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From: rbt@cernvax.UUCP (roberto divia)
Newsgroups: comp.sys.m68k
Subject: Re: 68882 Exception Handling
Keywords: 68882, exceptions, floating point
Message-ID: <1641@cernvax.UUCP>
Date: 13 Mar 90 11:14:10 GMT
References: <1990Mar12.222857.19372@sctc.com>
Distribution: comp
Organization: CERN, European Laboratory for Particle Physics
Lines: 16

In article <1990Mar12.222857.19372@sctc.com> briel@sctc.com (Marc Briel ) writes:
>The manual states that FSAVE/FRESTORE must be performed on entry/exit
>for any exception or interrupt regardless of whether it if FPU related
>or not. Is this an absolute requirement or just an easy way to solve
>an otherwise complex problem?
>
>I have performance concerns and would like to avoid time consuming
My opininion is that the FSAVE/FRESTORE is needed only if the interrupt service
routine/exception handler uses the coprocessor. Also, you are forced to reset
the coprocessor if the exception handler will not execute a "clean" return. For
"normal" interrupt service routines, the coprocessor can be ignored.
-- 
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