Date: Sat, 19 Nov 2011 23:53:46 +0000 From: Alexander Best <arundel@freebsd.org> To: Dimitry Andric <dim@FreeBSD.org> Cc: freebsd-toolchain@freebsd.org Subject: Re: CPUTYPE=native handling Message-ID: <20111119235346.GA57138@freebsd.org> In-Reply-To: <4EB8E07B.5070908@FreeBSD.org> References: <20111108002556.GA91218@freebsd.org> <4EB8E07B.5070908@FreeBSD.org>
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On Tue Nov 8 11, Dimitry Andric wrote:
> On 2011-11-08 01:25, Alexander Best wrote:
> > i've seen dozens of issues, where people set CPUTYPE=native. although this
> > works in a lot of cases, it doesn't in others. why don't we simply add
> > something like
> >
> > . if ${CPUTYPE} == "native"
> > . error "bla"
> > . endif
> >
> > in share/mk/bsd.cpu.mk for now? or at least for the archs, where "native" is
> > known to cause problems.
>
> What does this solve? Don't you think it is better to try to fix the
> actual problems? Some people like being able to optimize for their
> specific CPU, however much you can shoot yourself in the foot with it.
just wanted to report that i found an issue with CPUTYPE "native". simply do
the following on amd64 (i tested this on ref9-amd64.freebsd.org):
make.conf:
CPUTYPE ?= native
CFLAGS = -O2 -pipe -fno-strict-aliasing -funroll-loops -fno-builtin
KERNCONF = GENERIC
now 'make buildworld' and enjoy the signal 11. ;)
setting CPUTYPE to nocona or commenting it out lets 'mak buildworld' succeed.
cheers.
alex
there's a problem report for this already:
http://www.freebsd.org/cgi/query-pr.cgi?pr=gnu/149712
>
> I haven't seen any consistent bug reports yet, just a lot of complaints
> that indicate a rather high probability of PEBKAC.
>
> And just to counter the nay-saying, I compiled a number of boxes with
> clang -march=native (mostly of the Xeon/i7 variant) and I haven't seen
> any problems at all.
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