Sender: rich AT phekda DOT freeserve DOT co DOT uk
Message-ID: <3EAE2D6D.5E329F3F@phekda.freeserve.co.uk>
Date: Tue, 29 Apr 2003 08:44:45 +0100
From: Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
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To: Andris Pavenis <pavenis AT latnet DOT lv>
CC: djgpp-workers AT delorie DOT com, Ben Peddell <killer DOT lightspeed AT bigpond DOT com>,
   rudd AT cyberoptics DOT com
Subject: Re: gcc 3.x breaks ABI compatibility? [Was: Re: Bug 00314 -- div() 
 still  broken]
References: <3e9c6920$0$21928$afc38c87@> <lzLqa.23283$1s1 DOT 356122 AT newsfeeds DOT bigpond DOT com> <3EABA5AA DOT 99B8EDE3 AT phekda DOT freeserve DOT co DOT uk> <200304280954 DOT 02899 DOT pavenis AT latnet DOT lv>
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Reply-To: djgpp-workers AT delorie DOT com

Hello.

Andris Pavenis wrote:
> 
> On Sunday 27 April 2003 12:40, Richard Dawe wrote:
[snip]
> > I've just looked at the gcc 2.95.2 sources and it looks like
> > -fpcc-struct-return (i.e.: use memory) is the default there.
> >
> > The gcc 3.2.2 source seems to default to using registers. See the end
> > gcc/config/i386/djgpp.h:
> >
> > /* Don't default to pcc-struct-return, because gcc is the only compiler,
> >    and we want to retain compatibility with older gcc versions.  */
> > #define DEFAULT_PCC_STRUCT_RETURN 0
> >
> > Why is this defined? I couldn't see a ChangeLog entry for djgpp.h. AFAICT
> > this breaks backwards compatibility, i.e.: the opposite of what the
> > comment says. Is there something I'm missing?
> 
> I copied it from other i386 targets. GCC-3.2.2 didn't compile without
> defining DEFAULT_PCC_STRUCT_RETURN, as there is no default

Not all i386 targets define DEFAULT_PCC_STRUCT_RETURN to be 0. Linux and
NetBSD ELF don't.

I think we need to use the same as the default for 2.95.x, i.e.:

#define DEFAULT_PCC_STRUCT_RETURN 1

This is a pretty critical bug. Do you have any plans to rebuild gcc 3.2.2 (or
3.2.3) with this fix?

Thanks, bye, Rich =]

-- 
Richard Dawe [ http://www.phekda.freeserve.co.uk/richdawe/ ]