Re: sh64 simulator register numbers

[Andrew Cagney <ac131313 at ges dot redhat dot com>]

> Andrew Cagney wrote:
>
> > See the directory gdb/regformats/ and (more importantly) the mail
> > archives for information on the changes that are being made to GDB so
> > that it will eventually be able to handle remote register numbers.
>
> Hmm. Interesting.  But the documentation seems to be mostly in the 
> 'looking for volunteers' stage.
>
> Can you give some salient time frames and/or keywords to narrow down the
> search space a bit?
Some words would include regcache remote.c (especially all recent patches).

> > > !   /* SHmedia */
> > > !   SIM_SH64_R0_REGNUM = 128,
>
> So you want this assignment to 128 be dropped, so that SIM_SH64_R0_REGNUM
> just gets the next free number?
Yes, a pure enum.  As mentioned before, the d10v et.al. all do this.

> The rest is all relative to SIM_SH64_R0_REGNUM.
> There are 64 general purpose registers, starting with R0.  The stack
> pointer is R15. 
> > > !   SIM_SH64_SP_REGNUM   = SIM_SH64_R0_REGNUM+15,
If a register has an alternative name, define that in a separate enum vis:

	enum {
	SIM_SH64_SP_REGNUM = SIM_SH64_R15_REGNUM
	};

> After the general purpose registers, we want the program counter.
> Is this assignment OK with you?
>
> > > !   SIM_SH64_PC_REGNUM   = SIM_SH64_R0_REGNUM+64,
No.  See above.

> Or do you want r63 to be assigned a number relative to r0, and then
> get automatically the next number for pc?
>
> Or should we enumerate all 64 of the general purpose registers?
Yes.

> Similar considerations apply to the 64 control registers,
> 8 target registers, how to assign a number to fpscr, and
> the 64 floating point registers.
Andrew