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From: briel@sctc.com (Marc Briel )
Newsgroups: comp.sys.m68k
Subject: 68882 Exception Handling
Keywords: 68882, exceptions, floating point
Message-ID: <1990Mar12.222857.19372@sctc.com>
Date: 12 Mar 90 22:28:57 GMT
Distribution: comp
Organization: Secure Computing Technology Corporation
Lines: 17


A question on the 68882 Floating Point Coprocessor:

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
FSAVE/FRESTORE operations wherever possible. Does anyone know the
specific cases where save/restore are absolutely required?

				Thank you in advance for any replies,
				
				Marc Briel
				
				Briel@sctc.com