8 ms·

RISC-V port accepted for inclusion in GCC

150 points by edelsohn 10y ago

AdmiralAsshat 10y ago
Given the momentum of Coreboot and Libreboot for having completely "free and open" architecture, how many years away are we from having commercial laptops available using RISC-V processors?
- NoOn3 10y ago
  We don't have even RISC-V commercial processocrs available yet...
  - ajross 10y ago
    SiFive is shipping real silicon now. But it's a microcontroller implementation without a MMU, so not something you'd put in a laptop. They have a 64 bit synthesizable application core listed as a product too (and what appears to be HDL source for it on github), but I can't find a reference to anyone actually using it yet.
    - NoOn3 10y ago
      Yes, I know and I bake them, but it's not suitable for laptops and it's microcontroller :)
  - progman 10y ago
    Soon we'll have. Google, HP, Oracle Join RISC-V http://www.eetimes.com/document.asp?doc_id=1328561 http://www.eetimes.com/document.asp?doc_id=1328561 Adapteva: Why I will be using RISC-V in my next chip http://www.adapteva.com/andreas-blog/why-i-will-be-using-the-risc-v-in-my-next-chip/ http://www.adapteva.com/andreas-blog/why-i-will-be-using-the...
- nine_k 10y ago
  Probably many: the processor has to be made by millions (per model, not in total) to become reasonably priced, and it will still be slower and/or hotter than an offering from Intel who have spend untold man-years honing their architecture. Think Talos and IBM Power8, IBM being a serious force behind the Power architecture, with companies like Google among its customers. RISC-V should have a key advantage and exploit it. IDK if the advantage of openness would be key for general-purpose laptops. Special laptops would probably be available but pricey; compare to other niche laptops, like highly-protected ones.
  - throwawayish 10y ago
    It's completely unreasonable to expect some underdog architecture to get anywhere close to the big ones, which have pured dozens of billions of dollars into research over decades to optimize their designs, tooling and fabrication. A reasonable expectation is to get some low-end-ish CPUs out that might be on the same level (in terms of efficiency) than older, not really optimised ARM designs. The biggest incentive RISC-V can offer is less legacy bullshit (like AArch64) and the fact that you don't have to pair royalties to ARM. Perhaps better standardisation of peripherals compared to ARM, so less time/money spent on integration, BSPs and stuff like that. (And even then: Looking at recent POWER one can see that they can outperform related Intel offerings, while being drastically less efficient.)
    - whazor 10y ago
      Many of those billions of dollars went into production of chips, which is mostly a generic process where chip architecture is unaffected. Furthermore, research about architecture of chips has been published and can be used to create faster chips. But I have to agree that it is not easy. Especially because chip design is partly generated by software and computed by many powerful machines.
      - komali2 10y ago
        What about the architecture/design itself, is any of that open? Could I find a design, send it off to china, and have them print off a couple hundred, even at a much higher price than some other processor?
- stephenmm 10y ago
  Not sure but I bet that ARM is starting to pay it some attention! The great thing about being open is it allows academics and inventors to try out new ideas and have the ISA and associated "backend" flows just work without the worry of having to pay for licenses.
- detaro 10y ago
  I'm not sure I'd describe Coreboot and Libreboot as "having momentum", at least not at the level where anyone is thinking about them while making PC hardware? For RISC-V, the biggest issue seems to be a) actually designing a full chip with all the necessary peripherals (assuming just scaling the core bits is comparatively easy) and b) motivating someone to invest the fab time. I guess many potential commercial users will continue going with ARM, just because it is proven, designs and knowledge are available, ... Before laptops, I'd expect more microcontroller-type stuff, where customization and license costs probably are more relevant, less complex periphery is used and the necessary fabrication capacity is more easily available.
  - dublinben 10y ago
    Coreboot is used on many (if not most) Chromebooks, which is one of the fastest growing segments of PCs. If that's not momentum, I don't know what is.
    - pgeorgi 10y ago
      All Chromebooks (and their siblings: Bases, Boxes, Bits) since 2013.
- cmrdporcupine 10y ago
  I think (though I'm no expert) it's more likely that RISC-V will be in embedded devices and appliances around your house than in your laptop, where even ARM is a dubious proposition at this point. Given the open IP and ease of customization, we might even see RISC-V inside peripherals or on the motherboard in a PC doing specialized tasks. But not as the main CPU.
- nickik 10y ago
  Completele free and open is going to be difficult. Even the already existing and announced RISC-V boards you have non open hard or software involved. Its still going to be a huge step foreward. But I think within the next year or two, we should get something that can run Linux resonable well and is mostly open. Actuall production laptops is going to be difficult. Im rather waiting for "build it yourself laptop" kits, or something along those lines. There are allready projects like it, for other hardware. Maybe somebody from SiFive or lowRISC can comment. They probebly have the best information.
saurik 10y ago
https://news.ycombinator.com/item?id=13381070 https://news.ycombinator.com/item?id=13381070 ^ Related discussion from when this port was submitted.
ktta 10y ago
I remember hearing something about there being problems with RISC-V+GCC since FSF wanted copyright assigned to them. [1] RISC-V did make it to llvm[2], with there being healthy development there. I remember Fedora running on RISC-V successfully. Anyone know what happened with the whole copyright assignment problem? [1]:https://news.ycombinator.com/item?id=12633037 https://news.ycombinator.com/item?id=12633037 [2]:http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.html http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.... EDIT: I found a comment[3] in the old submission which answers my question. [3]:https://news.ycombinator.com/item?id=13385968 https://news.ycombinator.com/item?id=13385968
WhitneyLand 10y ago
How important was it to get support into gcc? llvm wouldn't have been enough?
- _chris_ 10y ago
  Can you compile linux with llvm?
  - WhitneyLand 10y ago
    I don't know actually, clang/llvm doesn't compile linux?

