[OpenMP] Change OpenMP default version in documentation and help text for -fopenmp-version

[AntonRydahl]

Summary

As discussed on the weekly OpenMP meeting on the second of August 2023, the default version
in the OpenMP documentation shoud be changed from OpenMP 5.0 to 5.1.

[tianshilei1992]

flang/test/Driver/driver-help.f90

55

Does Flang also switch to 5.1 by default?

[AntonRydahl]

I was a bit too fast. I changed OpenMPSupport.rst to point to both the OpenMP 5.0 and OpenMP 5.1 implementation status.

[AntonRydahl]

flang/test/Driver/driver-help.f90

55

As far as I know, flang is still OpenMP 1.1 by default but still depends on the same command line options as clang.

[clementval]

flang/test/Driver/driver-help.f90

55

flang does not differentiate between versions.

[tianshilei1992]

flang/test/Driver/driver-help.f90

55

I see.

[jdoerfert]

flang/test/Driver/driver-help.f90

55

I would remove the flang part of the wording for now.

[clementval]

flang/test/Driver/driver-help.f90

55

+1

[AntonRydahl]

Removing information about Flang default version of OpenMP.

[AntonRydahl]

The unit test that fails, flang/test/Driver/omp-driver-offload.f90, also fails on main. I don't see that it should be related to this patch.

flang/test/Driver/driver-help.f90

55

Thanks a lot for pointing this out. Is the new hep text fine?

[AntonRydahl]

Removed whitespace that caused CI tests to fail.

[AntonRydahl]

Rebased on main.

clang/docs/OpenMPSupport.rst

 
 * #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.
 
 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.
 
-For the list of supported features from OpenMP 5.0 see `OpenMP implementation details`_.
+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.
 

 | misc                         | pointer/reference to pointer based array reductions          | :none:`unclaimed`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc                         | prevent new type definitions in clauses                      | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | memory model                 | memory model update (seq_cst, acq_rel, release, acquire,...) | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 
 
+.. _OpenMP 51 implementation details:
+
 OpenMP 5.1 Implementation Details
 =================================
 
 The following table provides a quick overview over various OpenMP 5.1 features
 and their implementation status, as defined in the technical report 8 (TR8).
 Please post on the
 `Discourse forums (Runtimes - OpenMP category)`_ for more
 information or if you want to help with the

clang/include/clang/Driver/Options.td

def fomit_frame_pointer : Flag<["-"], "fomit-frame-pointer">, Group<f_Group>,
   HelpText<"Omit the frame pointer from functions that don't need it. "
   "Some stack unwinding cases, such as profilers and sanitizers, may prefer specifying -fno-omit-frame-pointer. "
   "On many targets, -O1 and higher omit the frame pointer by default. "
   "-m[no-]omit-leaf-frame-pointer takes precedence for leaf functions">;
 def fopenmp : Flag<["-"], "fopenmp">, Group<f_Group>, Flags<[CC1Option, NoArgumentUnused, FlangOption, FC1Option]>,
   HelpText<"Parse OpenMP pragmas and generate parallel code.">;
 def fno_openmp : Flag<["-"], "fno-openmp">, Group<f_Group>, Flags<[NoArgumentUnused]>;
 def fopenmp_version_EQ : Joined<["-"], "fopenmp-version=">, Group<f_Group>, Flags<[CC1Option, NoArgumentUnused, FlangOption, FC1Option]>,
-  HelpText<"Set OpenMP version (e.g. 45 for OpenMP 4.5, 50 for OpenMP 5.0). Default value is 50 for Clang and 11 for Flang">;
+  HelpText<"Set OpenMP version (e.g. 45 for OpenMP 4.5, 51 for OpenMP 5.1). Default value is 51 for Clang">;
 defm openmp_extensions: BoolFOption<"openmp-extensions",
   LangOpts<"OpenMPExtensions">, DefaultTrue,
   PosFlag<SetTrue, [CC1Option, NoArgumentUnused],
           "Enable all Clang extensions for OpenMP directives and clauses">,
   NegFlag<SetFalse, [CC1Option, NoArgumentUnused],
           "Disable all Clang extensions for OpenMP directives and clauses">>;
 def fopenmp_EQ : Joined<["-"], "fopenmp=">, Group<f_Group>;
 def fopenmp_use_tls : Flag<["-"], "fopenmp-use-tls">, Group<f_Group>,

