[PATCH v4 1/2] MIPS: support mips*64 as CPU and gnuabi64 as ABI

[Maciej W. Rozycki]

Nick, please hold on with 2.41 until this incompatible ABI change has been 
sorted.

On Wed, 19 Apr 2023, Richard Sandiford wrote:

> > For MIPS64r6 ports, Debian as an example, `mipsisa64r6el` is
> > used as the cpu name in triple.
> > Let's recognize them by `mips*64*(el)`.
> >
> > For 64bit Ports, like Debian's mips64el and mips64r6el ports,
> > `gnuabi64` is used as the abi section.
> > Let's use N64 abi by default for the triple with gnuabi64.
> > ---
> >  bfd/config.bfd                                     | 14 ++++++++++++--
> >  .../testsuite/binutils-all/mips/mips-note-2-n32.d  |  1 +
> >  gas/configure                                      |  5 ++++-
> >  gas/configure.ac                                   |  5 ++++-
> >  gold/configure.tgt                                 | 14 ++++++++++++++
> >  ld/configure.tgt                                   | 12 ++++++++++--
> >  6 files changed, 45 insertions(+), 6 deletions(-)
> 
> OK, thanks.

 So this has changed the default ABI from o32 to n32 for `mipsisa64-*-*' 
targets and the like, which I only realised by getting odd results from an 
attempt to make a test case for another change of YunQiang's I have begun 
reviewing now.

 I can't find this rather significant and incompatible change of semantics 
mentioned anywhere in the trail of messages associated with this patch 
submission, let alone the change description.  Have you been aware of it 
and acked the change regardless, or has it slipped through?

 It seems to me such a major change, even if actually approved, should be 
rather prominently mentioned in the change description with rationale 
given, and made on its own rather than with other modifications.

 NB I'm stuck with the other review until this has been sorted and may 
have to revert this change too, as I have the other change ready to commit 
except for conflicting test results.  Also we need to be careful not to 
let this get downstream with 2.41 unless we're very, very sure it is the 
right change to make.

  Maciej