Initialization of link-time specialized groupshared array about slang

[csyonghe]

Our front-end currently don't allow empty initializing arrays whose size is not known at compile time. But it seems that you can work around this by initializing the array explicitly in the entrypoint. Or you can try something like:

groupshared uint totals[workgroup_subgroups] = __makeArrayFromElement<workgroup_subgroups>(0);

__intrinsic_op(makeArrayFromElement)
Array<uint, N> __makeArrayFromElement<let N:int>(uint element);

[csyonghe]

Note that initialization of groupshared variable is not a currently supported feature. The compiler currently generates in-efficient code in that every thread will try to assign to the variable at the begining of the entrypoint.

[kevinboulain]

If it weren't for the extern length, the initialization would have compiled. Is the link phase (when extern/export is resolved) not considered compile time?
Though, as you said, it would have resulted in inefficient code. Should initialization of groupshared memory be disallowed by default then (to avoid a potential surprise if nothing better can be done)?

(Feel free to close by the way, especially if you judge nothing is really broken here.)

[csyonghe]

Yeah, I think we need to work on the diagnostic to disallow initialization of groupshared variables as a separate issue.

Closing this one.