
Apple facing huge chip patent bill after losing case - jnord
http://www.bbc.com/news/technology-34524785
======
devit
Looks like the "idea" of the patent in the description is to use a predictor
to predict when a STORE and LOAD alias and not speculate the LOAD and any
instruction depending on the load (although the claims generalize this to any
non-static dependency).

As it generally happens in software/hardware patents, the claimed solution
seems quite obvious whenever one wants to solve that particular problem, and
the hard part is the "execution", i.e. implementing it efficiently and
figuring out whether the tradeoffs are worth it.

So assigning patents to things like this seems really dumb.

~~~
roc
Luckily, patents aren't granted for ideas, but for specific executions.
Granted, the execution is generally defined at a higher level than, say, "this
exact chunk of silicon". But it's at a much lower level than the "idea".

~~~
Tloewald
When it comes to digital technology patents are often granted for ideas or
concepts so general as to be ridiculous. Whether those patents stand up in
court is another thing but even there -- as in this case -- there are no
guarantees of sanity. I hope Apple will appeal.

~~~
baldfat
The more general and broad the patent the more valuable it is. The system
rewards big general patents.

------
rayiner
This PDF explains what I discuss below in more detail:
[http://moodle.technion.ac.il/pluginfile.php/315285/mod_resou...](http://moodle.technion.ac.il/pluginfile.php/315285/mod_resource/content/1/tutorial3_winter_2013.pdf).
Prediction of aliasing is discussed on slide 25.

The patent in question pertains to an optimization of what these days you'd
call "memory disambiguation." In a processor executing instructions out of
order, data dependencies can be known or ambiguous. A known data dependency
is, for example, summing the results of two previous instructions that
themselves each compute the product of two values. An ambiguous data
dependency is usually a memory read after a memory write. The processor
usually does not know the address of the store until it executes the store. So
it can't tell whether a subsequent load must wait behind the store (if it
reads from the same address), or can safely be moved ahead of it (if it reads
from a different address).

If you have the appropriate machinery, you can speculatively execute that
later load instruction. But you need some mechanism to ensure that if you
guess wrong--that subsequent load really does read from the same address as
the earlier store--you can roll back the pipeline and re execute things in the
correct order.

But flushing that work and replaying is slow. If you've got a dependent store-
load pair, you want to avoid the situation where misspeculation causes you to
have to flush and reply every time. The insight of the patent is that these
dependent store-load pairs have temporal locality. Using a small table, you
can avoid most misspeculations by tracking these pairs in the table and not
speculating the subsequent load if you get a table hit. That specific use of a
prediction table is what is claimed by the patent.

Maybe this is worth a patent, or maybe not. For what it's worth, I don't think
anybody was doing memory disambiguation at all in 1996. Intel was one of the
first (maybe the first) to do so commercially in the mid-2000's. Apple's
Cyclone architecture also does it, and I think it was the first in the low-
power SoC space to do it.

~~~
mzs
Alpha 21264 (also from '96) had load store buffers that would notice the
dependence violations and flush the pipeline during speculative execution.
Sparc and power also had this to some extent with write buffers. I can't think
of any that used a predictor though to decide whether to execute speculatively
or not back then, they all just either did or stalled on the first potential
violation. The patent appears novel for the time to me, thank you for digging
it up and explaining.

~~~
rayiner
DEC was working on it, allegedly for EV8:
[https://www.cis.upenn.edu/~cis501/papers/store-
sets.pdf](https://www.cis.upenn.edu/~cis501/papers/store-sets.pdf). They cite
to the inventor of the patent in question: "Independently, Moshovos et al.
published a comprehensive description of memory dependence prediction. This is
the first published work identifying that memory dependencies are problematic
for out-of-order machines."

~~~
mzs
That's a great paper and insight, thanks again.

------
msravi
UWisc has always been very aggressive with its patents. I recall sometime
during 2002 or thereabouts, while working for a reasonably big semiconductor
company with DSP/ARM processors, one of the guys in our team with an interest
in computer architecture, used the company network to download and play with a
simulator or something (might have been simplescalar). A few weeks later the
head of our group gets contacted by the company lawyers saying that UWisc was
asking for licensing costs for using their tools (they provided the ip address
that was used to download the tools). I'm not sure how it was resolved
finally, but I don't think the company paid.

