[BUG] iOS builds fail with float16 issue about mlx

[davidkoski]

Yeah, I think previously the mlx-swift side didn't include the accelerate back end:

https://github.com/ml-explore/mlx-swift/blob/main/Package.swift#L78

(these are files not to build)

                // opt-out of these backends (using metal)
                "mlx/mlx/backend/no_metal",
                "mlx/mlx/backend/accelerate",

When I prepared the build for v0.14.0 I had to revamp the build quite a bit to deal with the JIT and I reconciled what CMake does with the swiftpm build.

So you are right, it has probably been like this for a while but we were not using it and so had not seen this.

[awni]

@davidkoski can you share some steps for how to reproduce this? I'm building mlx-swift main using Xcode 15.3 and macOS 14.5 and the build is fine. Do you only get the error on 14.4? Or do I need to build something specific to see the issue?

[davidkoski]

The easiest is to try building this branch for iOS:

• https://github.com/davidkoski/mlx-swift/tree/v0.14.0

You will to change various vecLib includes:

- #include <vecLib/vDSP.h>
+ #include <Accelerate.h>

but those are trivial

[davidkoski]

I am using Xcode 15.3 on macOS 14.4 but I don't think it is environment dependent -- the key is building for iOS.

[awni]

Thanks I can reproduce it now. I'm a little confused by what's going on here. The code that is failing has been there for a while now.. so any idea what changed that broke the compilation?

[awni]

This is safe to close I believe.