Manually set sret parameter

[Andrew Pinski]

On Sun, Jun 29, 2025, 7:36 AM Antoni Boucher via Gcc <gcc@gcc.gnu.org>
wrote:

> Hi.
> Is there a way in GENERIC to specify that a parameter will be passed in
> "sret", or is this solely controlled by the hook struct_value_rtx?
>

It is only controlled by the hook.
What exactly are trying to do?
You could set the return slot optimization bit on the call expression if
you want the lhs of a call not to be copied and just passed as the address
via sret.

That is if you have:
StructVar = func(...);

You set the return slot optimization bit on the call expr in generic and
which will copy that bit to the gimple GIMPLE_CALL and then during expand
will again copy it back to the generic call_expr and expand will use the
target for the address.

Is that what you are looking for?


Thanks,
Andrew

Thanks.
>