9 ms·

The Lexra/MIPS Story

130 points by luu 10y ago

nickpsecurity 10y ago
This is interesting for those of us interesting in squeezing what we can out of older nodes for lower, dev costs or verifiability. Their CPU's did quite a bit for push-button synthesis. The Stream processor linked had impressive capabilities for 130nm. I'm bookmarking it in case it is useful in future. I was thinking the I.P. might still be useful depending on acquirer until I saw the name: MIPS Technologies Inc. (sighs) I doubt they'll play ball. So, now I think of using its tricks in a RISC-V CPU instead. ;)
bitwize 10y ago
> An instruction set is a language of commands given to a machine. Nobody can patent, copyright, or otherwise own a language or an instruction set. This is wrong. Intel owns patents which protect the Itanium ISA. Non-Intel Itanium implementations would infringe on the patents, not that anyone would want to make one.
- PeCaN 10y ago
  Intel also has patents on many x86_64 extensions and AMD has patents on x86_64 itself. I believe MMX expired recently, so a Pentium III level CPU could be implemented without infringing on ISA patents. Hitachi still has patents on SH4 (though they expire this year). IBM has patents on POWER8. Oracle and Fujitsu have patents on SPARC. etc. Incidentally, I believe HP also owns some of the Itanium patents.
- new299 10y ago
  I'd love to see a detailed write-up on how an ISA is protected. I've never really understood what protects the x86 instruction set. I'd always assumed there were patents covering implementation details which would make an effective implementation extremely difficult. Can you really patent a list of instructions?
  - Taniwha 10y ago
    Intel's ISA is protected by fear of its army of lawyers, something from which no small company could (financially) survive a head on attack. I worked on an x86 clone 20 years back, we analysed Intel's patents in depth to make sure we were safe, the biug one for us was Intel's segmentation/MMU patent - they essentially had patented segmentation followed by (unrelated) mmu processing - there was obvious prior art (cough 360, cough) but that's a bit of crap shoot, I came up with a brilliant way around this, only to discover a patent from someone else in the process of doing an x86 clone (Exponential I think). In the end we conflated our segmentation hardware and our TLBs effectively bypassing the core of Intel's patent You can't patent a list of instructions, you can copyright a bunch of mnemnomics
    - new299 10y ago
      That's really interesting thanks! I wonder if the army of lawyers protection also holds for ARM. Or perhaps there licenses are cheap enough that people don't care.
- willvarfar 10y ago
  The article explains: > Though you can not patent an instruction set, you can patent machines and methods that are necessary to implement a particular unusual instruction that is part of the instruction set. That legally blocks competitors from creating a fully compatible clone of your processor. The author is making a very clear and correct distinction. It continues: > There are four instructions in the MIPS-I instruction set that were protected by one US patent, 4,814,976. These instructions, lwl, lwr, swl, and swr are known as the unaligned load and store instructions.
asb 10y ago
Given the discussion of patents and instruction sets, you may be interested in the work of David Patterson and his student Tony Chen in tracking prior at of all RISC-V instructions http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-6.html http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-6....
hajile 10y ago
The biggest issues of the case to me were that MIPS believed that hardware patents cover software emulation and (even assuming that the first case is true) that Lexra could somehow be held responsible for software companies choosing to infringe. It's like holding a car manufacturer responsible because a driver decided to head into oncoming traffic. I don't understand why these cases weren't immediately thrown out as the garbage they were. MIPS wasn't a mega-corp like Samsung or Apple which can bring lots of pressure on the system. Why did the court make such a boneheaded decision on appeal?
- revelation 10y ago
  It seems the biggest issue is that you can patent "unaligned loads" in a way that covers both a hardware instruction and software fault handler. These are very different things. The software fault handler doesn't even do unaligned loads, naturally.
  - angersock 10y ago
    As I understand it, patents cover results and not so much mechanisms. It's just that people tend to listen the intermediate results in such detail as to appear that they cover mechanisms. Which is, of course, fucking insane, but nobody seems to want to act on that.
    - jakub_h 10y ago
      If it covers results, what about the virtual ISAs that allow you to load data from any address of a byte-adressed memory and their implementations include optimizations?
    - rayiner 10y ago
      The patent doesn't cover the result of an unaligned load. It covers the specific mechanism of doing an unaligned load using two instructions and a shifter to get the two pieces into the right place in the target register. You can read the claims here: https://www.google.com/patents/US4814976 https://www.google.com/patents/US4814976.
Artlav 10y ago
In the end, patents only ensure that good things go down the toilet. Why do companies continue making them?
- dkarapetyan 10y ago
  Same reason nations stockpile nuclear weapons.
  - wolfgke 10y ago
    There is a serious social movement in society against nuclear armament/for nuclear disarmament (in Germany at the beginning of the 80th this even lead to the founding of a completely new party). On the other hand there is no strong social movement against patents.
    - jdub 10y ago
      Sure there is, but it's quite reasonably smaller and/or less visible than a social movement standing against a fundamental existential threat.
