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From: guy@rlgvax.UUCP (Guy Harris)
Newsgroups: net.unix-wizards
Subject: Re: Some hacks I'll share!
Message-ID: <1804@rlgvax.UUCP>
Date: Sun, 11-Mar-84 02:33:50 EST
Article-I.D.: rlgvax.1804
Posted: Sun Mar 11 02:33:50 1984
Date-Received: Mon, 12-Mar-84 04:58:12 EST
References: <98@isrnix.UUCP>
Organization: CCI Office Systems Group, Reston, VA
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		2) A floating point load (double prec. again) 
		   followed by a floating point store is just a weeeee
		   bit faster than the appropriate number of 'mov'
		   instructions (assuming the cache is disabled).
		   I'll bet on the 11/70 you could use floating point
		   load/stores for twice the speed over conventional
		   mov's.

You could use that as long as the Floating Interrupt on Uninitialized
Variable trap is disabled; otherwise, the bit pattern for -0.0 will cause
a trap.  (I assume that the floating load and store don't normalize, as
the "Min" and "Max" times for LDF are the same, which wouldn't be the case
if they normalized - unless there's a barrel shifter in there).

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy