[HN Gopher] Open-source high-performance RISC-V processor
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Open-source high-performance RISC-V processor
Author : burakemir
Score : 227 points
Date : 2023-03-26 10:32 UTC (12 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| rwmj wrote:
| The license in case anyone was wondering:
| https://spdx.org/licenses/MulanPSL-2.0.html Seems BSD-ish and it
| is approved by OSI: https://opensource.org/license/mulanpsl-2-0/
| eyyheidihfvv wrote:
| [flagged]
| eyyheidihfvv wrote:
| [flagged]
| artemonster wrote:
| are there any books to learn about advanced cpu design with
| dispatch queues, microop schedulers, etc. the most I could find
| would cover basics of CPU design, not advanced stuff.
| DeathArrow wrote:
| If China manages to reduce its dependency of US based tech like
| CPUs, I wonder how this will affect the two economies.
|
| Would it be a viable idea to buy shares in China based tech
| companies now? The thinking is that if CCP pushes something real
| hard by investing large amounts of resources in it, the chances
| are higher that they will succeed. Not tomorrow but in 10 or 20
| years. Conversely, if US based tech companies will have
| competition, it is likely that their value will go down a bit at
| one point.
|
| Also, it's possible that if China builds domestic silicon tech we
| will see a race to the bottom if they will want to aggressively
| price their products and try to undercut their competitors. Then
| it might be a bad idea to own any shares in tech companies, no
| matter where they are located.
| bee_rider wrote:
| Competition is good, if the US and China end up competing to
| make more interesting CPUs, everybody wins. We're wasting a lot
| of good brains in the US on ad companies and food delivery
| apps, a real competitor to focus our attention would be great,
| in my opinion.
| DeathArrow wrote:
| I never looked at it in good/bad terms, but you are,
| probably, right.
|
| I was more interested in terms of investment.
| tiedieconderoga wrote:
| >Conversely, if US based tech companies will have competition,
| it is likely that their value will go down a bit at one point.
|
| Keep thinking. If US tech firms don't have much competition
| right now, they are not incentived to innovate or improve their
| products. If they had more competition, they would need to put
| up or shut up, rather than reaping profits from money they
| might otherwise spend on R&D.
|
| Personally, I think that if you put competitive pressure on a
| large and lazy incumbent, they will either increase in value or
| fold outright. (Or convince politicians to bail them out, write
| protectionist legislation, etc.)
| DeathArrow wrote:
| Yes, US companies will have the incentive to innovate and
| better themselves. But my question is just about the material
| outcomes: how will the shares of US and China based companies
| be affected.
| still_grokking wrote:
| One more thing to consider: The new iron curtain, now called
| "sanctions".
|
| My best guess currently would be that the US will try to outlaw
| the competing market should one arise: The US will just forbid
| its people and the people in the allied countries to make
| business with China, like they do with a lot of other
| countries, like Russia or Iran.
|
| It's unlikely this would happen immediately as the US is
| currently still depended on China. But as the economic war
| intensives walling-off will happen at some point. There are
| already "sanctions" in place against Chinese companies in some
| market areas. This will likely only worsen over time.
|
| You can still invest in China, sure. But you will be forced to
| move there at some point, or loss everything over there, I
| guess.
| delusional wrote:
| It's important to also consider how much you trust the CCP to
| actually pay out your hypothetical shares, should they ever
| become worth anything. It's possible that they may just
| confiscate them (or outlaw foreigners from trading or something
| similar).
| DeathArrow wrote:
| Are there precedents in which they didn't pay out?
| loeg wrote:
| There are examples where the CCP has materially reduced the
| stock price (e.g., by forbidding the company from making a
| profit) after it was marketed to western investors. And the
| typical ownership structure (VIEs) is incredibly fragile.
| As an individual I would not concentrate investment in
| Chinese companies due to CCP risk.
|
| The SEC has this to say:
| https://www.sec.gov/corpfin/disclosure-considerations-
| china-...
