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From: Nate Williams <nate@mt.sri.com>
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To: Bruce Evans <bde@zeta.org.au>
Cc: Nate Williams <nate@mt.sri.com>,
	Marcel Moolenaar <marcel@FreeBSD.org>, cvs-committers@FreeBSD.org,
	cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/i386/include signal.h
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> > > You would restore as necessary to prevent clobbering of local variables
> > > that are stored in registers at the time of the longjmp.
> > 
> > Umm, I thought Marcel's comment was that we would be now supporting
> > floating point context.  In that case, then we should restore the FP
> > state, shouldn't we?  What else would be necessary to support FP state?
> 
> Supporting floating point in signal handlers will allow less restoring/
> resetting of FP state in setjmp()/longjmp().  Now, on i386's, the FP state
> is undefined in signal handlers, and to make longjmp() from signal handlers
> sort of work we reset to a default state, except we restore the FP control
> word to its value at the time of the setjmp().  When the state is set to a
> default for signal handling, the reset/restore will be unnecessary.

Great, thanks for the clarification...


Nate


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