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Is MIPS Dead? Lawsuit, Bankruptcy, Maintainers Leaving and More
- api 7y agoThe writing's been on the wall for MIPS for ages. AFAIK it's not better than ARM in any meaningful way.
- unixhero 7y agoWell, good times were had!
- yjftsjthsd-h 7y agoLicensing?
- variaga 7y agoMy experience is that MIPS and ARM licensing are equally bad. As an anecdote, I have personally switched a MIPS core to an ARM core in an SoC revision specifically because ARM gave us better licensing terms than MIPS. It was a pain because MIPS big endian and ARM big endian are not directly compatible with each other.
- notacoward 7y agoMaybe it has changed, or maybe it depends on what level of IP you're licensing. The company I worked at in 2006-2009 had gone with MIPS because they were incorporating that with all sorts of other logic (from third parties plus custom) and the cost for that type of license from Arm would have bankrupted them instantly.
- boznz 7y agoIsnt mips open source ?
- pm321 7y agoThe creator of ARM speaks well of RISC-V and considers ARM yesterday's old news and has moved on. Comparing MIPS to ARM in essentials of architecture is MIPS more beautiful? ARM I understand is a mess that has evolved for its niche.
- arnd 7y agoI find the latest architecture versions are all remarkably similar as they have all adapted to the same environment: The old 32-bit Arm (now called Aarch32) was quite different and only somewhat RISC-like. Arm's Aarch64 however is mostly derived from MIPS64 with a lot of modernization plus some parts (exception levels) from 32-bit Arm. MIPSr6 was an attempt of modernizing MIPSr5 by removing all the ugly bits (delay slots!) but the incompatible instruction encoding prevented it from being widely adopted. You cannot buy a single MIPSr6 machine that a mainline Linux runs on. RISC-V's design looked at all RISC architectures (Berkely RISC, MIPS, SPARC, Power, Arm, ...) for inspiration and took the best parts of each. Leaving out all the historic baggage means it's simpler (the manual is a fraction of the size), but most of the important decisions are the same as in MIPSr6 and Armv8/Aarch64. One notable difference is the handling of compressed (16-bit) instructions: ARMv8/Aarch64 doesn't have them at all (like RISC-I/RISC-II, ARMv3 and MIPS-V), MIPSr6/microMIPS needs to switch between formats (like ARMv4T through ARMv6) and in RISC-V they are optional but can be freely mixed (somewhat like ARMv7 and nanoMIPS).
- ncmncm 7y agoIt's disappointing that RISC-V designers swallowed myths that resulted in unpleasant ISA details. For example, the notion that condition codes interfere with OoO execution has been repudiated; Power and x86 both now rename condition registers. Lack of popcount and rotate in the base instruction set are glaring omissions. (That x86 got popcount late, and that the bitmanip extension will have them if it ever gets ratified, are no excuse.) It was silly to make the compare instruction generate a 1 instead of the overwhelmingly more useful ~0. We only get a new ISA once in a generation. It is tragic when it is wrong. It is possible, in principle, that popcount and rotate could be added to the base 16-bit instructions, but I'm not holding my breath.
- justicezyx 7y agoWAVE computing used to be working on CGRA [1] chip as deep learning accelerators. I got in touch with a few folks there. They apparently failed that endeavor and pivoted to MIPS. [1] https://wavecomp.ai/wp-content/uploads/2018/12/WP_CGRA.pdf https://wavecomp.ai/wp-content/uploads/2018/12/WP_CGRA.pdf
- RcouF1uZ4gsC 7y agoMIPS dying is really the end of an era. I think it was the quintessential RISC processor of the early 90's. IIRC, Windows NT was developed on a MIPS machine to ensure that inadvertent x86 dependencies did not sneak into the code. I remember reading a PCWorld article comparing various processors. This was the time the Pentium came out. If my memory servers, the MIPS won the overall performance crown vs Pentium, PowerPC, and Alpha AXP.
- skissane 7y ago> IIRC, Windows NT was developed on a MIPS machine to ensure that inadvertent x86 dependencies did not sneak into the code. Not MIPS. Windows NT was initially developed on a more obscure RISC architecture, Intel i860. It was later ported to MIPS though.
- simcop2387 7y agoAnd ported to DEC Alpha too! It's one of my weirdly favorite ports of NT just because of how little use I believe it ever actually got.