------
DannyBee
In general, I welcome the day when universities get what is coming to them for
this kind of stuff (see also: Marvell vs CMU for 300+ million, reduced from
1.5 billion on appeal, etc).

In particular, given how much industry funds them, collaborates with their
professors, etc, what is going on now is a _remarkably stupid_ approach mostly
driven by tech transfer offices that want to prove their value.

Which will be "zero", once the tech industry starts cutting them off.

~~~
mentat
You think they're funding researchers at market rates?

~~~
DannyBee
Do you think the universities would really be getting _anywhere_ without the
help of the industries they are now pissing on?

Take away the faculty awards, industry collaborations, donated labs, donated
computing time, hiring of interns, etc.

------
Kristine1975
>The University of Wisconsin–Madison is a public research university

So it's a university [mainly] funded by the tax-payer. How can it be that the
research of this university isn't in the public domain? The public paid for
it, the public should reap the benefits without paying again.

Sure, Apple tries their hardest not to pay taxes, but the patent isn't limited
to them.

~~~
bpodgursky
> So it's a university [mainly] funded by the tax-payer

This is not true, at least for most states. For example, the UW system got 1.2
Billion from the state out of a 6 Billion dollar budget:
[https://www.wisconsin.edu/about-the-uw-
system/](https://www.wisconsin.edu/about-the-uw-system/)

The large majority of most state university funding comes through tuition,
research grants, and donations.

~~~
fisherjeff
Well the majority of tuition funding is on loan from the federal government
and I'm sure a big chunk of that grant money comes from DARPA, NSF, NIH, etc.

That's not necessarily to say their work should be in the public domain but it
would still be nice to see them focus on more productive uses of their IP
rather than just license fee extraction.

~~~
bpodgursky
The federal government generally makes a profit on student loans -- (most of
them) get paid back eventually.

~~~
fisherjeff
True. My point was more that their budget would look very different if not for
federal guarantees on those (relatively risky) loans.

------
ctz
Patent in question:
[http://www.google.co.uk/patents/US5781752](http://www.google.co.uk/patents/US5781752)

~~~
trengrj
"Table based data speculation" \- so a lookup table?? Would be interested in
knowing how innovative the patent is from someone with more knowledge in this
field.

~~~
timthorn
Bear in mind the patent was filed in 1996 when considering the level of
innovation.

~~~
masklinn
There were branch-predicting mainframes back in the 80s, though it really came
to the fore with the advent of superscalar microprocessors in the early 90s
(MIPS R8000 and DEC Alpha 21064), what is the paper's innovations above these?

~~~
matthewmacleod
It's pretty clear from even a cursory look – the patent covers a second level
of branch prediction, where the processor determines whether or not it should
bother speculatively executing an instruction based on the previous outcome of
that speculative execution.

Whether or not there was a prior implementation of this, I don't know – but
it's also obviously more than a simple saturating counter branch predictor or
whatever.

~~~
sitkack
[http://www.theonion.com/blogpost/fuck-everything-were-
doing-...](http://www.theonion.com/blogpost/fuck-everything-were-doing-five-
blades-11056)

So inductive patent expansion. Take previous innovation, add 1, profit.

What about L0 and L4 caches? Or Renaming sets of renamed registers? The
problem as others have outlined, that patents are not concrete enough. Simply
describing a problem is enough to be granted a patent. The value of the
description of most patents is zero, which afaik this opposite of their
intended effect as a record and transfer of technology.

~~~
oldmanjay
The blithe dismissal of the value incremental improvement doesn't make you
look smarter.

~~~
sitkack
Thanks for the bespoke advice.

------
monochromatic
How is this journalism? It doesn't even tell you the damn patent number.

~~~
DanBC
At the top of the gray bar there's a "Contact BBC News" link. (Not the
"contact us" link at the very bottom of the page.)

