Expand description
Backend for MSL (Metal Shading Language).
Binding model
Metal’s bindings are flat per resource. Since there isn’t an obvious mapping from SPIR-V’s descriptor sets, we require a separate mapping provided in the options. This mapping may have one or more resource end points for each descriptor set + index pair.
Entry points
Even though MSL and our IR appear to be similar in that the entry points in both can
accept arguments and return values, the restrictions are different.
MSL allows the varyings to be either in separate arguments, or inside a single
[[stage_in]]
struct. We gather input varyings and form this artificial structure.
We also add all the (non-Private) globals into the arguments.
At the beginning of the entry point, we assign the local constants and re-compose the arguments as they are declared on IR side, so that the rest of the logic can pretend that MSL doesn’t have all the restrictions it has.
For the result type, if it’s a structure, we re-compose it with a temporary value holding the result.
Modules
Structs
- A subset of options that are meant to be changed per pipeline.
- Information about a translated module that is required for the use of the result.