- pavlov 7y agoI’m pretty sure the PowerPC port of Windows NT was the least used. It was the first to be discontinued, at least.
- toast0 7y agoThe Alpha port made it through to early release candidates of Windows 2000, and somebody is using it, because there were PuTTY builds for it.
- vetrom 7y agoI've seen live Alpha installations of windows NT driving RIPs at large format printing shops in the 90s. It was also not unheard of at VMS shops.
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- Traster 7y agoI remember listening to some guy from ImgTec brag about how MIPS is the 4th biggest instruction set in the world as if MIPS had like 20% market share rather 1% or whetever ridiculous market share ImgTec had bought their way into. That was literally at the peak when ImgTec were on top of the world, they'd just built a new campus and were spending like there was no tomorrow. Then Apple drank their milkshake, and they had to sell everything. Even then though, it was really bizarre that anyone was still trying to make MIPs a thing. MIPS has been the walking dead for a couple of decades now. It's really time to let go. Especially since there are actually interesting things happening in the ISA space with RISC-V.
- AnimalMuppet 7y agoPardon my ignorance, but... is RISC-V all that much more alive than MIPS? My impression is that MIPS has a past, RISC-V may have a future, but neither has much of a present.
- simcop2387 7y agoFor desktop or server class stuff, RISC-V is still shaking out but there are attempts to make it happen on-going right now. For everything else you've got companies like Western Digital that have committed to shipping a billion[2] RISC-V processors for their own devices, and many others. [1] Just take a look at their membership page for people funding or helping develop the processors, https://riscv.org/members-at-a-glance/ https://riscv.org/members-at-a-glance/ [1] https://www.westerndigital.com/company/innovations/risc-v https://www.westerndigital.com/company/innovations/risc-v [2] https://www.extremetech.com/computing/281891-western-digital-announces-plans-for-its-own-risc-v-processor https://www.extremetech.com/computing/281891-western-digital...
- opencl 7y agoThe only hardware actually currently shipping in meaningful quantities are a handful of microcontrollers. The U540 is pretty much a Raspberry Pi level of SoC but it's only shipped in tiny quantities on expensive dev boards. It's just too new for anything else yet, the higher performance stuff takes years from the start of design work to shipping silicon.
- vardump 7y agoARM and RISC-V have collectively removed any remaining niches (or future prospects) for MIPS.
- lsllc 7y agoExcept that there aren't really any practical (affordable!) RISC-V based Linux boards/modules. The Onion Omega2S is based on a MediaTek MT7688 (MIPS32LE) and since the demise of the CHIP-Pro, is really the only inexpensive surface mount Linux SoM left. https://onion.io/store/omega2s/ https://onion.io/store/omega2s/
- vardump 7y agoThat's why I said also "future prospects". It's likely RISC-V will for the very least fill certain niches.
- lsllc 7y agoRight, I just hope they do it quickly! I'd love to see a low cost (e.g. RPi priced) RISC-V based SoM that runs Linux.
- apple4ever 7y agoThe Omega2 is pretty nice, but they do need to improve the ecosystem.
- 0xTJ 7y agoI can't wait for there to be affordable MMU-equipped RISC-V dev boards.
- strooper 7y agoMay be its days are numbered, but MIPS still has significant presence in the low to medium end routers (Mediatek's MT72xx, Atheros AR7xxx so on).
- dashwav 7y agoMIPS still has a very large presence in the education sector as well - MIPS asm is very easy to learn because of how consistent it's syntax is and the plethora of open source debuggers as well. Learning MIPS was what originally got me interested in ASM programming since we had a class that was focused on MIPS code and another class that had us build a digital MIPS processor from scratch. The combination of these two classes really sold me on the magic of super low-level programming.
- 333c 7y agoYep, I also learned MIPS in my CS class. It's pretty nice to program in.
- saagarjha 7y agoIt’s nice until you get to its annoying and fairly irrelevant pipelining model.
- zozbot234 7y agoThe ubiquitous delay slots in MIPS are one instruction-set feature that has aged really badly. RISC-V actively got rid of it in their design because it ends up being such a hindrance to, e.g. out-of-order implementations.
