[OPENMP] Info about OpenMP Support in Users Manual

[hans]

Thanks!

docs/UsersManual.rst

1860 ↗

(On Diff #32548)

s/clang/Clang/ to be consistent with the rest of the manual

1877 ↗

(On Diff #32548)

s/this options/this option/

[ABataev]

Update after review

[kkwli0]

docs/UsersManual.rst

1860 ↗

(On Diff #32653)

Clang supports all OpenMP 3.1 directives and clauses. In addition, some features of OpenMP 4.0 are supported. For example, ''#pragma omp simd'', ..., and ''#pragma omp taskgroup'' directives.

1868 ↗

(On Diff #32653)

Should it be :option:-fopenmp=libomp?

[ABataev]

Update after review from Kelvin

cfe/trunk/docs/UsersManual.rst

 Objective-C Language Features
 =============================
 
 .. _objcxx:
 
 Objective-C++ Language Features
 ===============================
 
+.. _openmp:
+
+OpenMP Features
+===============
+
+Clang supports all OpenMP 3.1 directives and clauses.  In addition, some
+features of OpenMP 4.0 are supported.  For example, ``#pragma omp simd``,
+``#pragma omp for simd``, ``#pragma omp parallel for simd`` directives, extended
+set of atomic constructs, ``proc_bind`` clause for all parallel-based
+directives, ``depend`` clause for ``#pragma omp task`` directive (except for
+array sections), ``#pragma omp cancel`` and ``#pragma omp cancellation point``
+directives, and ``#pragma omp taskgroup`` directive.
+
+OpenMP support is disabled by default. Use :option:`-fopenmp=libomp` to enable
+it. Support for OpenMP can be disabled with :option:`-fno-openmp`.
+
+Controlling implementation limits
+---------------------------------
+
+.. option:: -fopenmp-use-tls
+
+ Controls code generation for OpenMP threadprivate variables. In presence of
+ this option all threadprivate variables are generated the same way as thread
+ local variables, using TLS support. If :option:`-fno-openmp-use-tls`
+ is provided or target does not support TLS, code generation for threadprivate
+ variables relies on OpenMP runtime library.
 
 .. _target_features:
 
 Target-Specific Features and Limitations
 ========================================
 
 CPU Architectures Features and Limitations
 ------------------------------------------