diff --git a/clang/docs/OpenMPSupport.rst b/clang/docs/OpenMPSupport.rst index 04a9648ca294..7b567c966ee5 100644 --- a/clang/docs/OpenMPSupport.rst +++ b/clang/docs/OpenMPSupport.rst @@ -17,60 +17,50 @@ 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 mac OS. +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: diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index a95a4b90570b..4a5e5aad936b 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/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 ---------------------