Optimizationsdisabled?

Peter Wemm peter at wemm.org
Fri Jun 11 17:58:12 GMT 2004


On Friday 11 June 2004 10:31 am, Mike Jakubik wrote:
> Hello,
>
> I have recntly aquired an AMD64 machine, and during an update to
> -CURRENT i noticed that the compiler options seem to eliminate a lot
> of optimizations such as mfpmath=387 -mno-sse -mno-sse2 -mno-mmx
> -mno-3dnow -msoft-float etc.. Does this mean all of these are
> disbled? Also, setting CPUTYPE to athlon-xp does not seem to affect
> the optimizations at all (even when compiling ports). I was hoping to
> run a full 64bit system, but this is sort of discouraging. Can some
> shed some light as to why this is?

No, it just means that we cannot use floating point code in the kernel.  
On amd64, gcc expects to be able to use them.. for example, there is 
special handling of xmm registers in varargs function calls.  Since 
floating point, sse/sse2/etc are reserved for the user, this would 
cause big problems.

All this stuff is enabled for user applications.

Do not set CPUTYPE to anything.  By default gcc uses all the 
optimizations for everything, including userland and ports.

-- 
Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com
"All of this is for nothing if we don't go to the stars" - JMS/B5


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