who can explain the pseudo-registers and its mechanism to me?thanks

[Wu Zhou]

On Fri, 4 Nov 2005, Michael Snyder wrote:

> "ayang" <mysea000 at 163 dot com> wrote:
> > hello,
> >      I am puzzled by the the pseudo-registers and its mechanism when I >
> read the gdb source.It is not described in gdbint.who can explain the >
> pseudo-registers and its mechanism to me?thanks.
> 
> Pseudo-registers are fake registers that do not exist
> (at least as represented) on the target.  The basic distinction
> is that gdb fetches the values of "real" registers from the
> target, but computes or composes the values of "pseudo" registers
> locally.  An example might be a double-wide pseudo-register
> that is composed from the values of two ordinary registers.
> GDB fetches the values of the two ordinary registers, but
> then combines them to produce the value of the pseudo-register.
> 
> If a user changes the value of the pseudo-register, it may
> be necessary for gdb to change the target values from which
> the pseudo-register was composed.
> 

Good explanation.  At least for me. :-) Maybe this can get into <<GDB 
internal>>?

Just my two cents anyway.

Regards
- Wu Zhou