|
| > Current regulations in China limit or prohibit foreign
| investment in Chinese companies operating in certain
| industries. For example, there are restrictions on foreign
| ownership of telecommunications companies and prohibitions
| on ownership of educational institutions.[7] To circumvent
| these restrictions, many China-based Issuers form non-
| Chinese holding companies that enter into contractual
| arrangements, intended to mimic direct ownership, with
| Chinese operating companies. Through these contractual
| arrangements, the China-based Issuer is generally able to
| consolidate the Chinese operating company, commonly
| referred to as a variable interest entity or VIE, in its
| financial statements, although whether the China-based
| Issuer maintains legal control of the Chinese operating
| company is a matter of Chinese law. Under this structure,
| the Chinese operating company, in which the China-based
| Issuer cannot hold an equity interest, typically holds
| licenses and other assets that the China-based Issuer
| cannot hold directly.
|
| > These China-based Issuer VIE structures pose risks to
| U.S. investors that are not present in other organizational
| structures. For example, exerting control through
| contractual arrangements may be less effective than direct
| equity ownership, and a company may incur substantial costs
| to enforce the terms of the arrangements, including those
| relating to the distribution of funds among the entities.
| Further, the Chinese government could determine that the
| agreements establishing the VIE structure do not comply
| with Chinese law and regulations, including those related
| to restrictions on foreign ownership, which could subject a
| China-based Issuer to penalties, revocation of business and
| operating licenses, or forfeiture of ownership interests.
|
| > Legal claims, including federal securities law claims,
| against China-based Issuers, or their officers, directors,
| and gatekeepers, may be difficult or impossible for
| investors to pursue in U.S. courts. Even if an investor
| obtains a judgment in a U.S. court, the investor may be
| unable to enforce such judgment, particularly in the case
| of a China-based Issuer, where the related assets or
| persons are typically located outside of the United States
| and in jurisdictions that may not recognize or enforce U.S.
| judgments.
|
| And of course, see Levine on the subject:
|
| https://www.bloomberg.com/news/newsletters/2021-07-07/money
| -...
|
| https://www.bloomberg.com/opinion/articles/2021-08-02/chine
| s...
| DeathArrow wrote:
| Even then, you can make some money by indirectly
| investing in China's tech infrastructure by buying shares
| in a company that will buy and use hardware made in
| China.
| HopenHeyHi wrote:
| > The thinking is that if CCP pushes something real hard by
| investing large amounts of resources in it, the chances are
| higher that they will succeed. Not tomorrow but in 10 or 20
| years.
|
| China's ASML is Years and Years Behind:
| https://www.youtube.com/watch?v=DtOyW-JpJjM
|
| tl;dw - Nope. Can't just throw money at this problem.
| DeathArrow wrote:
| If a Chinese company isn't directly under US sanctions like
| Huawei is they can still use TSMC to fab chips.
| sitkack wrote:
| 28nm can cover the vast majority of chip production needs for
| the next 5-10 years. Most things don't need an advanced node.
|
| By the time SMEE is hitting 5nm, processes for 3d will be
| mature. I wouldn't discount any of this at this point.
| eunos wrote:
| 28nm with multi patterning can go to lower process node.
| SMIC has experience up to 7nm for that. I think early TSMC
| 7nm used DUV.
| mnau wrote:
| SMEE won't be making EUV, it has it's hands full of DUV.
|
| Chinese Academy of Sciences will (a spinoff company for
| commercialization), they publish research papers on EUV and
| so on.
|
| Multiple project are being developed in parallel.
| DeathArrow wrote:
| Yes, I know. I didn't say SMEE will create EUV, I said
| China will. I don't think differentiation between various
| industrial arms of CCP is of importance.
|
| Right now they've made bets on a large scale of different
| technologies. Many of them failed already. Probably they
| will focus on a few and succeed in a not very long time
| scale.
| DeathArrow wrote:
| 28nm is good for everything besides mobile, desktop and
| server which is a huge market.
|
| I guess China will crack EUV in some time.
