Re: ICC Profile

Richard Freeman <rich0 <at> gentoo.org> posted 4880F05D.4010905 <at> gentoo.org,
excerpted below, on  Fri, 18 Jul 2008 15:34:53 -0400:

> Personally, I use -Os across the board when it doesn't break.  As you
> said I tend to be memory/IO bound, and optimizing for size helps with
> both (swapping causes IO).  I'd probably benefit from using -O3 on the
> aforementioned CPU-intensive apps.

I did before gcc-4.3, but with 4.3, several of the other flags (-freorder-
blocks-and-partition, for instance, which increases cache hit rates but 
also increases size) I was using folded into -O2 but not -Os, and I 
decided -O2 was a better choice as a result.

Has anyone done a study of -Os vs -O2 with gcc-4.3.x, similar to the ICC/
gcc-4.x study linked upthread?  On x86_64 would be an extra bonus, 
particularly if it were on AMD, or if both Intel and AMD were studied, as 
would the effect of such flags as -freorder-blocks-and-partition, as 
mentioned above.  I'd love to see links, if so!

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

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