[llvm] [Offload] Implement better level zero dispatch (PR #218367)

[Łukasz Plewa via llvm-commits]

================
@@ -52,9 +54,62 @@ Error L0QueueTy::dispatchLaunchKernel(ze_kernel_handle_t Kernel,
                                       ze_event_handle_t *WaitEvents) {
   // Unlock KEnv lock after launching the kernel.
   llvm::scope_exit UnlockGuard([&KEnv]() { KEnv.Lock.unlock(); });
-  return CmdList->appendLaunchKernelWithArgs(
-      Kernel, &KEnv.GroupCounts, &KEnv.GroupSizes, KEnv.ArgPtrs, SignalEvent,
-      NumWaitEvents, WaitEvents, KEnv.IsCooperative);
+
+  bool AppendLaunchKernelWithArgsAvailable =
+      Device.getL0Context().LaunchKernelWithArguments.available();
+
+  if (AppendLaunchKernelWithArgsAvailable &&
+      Device.getL0Context().AppendLaunchKernelSupported.load(
+          std::memory_order_acquire)) {
+    auto Err = CmdList->appendLaunchKernelWithArgs(
+        Kernel, &KEnv.GroupCounts, &KEnv.GroupSizes, KEnv.ArgPtrs, SignalEvent,
+        NumWaitEvents, WaitEvents, KEnv.IsCooperative);
+
+    if (!Err)
+      return Plugin::success();
+
+    // Check if Err is ErrorCode::UNSUPPORTED, if so consume it
+    Err = llvm::handleErrors(
+        std::move(Err),
+        [&](std::unique_ptr<error::OffloadError> E) -> llvm::Error {
+          if (E->convertToErrorCode() ==
+              error::make_error_code(error::ErrorCode::UNSUPPORTED))
+            return llvm::Error::success(); // Swallow error
+          return llvm::Error(std::move(E));
+        });
+
+    if (Err) {
+      // Err is still here, so it was not ErrorCode::UNSUPPORTED
+      return Err;
+    }
----------------
lplewa wrote:

```suggestion
    // Err is still here, so it was not ErrorCode::UNSUPPORTED
    if (Err) 
      return Err;
```

https://github.com/llvm/llvm-project/pull/218367