[llvm] [TLI] Add support for lgamma libcall. (PR #114536)

[via llvm-commits]

c8ef wrote:

> Constant folding support will be submitted in a subsequent patch.

In my experience, constant folding the gamma function is not easy because it requires invoking the corresponding libc function, which is implemented differently on various platforms. I have noticed different return values on Windows and Linux (x86), two of the most commonly used platforms. Writing a test case to satisfy the LLVM build bot may not be that trivial. Good luck!

https://github.com/llvm/llvm-project/pull/114536