| TheLocksmith wrote:
| Has somebody compare-able DMips/Mhz numbers for:
|
| * Intel i7-4600U CPU DMips/Mhz (I found about 10 DMips/Mhz)
|
| * RISC-V VRoom = 10.3 DMips/MHz (still in development)
|
| * RISC-V XiangShan = ?
|
| * RISC-V others ?
| sylware wrote:
| with out-of-order and branch predicting CPUs, those metrics are
| highly questionable.
|
| Better "benchmark" real stuff: CPU bound AAA games, etc.
| nine_k wrote:
| Most AAA games have not been ported to RISC-V yet.
|
| But I bet pytorch has been, and also openCV and other
| compute-heavy stuff. (And Doom, of course.)
| mhh__ wrote:
| I'm guessing pytorch probably doesn't branch as much as a
| game.
|
| One of the best "real" Benchmarks is compiling the Linux
| kernel, the issue is that on an emulator/verilog simulator
| that could take a very long time.
| [deleted]
| drmpeg wrote:
| I also use this benchmark for a real world estimate.
| Here's some numbers. For the pretty ginormous Ubuntu
| kernel config for RISC-V, it's 7.5 hours on the HiFive
| Unmatched (at 1.5 GHz) versus 25 minutes cross compiled
| on a E5-1650 V4 Dell box.
| tormeh wrote:
| Tangential, but I'm intrigued to see Chisel having such success.
| Can anyone in the know comment on how it's doing and what impact
| it has in the hardware industry?
| snvzz wrote:
| I understand SiFive uses it heavily.
| jvican wrote:
| Interested in this as well. Also curious how it fares in
| comparison with BlueSpec and other technologies in this space
| (like HardCaml).
| londons_explore wrote:
| Odd choice to do hardware design in scala...
|
| I wasn't aware of any other big players doing this... I suspect
| it will limit the impact this project can have if industry can't
| adopt it easily into existing processes.
| still_grokking wrote:
| Almost all of RISC-V is Scala land!
|
| Scala has actually some stand in HW development and high-
| performance computing. See also https://spatial-lang.org/ which
| is another Scala DSL, this time for accelerators.
|
| Scala in general is a much underrated language. One of the most
| powerful high level languages, but with a concise and very
| clean core. Since the new syntax was introduced in version 3 it
| even looks amazingly beautiful.
|
| I know, people (frankly especially here on HN) are repeating
| some FUD about this language, but this are usually issues
| solved a decade ago.
|
| People should really reconsider trying out Scala. Especially
| the new major version 3.
|
| https://virtuslab.com/blog/the-most-common-scala-myths-debun...
| tasuki wrote:
| > Odd choice to do hardware design in scala...
|
| Why? (I know nothing about hardware design, but know a thing or
| two about Scala. All the languages better than Scala are used
| even less than Scala.)
| rapiz wrote:
| It's actually chisel. But github marks it as scala because
| chisel is based on scala.
|
| Other HDL based on scala includes SpinalHDL.
|
| These two HDL are pretty welcomed because of opensource and
| usability. You can find lots of projects in them. Notably
| rocket-chip, which is also in chisel.
| https://github.com/chipsalliance/rocket-chip
|
| They're around for a while but still young and some people are
| pushing for adoption.
| monocasa wrote:
| It is scala. Chisel is just a scala framework. Conceptually
| it's not quite an HDL but instead a scala program that
| metaprograms the actual RTL netlist. So there's no chisel
| compiler other than the standard scala one that comes with
| sbt; you then run the resulting chisel program on your
| computer to generate the netlist.
| phendrenad2 wrote:
| It's scala + a DSL called "chisel" that you write by
| chaining scala keywords and symbols in the right order.
|
| There, solved it once and for all. :)
| georgelyon wrote:
| This is not strictly true anymore as the low-level (FIRRTL)
| compilation is powered by CIRCT
| (http://GitHub.com/llvm/circt) which is built using MLIR
| (part of the LLVM project: https://GitHub.com/llvm/llvm-
| project)
| dkjaudyeqooe wrote:
| It's Chisel < https://www.chisel-lang.org/ > which runs on
| Scala and generates synthesizable Verilog for hardware
| implementation.
