Slightly tangent, but AMD is also working on amdgcnspirv (i.e. AMD-flavored SPIR-V) that'll hopefully result in a similar user experience like PTX [1].
[1]: https://github.com/ROCm/ROCm/issues/3985#issuecomment-254616...
[1]: https://github.com/ROCm/ROCm/issues/3985#issuecomment-254616...