For this article it's here:
[http://www.bbc.co.uk/news/20039682](http://www.bbc.co.uk/news/20039682)

Please do let them know that they need to start linking, or at least naming,
documents that they're talking about. They do it all the time and I agree it's
annoying. They'll discuss a medical study and not have any links to it.
Sometimes they don't even name the report nor where it appeared.

~~~
talmand
When I see examples of that my nature is to immediately question the validity
of the story.

------
skaevola
I'm curious how the university could discover that Apple was using its patent.
The internal characteristics of the processor must be secret, right? Do they
examine die photos and reconstruct the gate netlist?

~~~
brudgers
[IANAL]

There's a discovery process for civil cases.

~~~
skaevola
So the university goes through this process with all semiconductor companies
that are developing processors, just to be sure that they're not infringing?

------
DannoHung
I have one question: Do the professors teach this technique in classes?

I mean, that'd be funny, right? Teaching students something that you patented,
waiting a few years for them to go into industry and apply what they learned,
then suing them for it.

------
bitmapbrother
I have no sympathy for Apple in this matter. Considering the worthless, prior
art ridden patents they used against their competitors they deserve the
blowback. And in keeping with their modus operandi they ignored the University
of Wisconsin and wilfully infringed the patent.

~~~
TheOtherHobbes
UW should take the money and use it to endow a chair of processor engineering.

Or maybe a table of processor engineering. That could work too.

------
abluecloud
$862m isn't that huge in the grand scheme of things. Not to mention, it's most
likely _not_ going to be $862m, my guess is it'll be less.

~~~
brownegg
If it's $862m, last I checked, it will take them about 30 hours to bring in
the necessary revenue--if they want to pay out of profits (I'm totally
guessing here, what are real net margins on their hardware? 15-20%?), it'll
take a couple days.

~~~
bshimmin
Man, that's such a humbling stat. Many of us here don't even earn that in a
_year_!

~~~
chucknelson
$862 million?

> Man, that's such a humbling stat. Many of us here don't even earn that in a
> _lifetime_!

FTFY

Unless I missed the /s ;)

~~~
delecti
Even more exaggerated than that. Many families don't earn that across several
generations. That's about 17,000 years at $50,000/year. At 40 years of working
life, you'd need over 400 people.

~~~
beeboop
The combined income earned by anyone in the entirety of history who is the
least bit related to me, adjusted for PPP, probably does not equal $800MM+.

------
dba7dba
$862m? Isn't that little bit less than what Samsung paid to Apple?

I tell ya, this tech news stuff is sometimes more entertaining than
infotainment on TV.

------
cozzyd
Awesome, maybe the Brewers need a new stadium too.

------
bwilliams18
What if patents could only be held by individuals and not corporations?

~~~
viewer5
And then the individuals would grant use licenses to the corporations, so they
can implement the process/manufacture the good/etc?

~~~
rhino369
That is essentially how it works now actually. The patent has to be awarded to
an inventor (or more than one) who is a natural person. But they initially
assign it to a company, when it's done by someone working for that company.

------
werber
I don't get how they settled out of court and then did it again, that seems
really bizare.

~~~
dtech
Settled with a different company.

~~~
monochromatic
Article says it was UW in both cases.

edit: disregard, I don't read good

~~~
msbarnett
UW holds the patent.

UW sued Intel. This lawsuit was settled.

UW then sued Apple. A different company.

Why would the fact that the suit with Intel was settled impact their ability
to sue Apple? What's the source of confusion here?

~~~
monochromatic
Whoops, I can't read this morning.

------
propter_hoc
This is sort of a depressing precedent. Do we really want to turn our
universities into patent trolls?

~~~
galilyou498
If they are trolling other patent trolls, then why not?

~~~
danbee
Two wrongs don't make a right.

~~~
ChrisLTD
A self-destructive spiral might spur legislative action.

------
mtgx
You know what they say: Live by the patent sword...

Why doesn't Apple start lobbying for real patent reform?

~~~
rwmj
Because it makes no sense for them to do so. Large companies join in cross-
licensing agreements, keeping smaller competitors out. Occasionally some small
player comes along with an important patent, and they refuse to be bought off
and win in court. That makes the news like today because it happens so rarely.
But it's a price worth paying to keep competition out of the market.

Competition is so tedious.

~~~
dtech
This isn't a small company with a new idea that doesn't want to be bought out,
this is an university.