|
| It was created and used by the same group that created RISC-V
| so it makes perfect sense.
|
| SiFive, arguably the biggest player in RISC-V, use Chisel to
| design their processors.
| blacklion wrote:
| I wonder, which instruction fusions are implemented, as it is key
| to high-performance RISC-V and the reason not to have conditional
| movs & alike in macro-ISA.
|
| Unfortunately, documentation for Micro-ISA is in Chinese only :-(
| samvher wrote:
| Why is that, that they are key to performance with RISC-V? And
| why are they the reason not to have conditional moves? Would
| love to know more!
| jabbany wrote:
| Frankly, these days machine translation is more than enough to
| reproduce most technical documents at an acceptably high level
| of accuracy.
|
| Fwiw, this is the relevant link: https://xiangshan-
| doc.readthedocs.io/zh_CN/latest/frontend/d...
| karasoft wrote:
| [dead]
| rapiz wrote:
| This is part of China's effort to have its own IC industry. The
| project is now owned by BOSC, Beijing Open Source Chip Research
| Instiutute[1]
|
| [1] https://www.bosc.ac.cn/yjyjs
| RobotToaster wrote:
| It's impressive how quickly they seem to have embraced open
| source.
| pstoll wrote:
| You mean the "contributing" part of OSS?
| RobotToaster wrote:
| Well, yes.
|
| I was more talking about the government though, which isn't
| otherwise famous for it's love of openness. I'm not aware
| of any government currently promoting FOSS/FOSH as much as
| China's is.
| totalhack wrote:
| Was gonna flag this same thing. Maybe their hoping for help
| from the open source community?
| DeathArrow wrote:
| China has a very diverse mix of technology. They use x86, ARM,
| MIPS, RISC-V and others. I don't know if splitting the efforts
| in many different directions makes sense.
| snek_case wrote:
| China is a huge country with a much bigger hardware industry
| than the US. Seems to me it's normal not everyone there is
| working with the same technology. It's just a massive number
| of different companies doing different things.
|
| That being said, RISC-V is gaining a lot of traction. I
| wouldn't be surprised if it starts to become a real challenge
| to ARM in the next five years. You just need mature tooling
| and better cores. Probably also need a wider variety of
| smaller cores for embedded applications available at the
| right price points.
| sylware wrote:
| Sad this is tainted by the current US-china conflict on chip
| manufacturing.
|
| But there are good guys everywhere (and bad too), and anything
| pushing a world-wide royalty free modern ISA toward "real-life"
| usage does its part.
|
| I hope one day I'll buy a AAA game, with a noscript/basic (x)html
| browser and play it on highly performant RISC-V CPU.
|
| Don't forget, the bad guys hate simple but able to do a good
| enough job, stable in time standards.
| marcodiego wrote:
| > I hope one day I'll buy a AAA game, with a noscript/basic
| (x)html browser and play it on highly performant RISC-V CPU.
|
| What a dream! I'd add the game would be open source; don't care
| about the art though.
| DeathArrow wrote:
| China already surpassed US economy according to some studies. And
| it was at 1/100 of US economy tens of years ago.
|
| Part of this rise to power is due to US companies investing
| there, buying and giving know-how in the process, but the huge
| part is they've built some of the world best learning systems,
| the state is massively investing in education, they invest more
| than any other country in research. And, perhaps one of the
| biggest factors, unthinkable in the West, is that Chinese
| economic entities are cooperating instead of being secretive. If
| one Chinese company will develop something, you can bet the rest
| will learn that fast and will use it in the next economic cycle.
| In China all knowledge is in fact a big open source scheme. Every
| new startup can benefit from the know how, experience and
| research done by others. This accelerates accomplishments like
| crazy.
