make buildworld ERROR in RELENG_5 with WITH_LIB32 (amd64)

[Sean McNeil]

On Tue, 2005-03-15 at 13:37 +0100, Dag-Erling Smørgrav wrote:
> Sean McNeil <sean at mcneil.com> writes:
> > This has been discussed before.  You are trying to compile with
> > optimization -O2 and it isn't supported.
> 
> It is supposed to be supported.  The people who say it isn't are the
> ones who keep introducing (and refusing to fix) bugs that break it.

More accurately, there exist bugs that have not been fixed yet.  These
could have been there forever, or are introduced by a faulty compiler.

Also, RELENG_5 is set up to compile as -O -pipe, not -O2
-fno-strict-aliasing -pipe.  There is good reason for this IMHO.  As
long as the default settings are not -O2, then I would say it is not
supported.

> >                                           You'll have to remove any
> > custom settings of CFLAGS in your /etc/make.conf.  Also, there are bugs
> > in the current amd64 compiler version that prevent proper functionality
> > at -O2.
> 
> Please either document that claim, or retract it.

I am not a maintainer, so I cannot insert any documentation to make this
claim.  You can, however, scan the -current list and possibly this one
and discover several claims about it.

Alexander's problem was actually that he used -O2 without using
-fno-strict-aliasing.  That is why he got his error.  But I have
personally encountered various SIGFPE signals with the tcl port when
compiled with -O2 -fno-strict-aliasing -pipe.  This first-hand knowledge
plus various reports from other FreeBSD users gave me the courage to
make this claim.  Until such time as tcl 8.4 or gcc is updated so it
works without issues on RELENG_5 when compiled with -O2, I will continue
to make the claim that -O2 is broken on AMD64.

Cheers,
Sean