- deleted 10y ago
  [deleted]
zackmorris 10y ago
Computer Organization and Design by Patterson and Hennessy is still sitting on my shelf, saved from my computer engineering classes at UIUC. It's probably the closest thing I have to a definitive source on the hard limits faced in processor design. IMHO since I graduated in 1999 there has been almost no innovation in processor cores, and in fairness, maybe there couldn’t have been (as the limits were well understood by then). Instead the industry opted to go with smaller and smaller features which led to skyscraper interconnects that act as much like transmission lines as wires, with deep pipelines and large areas of the chip devoted to branch prediction, large percentages of chip area devoted to cache, niche processing units like GPUs on-chip rather than general purpose DSP for multiprocessing, obfuscated microcode rather than RISC, just layers and layers of cruft that were driven more by demands for single-threaded performance and low power consumption than innovation for its own sake. So it shouldn’t be any real surprise that Moore’s law died somewhere around 2005, give or take. Computers today are still the 3 MHz they were then, transistor counts have gone up but real-world performance has increased mostly due to faster DDR and SSD, not faster cores. To get an idea of how far behind CPUs have fallen, just look at the throughput of any video card vs, say, a Core i7. We’re talking 3 orders of magnitude better performance for GPUs, about what a decade and a half of compounded transistor count for a multicore architecture would predict. So it saddens me that there never really were other competitors to CISC for consumers. I wonder if something like an ARM or AMD with a MIPS instruction set aiming for more cores like the Teraflops or Kilocore that ran OpenGL (and TensorFlow and other AI libs had they existed) natively might have done for computing back in the day. But it was a strange time in history after the Dot Bomb. The carpet got pulled out of research at a time when it was perhaps needed most. Everyone had to pull themselves up by their bootstraps and we all became entrepreneurs instead of engineers. Maybe that’s a good thing, maybe it’s not, I don’t really know. But I do know that we’ve had about a 15 year setback in computing and we are roaming the desert of informal methods on some kind of walkabout or vision quest to see where it’s all headed. Personally, I don’t see any future here if we don’t fix the fundamental problems in patents and intellectual property. It’s fun and everything to be hip about technology but at the end of the day someone has to push the state of the art forward. I know precisely what I want: as many general purpose cores as possible running as fast as possible with a self-organizing interconnect to as many other computers as possible so I can run the simulations I thought we’d be running by now. I want a stream to that computer, no fancy libraries in my way, no proprietary OS. I want to program it with MATLAB, Erlang, Go, Clojure Haskell, Scala, etc etc etc. I don’t want CUDA, I don’t want to have to lease time from the cloud, I don’t want to have to depend on the largess of billion dollar companies’ research programs to innovate in AI. I may have forgotten the details of how to achieve these things but I haven’t forgotten the original dream of ever-cheaper transistors giving every person access to a supercomputer and eventually R2D2. We’ve scaled data but we simply haven’t scaled processing.
dkarapetyan 10y ago
I think this is why humans fail. I think we'd be much further along if the kind of short term mindset driven by short term business goals outlined in this article were the exception instead of the rule. Patents in software and hardware design should not exist at all given the mathematical and physical underpinning of both disciplines. There is creativity involved and the original inventors should get due credit but not to the point of being able to sue an equally good competitor with equally good inventors into oblivion. Everyone is worse off because of what happened here.
- rayiner 10y ago
  There isn't some abstract mathematical truth at issue in the MIPS patents, but a clever way of doing unaligned loans in an otherwise word-oriented machine. And the value of the patent isn't "giving inventors credit" but instead enabling a particular sort of business model: the R&D-only company. None of the companies discussed in the article: MIPS, Lexra, and ARM, would exist without IP protection. They'd never make any money if companies could just copy their designs for free. The only viable model would be to vertically integrate and build complete processors like Intel does. And that probably would've made it impossible to build up the rich ecosystem of compatible cores that you see with ARM.
  - dkarapetyan 10y ago
    The issue is that given two hardware engineers both of them would have come up with the same clever design. In fact I'm almost certain this could be posed as a constraint satisfaction problem and I could even get a SAT solver to come up with the same design. The mathematical constraints basically force the design. So I disagree with you. It is indeed an abstract truth. The foundations are axiomatic. There are only so many theorems (clever tricks) you can come up with given the foundation. The law overstepped because of fundamental misunderstandings of how the engineering, theory, and practice are combined in something like software and hardware design. I also did not say there shouldn't be limited forms of protection to enable the license based business model but being able to outmaneuver your competitor legally instead of through proper design and engineering is why progress is hampered and why the patent model is fundamentally broken.
cia48621793 10y ago
After that where did the disbanded engineers went? Intel?

