Update development status for OpenMP 6.0

[CatherineMoore]

No description provided.

[llvmbot]

@llvm/pr-subscribers-clang

Author: None (CatherineMoore)

Changes

---

Patch is 153.39 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/150700.diff

1 Files Affected:

• (modified) clang/docs/OpenMPSupport.rst (+506-500)

diff --git a/clang/docs/OpenMPSupport.rst b/clang/docs/OpenMPSupport.rst
index fc44f4c18d01c..58cd10ad4d8fa 100644
--- a/clang/docs/OpenMPSupport.rst
+++ b/clang/docs/OpenMPSupport.rst
@@ -1,500 +1,506 @@
-.. raw:: html
-
-  <style type="text/css">
-    .none { background-color: #FFCCCC }
-    .part { background-color: #FFFF99 }
-    .good { background-color: #CCFF99 }
-  </style>
-
-.. role:: none
-.. role:: part
-.. role:: good
-
-.. contents::
-   :local:
-
-==============
-OpenMP Support
-==============
-
-Clang fully supports OpenMP 4.5, almost all of 5.0 and most of 5.1/2.
-Clang supports offloading to X86_64, AArch64, PPC64[LE], NVIDIA GPUs (all models) and AMD GPUs (all models).
-
-In addition, the LLVM OpenMP runtime `libomp` supports the OpenMP Tools
-Interface (OMPT) on x86, x86_64, AArch64, and PPC64 on Linux, Windows, and macOS.
-OMPT is also supported for NVIDIA and AMD GPUs.
-
-For the list of supported features from OpenMP 5.0 and 5.1
-see `OpenMP implementation details`_ and `OpenMP 51 implementation details`_.
-
-General improvements
-====================
-- New collapse clause scheme to avoid expensive remainder operations.
-  Compute loop index variables after collapsing a loop nest via the
-  collapse clause by replacing the expensive remainder operation with
-  multiplications and additions.
-
-- When using the collapse clause on a loop nest the default behavior
-  is to automatically extend the representation of the loop counter to
-  64 bits for the cases where the sizes of the collapsed loops are not
-  known at compile time. To prevent this conservative choice and use
-  at most 32 bits, compile your program with the
-  `-fopenmp-optimistic-collapse`.
-
-
-GPU devices support
-===================
-
-Data-sharing modes
-------------------
-
-Clang supports two data-sharing models for Cuda devices: `Generic` and `Cuda`
-modes. The default mode is `Generic`. `Cuda` mode can give an additional
-performance and can be activated using the `-fopenmp-cuda-mode` flag. In
-`Generic` mode all local variables that can be shared in the parallel regions
-are stored in the global memory. In `Cuda` mode local variables are not shared
-between the threads and it is user responsibility to share the required data
-between the threads in the parallel regions. Often, the optimizer is able to
-reduce the cost of `Generic` mode to the level of `Cuda` mode, but the flag,
-as well as other assumption flags, can be used for tuning.
-
-Features not supported or with limited support for Cuda devices
----------------------------------------------------------------
-
-- Cancellation constructs are not supported.
-
-- Doacross loop nest is not supported.
-
-- User-defined reductions are supported only for trivial types.
-
-- Nested parallelism: inner parallel regions are executed sequentially.
-
-- Debug information for OpenMP target regions is supported, but sometimes it may
-  be required to manually specify the address class of the inspected variables.
-  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 post on the
-`Discourse forums (Runtimes - OpenMP category)`_ for more
-information or if you want to help with the
-implementation.
-
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-|Category                      | Feature                                                      | Status                   | Reviews                                                               |
-+==============================+==============================================================+==========================+=======================================================================+
-| loop                         | support != in the canonical loop form                        | :good:`done`             | D54441                                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | #pragma omp loop (directive)                                 | :part:`partial`          | D145823 (combined forms)                                              |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | #pragma omp loop bind                                        | :part:`worked on`        | D144634 (needs review)                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | collapse imperfectly nested loop                             | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | collapse non-rectangular nested loop                         | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | C++ range-base for loop                                      | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | clause: if for SIMD directives                               | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| loop                         | inclusive scan (matching C++17 PSTL)                         | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| memory management            | memory allocators                                            | :good:`done`             | r341687,r357929                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| memory management            | allocate directive and allocate clause                       | :good:`done`             | r355614,r335952                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| OMPD                         | OMPD interfaces                                              | :good:`done`             | https://reviews.llvm.org/D99914   (Supports only HOST(CPU) and Linux  |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| OMPT                         | OMPT interfaces (callback support)                           | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| thread affinity              | thread affinity                                              | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | taskloop reduction                                           | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | task affinity                                                | :part:`not upstream`     | https://github.com/jklinkenberg/openmp/tree/task-affinity             |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | clause: depend on the taskwait construct                     | :good:`done`             | D113540 (regular codegen only)                                        |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | depend objects and detachable tasks                          | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | mutexinoutset dependence-type for tasks                      | :good:`done`             | D53380,D57576                                                         |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | combined taskloop constructs                                 | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | master taskloop                                              | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | parallel master taskloop                                     | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | master taskloop simd                                         | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| task                         | parallel master taskloop simd                                | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| SIMD                         | atomic and simd constructs inside SIMD code                  | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| SIMD                         | SIMD nontemporal                                             | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | infer target functions from initializers                     | :part:`worked on`        |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | infer target variables from initializers                     | :good:`done`             | D146418                                                               |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | OMP_TARGET_OFFLOAD environment variable                      | :good:`done`             | D50522                                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | support full 'defaultmap' functionality                      | :good:`done`             | D69204                                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | device specific functions                                    | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: device_type                                          | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: extended device                                      | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: uses_allocators clause                               | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: in_reduction                                         | :part:`worked on`        | r308768                                                               |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | omp_get_device_num()                                         | :good:`done`             | D54342,D128347                                                        |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | structure mapping of references                              | :none:`unclaimed`        |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | nested target declare                                        | :good:`done`             | D51378                                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | implicitly map 'this' (this[:1])                             | :good:`done`             | D55982                                                                |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | allow access to the reference count (omp_target_is_present)  | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | requires directive                                           | :good:`done`             |                                                                       |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: unified_shared_memory                                | :good:`done`             | D52625,D52359                                                         |
-+------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | clause: unified_address                                      | :part:`partial`          |                                                                       |
-+------------------------------+--------------------------------------------------------------+-------------------------...
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