|
| So, to recap: CCP makes good plans for very large time scales,
| they have one of best education systems, they try to educate as
| much people as possible, they invest heavily in research,
| companies are more likely to cooperate instead of competing,
| knowledge is shared.
|
| It's a perfect recipe for success. And I just wonder why other
| countries can't apply the same recipe.
| still_grokking wrote:
| > It's a perfect recipe for success. And I just wonder why
| other countries can't apply the same recipe.
|
| Because in capitalistic market economies you need to compete.
| This is a law of nature! Or something like that... /s
|
| I would indeed like to see how this works in reality on side in
| China. But China has one big issue: Its written language. This
| is something that makes me really fear the idea to go there. If
| they would just manage to finally switch to some proper writing
| system, so even dumb boys like me could learn it, I would
| invest some time and try to learn the language. But as long as
| you need to memorize thousands of signs (and can't even use a
| dictionary...) this is really off-putting. I'm dyslexic and
| have already problems to write correctly in my mother tongue
| (German), and had a very hard time to learn English. The second
| most useful language to put effort in would be Chinese, sure.
| But this writing system, oh boy...
|
| The Chines are smart and have a powerful government. Why can't
| they make this Pinyin finally happen? It would make learning
| reading and writing likely even easier for the still illiterate
| people on the Chines country side. (And no, I don't buy the
| argument that you need the signs to distinguish meaning for
| things that sound alike. The spoken language has no signs and
| it still works fine. And the whole language is anyway very
| context depended, so you need to think about the meanings of
| words or phrases quite precisely anyway.)
| tomcam wrote:
| Why convert to Pinyin? Simplified Chinese is about 80% more
| efficient. How would you like to see every piece of English
| take up 400% more space?
|
| The more I think about your comment the more I suspect you're
| trolling, though. Good work!
| DeathArrow wrote:
| Well I was formally diagnosed with dislexia and ADHD, which
| is worse. I can tell you what I did. I worked hard, read a
| lot, taught myself to finish projects. And I did lots of
| accomplishments and way more than my peers without ADHD.
| tomcam wrote:
| Yeah no. The education system you're referring to is optimized
| strictly for performance on standardized tests. From a very
| early age kids are trained to answer test questions, not to
| understand those questions or how to apply them in real life.
| It has been this way in China for thousands of years; their
| civil service exams were the only way to move ahead of your
| station in life without connections.
|
| Innovating is not done in polite company in China. If you come
| up with a clever new way of doing something, there is an
| extremely high possibility that your superiors will suppress it
| on the off chance that it could embarrass them ("lose face").
|
| These big long term plans you're referring to exist, but in the
| plane of reality you imagine. There is nothing like a
| meritocracy in the CCP. That is even more true now than 10
| years ago, because Xi has systematically removed dissenting
| voices in what you have heard is an anti-corruption campaign.
| Companies like Blackrock, and Boeing are breathtakingly corrupt
| and are taking us taxpayers for a huge ride. But they can
| usually do a pretty competent job of getting the job done. They
| are run by technocrats, who often have an engineering
| background.
|
| Imagine if the top 10 levels or so of any of these companies
| were nothing but connected people and their friends and
| children. That's what happens to all of these projects in
| China. China can't build a 5m chip or a new type of wing or a
| useful new programming language. Most of the people who could
| even do that job are either out of the country or unable to be
| recognized for their work.
| ivzhh wrote:
| Professor Bao of the OpenXiangShan team is known for his
| outspokenness, particularly in advocating for the academic model
| of the RISELab at UC Berkeley, which he often refers to as "Open
| Source Heavy Industry". As a result, he is a strong proponent of
| the OpenXiangShan project, as he firmly believes that it is the
| ideal means of producing high-quality research.
| DeathArrow wrote:
| All research in China is publicly shared. And while it is
| encouraged by the CCP is not demanded by law. It's a cultural
| fact and any entity in China can learn about R&D done by any
| entity, no matter if state owned or public owned, provided it
| is not classified as a secret.
