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

llvm-svn: 286115

This change set disables creation of the monitor thread by default.  The global
counter maintained by the monitor thread was replaced by logic that uses system
time directly, and cyclic yielding on Linux target was also removed since there
was no clear benefit of using it. Turning on KMP_USE_MONITOR variable (=1)
enables creation of monitor thread again if it is really necessary for some
reasons.

Differential Revision: https://reviews.llvm.org/D24739

llvm-svn: 282507

Cleanup - unused code removal.
TODO: consider to remove (replace with flag class methods)
also kmp_wait_64 and kmp_release_64 routines.

Patch by Andrey Churbanov

Differential Revision: http://reviews.llvm.org/D21332

llvm-svn: 272697

llvm-svn: 268462

llvm-svn: 256790

The OMPT specification has changed. This revision brings the LLVM OpenMP
implementation up to date.

Technical overview of changes:
Previously, a public weak symbol ompt_initialize was called after the OpenMP
runtime is initialized. The new interface calls a global weak symbol ompt_tool
prior to initialization. If a tool is present, ompt_tool returns a pointer to
a function that matches the signature for ompt_initialize. After OpenMP is 
initialized the function pointer is called to initialize a tool.
Knowing that OMPT will be enabled before initialization allows OMPT support to
be initialized as part of initialization instead of back patching
initialization of OMPT support after the fact.
Post OpenMP initialization support has been generalized moves from
ompt-specific.c into ompt-general.c, since the OMPT initialization logic is no
longer implementation specific.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D12998

llvm-svn: 248187

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

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

llvm-svn: 241832

These changes are mostly in comments, but there are a few
that aren't.  Change libiomp5 => libomp everywhere.  One internal
function name is changed in kmp_gsupport.c, and in kmp_i18n.c, the
static char[] variable 'name' is changed to "libomp".

llvm-svn: 238712

llvm-svn: 236117

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.

llvm-svn: 219214

This release use aligns with Intel(r) Composer XE 2013 SP1 Product Update 2 

New features
* The library can now be built with clang (though wiht some
  limitations since clang does not support 128 bit floats)
* Support for Vtune analysis of load imbalance
* Code contribution from Steven Noonan to build the runtime for ARM*
  architecture processors 
* First implementation of runtime API for OpenMP cancellation

Bug Fixes
* Fixed hang on Windows (only) when using KMP_BLOCKTIME=0

llvm-svn: 197914

llvm-svn: 191506