Date: Sun, 4 Mar 2018 19:32:09 +0100 From: Christian Ullrich <chris@chrullrich.net> To: Warner Losh <imp@bsdimp.com>, Dimitry Andric <dim@freebsd.org> Cc: FreeBSD-STABLE Mailing List <freebsd-stable@freebsd.org> Subject: Re: "Cross" building for same architecture, different CPUTYPE Message-ID: <f24d5c35-2afe-1c88-c197-5d16dad80633@chrullrich.net> In-Reply-To: <CANCZdfqzZrjseYZybt%2BcDv5MLJEK5uZqtGvJCnPrLC6TNtBrJg@mail.gmail.com> References: <2126f358-c827-ecf0-109b-0488c5b155b6@chrullrich.net> <D30A88D2-6DFB-4535-8735-C71A43DEEB6B@FreeBSD.org> <CANCZdfqzZrjseYZybt%2BcDv5MLJEK5uZqtGvJCnPrLC6TNtBrJg@mail.gmail.com>
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* Warner Losh wrote:
> On Sun, Mar 4, 2018 at 10:43 AM, Dimitry Andric <dim@freebsd.org
> <mailto:dim@freebsd.org>> wrote:
>
> Again, this depends on how exactly you are overriding CPUTYPE.
>
> I'd suggest *NOT* setting CPUTYPE and instead using TARGET_CPUTYPE to do
> these sorts of things. CPUTYPE is known to only work on native builds
Doesn't work either, sorry:
[chul@build /usr/obj/slm/usr/src/tmp/legacy/usr/bin]$ CCACHE_DISABLE=yes
MAKEOBJDIRPREFIX=/usr/obj/slm make TARGET_CPUTYPE=slm -j4 buildworld
buildkernel
...
[chul@build /usr/obj/slm/usr/src/tmp/legacy/usr/bin]$ objdump -d install
| fgrep '(bad)' | wc -l
8345
This objdump (in base, "GNU objdump 2.17.50 [FreeBSD] 2007-07-03") does
not understand AVX, and most of the (bad)s are c4 and c5 prefixes, aka AVX.
For /usr/obj/slm/usr/src/lib/libc/libc.so.7 I get a lot of (bad), too,
but these seem to be instructions that the chip actually has, only the
old objdump does not know them.
The same happens with the TARGET_CPUTYPE in make.conf , and also if I
spell it "silvermont". bsd.cpu.mk turns "slm" into "silvermont", but
somehow it ends up as "-march=slm" on the command line again. gcc's docs
say "-march=silvermont", and clang is apparently notorious for not
providing any useful detail on what architecture variants it supports.
Should I try make release? I'm really interesting in something that will
bring down build time, because buildworld/buildkernel on the Atom takes
24 hours without ccache and at least 8 with.
--
Christian
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