That's implementation details. SYCL and HIP are programming languages (more specifically C++ dialects), ROCm is an implementation of HIP that uses machine code. Intel DPCPP/icpx is an implementation of SYCL that uses SPIR-V.
There exists a HIP implementation that also compiles to SPIR-V, chipStar. And one can in theory write a SYCL compiler that generates machine code (maybe with openSYCL's HIP/ROCm backend?)