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Jim Mellander wrote:
> I would prefer to take the performance hit by sinking back into the 
> pre-SSE days.  I didn't see any option for disabling the use of SSE in 
> the Luajit code - can this be done via a define?

Workaround: redefine JIT_F_CPU_SSE2 in src/ljit.h to 0.

> Alternatively, is 
> there some way to detect that although the CPU supports SSE, the kernel 
> doesn't, and dynamically disable that code under the circumstances?

The CPUID detection is in fact designed to do exactly this (to
benefit older operating systems). But apparently FreeBSD 4.x
doesn't play by the rules if the option is disabled. AFAIK it has
been fixed in newer versions.

> However, this is a production kernel, for which any changes need to go
> thru a time-consuming QA process, as well as requiring me to run the
> gauntlet of fascist system administration :-(

Never surrender to bureaucracies. Queue one change request now
and get what you need in a few months. Queue three change
requests every day and within two weeks you get your own box.