6 ms·

Petalisp: Elegant High Performance Computing

140 points by mpweiher 3y ago

fredrikholm 3y ago
Elegant High Performance Computing # Performance [benchmarks?] Coming soon! I've seen quite a few elegant and within-an-order-of-magnitude-of-semi-optimized-C CL programs throughout the years, but can one make such a statement without benchmarks? What do we mean by high performance?
- thumbuddy 3y ago
  I also share this concern. I hope it at least beats out naive implementations of these algorithms, but I wouldn't be surprised if it was far from SOTA or standard tooling.
- jackdaniel 3y ago
  While I'm not using Petalisp I can attest that Marco is known for delivering high quality software with a strong focus on performance. I suspect that the phrase "Coming soon!" means exactly that - when he'll make them they will be published.
  - norir 3y ago
    Regardless of their skill, they only get one chance to make a first impression.
    - CodeSgt 3y ago
      We don’t know if they chose to share it on HN just yet or if this post was made by a fan of the project.
      - phoe-krk 3y ago
        A fan, the author of Petalisp is https://news.ycombinator.com/user?id=heisig https://news.ycombinator.com/user?id=heisig
    - jackdaniel 3y ago
      I don't know what do you try to convey. The link is shared by a third-party.
- distcs 3y ago
  > I've seen quite a few elegant and within-an-order-of-magnitude-of-semi-optimized-C CL programs throughout the years, but can one make such a statement without benchmarks? What do we mean by high performance? This is someone's project that is still in development. The person who posted this on HN and the person who created this project are not same. The benchmarks will become available when they will become available.
- MarioMan 3y ago
  In this context, High Performance Computing (HPC) refers to a computing paradigm where high-performance computers work on a distributed problem (e.g., supercomputers), not the actual performance of this code generator. All it means here is that it generates parallel, distributed code intended for use by HPC platforms. See: https://en.wikipedia.org/wiki/High-performance_computing https://en.wikipedia.org/wiki/High-performance_computing
- heisig 3y ago
  Petalisp author here. I apologize that the README is somewhat lacking, but it wasn't me who posted this on HN. As you may have seen on the commit history, a lot of exciting things have happened over the last few months. However, there are also a few stupid performance bugs left, so I am delaying the release of any performance numbers until those have been fixed. Otherwise, I fear that people will simply misinterpret the results. Nevertheless, I can already state that the single-core performance of Petalisp programs is exactly like that of a C program - simply because Petalisp compiles its programs to C when possible. (Although I also have that long-term agenda of using sb-simd to reach that performance in pure CL some day.) In addition, Petalisp is quite good at automatically parallelizing programs, and we already have most of the infrastructure for distributed and heterogeneous computing in place. I will write a more detailed post for the HN crowd once I have reliable performance numbers and once I finished writing the documentation. Feel free to ask me further questions.
  - medo-bear 3y ago
    This would be an exciting read. Im cretainly looking forward to it. Is there a read me for the required infrastructure setup in the works?
    - heisig 3y ago
      I am not sure what you mean by "required infrastructure setup". Installing Petalisp is a single call to (ql:quickload :petalisp) - assuming you have Quicklisp installed. If you also have a C compiler available, and an executable named cc pointing to that compiler, Petalisp will use that to speed up your codes further. About the required hardware - anything that runs SBCL or CCL can also run Petalisp.
      - medo-bear 3y ago
        Sorry I should have been more specific. I meant a distributed computing system setup
        3y ago
ianai 3y ago
Sounds like it’s mostly lisp. How mathematically correct and proven (in the math sense) is lisp?
- thumbuddy 3y ago
  Do you mean what guarantees does Lisp offer? Not sure what you mean.
- deleted 3y ago
  [deleted]
- ravi-delia 3y ago
  Depends on the implementation, but SBCL has all the usual suspects to decent precision. The standard specifies branch cuts and such, and I've never heard any complaints. This is just a backbone for array computations, at a lower level than numpy. It's more about JIT-compilation of a small handful of operations than math overall
