[libcxx-commits] [libcxx] [libcxx] Use `lgamma` rather than `lgamma_r` with LLVM libc (PR #109556)

[Joseph Huber via libcxx-commits]

jhuber6 wrote:

I'm fine with this in general, since I think once the LLVM libc implements `lgamma` it is probably fine to not provide the `signgam` external global. This isn't mentioned in the standard, so it's probably an extension GNU / POSIX made than then had to make `lgamma_r` to escape from once people started realizing global state was bad. I'm just saying that *neither* `lgamma` nor `lgamma_r` are provided right now, the builtin will just make the symbol undefined (but I guess you can compile it?) It's the same as if you just put `double lgamma(double)` in the file without ever definint it.

https://github.com/llvm/llvm-project/pull/109556