flang/test/Driver/driver-help-hidden.f90

 ! CHECK-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! CHECK-NEXT: -fno-integrated-as     Disable the integrated assembler
 ! CHECK-NEXT: -fno-signed-zeros      Allow optimizations that ignore the sign of floating point zeros
 ! CHECK-NEXT: -fno-stack-arrays      Allocate array temporaries on the heap (default)
 ! CHECK-NEXT: -fno-version-loops-for-stride
 ! CHECK-NEXT:                        Do not create unit-strided loops (default)
 ! CHECK-NEXT: -fopenacc              Enable OpenACC
 ! CHECK-NEXT: -fopenmp-version=<value>
-! CHECK-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 50 for OpenMP 5.0). Default value is 50 for Clang and 11 for Flang
+! CHECK-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 51 for OpenMP 5.1). Default value is 51 for Clang
 ! CHECK-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! CHECK-NEXT: -foptimization-record-file=<file>
 ! CHECK-NEXT:                        Specify the output name of the file containing the optimization remarks. Implies -fsave-optimization-record. On Darwin platforms, this cannot be used with multiple -arch <arch> options.
 ! CHECK-NEXT: -foptimization-record-passes=<regex>
 ! CHECK-NEXT:                        Only include passes which match a specified regular expression in the generated optimization record (by default, include all passes)
 ! CHECK-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! CHECK-NEXT: -freciprocal-math      Allow division operations to be reassociated
 ! CHECK-NEXT: -fsave-optimization-record=<format>

flang/test/Driver/driver-help.f90

 ! HELP-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
 ! HELP-NEXT: -fno-integrated-as      Disable the integrated assembler
 ! HELP-NEXT: -fno-signed-zeros      Allow optimizations that ignore the sign of floating point zeros
 ! HELP-NEXT: -fno-stack-arrays      Allocate array temporaries on the heap (default)
 ! HELP-NEXT: -fno-version-loops-for-stride
 ! HELP-NEXT:                        Do not create unit-strided loops (default)
 ! HELP-NEXT: -fopenacc              Enable OpenACC
 ! HELP-NEXT: -fopenmp-version=<value>
-! HELP-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 50 for OpenMP 5.0). Default value is 50 for Clang and 11 for Flang
+! HELP-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 51 for OpenMP 5.1). Default value is 51 for Clang
 ! HELP-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-NEXT: -foptimization-record-file=<file>
 ! HELP-NEXT:                        Specify the output name of the file containing the optimization remarks. Implies -fsave-optimization-record. On Darwin platforms, this cannot be used with multiple -arch <arch> options.
 ! HELP-NEXT: -foptimization-record-passes=<regex>
 ! HELP-NEXT:                        Only include passes which match a specified regular expression in the generated optimization record (by default, include all passes)
 ! HELP-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! HELP-NEXT: -freciprocal-math      Allow division operations to be reassociated
 ! HELP-NEXT: -fsave-optimization-record=<format>

 ! HELP-FC1-NEXT:                        Do not create unit-strided loops (default)
 ! HELP-FC1-NEXT: -fopenacc              Enable OpenACC
 ! HELP-FC1-NEXT: -fopenmp-host-ir-file-path <value> 
 ! HELP-FC1-NEXT:                        Path to the IR file produced by the frontend for the host.
 ! HELP-FC1-NEXT: -fopenmp-is-target-device
 ! HELP-FC1-NEXT:                        Generate code only for an OpenMP target device.
 ! HELP-FC1-NEXT: -fopenmp-target-debug  Enable debugging in the OpenMP offloading device RTL
 ! HELP-FC1-NEXT: -fopenmp-version=<value>
-! HELP-FC1-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 50 for OpenMP 5.0). Default value is 50 for Clang and 11 for Flang
+! HELP-FC1-NEXT:                        Set OpenMP version (e.g. 45 for OpenMP 4.5, 51 for OpenMP 5.1). Default value is 51 for Clang
 ! HELP-FC1-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-FC1-NEXT: -fpass-plugin=<dsopath> Load pass plugin from a dynamic shared object file (only with new pass manager).
 ! HELP-FC1-NEXT: -freciprocal-math      Allow division operations to be reassociated
 ! HELP-FC1-NEXT: -fstack-arrays         Attempt to allocate array temporaries on the stack, no matter their size
 ! HELP-FC1-NEXT: -fsyntax-only          Run the preprocessor, parser and semantic analysis stages
 ! HELP-FC1-NEXT: -funderscoring         Appends one trailing underscore to external names
 ! HELP-FC1-NEXT: -fversion-loops-for-stride
 ! HELP-FC1-NEXT:                        Create unit-strided versions of loops

openmp/docs/CommandLineArgumentReference.rst

 ``-static-openmp``
 ^^^^^^^^^^^^^^^^^^
 Use the static OpenMP host runtime while linking.
 
 ``-fopenmp-version=<arg>``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 Set the OpenMP version to a specific version ``<arg>`` of the OpenMP standard. 
 For example, you may use ``-fopenmp-version=45`` to select version 4.5 of 
-the OpenMP standard. The default value is ``-fopenmp-version=50`` for ``Clang`` 
-and ``-fopenmp-version=11`` for ``flang-new``.
+the OpenMP standard. The default value is ``-fopenmp-version=51`` for ``Clang``.
 
 .. _offload_command_line_arguments:
 
 Offloading Specific Command-Line Arguments
 ------------------------------------------
 
 .. _fopenmp-targets: