_acquired_nest_lock_first
* ompt_event_acquired_nest_lock_next
* ompt_event_init_lock
* ompt_event_init_nest_lock
* ompt_event_destroy_lock
* ompt_event_destroy_nest_lock

For the acquired events the depths of the locks ist required, so a return value
was added similiar to the return values we already have for the release lock
routines.

Patch by Tim Cramer

Differential Revision: http://reviews.llvm.org/D13689

llvm-svn: 250526

* Avoid computing state needed only by OMPT unless the ompt_enabled flag is set.
* Properly handle a corner case in OMPT where team == NULL.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D13502

llvm-svn: 249857

Added (optional) sockets to the syntax of the KMP_PLACE_THREADS environment variable.
Some limitations:
* The number of sockets and then optional offset should be specified first (before other parameters).
* The letter designation is mandatory for sockets and then for other parameters.
* If number of cores is specified first, then the number of sockets is defaulted to all sockets on the machine; also, the old syntax is partially supported if sockets are skipped.
* If number of threads per core is specified first, then the number of sockets and cores per socket are defaulted to all sockets and all cores per socket respectively.
* The number of cores per socket cannot be specified before sockets or after threads per core.
* The number of threads per core can be specified before or after core-offset (old syntax required it to be before core-offset);
* Parameters delimiter can be: empty, comma, lower-case x;
* Spaces are allowed around numbers, around letters, around delimiter.
Approximate shorthand specification:
KMP_PLACE_THREADS="[num_sockets(S|s)[[delim]offset(O|o)][delim]][num_cores_per_socket(C|c)[[delim]offset(O|o)][delim]][num_threads_per_core(T|t)]"

Differential Revision: http://reviews.llvm.org/D13175

llvm-svn: 249708

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

llvm-svn: 248189

Conditionally include the fork_context parameter to __kmp_join_call()
only if OMPT_SUPPORT=1

Differential Revision: http://reviews.llvm.org/D12495

llvm-svn: 246460

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

llvm-svn: 244677

llvm-svn: 244034

This patch makes it possible for a performance tool that uses call stack
unwinding to map implementation-level call stacks from master and worker
threads into a unified global view. There are several components to this patch.

include/*/ompt.h.var
  Add a new enumeration type that indicates whether the code for a master task
    for a parallel region is invoked by the user program or the runtime system
  Change the signature for OMPT parallel begin/end callbacks to indicate whether
    the master task will be invoked by the program or the runtime system. This
    enables a performance tool using call stack unwinding to handle these two
    cases differently. For this case, a profiler that uses call stack unwinding
    needs to know that the call path prefix for the master task may differ from
    those available within the begin/end callbacks if the program invokes the
    master.

kmp.h
  Change the signature for __kmp_join_call to take an additional parameter
  indicating the fork_context type. This is needed to supply the OMPT parallel
  end callback with information about whether the compiler or the runtime
  invoked the master task for a parallel region.

kmp_csupport.c
  Ensure that the OMPT task frame field reenter_runtime_frame is properly set
    and cleared before and after calls to fork and join threads for a parallel
    region.
  Adjust the code for the new signature for __kmp_join_call.
  Adjust the OMPT parallel begin callback invocations to carry the extra
    parameter indicating whether the program or the runtime invokes the master
    task for a parallel region.

kmp_gsupport.c
  Apply all of the analogous changes described for kmp_csupport.c for the GOMP
    interface
  Add OMPT support for the GOMP combined parallel region + loop API to
    maintain the OMPT task frame field reenter_runtime_frame.

kmp_runtime.c:
  Use the new information passed by __kmp_join_call to adjust the OMPT
    parallel end callback invocations to carry the extra parameter indicating
    whether the program or the runtime invokes the master task for a parallel
    region.

ompt_internal.h:
  Use the flavor of the parallel region API (GNU or Intel) to determine who
    invokes the master task.

Differential Revision: http://reviews.llvm.org/D11259

llvm-svn: 242817

1.) in kmp_csupport.c, move computation of parameters only needed for OMPT tracing
inside a conditional to reduce overhead if not receiving ompt_event_master_begin
callbacks.
2.) in kmp_gsupport.c, remove spurious reset of OMPT reenter_runtime_frame (which 
is set in its caller, GOMP_parallel_start correct placement of #if OMP_TRACE so 
that state is maintained even if tracing support not included.  
3.) in z_Linux_util.c, add architecture independent support for OMPT by setting 
and resetting OMPT's exit_frame_ptr before and after invoking a microtask.  
4.) On the Intel MIC, the loader refuses to retain static symbols in the 
libomp.so shared library, even though tools need them. The loader could not be
bullied into doing so. To accommodate this, I changed the visibility of OMPT 
placeholder functions to public. This required additions in exports.so.txt, 
adding extern "C" scoping in ompt-general.c so that the public placeholder
symbols won't be mangled.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D11062

llvm-svn: 242052

As an ongoing effort to sanitize the openmp code, these changes delete 
variables that aren't used at all.
http://lists.cs.uiuc.edu/pipermail/openmp-dev/2015-June/000701.html

Patch by Jack Howarth

llvm-svn: 239334

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

llvm-svn: 239326

The following change is needed to suppress the "variable 'retval' is used 
uninitialized whenever 'if' condition is false" warnings in runtime/src/kmp_csupport.c.
This change just initializes 'retval' to 0.
http://lists.cs.uiuc.edu/pipermail/openmp-dev/2015-June/000667.html

Patch by Jack Howarth

llvm-svn: 238954

These fixes make doxygen happy.

llvm-svn: 238061

llvm-svn: 236753

D9302.partial2: cleanup of ittnotify checks, that eliminats redundant notifications in case of nested regions.

llvm-svn: 236631