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Date: Sun, 19 May 1996 04:48:05 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199605181848.EAA11220@godzilla.zeta.org.au>
To: asami@cs.berkeley.edu, bde@zeta.org.au
Subject: Re: some more on fast bcopy
Cc: ccd@stampede.cs.berkeley.edu, current@freebsd.org
Sender: owner-current@freebsd.org
X-Loop: FreeBSD.org
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> * It should work better with a kernel mode trap handler for "FPU not
> * available" :-).  Add a T_DNA case for kernel mode in trap() by copying

>OK, I implemented it.  Will this work?

It seems to work here.

> * Also, the `intr_nesting_level > 0' case needs to preserve the TS bit.
> * This case probably hasn't been executed yet (it will be executed when
> * bcopy() uses fastmove() and an interrupt handler calls bcopy()).

>Oh, really?  I thought it was saved via %edx.

I missed that.  It would probably be cleanest to save it via %edx in
both cases.

I'm running with a fast bzero (8 fstl's in a loop) too.  It is much simpler
than fastmove since it doesn't need to worry about context switches.  bcopy
need not worry either (except for bugs).

Bruce