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

[Joern Rennecke <joern.rennecke@st.com>]

ezannoni@redhat.com wrote:
> This can be worked around in gdb with
> STAB_REG_TO_REGNUM/DWARF2_REG_TO_REGNUM functions. Other targets do
> this.

OK, but I see no point in setting up such a mapping when there is
no data it would operate on.
	
>  > This shouldn't really matter since these registers should
>  > not appear in debug information with the ABIs currently
>  > in use.  It is confusing, however, that gcc pretends that
>  > this is part of the interface.  I therefore propose to remove
>  > mappings for T and GDB from SH_DBX_REGISTER_NUMBER.
> 
> I am not sure I understand your last sentence. You want to remove T
> from the mapping? It is not strictly necessary.

The presense of T and gdb in the mapping is just confusing, since there
is no interface for these registers between gcc and gdb at the present,
and no reason for it to be.  If we ever think we have to put a user variable
into T and/or gbr, and express this in debug information, we can still pick
a number, and make it consistent between gcc and gdb at the same time.

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