Re: PATCH: add pa2.0 system instructions

["Jerry Quinn" <jquinn@nortelnetworks.com>]

>> "jeff" == Jeffrey A Law <law@cygnus.com> writes:

 >> Ultimately, if we can free up enough codes to cover the new syntax, we
 >> wouldn't have to play funky games with opcode names.
 jeff> We need ~25 or so to make the assembler work.  Possibly few more for
 jeff> the disassembler.

 >> If you are willing to consider prefixing, we could also prefix the codes
 >> for completers.  That would certainly free up enough codes to handle
 >> everything
 jeff> I'm certainly willing to consider it.  I don't like using the non-ascii
 jeff> stuff.

In that case I'll work up a couple of prefixing patches to free up codes.  I
did a bit of counting and came up with the following categories and counts:

float register	      12
immediate values      18 (15 if we don't include branch displacements)
completers	      6
conditions	      13
spu and coproc	      7

I included the 64 bit condition flag, long displ load/store immediates and
completers in these counts.  Immediate values also include shift counts and
other such things.

I'd suggest we prefix the float regs and either conditions or immediate
values.  That should get us into the right territory.  It appears that a bunch 
of the new codes we need are completers, so if we prefix completers, that
would also be a big help.

Jerry