Path: utzoo!attcan!uunet!mcsun!hp4nl!philapd!ssp11!dolf
From: dolf@idca.tds.PHILIPS.nl (Dolf Grunbauer)
Newsgroups: comp.sys.m68k
Subject: Re: 68882 Exception Handling
Keywords: 68882, exceptions, floating point
Message-ID: <688@ssp11.idca.tds.philips.nl>
Date: 15 Mar 90 19:51:49 GMT
References: <13789@watcgl.waterloo.edu> <73@demott.COM>
Distribution: comp
Organization: Philips Information Systems, Apeldoorn, The Netherlands
Lines: 20

In article <73@demott.COM> kdq@demott.COM (Kevin D. Quitt) writes:
]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.
Correct, although I think most OS processes don't require FP instructions,
so at least they are candidates.
-- 
Dolf Grunbauer          Tel: +31 55 433233  Internet dolf@idca.tds.philips.nl
Philips Telecommunication and Data Systems  UUCP ....!mcvax!philapd!dolf
Dept. SSP, P.O. Box 245, 7300 AE Apeldoorn, The Netherlands         n   n   n
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