[PATCH] D94597: [X86] Lower calls with clang.arc.attachedcall bundle

[Ahmed Bougacha via Phabricator via llvm-commits]

ab added a comment.

Can you (or @ahatanak) explain why/how this needs to be different from aarch64?  In particular I don't think I understand why you need to emit the retainARV/claimARV calls this late, that seems like quite a drastic difference in behavior for the bundle.
I read through the discussion in D92808 <https://reviews.llvm.org/D92808> but it sounds like that predates the x86_64-specific behavior, right?  But skimming around the various passes involved I'm not actually sure who emits the retainARV/claimARV calls on aarch64.



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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:4400
+  } else if (CLI.CB && objcarc::hasAttachedCallOpBundle(CLI.CB)) {
+    // Calls with a "clang.arc.rv" bundle are special. They should be expanded
+    // to the call, directly followed by a special marker sequence and a call to
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`clang.arc.rv` -> `clang.arc.attachedcall`, right?  same below


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:4408
+    // target.
+    unsigned Sel = objcarc::hasAttachedCallOpBundle(CLI.CB, true) ? 0 : 1;
+    Ops.insert(Ops.begin() + 1, DAG.getTargetConstant(Sel, dl, MVT::i32));
----------------
`Sel` is a bit confusing, especially in an objc context ;)


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