Arch Linux

ssl6

Member

From: Ottawa, ON, CA

Registered: 2007-08-30

Posts: 594

cflags or make flags?

looking at the wiki, for makepkg.conf. and i have a quick qestion, im having a hard time find an answer. for the auto detect setting for march, native, i guess it is. is there a command you can punch in, that will detect your cpu, and tell you what to put there? did i say that right?

---

this is a signature

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,577

Re: cflags or make flags?

Not really, but if you read the relevant page of the GCC manual at their site, it shouldn't be hard.

Use march=native, or use 'cat /proc/cpuinfo' / 'uname -a' / etc. to find your CPU and use the manual to decide what -march= option that would be. Post the name of your CPU and we can help, too.

ssl6

Member

From: Ottawa, ON, CA

Registered: 2007-08-30

Posts: 594

Re: cflags or make flags?

i've been using those. right now im using march=athlon64-sse3 on an athlon64 6000, which is fine. but i was looking at the gentoo wiki, for make flags, since it seems to have few more safe flags for different cpu's that arent on our wiki, maybe we should link that page? i was mostly curious, because i have a duron 1200 on a board here sort hacked together, and some of the info on they're wiki is saying that my duron is a crippled palamino when i was pretty sure its a crippled thunderbird, the issue is that one of those would use march=athlon-xp and the other would be athlon-tbird. maybe my thinking is just off today and i got it mixed up

Last edited by ssl6 (2009-03-16 04:51:50)

---

this is a signature

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,577

Re: cflags or make flags?

Specific parts of the manual, which may be helpful.

http://gcc.gnu.org/onlinedocs/gcc-4.3.3 … tions.html
http://gcc.gnu.org/onlinedocs/gcc-4.3.3 … tions.html

The manual suggests the difference between athlon-xp and athlon/athlon-tbird (they are the same, it suggests) is that the latter only has prefetch SSE support, and the former has full SSE -- at least, the difference to GCC.
So, from there, we go to Wikipedia: http://en.wikipedia.org/wiki/Duron
It says that there are multiple cores used in the Durons, and that the original one, "Spitfire", had only prefetch SSE (use -march=athlon or -march=athlon-tbird). The other, later revisions have full SSE (use -march=athlon-xp). The page also describes other differences between the cores that you can use to find out which one you have. Google tells me the Duron 1200 ran at 1200MHz, which only the Morgan core offered. So, you have a Morgan.

Therefore, you want -march=athlon-xp on your Duron.

If you have other questions about CFLAGs, post them here if you want, but please read those two linked manual sections first

Last edited by Ranguvar (2009-03-16 11:22:22)