Tracking progress for constexpr cmath (P0533R9, P1383R2)

[cor3ntin]

constexpr cmath papers (P0533R9, P1383R2 for C++23 and C++26 will take a while to implement.

As we plan to implement builtins in clang using llvm-libc' math functions, and then use that to implement libc++, it would be useful to have a page that tracks what builtins are implemented, what libc features are missing, and what is supported by libc++.

That would let

• LLVM contributors coordinate more effectively
• Let users know what they can use
• Let other implementers synchronize (MSVC wants to use libc, and MSSTL wants to be clang compatible)

I'm not sure if the best place would be a GitHub issue or an RST file somewhere.
Note that libc does an excellent job of tracking what they support https://libc.llvm.org/headers/math/index.html.

[llvmbot]

@llvm/issue-subscribers-libc

Author: cor3ntin (cor3ntin)

`constexpr` cmath papers ([P0533R9](https://wg21.link/P0533R9), [P1383R2](https://wg21.link/P1383R2) for C++23 and C++26 will take a while to implement.

As we plan to implement builtins in clang using llvm-libc' math functions, and then use that to implement libc++, it would be useful to have a page that tracks what builtins are implemented, what libc features are missing, and what is supported by libc++.

That would let

• LLVM contributors coordinate more effectively
• Let users know what they can use
• Let other implementers synchronize (MSVC wants to use libc, and MSSTL wants to be clang compatible)

I'm not sure if the best place would be a GitHub issue or an RST file somewhere.
Note that libc does an excellent job of tracking what they support https://libc.llvm.org/headers/math/index.html.

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor has already been assigned to this issue. If you believe that no one is actually working on it despite an assignment, ping the person. After one week without a response, the assignee may be changed.
2. In the comments of this issue, request for it to be assigned to you, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: cor3ntin (cor3ntin)

`constexpr` cmath papers ([P0533R9](https://wg21.link/P0533R9), [P1383R2](https://wg21.link/P1383R2) for C++23 and C++26 will take a while to implement.

As we plan to implement builtins in clang using llvm-libc' math functions, and then use that to implement libc++, it would be useful to have a page that tracks what builtins are implemented, what libc features are missing, and what is supported by libc++.

That would let

• LLVM contributors coordinate more effectively
• Let users know what they can use
• Let other implementers synchronize (MSVC wants to use libc, and MSSTL wants to be clang compatible)

I'm not sure if the best place would be a GitHub issue or an RST file somewhere.
Note that libc does an excellent job of tracking what they support https://libc.llvm.org/headers/math/index.html.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: cor3ntin (cor3ntin)

`constexpr` cmath papers ([P0533R9](https://wg21.link/P0533R9), [P1383R2](https://wg21.link/P1383R2) for C++23 and C++26 will take a while to implement.

As we plan to implement builtins in clang using llvm-libc' math functions, and then use that to implement libc++, it would be useful to have a page that tracks what builtins are implemented, what libc features are missing, and what is supported by libc++.

That would let

• LLVM contributors coordinate more effectively
• Let users know what they can use
• Let other implementers synchronize (MSVC wants to use libc, and MSSTL wants to be clang compatible)

I'm not sure if the best place would be a GitHub issue or an RST file somewhere.
Note that libc does an excellent job of tracking what they support https://libc.llvm.org/headers/math/index.html.

[0w0zzzzzz]

hi @cor3ntin, I would like to work on this issue, and I have a couple of questions:

1. Where can I find all math functions that libc++ is expected to implement, and which features already implemented.
2. Is it acceptable to create a new RST file under "libcxx/docs/Status", similar to Parallelism.rst which tracks the status of the Parallelism TS implementation?