Optimizationsdisabled?

[David O'Brien]

On Fri, Jun 11, 2004 at 01:31:42PM -0400, 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

One can't use FP in the kernel as in userland.  This is quite normal for
UNIX kernels.  You don't see all the "-mno-" on FreeBSD/i386 because GCC
doesn't default to the "ON" state for those by default [because older
i386 family CPU's don't support those features].

PowerPC and Sparc64 also use -msoft-float.

> 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?

Why is this "so discouraging"?  Have you benchmarked anything on your
64-bit AMD64 machine?  You'll find it beats the sh*t out of other
machines.

An Opteron is not an athlon-xp, please don't set CPUTYPE telling it so in
64-bit mode.  There is a single AMD64 CPU core, so GCC knows how to fully
schedule for it by default (what other default could gcc have??).

-- 
-- David  (obrien at FreeBSD.org)