[OPENMP][DOCS] Release notes/OpenMP support updates, NFC.

Differential Revision: https://reviews.llvm.org/D56733

llvm-svn: 351580

clang/docs/OpenMPSupport.rst

@@ -17,61 +17,51 @@
 OpenMP Support
 ==================
 
+Clang supports the following OpenMP 5.0 features
+
+* The `reduction`-based clauses in the `task` and `target`-based directives.
+
+* Support relational-op != (not-equal) as one of the canonical forms of random
+  access iterator.
+
+* Support for mapping of the lambdas in target regions.
+
+* Parsing/sema analysis for the requires directive.
+
+* Nested declare target directives.
+
+* Make the `this` pointer implicitly mapped as `map(this[:1])`.
+
+* The `close` *map-type-modifier*.
+
 Clang fully supports OpenMP 4.5. Clang supports offloading to X86_64, AArch64,
 PPC64[LE] and has `basic support for Cuda devices`_.
 
-Standalone directives
-=====================
-
-* #pragma omp [for] simd: :good:`Complete`.
-
 * #pragma omp declare simd: :partial:`Partial`.  We support parsing/semantic
   analysis + generation of special attributes for X86 target, but still
   missing the LLVM pass for vectorization.
 
-* #pragma omp taskloop [simd]: :good:`Complete`.
-
-* #pragma omp target [enter|exit] data: :good:`Complete`.
-
-* #pragma omp target update: :good:`Complete`.
-
-* #pragma omp target: :good:`Complete`.
-
-* #pragma omp declare target: :good:`Complete`.
-
-* #pragma omp teams: :good:`Complete`.
-
-* #pragma omp distribute [simd]: :good:`Complete`.
-
-* #pragma omp distribute parallel for [simd]: :good:`Complete`.
-
-Combined directives
-===================
-
-* #pragma omp parallel for simd: :good:`Complete`.
-
-* #pragma omp target parallel: :good:`Complete`.
-
-* #pragma omp target parallel for [simd]: :good:`Complete`.
-
-* #pragma omp target simd: :good:`Complete`.
-
-* #pragma omp target teams: :good:`Complete`.
-
-* #pragma omp teams distribute [simd]: :good:`Complete`.
-
-* #pragma omp target teams distribute [simd]: :good:`Complete`.
-
-* #pragma omp teams distribute parallel for [simd]: :good:`Complete`.
-
-* #pragma omp target teams distribute parallel for [simd]: :good:`Complete`.
-
-Clang does not support any constructs/updates from OpenMP 5.0 except
-for `reduction`-based clauses in the `task` and `target`-based directives.
-
 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.
 
+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.
+
+- The default schedules for the `distribute` and `for` constructs in a
+  parallel region and in SPMD mode have changed to ensure coalesced
+  accesses. For the `distribute` construct, a static schedule is used
+  with a chunk size equal to the number of threads per team (default
+  value of threads or as specified by the `thread_limit` clause if
+  present). For the `for` construct, the schedule is static with chunk
+  size of one.
+  
+- Simplified SPMD code generation for `distribute parallel for` when
+  the new default schedules are applicable.
+
 .. _basic support for Cuda devices:
 
 Cuda devices support

clang/docs/ReleaseNotes.rst

@@ -133,7 +133,36 @@ ABI Changes in Clang
 OpenMP Support in Clang
 ----------------------------------
 
-- ...
+- OpenMP 5.0 features
+
+  - Support relational-op != (not-equal) as one of the canonical forms of random
+    access iterator.
+  - Added support for mapping of the lambdas in target regions.
+  - Added parsing/sema analysis for the requires directive.
+  - Support nested declare target directives.
+  - Make the `this` pointer implicitly mapped as `map(this[:1])`.
+  - Added the `close` *map-type-modifier*.
+
+- Various bugfixes and improvements.
+
+New features supported for Cuda devices:
+
+- Added support for the reductions across the teams.
+
+- Extended number of constructs that can be executed in SPMD mode.
+
+- Fixed support for lastprivate/reduction variables in SPMD constructs.
+
+- New collapse clause scheme to avoid expensive remainder operations.
+
+- New default schedule for distribute and parallel constructs.
+
+- Simplified code generation for distribute and parallel in SPMD mode.
+
+- Flag (``-fopenmp_optimistic_collapse``) for user to limit collapsed
+  loop counter width when safe to do so.
+
+- General performance improvement.
 
 CUDA Support in Clang
 ---------------------