Web Shading Language is a non-starter. I looked quite closely at the specification. Apple has argued in the WebGPU WG that SPIR-V is not defined enough, semantically, to be meaningful, but WSL is even worse. Sometimes, it's even explained in terms of SPIR-V, like in the case of discard, where it was hastily explained in terms of SPIR-V's OpKill after we identified it was completely missing.

Apple has blocked any possibility of using a SPIR-V profile, sometimes with bad-faith arguments, despite it being the suggestion of all other vendors and the graphics community participating in the WG.

The team working on the WSL compiler had to have dominator analysis patiently explained to them, and then told us it was too complex of a concept, despite being something learned about in Compilers 101.