[llvm] [Offload] Implement the remaining initial Offload API (PR #122106)

[Callum Fare via llvm-commits]

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@@ -16,8 +16,8 @@ def : Function {
     let details = [];
     let params = [
         Param<"ol_queue_handle_t", "Queue", "handle of the queue", PARAM_IN>,
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callumfare wrote:

That's an interesting idea. A special `host` device could get a bit weird outside of memory operations - could you enqueue kernels and other work on it? It doesn't seem like it would fit in well with the existing host plugin. I think we'd want the host plugin to be a in a usable state wrt memory (targetDataExchange isn't implemented) and kernel execution, to guarantee the host is always present. And also it currently exposes a hard-coded number of devices rather than a single device.

I'd prefer getting something close to what's in this PR in for now, since it reflects the reality of the existing plugins, but with the caveat that we expect it may change soon, and we could discuss an improved design in a future meeting?


https://github.com/llvm/llvm-project/pull/122106