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

[Segher Boessenkool <segher at kernel dot crashing dot org>]

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).


Segher