Re: RFA: general prologue analysis framework

Ulrich Weigand
2005-10-17T18:52:32Z

Jim Blandy wrote:

> The comment for make_pv_area was misleading. Here's a better comment:
>
> /* Create a new area, tracking stores relative to the original value
> of BASE_REG. Stores to constant addresses, unknown addresses, or
> to addresses relative to registers other than BASE_REG will trash
> this area; see pv_area_store_would_trash. */
> struct pv_area *make_pv_area (int base_reg);

Yes, this is what I figured out in the meantime, sorry for the confusion.
The new comment is definitely better, though ...

I'll see how I can adapt the s390 code to use the new interface.
There's one point I'm not quite sure how to handle: it can happen that
the same register is saved multiple times to the stack (e.g. %r6 once in
the save area and once as incoming argument register). In this case,
the s390 heuristic is that the slot at the highest address is the real
save area slot. I'm not sure how to fit this into the generic routine ...

Bye,
Ulrich

--
Dr. Ulrich Weigand
Linux on zSeries Development
Ulrich.Weigand@de.ibm.com