DragonFly kernel List (threaded) for 2003-12
Re: libcaps thread testing code committed
:I dont think this will work. Anything before the pIII did not have SSE,
:so PPro, PII, old Xeons are now useless? Also, even the pIII only had
:SSE, not SSE2, so there is no way to do double precision floating point
:with just SSE. Any Athlon before they went to XP I believe does not
:have SSE, and I think there might also be no SSE2 in AMD Chips except
:Athlon64 and maybe Barton. I dont think this many CPU families can be
:dropped. They will have to be supported though.
Right. We can't drop support for the original NPX floating point.
However, that doesn't mean we have to save/restore the npx fp context
for programs that do not use it at all. This would be an easy
optimization. What we can't do is use OS support to optimize mixed
threaded environments where some threads use NPX and others use SSE*.
In mixed environments the threading system either has to be told which
threads are using what, or it has to save sufficient context to cover
all FP subsystems in use (npx, sse, etc).