130 points by luu 10y ago

This is interesting for those of us interesting in squeezing what we can out of older nodes for lower, dev costs or verifiability. Their CPU's did quite a bit for push-button synthesis. The Stream processor linked had impressive capabilities for 130nm. I'm bookmarking it in case it is useful in future. I was thinking the I.P. might still be useful depending on acquirer until I saw the name: MIPS Technologies Inc. (sighs) I doubt they'll play ball. So, now I think of using its tricks in a RISC-V CPU instead. ;)

bitwize 10y ago

> An instruction set is a language of commands given to a machine. Nobody can patent, copyright, or otherwise own a language or an instruction set. This is wrong. Intel owns patents which protect the Itanium ISA. Non-Intel Itanium implementations would infringe on the patents, not that anyone would want to make one.

PeCaN 10y ago
Intel also has patents on many x86_64 extensions and AMD has patents on x86_64 itself. I believe MMX expired recently, so a Pentium III level CPU could be implemented without infringing on ISA patents. Hitachi still has patents on SH4 (though they expire this year). IBM has patents on POWER8. Oracle and Fujitsu have patents on SPARC. etc. Incidentally, I believe HP also owns some of the Itanium patents.
new299 10y ago
I'd love to see a detailed write-up on how an ISA is protected. I've never really understood what protects the x86 instruction set. I'd always assumed there were patents covering implementation details which would make an effective implementation extremely difficult. Can you really patent a list of instructions?
- Taniwha 10y ago
  Intel's ISA is protected by fear of its army of lawyers, something from which no small company could (financially) survive a head on attack. I worked on an x86 clone 20 years back, we analysed Intel's patents in depth to make sure we were safe, the biug one for us was Intel's segmentation/MMU patent - they essentially had patented segmentation followed by (unrelated) mmu processing - there was obvious prior art (cough 360, cough) but that's a bit of crap shoot, I came up with a brilliant way around this, only to discover a patent from someone else in the process of doing an x86 clone (Exponential I think). In the end we conflated our segmentation hardware and our TLBs effectively bypassing the core of Intel's patent You can't patent a list of instructions, you can copyright a bunch of mnemnomics
  - new299 10y ago
    That's really interesting thanks! I wonder if the army of lawyers protection also holds for ARM. Or perhaps there licenses are cheap enough that people don't care.
willvarfar 10y ago
The article explains: > Though you can not patent an instruction set, you can patent machines and methods that are necessary to implement a particular unusual instruction that is part of the instruction set. That legally blocks competitors from creating a fully compatible clone of your processor. The author is making a very clear and correct distinction. It continues: > There are four instructions in the MIPS-I instruction set that were protected by one US patent, 4,814,976. These instructions, lwl, lwr, swl, and swr are known as the unaligned load and store instructions.

asb 10y ago

Given the discussion of patents and instruction sets, you may be interested in the work of David Patterson and his student Tony Chen in tracking prior at of all RISC-V instructions http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-6.html http://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-6....

hajile 10y ago

The biggest issues of the case to me were that MIPS believed that hardware patents cover software emulation and (even assuming that the first case is true) that Lexra could somehow be held responsible for software companies choosing to infringe. It's like holding a car manufacturer responsible because a driver decided to head into oncoming traffic. I don't understand why these cases weren't immediately thrown out as the garbage they were. MIPS wasn't a mega-corp like Samsung or Apple which can bring lots of pressure on the system. Why did the court make such a boneheaded decision on appeal?

revelation 10y ago
It seems the biggest issue is that you can patent "unaligned loads" in a way that covers both a hardware instruction and software fault handler. These are very different things. The software fault handler doesn't even do unaligned loads, naturally.
- angersock 10y ago
  As I understand it, patents cover results and not so much mechanisms. It's just that people tend to listen the intermediate results in such detail as to appear that they cover mechanisms. Which is, of course, fucking insane, but nobody seems to want to act on that.
  - jakub_h 10y ago
    If it covers results, what about the virtual ISAs that allow you to load data from any address of a byte-adressed memory and their implementations include optimizations?
  - rayiner 10y ago
    The patent doesn't cover the result of an unaligned load. It covers the specific mechanism of doing an unaligned load using two instructions and a shifter to get the two pieces into the right place in the target register. You can read the claims here: https://www.google.com/patents/US4814976 https://www.google.com/patents/US4814976.

