[PATCH] D18092: Swift Calling Convention: add swifterror attribute

[Manman Ren via llvm-commits]

manmanren added a comment.

Thanks Mehdi for reviewing!

Manman


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Comment at: docs/LangRef.rst:1070
@@ +1069,3 @@
+    to get the pointer to the error object. This is not a valid attribute for
+    return values and can only be applied to one parameter.
+
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Loading and storing from the parameter will be optimized to reading and writing a specific register in backends that support swifterror.

A ``swifterror`` argument must be produced by an ``alloca`` instruction tagged with the ``swifterror`` keyword. Accessing the swifterror value in the caller will be optimized as well in backends that support swifterror.


http://reviews.llvm.org/D18092