Date: Wed, 31 Jan 2007 23:40:38 +1100 From: Scott Killen <salkillen@internode.on.net> To: freebsd-questions@freebsd.org Subject: gcc compiler cputype, prescott or nocona confusion Message-ID: <200701312340.38593.salkillen@internode.on.net>
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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? Regards Scott K
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