Re: [RFC Patch], PowerPC memory support pre-gcc9, patch #1

[Michael Meissner <meissner@linux.vnet.ibm.com>]

On Tue, Mar 20, 2018 at 08:01:57AM -0500, Segher Boessenkool wrote:
> Hi!  Some comments...
> 
> On Wed, Mar 14, 2018 at 06:54:08PM -0400, Michael Meissner wrote:
> > The first patch in the series moves most of the reg_addr structure from
> > rs6000.c to rs6000-protos.h, so that in the next patch, we can start splitting
> > some of the address code to other files.
> 
> Is that the correct header?  It currently contains only function
> prototypes, and the name indicates that is what it should be.
> 
> >     1)	I was playing with making r12 be fixed with a new option (not in this
> > 	set of patches), and I noticed it wasn't reflected in the -mdebug=reg
> > 	debug dump, due to the debug dump being done before the conditional
> > 	registers are setup.  I made the debug dump set conditional registers.
> 
> Various ABIs use r12 for various things.  It's also used for split stack.
> Besides that it is available for programs to do with as they please.
> 
> > I likely will remove the undocumented toc-fusion all together, and eventually
> > rework the p8/p9 fusion support.
> 
> Did it ever give any performance improvement?
> 
> > 2018-03-14  Michael Meissner  <meissner@linux.vnet.ibm.com>
> > 	* config/rs6000/rs6000-protos.h (regno_or_subregno): Add
> > 	declaration.
> 
> There is a generic reg_or_subregno, how does this differ?  If we need
> it please change the name so the difference is clear.
> 
> It is very hard to review these patches.  Please do patches that only
> move or rename things, not changing functionality, as separate patches
> (usually before everything else).

Ok, but if you want me to shove everything back into rs6000.c that simplifies
things.  Some of the artiface is to support the reg_addr stuff in multiple
locations.

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.vnet.ibm.com, phone: +1 (978) 899-4797