[llvm] [OpenMP][offload] Add LIBOMPTARGET_KERNEL_EXE_TIME (PR #222105)

[Shilei Tian via llvm-commits]

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@@ -1146,6 +1176,10 @@ struct AMDGPUStreamTy {
   /// The device agent where the stream was created.
   hsa_agent_t Agent;
 
+  /// Factor converting HSA clock ticks into nanoseconds. Only used when kernel
+  /// duration tracing is enabled.
+  double TicksToTime;
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shiltian wrote:

This is half baked. On one hand, it is via a "call back" which makes it look like a "plugin" interface; on the other hand, it needs a state in the generic part of the code.

https://github.com/llvm/llvm-project/pull/222105