clang + ARM + byval structures

[Manman Ren]

Hi Stepan,

We already use byval to pass structs with size > 64 bytes. 
We should be able to use byval for all structs in terms of correctness. The threshold was chosen to be 64 because of efficiency concerns.
If you think 64 is not a great threshold, feel free to present some data and use byval for small structs.

Thanks,
Manman

On May 6, 2013, at 11:30 AM, Stepan Dyatkovskiy wrote:

> Hi Manman. Since we have fixed byval in LLVM, it is possible to pass byval structures "directly" to llvm core: I mean without casting it to arrays. The only two questions:
> 1. Do we really need that? :-) (I hope, but not sure :-) )
> 2. If so, in which cases we can pass structs "as-is" ?
> 
> -Stepan