[ping*n] aarch64: move and adjust PROBE_STACK_*_REG

[Olivier Hainque]

Hello,

Another ping for this as a new end of stage1 approaches,
please ?

While this may ring the bell of a more involved issue
with ABIs and the use of R18, this particular change doesn't
have that kind of implication.

Thanks a lot in advance!

With Kind Regards,

Olivier

> On 26 Oct 2020, at 12:08, Olivier Hainque <hainque@adacore.com> wrote:
> 
>> On 15 Oct 2020, at 08:38, Olivier Hainque <hainque@adacore.com> wrote:
>> 
>>> On 24 Sep 2020, at 11:46, Olivier Hainque <hainque@adacore.com> wrote:
>>> 
>>> Re-proposing this patch after re-testing with a recent
>>> mainline on on aarch64-linux (bootstrap and regression test
>>> with --enable-languages=all), and more than a year of in-house
>>> use in production for a few aarch64 ports on a gcc-9 base.
>>> 
>>> The change moves the definitions of PROBE_STACK_FIRST_REG
>>> and PROBE_STACK_SECOND_REG to a more appropriate place for such
>>> items (here, in aarch64.md as suggested by Richard), and adjusts
>>> their value from r9/r10 to r10/r11 to free r9 for a possibly
>>> more general purpose (e.g. as a static chain at least on targets
>>> which have a private use of r18, such as Windows or Vxworks).
>>> 
>>> OK to commit?
>>> 
>>> Thanks in advance,
>>> 
>>> With Kind Regards,
>>> 
>>> Olivier
>>> 
>>> 2020-11-07  Olivier Hainque  <hainque@adacore.com>
>>> 
>>> 	* config/aarch64/aarch64.md: Define PROBE_STACK_FIRST_REGNUM
>>> 	and PROBE_STACK_SECOND_REGNUM constants, designating r10/r11.
>>> 	Replacements for the PROBE_STACK_FIRST/SECOND_REG constants in
>>> 	aarch64.c.
>>> 	* config/aarch64/aarch64.c (PROBE_STACK_FIRST_REG): Remove.
>>> 	(PROBE_STACK_SECOND_REG): Remove.
>>> 	(aarch64_emit_probe_stack_range): Adjust to the _REG -> _REGNUM
>>> 	suffix update for PROBE_STACK register numbers.
>> 
>> <aarch64-regnum.txt>
>