[OpenCL][Docs] Release 13 notes

[Anastasia]

Summary

Major OpenCL functionality added in release 13.

[Anastasia]

Due to the release completion schedule and my planned absences, it is likely that this needs finalizing by the end of the week. Any small changes can still be added later on should you wish to improve something afterwards up until the release branch is frozen. I just want to make sure that we don't miss adding the main content for the release.

[Topotuna]

Overall, I think the release notes accurately describe tasks I have been working on. A couple of suggestions and minor grammatical changes provided.

clang/docs/ReleaseNotes.rst

159

function declarations - first word in singular form

168

Would it be worth mentioning that command line flag -cl-std=clc++1.0 is now allowed and preferred over -cl-std=clc++?

174

Fixed OpenCL C language version ... - past form of "fix" for consistency with other bullet points

194

Is there a reason why DOT is written in all capitals? If yes, then maybe it should be written like so in Arm dot product extension on line 177 as well?

218

I think this should be rephrased. NULL macro was already present in internal headers but now its value is redefined to nullptr. I would suggest listing it as:

- Redefined ``NULL`` macro in internal headers to be compatible with C++.

[Anastasia]

• Addressed review comments from @Topotuna
• Reordered items to group features and fixes

[Topotuna]

LGTM! Thanks

[Anastasia]

this is now on the release branch https://github.com/llvm/llvm-project/commit/9723fc15338e83737d0c5f7cbf415e7f1d9d1ec3

clang/docs/ReleaseNotes.rst

 Objective-C Language Changes in Clang
 -------------------------------------
 
-OpenCL C Language Changes in Clang
-----------------------------------
+OpenCL Kernel Language Changes in Clang
+---------------------------------------
 
-...
+
+Command-line interface changes:
+
+- All builtin types, macros and function declarations are now added by default
+  without any command-line flags. A flag is provided ``-cl-no-stdinc`` to
+  suppress the default declarations non-native to the compiler.
+
+- Clang now compiles using OpenCL C version 1.2 by default if no version is
+  specified explicitly from the command line.
+
+- Clang now supports ``.clcpp`` file extension for sources written in
+  C++ for OpenCL.
+
+- Clang now accepts ``-cl-std=clc++1.0`` that sets C++ for OpenCL to
+  the version 1.0 explicitly.
+
+Misc common changes:
+
+- Added ``NULL`` definition in internal headers for standards prior to the
+  version 2.0.
+
+- Simplified use of pragma in extensions for ``double``, images, atomics,
+  subgroups, Arm dot product extension. There are less cases where extension
+  pragma is now required by clang to compile kernel sources.
+
+- Added missing ``as_size``/``as_ptrdiff``/``as_intptr``/``as_uintptr_t``
+  operators to internal headers.
+
+- Added new builtin function for ndrange, ``cl_khr_subgroup_extended_types``,
+  ``cl_khr_subgroup_non_uniform_vote``, ``cl_khr_subgroup_ballot``,
+  ``cl_khr_subgroup_non_uniform_arithmetic``, ``cl_khr_subgroup_shuffle``,
+  ``cl_khr_subgroup_shuffle_relative``, ``cl_khr_subgroup_clustered_reduce``
+  into the default Tablegen-based header.
+
+- Added online documentation for Tablegen-based header, OpenCL 3.0 support,
+  new clang extensions.
+
+- Fixed OpenCL C language version and SPIR address space reporting in DWARF.
+
+New extensions:
+
+- ``cl_khr_integer_dot_product`` for dedicated support of dot product.
+
+- ``cl_khr_extended_bit_ops`` for dedicated support of extra binary operations.
+
+- ``__cl_clang_bitfields`` for use of bit-fields in the kernel code.
+
+- ``__cl_clang_non_portable_kernel_param_types`` for relaxing some restrictions
+  to types of kernel parameters.
+
+OpenCL C 3.0 related changes:
+
+- Added parsing support for the optionality of generic address space, images 
+  (including 3d writes and ``read_write`` access qualifier), pipes, program
+  scope variables, double-precision floating-point support. 
+
+- Added optionality support for builtin functions (in ``opencl-c.h`` header)
+  for generic address space, C11 atomics.  
+
+- Added ``memory_scope_all_devices`` enum for the atomics in internal headers.
+
+- Enabled use of ``.rgba`` vector components.
+
+C++ for OpenCL related changes:
+
+- Added ``__remove_address_space`` metaprogramming utility in internal headers
+  to allow removing address spaces from types.
+
+- Improved overloads resolution logic for constructors wrt address spaces.
+
+- Improved diagnostics of OpenCL specific types and address space qualified
+  types in ``reinterpret_cast`` and template functions.
+
+- Fixed ``NULL`` macro in internal headers to be compatible with C++.
+
+- Fixed use of ``half`` type.
 
 ABI Changes in Clang
 --------------------