Re: SH5 compact register numbering in gcc -> gdb interface

[Alexandre Oliva <aoliva@redhat.com>]

On May  7, 2002, Joern Rennecke <joern.rennecke@st.com> wrote:

> ac131313@cygnus.com wrote:
>> Humor me here.
>> 
>> How do you use dwarf2 cfi to unwind a compact register (saved on the
>> stack) back to a media register?  In addition to the address of the
>> saved register you'll need to know that only part of the register was
>> saved. Does CFI describe this?

> P.S.:  It is not trivial to make gcc emit different register numbers
> for different sizes, but for prologue cfi, that can be done by
> attaching a REG_FRAME_RELATED_EXPR note referring to a different
> register number when emitting the prologue.

But under this design, if we moved to a more efficient exception
handling mechanism, how would throw() know whether to restore the
SHcompact or the SHmedia register before returning to the exception
landing pad?

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer