[PATCH] D22203: Update the LangRef description of the 'returned' attribute

[Hal Finkel via llvm-commits]

hfinkel abandoned this revision.
hfinkel added a comment.

In http://reviews.llvm.org/D22203#479707, @sunfish wrote:

> The referenced WebAssembly optimization is a caller-side optimization, not a callee-side optimization, so it itself isn't actually a motivation for this LangRef change.
>
> Also, it's not clear what the optimization purpose of `returned` would be in the callee. If some IR producer or transformer knows that one of the argument values is returned, it should just set the return operand(s) to use the argument value, or a bitcast thereof, and let SSA form to describe the property naturally.


Yep. I'm not sure what I was thinking. I think perhaps David meant to generalize the description of the caller-side optimizations. I'll post a different patch.


http://reviews.llvm.org/D22203