150 points by edelsohn 10y ago

Given the momentum of Coreboot and Libreboot for having completely "free and open" architecture, how many years away are we from having commercial laptops available using RISC-V processors?

NoOn3 10y ago
We don't have even RISC-V commercial processocrs available yet...
- ajross 10y ago
  SiFive is shipping real silicon now. But it's a microcontroller implementation without a MMU, so not something you'd put in a laptop. They have a 64 bit synthesizable application core listed as a product too (and what appears to be HDL source for it on github), but I can't find a reference to anyone actually using it yet.
  - NoOn3 10y ago
    Yes, I know and I bake them, but it's not suitable for laptops and it's microcontroller :)
- progman 10y ago
  Soon we'll have. Google, HP, Oracle Join RISC-V http://www.eetimes.com/document.asp?doc_id=1328561 http://www.eetimes.com/document.asp?doc_id=1328561 Adapteva: Why I will be using RISC-V in my next chip http://www.adapteva.com/andreas-blog/why-i-will-be-using-the-risc-v-in-my-next-chip/ http://www.adapteva.com/andreas-blog/why-i-will-be-using-the...
nine_k 10y ago
Probably many: the processor has to be made by millions (per model, not in total) to become reasonably priced, and it will still be slower and/or hotter than an offering from Intel who have spend untold man-years honing their architecture. Think Talos and IBM Power8, IBM being a serious force behind the Power architecture, with companies like Google among its customers. RISC-V should have a key advantage and exploit it. IDK if the advantage of openness would be key for general-purpose laptops. Special laptops would probably be available but pricey; compare to other niche laptops, like highly-protected ones.
- throwawayish 10y ago
  It's completely unreasonable to expect some underdog architecture to get anywhere close to the big ones, which have pured dozens of billions of dollars into research over decades to optimize their designs, tooling and fabrication. A reasonable expectation is to get some low-end-ish CPUs out that might be on the same level (in terms of efficiency) than older, not really optimised ARM designs. The biggest incentive RISC-V can offer is less legacy bullshit (like AArch64) and the fact that you don't have to pair royalties to ARM. Perhaps better standardisation of peripherals compared to ARM, so less time/money spent on integration, BSPs and stuff like that. (And even then: Looking at recent POWER one can see that they can outperform related Intel offerings, while being drastically less efficient.)
  - whazor 10y ago
    Many of those billions of dollars went into production of chips, which is mostly a generic process where chip architecture is unaffected. Furthermore, research about architecture of chips has been published and can be used to create faster chips. But I have to agree that it is not easy. Especially because chip design is partly generated by software and computed by many powerful machines.
    - komali2 10y ago
      What about the architecture/design itself, is any of that open? Could I find a design, send it off to china, and have them print off a couple hundred, even at a much higher price than some other processor?
stephenmm 10y ago
Not sure but I bet that ARM is starting to pay it some attention! The great thing about being open is it allows academics and inventors to try out new ideas and have the ISA and associated "backend" flows just work without the worry of having to pay for licenses.
detaro 10y ago
I'm not sure I'd describe Coreboot and Libreboot as "having momentum", at least not at the level where anyone is thinking about them while making PC hardware? For RISC-V, the biggest issue seems to be a) actually designing a full chip with all the necessary peripherals (assuming just scaling the core bits is comparatively easy) and b) motivating someone to invest the fab time. I guess many potential commercial users will continue going with ARM, just because it is proven, designs and knowledge are available, ... Before laptops, I'd expect more microcontroller-type stuff, where customization and license costs probably are more relevant, less complex periphery is used and the necessary fabrication capacity is more easily available.
- dublinben 10y ago
  Coreboot is used on many (if not most) Chromebooks, which is one of the fastest growing segments of PCs. If that's not momentum, I don't know what is.
  - pgeorgi 10y ago
    All Chromebooks (and their siblings: Bases, Boxes, Bits) since 2013.
cmrdporcupine 10y ago
I think (though I'm no expert) it's more likely that RISC-V will be in embedded devices and appliances around your house than in your laptop, where even ARM is a dubious proposition at this point. Given the open IP and ease of customization, we might even see RISC-V inside peripherals or on the motherboard in a PC doing specialized tasks. But not as the main CPU.
nickik 10y ago
Completele free and open is going to be difficult. Even the already existing and announced RISC-V boards you have non open hard or software involved. Its still going to be a huge step foreward. But I think within the next year or two, we should get something that can run Linux resonable well and is mostly open. Actuall production laptops is going to be difficult. Im rather waiting for "build it yourself laptop" kits, or something along those lines. There are allready projects like it, for other hardware. Maybe somebody from SiFive or lowRISC can comment. They probebly have the best information.

saurik 10y ago

https://news.ycombinator.com/item?id=13381070 https://news.ycombinator.com/item?id=13381070 ^ Related discussion from when this port was submitted.

ktta 10y ago

I remember hearing something about there being problems with RISC-V+GCC since FSF wanted copyright assigned to them. [1] RISC-V did make it to llvm[2], with there being healthy development there. I remember Fedora running on RISC-V successfully. Anyone know what happened with the whole copyright assignment problem? [1]:https://news.ycombinator.com/item?id=12633037 https://news.ycombinator.com/item?id=12633037 [2]:http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.html http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.... EDIT: I found a comment[3] in the old submission which answers my question. [3]:https://news.ycombinator.com/item?id=13385968 https://news.ycombinator.com/item?id=13385968

WhitneyLand 10y ago

How important was it to get support into gcc? llvm wouldn't have been enough?

_chris_ 10y ago
Can you compile linux with llvm?
- WhitneyLand 10y ago
  I don't know actually, clang/llvm doesn't compile linux?