[PATCH] D140627: [orc] Pass big JITTargetMachineBuilder parameters by reference to avoid unnecessary copies

[Lang Hames via Phabricator via llvm-commits]

lhames added a comment.

Hi @fzou1,

JITTargetMachineBuilders are only moved around at startup at the moment, and they're only ~0.5kb. Have they been observed to have a performance impact? If so we should probably transfer them via `unique_ptr` to avoid the copies, but I'm not sure it's necessary yet.



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Comment at: llvm/docs/tutorial/BuildingAJIT1.rst:195-197
+    auto EPC = SelfExecutorProcessControl::Create();
+    if (!EPC)
+      return EPC.takeError();
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The introduction of EPC here seems unrelated to the other changes?


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Comment at: llvm/docs/tutorial/BuildingAJIT2.rst:61
   private:
-    ExecutionSession ES;
-    RTDyldObjectLinkingLayer ObjectLayer;
-    IRCompileLayer CompileLayer;
-    IRTransformLayer TransformLayer;
+    std::unique_ptr<ExecutionSession> ES;
 
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Is this change related to the rest of the patch?


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  https://reviews.llvm.org/D140627/new/

https://reviews.llvm.org/D140627