Date: Tue, 8 Nov 2011 22:32:53 +0100 From: Roman Divacky <rdivacky@freebsd.org> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-toolchain@freebsd.org, Dimitry Andric <dim@FreeBSD.org> Subject: Re: CPUTYPE=native handling Message-ID: <20111108213253.GA31062@freebsd.org> In-Reply-To: <20111108212352.GA39160@freebsd.org> References: <20111108002556.GA91218@freebsd.org> <4EB8E07B.5070908@FreeBSD.org> <20111108153856.GA90966@freebsd.org> <20111108210420.GA37161@freebsd.org> <20111108210905.GA28416@freebsd.org> <20111108212352.GA39160@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Nov 08, 2011 at 09:23:52PM +0000, Alexander Best wrote: > On Tue Nov 8 11, Roman Divacky wrote: > > clang will use "core2" for family=6 and model=15 > > > > check llvm/lib/Support/Host.cpp > > > > what is the problem? The fact that our gcc from the middle-ages > > does not recognize that? > > actually a few months ago quite a lot of gcc commits happend to add newer > optimisations (such as core2) to gcc and some commits aimed at modifying gcc, > so it would make the best -march=native choice there is. > > what's the clang command (similar to gcc -march=native -E -v - </dev/null), > one can use to check what actual optimisation clang turns "native" into? clang -### -march=native will show something like "-target-cpu" "k8-sse3" > also there seem to be cross-compilation issues. when people are running i386 > and want to cross-compile for amd64 and put CPUTYPE=core2 (or any other amd64 > cpu) into their make.conf, this gets downgraded by bsd.cpu.mk to prescott. > > see http://www.freebsd.org/cgi/query-pr.cgi?pr=conf/84800 > and > http://www.mail-archive.com/freebsd-hackers@freebsd.org/msg161451.html If gcc supports nocona now, the conf/84800 patch is ok. The same goes with downgrading core2 -> prescott. I have no idea what gcc supports these days. I think we should just skip the downgrading completely for clang as it either supports everything or can be made easily to support what it doesnt. roman
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20111108213253.GA31062>