|
| Taking this precept down, they don't care about IP. If one
| Chinese company makes a product, in a few weeks you can find
| lots of different Chinese companies selling the same product on
| Aliexpress. Some of better quality, some cheaper, some with
| added functionality some with less functionality.
|
| If you are to give your hardware design to a Chinese company
| and order a heavy lot you might have a good deal. But if your
| product is kind of successful, you shouldn't wonder if you see
| a lot of alternatives offered on Aliexpress by seemingly
| increasing unknown companies for a good rebate.
| panick21_ wrote:
| Some people might be interested in Ocelot:
|
| https://github.com/tenstorrent/riscv-ocelot
|
| Its basically the evolved BOOM Core from Berkley but with a full
| RISC-V Vector Unit attached.
|
| I had really hoped more people put more investment in BOOM.
| skavi wrote:
| by boom core, do you mean the latest "sonic boom"?
| panick21_ wrote:
| Yes, I'm not aware of anything after that:
|
| https://carrv.github.io/2020/papers/CARRV2020_paper_15_Zhao..
| ..
| eunos wrote:
| I'm more interested that they also developed an agile methodology
| for Hardware development here
| https://github.com/OpenXiangShan/XiangShan-doc/blob/main/pub... .
| rektide wrote:
| I'm squinting a lot to draw a net conclusion, but clearly a
| massive focus on testing & simulators.
|
| They notably seem to be validating & simulating C/C++ targets
| for a lot of this.
|
| They have a great breakdown of the tools they've used & build.
| Chisel, out of Berkeley, lies at the heart of almost
| everything. But they have reams of new tools they've madd.
| There's over a dozen simulators or tester pieces they said
| they've made. Which is epic, and makes total sense.
|
| Great paper thanks for sharing. I quickly scanned their gitbub
| repos. A lot of these tools probably arent iterated on as much
| & I just haven't got to them yet. The paper claims the
| overarching development structure is embodied on a tool MinJie,
| which the paper says is open source. Fantastic, fingers crossed
| 50%+ of the tooling here is available.
|
| I also feel like the US's OpenROAD deserves some shout out as
| related, relying on extremely good design checking/validators
| to be so agile at chipmaking that ML can spit out designs en
| mass & then we can run loss checks to find out how working the
| various designs are. Millions of monkeys on typewriters style
| ultra agile.
| snvzz wrote:
| Another very high performance effort is VRoom![0].
|
| As of the latest update in the blog, they are at 10.3 DMips/MHz.
|
| 0. https://moonbaseotago.github.io/
| tyingq wrote:
| >they are at 10.3 DMips/MHz
|
| I understand Dhrystone isn't everything, but that's pretty
| impressive, and up there with high performance CPUs from the
| established players.
| codedokode wrote:
| As I understand that is performance in a simulator, and it is
| unknown what delays are going to be between pipeline stages
| on real hardware.
| gchadwick wrote:
| 'Isn't everything' is a huge understatement. It's a
| performance nice smoke test for a CPU in that if it isn't
| hitting the numbers you'd expect given the microarchitecture
| (issue width etc) you know there's a problem and due to the
| simplicity of the benchmark it shouldn't be hard to analyse
| and track down.
|
| Though there's way more a modern high performance CPU needs
| to do. It doesn't do anything meaningful to stress the memory
| system for instance. Hitting good Drystone numbers is stage 1
| in a long process to building a modern high performance CPU.
| tyingq wrote:
| That's fair. Perhaps "is only an imperfect early indicator"
| would have been better than "isn't everything".
| rektide wrote:
| The practically live blogging of this VRoom! core is such a
| glorious thing to behold.
|
| Amazing work. And it's talked about!! We can see learn & follow
| that. One of the most unique singular experiences in the modern
| world, creating a high performance core, and we can read about
| it, see the process unfold, see the team iterate. Gobsmackingly
| amazing.
| mdp2021 wrote:
| Does anybody have a list of DMips/MHz per CPU results, for
| comparison?
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