Re: [RFA] PPC ABI compliance fix

[Kevin Buettner <kevinb@redhat.com>]

On Mar 22,  2:28pm, Elena Zannoni wrote:

> Back in November, gcc changed the way structures <= 8 bytes are
> returned on the PPC. The change was made to be compliant with the
> SVR4 ABI.
> 
> http://gcc.gnu.org/ml/gcc-patches/2001-11/msg01468.html
> 
> The abi specifies that such structures are passed in r3 and r4.
> Bigger structures are passed in memory.
> 
> Gcc was passing every structure in memory.  The change was made for
> embedded targets, but not for natives (PowerPC Linux, NetBSD, and
> FreeBSD).
> 
> Of course this change breaks binary compatibility with older gcc's.
> Not sure what to do about that, if anything, the case it covers is a
> corner case, anyway.

Hmm...  I have a hunch that, eventually, the natives will need to
change too.

For now though, your change is okay.

(Alternately, we could take a really hard nosed stance and implement
the ABI exactly as written and just put up with the failures.)

Kevin