  - alecmg 3y ago
    without knowing much of either, sounds like petalisp to lisp relation is numba to python. Or numba to numpy?
- jackdaniel 3y ago
  Maxima is implemented in Common Lisp. The language features full numeric tower with bignums and rationals - generally it is a very good language for number crunching.
- theLiminator 3y ago
  There's nothing that makes lisp mathematically more correct. It might be easier to write correct code in (emphasis on the might). You could say lisp is more elegant though, as everything is an expression and the language is homoiconic.
  - matheusmoreira 3y ago
distcs 3y ago
> Not everyone has the time to learn Common Lisp. How true is this? I've learnt both CL and Python and it took me an order of magnitude less time to learn CL.
- ravi-delia 3y ago
  Setting aside the fact that naively we'd obviously expect basic python to take less time than basic CL, there's plenty of people who are already working in python. So time to learn python (remaining) is 0, compared to non-zero for CL.
  - shakow 3y ago
    > we'd obviously expect basic python to take less time than basic CL That's only obvious if you already know another language. IME, Lisp-likes are neither worse nor better than Python-likes for beginners.
  - distcs 3y ago
    > So time to learn python (remaining) is 0, compared to non-zero for CL. I don't understand your point. The time to learn Python for someone who knows Python is 0, obviously. But then the time to learn CL for someone who knows CL is also 0. What's your point? I wanted to find out whether others who have learnt both Python and CL also find CL easier to learn than Python like I did. Your answer tries to be clever but ignores my actual question!
    - magicalhippo 3y ago
      > What's your point? Perhaps that the number of people who already know Python is significantly larger than those who already know CL? For example, the intro to programming classes that physicists take (ie those that might end up writing HPC code) at the University I went to has been Python-based for well over a decade.
    - ravi-delia 3y ago
      I definitely found Python easier to learn, although now I find common lisp easier to use (Commas are terrible, and for what- infix syntax?). But in terms of why the README might say that not everyone has time to learn common lisp, my point was that it's just an obvious truism that more language bindings increases the potential userbase. To someone who already knows python, python bindings make using Petalisp that much easier. To someone who doesn't know Python, well then they can pick up Python or CL at their leisure.
moelf 3y ago
the name Petalisp cracks me up, because that's basically what Julia is: 1. Peta - https://www.hpcwire.com/off-the-wire/julia-joins-petaflop-club/ https://www.hpcwire.com/off-the-wire/julia-joins-petaflop-cl... 2. Lisp - https://discourse.julialang.org/t/cas-benchmarks-symbolics-jl-and-maxima/58359/17?u=jling https://discourse.julialang.org/t/cas-benchmarks-symbolics-j... Julia has a lisp origin story, see also: https://github.com/JeffBezanson/femtolisp https://github.com/JeffBezanson/femtolisp
- wodenokoto 3y ago
  Lisp stat landing page basically sounds like Julia, except they “kept” the syntax and it can compile. I don’t know how mature it is, but it’s sale pitch really speaks to me. https://lisp-stat.dev/ https://lisp-stat.dev/
  - Archit3ch 3y ago
    Also in the "Julia that can compile" family: https://lbstanza.org/ https://lbstanza.org/
    - nsajko 3y ago
      The "Julia that can compile" characterization is misleading, because Julia is based on LLVM-backed compilation (a Julia interpreter exists as a user package, however it's used only for debugging). I'd restate that as "Julia without the power of run-time on-demand compilation". Although your point was probably more in the direction of "Julia but it's trivial to get it statically compiled".
      - jballanc 3y ago
        Getting Julia to statically compile is not even that hard anymore. I think people are merely turned off by the lack of a (consistent, well supported) story around distributing Julia apps as single, statically-compiled binaries.
        3y ago
abrax3141 3y ago
I’ve thought many times - like literally every time I use Tf - that I should hack a Lisp interface to it. But, of course, PotAU, I never get a round twit.

