[Openmp-commits] [openmp] [openmp] Add support for arm64ec to libomp (PR #176151)

[Jacek Caban via Openmp-commits]

cjacek wrote:

> Do you mean if the caller is an x86_64 function running in the emulator on Windows Arm64? I think this will still work, as the emulator will work out the entry thunks, so we should still be able to call it in this way.

No, it will not. For that to happen, the compiler would need to be responsible for calling the function, which is not the case when it is implemented in assembly.

> It would regardless only be a problem if the x86_64 code was calling in to libomp directly, and I can't really think why you wouldn't just use the x86_64 libomp in that case?

There are valid use cases for that. For example, you may have an x86_64 static library that you want to use. Another use case is when some files in a module are difficult to port (typically assembly files), and arm64ec allows you to keep them built as x86_64 while porting the rest of the code to arm64ec. As @mstorsjo said, it's probably not a blocker.

https://github.com/llvm/llvm-project/pull/176151