and insert the C++ templated declaration of __esimd_flat_atomic0 into esimd_builtins.h, correct? I have a question then - the signature may include const references to vectors, how to represent those?
More generally, if we want "C++ intrinsics" there should probably be a way to represent C++ types in the signature - ?

A vector is vector_type::type from

template <typename Ty, int N> struct vector_type {
  static constexpr int length = N;
  using type = Ty __attribute__((ext_vector_type(N)));
};

Looks like the issue is fixed in https://github.com/llvm/llvm-project/commit/6d2b75e0887ee87e247756c4d51733616bb2f356

Simplified patch. Updated title and description

I'm running OpenCL on an x886 and everything is fine, but there are a lot of build bots which build different targets on different architectures. Since there are no target option specified, c-index-test uses native target.

If I understand correctly, not all extensions are available on non-x86 targets and some declarations are marked as (invalid) - that is the only difference I saw

Fixed issue in test/Index/opencl-types.cl

Rebased to ToT.

Updated opencl-c.h header: fixed typos in built-in declarations. Applied comment from Alexey

Applied comments. Rebased to ToT

Rebase to the ToT

Updated tests

@yaxunl could you please review this patch?

Removed unnecessary empty line from test

Added test

Updated tests. Reverted usage of #pragma OPENCL EXTENSION my_ext : begin due to a failed LIT tests: test/Headers/opencl-c-header.cl

Applied comments from Anastasia. Updated patch with more code unified

Applied comments from Anastasia. Updated headers to conform with the latest spec

This is an initial version. I guess there are some other enums related to CK_ZeroToOCL* which also can be merged.

Updated patch with new functionality and tests

Applied comment from Anastasia