Re: Intel microcode fixes [A GOOD WAY OFF-TOPIC]

Adam D. Bradley (artdodge@cs.bu.edu)
Sat, 21 Nov 1998 13:37:39 -0500 (EST)


On Fri, 20 Nov 1998, Simon Kenyon wrote:

> On 19-Nov-98 doctor@fruitbat.org wrote:
> > Think of how the Intel Floating Point Bug would have been a
> > non-issue if Pentiums were microcode upgradable?
>
> i think that was a bad example to pick
> the floating point bug was (i believe) caused by crosstalk
> no amount of re-microcoding could have fixed that!

(Pulling out my computer architecture notes from spring '95...)

That bug was caused by a few incorrect border cases in the lookup table
used by the SRT radix-4 division module. 5 incorrect entries, to be
precise, where a quotient of 0 was returned instead of +2.

Are you thinking of another pentium bug? ;-)

Adam

--
You crucify all honesty             \\Adam D. Bradley  artdodge@cs.bu.edu
No signs you see do you believe      \\Boston University Computer Science
And all your words just twist and turn\\    Grad Student and Linux Hacker
Reviving just to crash and burn        \\                             <><
--------->   Why can't you listen as love screams everywhere?   <--------

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