[OpenMP][Docs] Provide implementation status details

This adds a more fine-grained list of OpenMP features with their
implementation status and associated reviews/commits.

Reviewers: kkwli0, ABataev, RaviNarayanaswamy, gtbercea, Hahnfeld

Subscribers: bollu, guansong, jfb, hfinkel, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64375

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@370930 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 132 insertions, 4 deletions

diff --git a/docs/OpenMPSupport.rst b/docs/OpenMPSupport.rst
index a8bfddce63..e71be1974c 100644
--- a/docs/OpenMPSupport.rst
+++ b/docs/OpenMPSupport.rst
@@ -2,12 +2,12 @@
 
   <style type="text/css">
     .none { background-color: #FFCCCC }
-    .partial { background-color: #FFFF99 }
+    .part { background-color: #FFFF99 }
     .good { background-color: #CCFF99 }
   </style>
 
 .. role:: none
-.. role:: partial
+.. role:: part
 .. role:: good
 
 .. contents::
@@ -17,7 +17,7 @@
 OpenMP Support
 ==================
 
-Clang supports the following OpenMP 5.0 features
+Clang supports the following OpenMP 5.0 features (see also `OpenMP implementation details`_):
 
 * The `reduction`-based clauses in the `task` and `target`-based directives.
 
@@ -37,7 +37,7 @@ Clang supports the following OpenMP 5.0 features
 Clang fully supports OpenMP 4.5. Clang supports offloading to X86_64, AArch64,
 PPC64[LE] and has `basic support for Cuda devices`_.
 
-* #pragma omp declare simd: :partial:`Partial`.  We support parsing/semantic
+* #pragma omp declare simd: :part:`Partial`.  We support parsing/semantic
   analysis + generation of special attributes for X86 target, but still
   missing the LLVM pass for vectorization.
 
@@ -129,3 +129,131 @@ Features not supported or with limited support for Cuda devices
   In some cases the local variables are actually allocated in the global memory,
   but the debug info may be not aware of it.
 
+
+.. _OpenMP implementation details:
+
+OpenMP 5.0 Implementation Details
+---------------------------------
+
+The following table provides a quick overview over various OpenMP 5.0 features
+and their implementation status. Please contact *openmp-dev* at
+*lists.llvm.org* for more information or if you want to help with the
+implementation.
+
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+|Category                      | Feature                                                      | Status                   | Reviews                                                               |
++==============================+==============================================================+==========================+=======================================================================+
+| loop extension               | support != in the canonical loop form                        | :good:`done`             | D54441                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | #pragma omp loop (directive)                                 | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | collapse imperfectly nested loop                             | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | collapse non-rectangular nested loop                         | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | C++ range-base for loop                                      | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | clause: nosimd for SIMD directives                           | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| loop extension               | inclusive scan extension (matching C++17 PSTL)               | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| memory mangagement           | memory allocators                                            | :good:`done`             | r341687,r357929                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| memory mangagement           | allocate directive and allocate clause                       | :good:`done`             | r355614,r335952                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| OMPD                         | OMPD interfaces                                              | :part:`not upstream`     | https://github.com/OpenMPToolsInterface/LLVM-openmp/tree/ompd-tests   |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| OMPT                         | OMPT interfaces                                              | :part:`mostly done`      |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| thread affinity extension    | thread affinity extension                                    | :good:`done`             |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | taskloop reduction                                           | :good:`done`             |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | task affinity                                                | :part:`not upstream`     |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | clause: depend on the taskwait construct                     | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | depend objects and detachable tasks                          | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | mutexinoutset dependence-type for tasks                      | :good:`done`             | D53380,D57576                                                         |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | combined taskloop constructs                                 | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | master taskloop                                              | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | parallel master taskloop                                     | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | master taskloop simd                                         | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| task extension               | parallel master taskloop simd                                | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| SIMD extension               | atomic and critical constructs inside SIMD code              | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| SIMD extension               | SIMD nontemporal                                             | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | infer target functions from initializers                     | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | infer target variables from initializers                     | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | OMP_TARGET_OFFLOAD environment variable                      | :good:`done`             | D50522                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | support full 'defaultmap' functionality                      | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | device specific functions                                    | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: device_type                                          | :good:`done`             |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: in_reduction                                         | :none:`unclaimed`        | r308768                                                               |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | omp_get_device_num()                                         | :part:`worked on`        | D54342                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | structure mapping of references                              | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | nested target declare                                        | :good:`done`             | D51378                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | implicitly map 'this' (this[:1])                             | :good:`done`             | D55982                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | allow access to the reference count (omp_target_is_present)  | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | requires directive (unified shared memory)                   | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: unified_address, unified_shared_memory               | :part:`worked on`        | D52625,D52359                                                         |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: reverse_offload                                      | :none:`unclaimed parts`  | D52780                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: atomic_default_mem_order                             | :none:`unclaimed parts`  | D53513                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: dynamic_allocators                                   | :none:`unclaimed parts`  | D53079                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | user-defined mappers                                         | :part:`worked on`        | D56326,D58638,D58523,D58074,D60972,D59474                             |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | mapping lambda expression                                    | :good:`done`             | D51107                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | clause: use_device_addr for target data                      | :good:`done`             |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | map(replicate) or map(local) when requires unified_shared_me | :part:`worked on`        | D55719,D55892                                                         |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| device extension             | teams construct on the host device                           | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| atomic extension             | hints for the atomic construct                               | :part:`worked on`        | D51233                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| base language                | C11 support                                                  | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| base language                | C++11/14/17 support                                          | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| base language                | lambda support                                               | :good:`done`             |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extension               | array shaping                                                | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extension               | library shutdown (omp_pause_resource[_all])                  | :none:`unclaimed parts`  | D55078                                                                |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extension               | metadirectives                                               | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extension               | conditional modifier for lastprivate clause                  | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extension               | user-defined function variants                               | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extensions              | pointer/reference to pointer based array reductions          | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc extensions              | prevent new type definitions in clauses                      | :none:`unclaimed`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+