Re: RFA: general prologue analysis framework

Daniel Jacobowitz
2005-10-13T18:03:51Z

On Thu, Oct 13, 2005 at 07:48:01PM +0200, Ulrich Weigand wrote:
> Jim Blandy wrote:
>
> > It looks like your data->gpr_slot[i] array effectively serves the same
> > purpose as an area. If we had generic code to scan an area and
> > populate a trad_frame_cache, areas might save you code.
>
> Possibly, yes. I'm not sure I completely understand the pv_area code
> yet -- it appears to be all based on the notion of a fixed base register;
> how to you handle the situation where the base (and/or offset) used to
> access the area change in the middle of the prologue? Maybe it would
> be better to always base the area on the CFA ...

Yeah, that's what I was thinking: define the CFA before processing any
instructions, handle memory relative to that (even though we don't know
its value yet), and then reverse the computation to work out the value
of the actual CFA.

--
Daniel Jacobowitz
CodeSourcery, LLC