- KMag 7y agoIt's also a hindrance to in-order implementations that have a different number of branch delay cycles (e.g. different number of pipeline stages or instructions taking a variable number of cycles) than the original implementation. Branch delay slots were a somewhat clever solution to reduce the complexity of the original implementation, but they baked implementation details into the ISA and became problematic when the implementation details changed.
- jojobas 7y agoAll hail Rick Belluzzo.
- csours 7y agoPlease help me remove some of my ignorance: ARM = RISC? Intel = CISC? ? = MIPS? What else is out there in large amounts?
- draw_down 7y agohttps://en.wikipedia.org/wiki/MIPS_architecture https://en.wikipedia.org/wiki/MIPS_architecture
- alxmdev 7y agoMIPS itself is a RISC, see https://en.wikipedia.org/wiki/MIPS_architecture https://en.wikipedia.org/wiki/MIPS_architecture As for what else is out there in large numbers, I think a lot of 8bit Z80 and AVR microcontrollers (like the ATmega328 used in Arduino Uno) are embedded in larger systems and go unnoticed. More recently I've seen the Xtensa (32bit RISC) catching on with the popular ESP32 and ESP8266 SOCs.
- deleted 7y ago[deleted]
- saagarjha 7y agoA number of others you might encounter in your embedded devices: 68k, AVR, Z80. (CISC, RISC, CISC, if you’re curious.)
- MrTortoise 7y agoi learnt how cpu work on spim
- iso-8859-1 7y agonah, you only learnt how to use them ;)
- joyj2nd 7y agohttps://en.wikipedia.org/wiki/Loongson https://en.wikipedia.org/wiki/Loongson
- yellowapple 7y agoRelevantly, Richard Stallman used to use a Lemote YeeLoong (notebook with a Loongson MIPS CPU) before he switched to a librebooted ThinkPad T400.
- tenebrisalietum 7y agoI don't think MIPS is going to completely disappear as long as Linux works on it. Someone somewhere in some country will keep making them as long as the licensing situation is more favorable for whatever use than ARM or x86. If the owning company is going bankrupt that means making MIPS CPUs will be cheaper than ARM or x86.
- garmaine 7y agoHardly. It means the IP will be sold off to someone else, who might just make it more expensive to milk some profit from the deal while pushing customers to their own platform.
- deleted 7y ago[deleted]
- yjftsjthsd-h 7y agoI was under the impression what MIPS was open sourced, in which case "owner" company should be irrelevant?
- zozbot234 7y agoNot so; there was a short-lived initiative to work towards some kind of open release, but it came to nothing. The article mentions that.
- DeathArrow 7y agoIn China they have lots of new MIPS developments based on existing MIPS architecture. The question it's not if someone will use some old MIPS ISA in a few years from now on, the question is if someone will improve the ISA from now on, in the same way x86 and ARM are consistently being improved. Some companies are still fabbing old Z80 CPUs, but that's not to say Z80 has a bright future.
- arnd 7y agoIngenic an Loongson both have architecture licenses and so far have kept releasing new chips with their own cores on a regular basis, including (in Loongson's case) some interesting enhancements. Both are also members in the RISC-V foundation already though, so it seems likely they would in the long run pivot their instruction sets to that, like others have done before them: Andes, C-Sky, Cortus, Cobham-Gaisler, NVIDIA, and presumably many more all keep supporting old products based on their previous designs while doing new development on RISC-V. CIP-United still promises to provide enhanced versions of the both the architecture and the MIPS Warrior cores for the Chinese market, regardless of what happens to MIPS Technologies. This may seem utterly futile now, but it is also the very thing that the US Committee on Foreign Investment was trying to prevent when it required MIPS to be spun out of Imagination Technologies when that got sold to Chinese investors.
- narrator 7y agoKOMDIV-64[1] is still using MIPS. It's improbable that one would encounter these chips outside of Russia weapons tech though. [1]https://en.wikipedia.org/wiki/KOMDIV-64 https://en.wikipedia.org/wiki/KOMDIV-64
- CalChris 7y agoIt's already been bought+sold a few times. (Stanford) MIPS Computer Systems SGI Spun off, IPO Imagination Tailwood Wave I might have missed one.
- DeathArrow 7y agoConsolidation, together with buyouts and bankruptcy made a part of the computing world much more boring. In the '90s and early 2000s there were lots of CPUs, computer systems, operating systems.