Re: Floating point in kernel mode, Win2003 64-bit

nospam_at_cristalink.com
Date: 04/22/04 

Date: Fri, 23 Apr 2004 11:07:56 +1200

I guess there must be *no* difference between kernel and user mode threads,
and the *whole* FPU must be saved during context switches. If I am not
wrong...

As I mentioned in the previous posting, Itanium allows 'smart' and 'lazy'
FPU state saving based on PSR.dfh/mfh, if the OS supports this feature. If
not then the OS must save/restore the whole FPU for every context switch.

"Ray Trent" <rat@synaptics.com.spamblock> wrote in message
news:OBzLucLKEHA.3728@TK2MSFTNGP12.phx.gbl...
> Hmmm. Do PASSIVE_LEVEL kernel worker threads have their FP context saved
> and restored when they are task-switched out to service other ready
> PASSIVE_LEVEL threads?
>

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