Path: utzoo!attcan!uunet!tank!ncar!mephisto!tut.cis.ohio-state.edu!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!srhqla!demott!kdq
From: kdq@demott.COM (Kevin D. Quitt)
Newsgroups: comp.sys.m68k
Subject: Re: 68882 Exception Handling
Keywords: 68882, exceptions, floating point
Message-ID: <73@demott.COM>
Date: 15 Mar 90 15:23:07 GMT
References: <13789@watcgl.waterloo.edu>
Reply-To: kdq@demott.COM (Kevin D. Quitt)
Distribution: comp
Organization: DeMott Electronics Co., Van Nuys CA
Lines: 26

In article <13789@watcgl.waterloo.edu> jvkelley@watcgl.waterloo.edu (Jeff Kelley) writes:
>In article <68@demott.COM> kdq@demott.COM (Kevin D. Quitt) writes:
>>
>>    You must also use FSAVE/FRESTORE if, as a result of your activity in
>>the interrupt routine, a different process will be running than the one
>>when you entered. 
>
>Is this still the case if the "different process" will not be using
>the fp coprocessor?  That is, if we assume the operating system knows
>which processes will use the coprocessor and which will not, is it
>possible to perform an FSAVE/FRESTORE only when context switches
>occur (directly or indirectly) between processes using the coprocessor?

    In theory, you're correct.  In practice, it's a little hard to
guarantee someone won't slip a FP instruction in.

kdq
-- 

Kevin D. Quitt                          Manager, Software Development
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