On 1/31/07, Jorn Argelo <[EMAIL PROTECTED]> wrote:
On Wed, 31 Jan 2007 23:40:38 +1100, Scott Killen <[EMAIL PROTECTED]> wrote: > Hi, > > When recompiling the world or kernel in FreeBSD i386 Rel 6.1 with, > > "# make buildworld" > or > "# make buildkernel KERNCONF=MYSMPCONF" > > (or building anything anything else for that matter), even though I have > "CPUTYPE?=nocona" set in my "/etc/make.conf" file the compiler seems to > head > back to a default of "-march=prescott" when compiling many of the > functions > on a Dual Xeon 3.6g (nocona) machine! > > This doesn't happen when compiling for other machine types, I've tried it > on a > Dual PentiumPro, Dual PII, Dual PIII setting the CPUTYPE to the correct > cpu > type and the -march sticks to the assigned cpu type through all operations > and produces nice quick optimized code. > > Why is this so? > > Is it because the "nocona" machine type optimization refers to the EMT64 > technology and thus is rejected when compiling for i386 targets rather > than > amd64 or emt64 targets and Gcc rejects it? That's right. AFAIK the Nocona core is a prescott with EM64T support (feel free to correct me if I am wrong). Basically you have an i386 version of FreeBSD, and with EM64T instructions enabled GCC will build a 64-bit version of FreeBSD. I think that's the reason it switches back to prescott. Jorn > > Regards > Scott K
For the record I used "nocona" with my dual xeon emt64 2.8 GHz and it broke my kernel. -- Regards, -Abdullah Ibn Hamad Al-Marri Arab Portal http://www.WeArab.Net/ _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
