[PATCH] D60485: [AArch64] Add support for MTE intrinsics

Thu Apr 25 03:52:41 PDT 2019

javed.absar marked an inline comment as done.
javed.absar added inline comments.

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Comment at: lib/CodeGen/CGBuiltin.cpp:7129-7131
+    // Although it is possible to supply a different return
+    // address (first arg) to this intrinsic, for now we set
+    // return address same as input address.
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t.p.northover wrote:
> I think this should be fixed now.  It looks like technical debt from the fact that the instructions only fairly recently gained that feature after the intrinsics were implemented internally. There's no good way to justify the current semantics to someone unaware of that history.
Not quite that really.  So the instruction did gain the feature recently like you mentioned. But the ACLE/intrinsics were designed and agreed upon after it and it was decided in ACLE discussions that the exta feature added complexity that need not be exposed at ACLE level yet. No big use case to justify complicating the ACLE MTE spec yet. Directly assembly can use that instruction though.

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  https://reviews.llvm.org/D60485/new/

https://reviews.llvm.org/D60485