140 points by mpweiher 3y ago

Elegant High Performance Computing # Performance [benchmarks?] Coming soon! I've seen quite a few elegant and within-an-order-of-magnitude-of-semi-optimized-C CL programs throughout the years, but can one make such a statement without benchmarks? What do we mean by high performance?

thumbuddy 3y ago
I also share this concern. I hope it at least beats out naive implementations of these algorithms, but I wouldn't be surprised if it was far from SOTA or standard tooling.
jackdaniel 3y ago
While I'm not using Petalisp I can attest that Marco is known for delivering high quality software with a strong focus on performance. I suspect that the phrase "Coming soon!" means exactly that - when he'll make them they will be published.
- norir 3y ago
  Regardless of their skill, they only get one chance to make a first impression.
  - CodeSgt 3y ago
    We don’t know if they chose to share it on HN just yet or if this post was made by a fan of the project.
    - phoe-krk 3y ago
      A fan, the author of Petalisp is https://news.ycombinator.com/user?id=heisig https://news.ycombinator.com/user?id=heisig
  - jackdaniel 3y ago
    I don't know what do you try to convey. The link is shared by a third-party.
distcs 3y ago
> I've seen quite a few elegant and within-an-order-of-magnitude-of-semi-optimized-C CL programs throughout the years, but can one make such a statement without benchmarks? What do we mean by high performance? This is someone's project that is still in development. The person who posted this on HN and the person who created this project are not same. The benchmarks will become available when they will become available.
MarioMan 3y ago
In this context, High Performance Computing (HPC) refers to a computing paradigm where high-performance computers work on a distributed problem (e.g., supercomputers), not the actual performance of this code generator. All it means here is that it generates parallel, distributed code intended for use by HPC platforms. See: https://en.wikipedia.org/wiki/High-performance_computing https://en.wikipedia.org/wiki/High-performance_computing
heisig 3y ago
Petalisp author here. I apologize that the README is somewhat lacking, but it wasn't me who posted this on HN. As you may have seen on the commit history, a lot of exciting things have happened over the last few months. However, there are also a few stupid performance bugs left, so I am delaying the release of any performance numbers until those have been fixed. Otherwise, I fear that people will simply misinterpret the results. Nevertheless, I can already state that the single-core performance of Petalisp programs is exactly like that of a C program - simply because Petalisp compiles its programs to C when possible. (Although I also have that long-term agenda of using sb-simd to reach that performance in pure CL some day.) In addition, Petalisp is quite good at automatically parallelizing programs, and we already have most of the infrastructure for distributed and heterogeneous computing in place. I will write a more detailed post for the HN crowd once I have reliable performance numbers and once I finished writing the documentation. Feel free to ask me further questions.
- medo-bear 3y ago
  This would be an exciting read. Im cretainly looking forward to it. Is there a read me for the required infrastructure setup in the works?
  - heisig 3y ago
    I am not sure what you mean by "required infrastructure setup". Installing Petalisp is a single call to (ql:quickload :petalisp) - assuming you have Quicklisp installed. If you also have a C compiler available, and an executable named cc pointing to that compiler, Petalisp will use that to speed up your codes further. About the required hardware - anything that runs SBCL or CCL can also run Petalisp.
    - medo-bear 3y ago
      Sorry I should have been more specific. I meant a distributed computing system setup
      - 3y ago

ianai 3y ago

Sounds like it’s mostly lisp. How mathematically correct and proven (in the math sense) is lisp?