Artlav 10y ago

In the end, patents only ensure that good things go down the toilet. Why do companies continue making them?

dkarapetyan 10y ago
Same reason nations stockpile nuclear weapons.
- wolfgke 10y ago
  There is a serious social movement in society against nuclear armament/for nuclear disarmament (in Germany at the beginning of the 80th this even lead to the founding of a completely new party). On the other hand there is no strong social movement against patents.
  - jdub 10y ago
    Sure there is, but it's quite reasonably smaller and/or less visible than a social movement standing against a fundamental existential threat.
deleted 10y ago
[deleted]

zackmorris 10y ago

Computer Organization and Design by Patterson and Hennessy is still sitting on my shelf, saved from my computer engineering classes at UIUC. It's probably the closest thing I have to a definitive source on the hard limits faced in processor design. IMHO since I graduated in 1999 there has been almost no innovation in processor cores, and in fairness, maybe there couldn’t have been (as the limits were well understood by then). Instead the industry opted to go with smaller and smaller features which led to skyscraper interconnects that act as much like transmission lines as wires, with deep pipelines and large areas of the chip devoted to branch prediction, large percentages of chip area devoted to cache, niche processing units like GPUs on-chip rather than general purpose DSP for multiprocessing, obfuscated microcode rather than RISC, just layers and layers of cruft that were driven more by demands for single-threaded performance and low power consumption than innovation for its own sake. So it shouldn’t be any real surprise that Moore’s law died somewhere around 2005, give or take. Computers today are still the 3 MHz they were then, transistor counts have gone up but real-world performance has increased mostly due to faster DDR and SSD, not faster cores. To get an idea of how far behind CPUs have fallen, just look at the throughput of any video card vs, say, a Core i7. We’re talking 3 orders of magnitude better performance for GPUs, about what a decade and a half of compounded transistor count for a multicore architecture would predict. So it saddens me that there never really were other competitors to CISC for consumers. I wonder if something like an ARM or AMD with a MIPS instruction set aiming for more cores like the Teraflops or Kilocore that ran OpenGL (and TensorFlow and other AI libs had they existed) natively might have done for computing back in the day. But it was a strange time in history after the Dot Bomb. The carpet got pulled out of research at a time when it was perhaps needed most. Everyone had to pull themselves up by their bootstraps and we all became entrepreneurs instead of engineers. Maybe that’s a good thing, maybe it’s not, I don’t really know. But I do know that we’ve had about a 15 year setback in computing and we are roaming the desert of informal methods on some kind of walkabout or vision quest to see where it’s all headed. Personally, I don’t see any future here if we don’t fix the fundamental problems in patents and intellectual property. It’s fun and everything to be hip about technology but at the end of the day someone has to push the state of the art forward. I know precisely what I want: as many general purpose cores as possible running as fast as possible with a self-organizing interconnect to as many other computers as possible so I can run the simulations I thought we’d be running by now. I want a stream to that computer, no fancy libraries in my way, no proprietary OS. I want to program it with MATLAB, Erlang, Go, Clojure Haskell, Scala, etc etc etc. I don’t want CUDA, I don’t want to have to lease time from the cloud, I don’t want to have to depend on the largess of billion dollar companies’ research programs to innovate in AI. I may have forgotten the details of how to achieve these things but I haven’t forgotten the original dream of ever-cheaper transistors giving every person access to a supercomputer and eventually R2D2. We’ve scaled data but we simply haven’t scaled processing.

dkarapetyan 10y ago

I think this is why humans fail. I think we'd be much further along if the kind of short term mindset driven by short term business goals outlined in this article were the exception instead of the rule. Patents in software and hardware design should not exist at all given the mathematical and physical underpinning of both disciplines. There is creativity involved and the original inventors should get due credit but not to the point of being able to sue an equally good competitor with equally good inventors into oblivion. Everyone is worse off because of what happened here.

rayiner 10y ago
There isn't some abstract mathematical truth at issue in the MIPS patents, but a clever way of doing unaligned loans in an otherwise word-oriented machine. And the value of the patent isn't "giving inventors credit" but instead enabling a particular sort of business model: the R&D-only company. None of the companies discussed in the article: MIPS, Lexra, and ARM, would exist without IP protection. They'd never make any money if companies could just copy their designs for free. The only viable model would be to vertically integrate and build complete processors like Intel does. And that probably would've made it impossible to build up the rich ecosystem of compatible cores that you see with ARM.
- dkarapetyan 10y ago
  The issue is that given two hardware engineers both of them would have come up with the same clever design. In fact I'm almost certain this could be posed as a constraint satisfaction problem and I could even get a SAT solver to come up with the same design. The mathematical constraints basically force the design. So I disagree with you. It is indeed an abstract truth. The foundations are axiomatic. There are only so many theorems (clever tricks) you can come up with given the foundation. The law overstepped because of fundamental misunderstandings of how the engineering, theory, and practice are combined in something like software and hardware design. I also did not say there shouldn't be limited forms of protection to enable the license based business model but being able to outmaneuver your competitor legally instead of through proper design and engineering is why progress is hampered and why the patent model is fundamentally broken.

cia48621793 10y ago

After that where did the disbanded engineers went? Intel?