[PATCH] Fix -mno-accumulate-outgoing-args -fasynchronous-unwind-tables (PR rtl-optimization/36419)

[Eric Botcazou]

> I agree that representing it in RTL rather than on the side would be
> cleaner.  But from what I can see, most of the targets set
> REG_FRAME_RELATED_EXPR to something that doesn't have RTX_FRAME_RELATED_P,
> so dwarf2out.c would be confused about them.  Furthermore, it is
> possible that some target already has different REG_FRAME_RELATED_EXPR
> on it (maybe not, haven't read all the backends to see what they set
> REG_FRAME_RELATED_EXPR on).

My understanding is that you can always add a new CFI, even if there is 
already one, just make a PARALLEL if needed.  So we could devise a new
RTL representation for DW_CFA_GNU_args_size and use it there.  But I
cannot really approve anything in this area so discussing this with a 
maintainer would probably be more productive. :-)

-- 
Eric Botcazou