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>
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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. romanhome | help
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