thumbuddy 3y ago
Do you mean what guarantees does Lisp offer? Not sure what you mean.
deleted 3y ago
[deleted]
ravi-delia 3y ago
Depends on the implementation, but SBCL has all the usual suspects to decent precision. The standard specifies branch cuts and such, and I've never heard any complaints. This is just a backbone for array computations, at a lower level than numpy. It's more about JIT-compilation of a small handful of operations than math overall
- alecmg 3y ago
  without knowing much of either, sounds like petalisp to lisp relation is numba to python. Or numba to numpy?
jackdaniel 3y ago
Maxima is implemented in Common Lisp. The language features full numeric tower with bignums and rationals - generally it is a very good language for number crunching.
theLiminator 3y ago
There's nothing that makes lisp mathematically more correct. It might be easier to write correct code in (emphasis on the might). You could say lisp is more elegant though, as everything is an expression and the language is homoiconic.
- matheusmoreira 3y ago

distcs 3y ago

> Not everyone has the time to learn Common Lisp. How true is this? I've learnt both CL and Python and it took me an order of magnitude less time to learn CL.

ravi-delia 3y ago
Setting aside the fact that naively we'd obviously expect basic python to take less time than basic CL, there's plenty of people who are already working in python. So time to learn python (remaining) is 0, compared to non-zero for CL.
- shakow 3y ago
  > we'd obviously expect basic python to take less time than basic CL That's only obvious if you already know another language. IME, Lisp-likes are neither worse nor better than Python-likes for beginners.
- distcs 3y ago
  > So time to learn python (remaining) is 0, compared to non-zero for CL. I don't understand your point. The time to learn Python for someone who knows Python is 0, obviously. But then the time to learn CL for someone who knows CL is also 0. What's your point? I wanted to find out whether others who have learnt both Python and CL also find CL easier to learn than Python like I did. Your answer tries to be clever but ignores my actual question!
  - magicalhippo 3y ago
    > What's your point? Perhaps that the number of people who already know Python is significantly larger than those who already know CL? For example, the intro to programming classes that physicists take (ie those that might end up writing HPC code) at the University I went to has been Python-based for well over a decade.
  - ravi-delia 3y ago
    I definitely found Python easier to learn, although now I find common lisp easier to use (Commas are terrible, and for what- infix syntax?). But in terms of why the README might say that not everyone has time to learn common lisp, my point was that it's just an obvious truism that more language bindings increases the potential userbase. To someone who already knows python, python bindings make using Petalisp that much easier. To someone who doesn't know Python, well then they can pick up Python or CL at their leisure.

moelf 3y ago

the name Petalisp cracks me up, because that's basically what Julia is: 1. Peta - https://www.hpcwire.com/off-the-wire/julia-joins-petaflop-club/ https://www.hpcwire.com/off-the-wire/julia-joins-petaflop-cl... 2. Lisp - https://discourse.julialang.org/t/cas-benchmarks-symbolics-jl-and-maxima/58359/17?u=jling https://discourse.julialang.org/t/cas-benchmarks-symbolics-j... Julia has a lisp origin story, see also: https://github.com/JeffBezanson/femtolisp https://github.com/JeffBezanson/femtolisp

wodenokoto 3y ago
Lisp stat landing page basically sounds like Julia, except they “kept” the syntax and it can compile. I don’t know how mature it is, but it’s sale pitch really speaks to me. https://lisp-stat.dev/ https://lisp-stat.dev/
- Archit3ch 3y ago
  Also in the "Julia that can compile" family: https://lbstanza.org/ https://lbstanza.org/
  - nsajko 3y ago
    The "Julia that can compile" characterization is misleading, because Julia is based on LLVM-backed compilation (a Julia interpreter exists as a user package, however it's used only for debugging). I'd restate that as "Julia without the power of run-time on-demand compilation". Although your point was probably more in the direction of "Julia but it's trivial to get it statically compiled".
    - jballanc 3y ago
      Getting Julia to statically compile is not even that hard anymore. I think people are merely turned off by the lack of a (consistent, well supported) story around distributing Julia apps as single, statically-compiled binaries.
      - 3y ago

abrax3141 3y ago

I’ve thought many times - like literally every time I use Tf - that I should hack a Lisp interface to it. But, of course, PotAU, I never get a round twit.