Comparing Parallel Functional Array Languages: Programming and Performance

91•vok•1y ago

Comments

yubblegum•1y ago

Chapel got a mention in the 'Related Work' section. I looked at it a few years ago and found it compelling (but I don't do HPC so it was just window watching). What's the HN feedback on Chapel?

https://chapel-lang.org/

marai2•1y ago

If you scroll down on the Chapel-lang website, there seems to be a lot of activity happening with this language. There is even going to be a ChapelCon 2025.

https://chapel-lang.org/blog/posts/chapelcon25-announcement/

throwaway17_17•1y ago

Chapel and Lustre (a parallel, distributed file system) from Cray were funded by DARPA’s High Productivity Computing Systems program. This work, along with Fortress, from Sun, were developed explicitly to enable and ‘simplify’ the programming of distributed “supercomputers”. The work and artifacts, along with the published documentation and research is of particularly high quality.

Even if you aren’t involved in HPC I’d say the concepts transfer or provide a great basis for parallel and distributed idioms and methodologies that can be adapted to existing languages or used in development of new languages.

TL;DR - Chapel is cool and if you are interested in the general subject matter (despite a different focus) Fortress, which is discontinued, should also be checked out.

bradcray•1y ago

@yubblegum: I'm unfairly biased towards Chapel (positively), so won't try to characterize HN's opinion on it. But I did want to note that while Chapel's original and main reason for being is HPC, now that everyone lives in a parallel-computing world, users also benefits from using Chapel in desktop environments where they want to do multicore and/or GPU programming. One such example is covered in this interview with an atmospheric science researcher for whom it has replaced Python as his go-to desktop language: https://chapel-lang.org/blog/posts/7qs-dias/

yubblegum•1y ago

Thank you Brad! I was in fact wondering about GPU use myself. Does it work with Apple's M# GPUs?

Btw, I was looking at the docs for GPU [1] and unsolicited feedback from a potential user is that the setup process needs to become less painful. For example, yesterday installed it via brew but then hit the setup page for GPU and noted I now needed to build from source.

(Back in the day, one reason some of Sun's Java efforts to extend Java's fieddom faltered was because of the friction of setup for (iirc) things like Applets, etc. I think Chapel deserves a far wider audiance.)

[1]: https://chapel-lang.org/docs/technotes/gpu.html#setup (for others - you obviously know the link /g)

p.s. just saw your comment from last year - dropping it here for others: https://news.ycombinator.com/item?id=39032481

bradcray•1y ago

@yubblegum: I'm afraid we don't have an update on support for Apple GPUs since last year's comment. While it comes up from time-to-time, nobody has opened an issue for it yet (please feel encouraged to!), and it isn't something we've had the chance to prioritize, where a lot of our recent work has focused on improving tooling support and addressing user requests.

I'll take your feedback about simplifying GPU-based installs back to our team, and have noted it on this thematically related issue: https://github.com/chapel-lang/chapel/issues/25187#issuecomm...

munchler•1y ago

Are these languages pure in the functional sense? E.g. Do they allow/encourage mutation? My understanding is that APL permits mutable state and side effects, but maybe they are rarely used in practice? If you're modifying the contents of an array in-place, I don't think it's reasonable to consider that functional.

zfnmxt•1y ago

Futhark, SaC, and Accelerate have purely functional semantics. Futhark has something called "in-place updates" that operationally mutate the given array, but semantically they work as if a new array is created (and are statically guaranteed to work this way by the type system).

RodgerTheGreat•1y ago

APL arrays are values in the same sense as value types in any functional language. You don't explicitly modify arrays in-place; if they happen to have a refcount of 1 operations may happen in-place as an optimization, but not in a manner which observably alters program behavior.

grg0•1y ago

Accelerate is a Haskell library/eDSL.

axman6•1y ago

I wasn’t expecting to personally know two of the authors, but having Accelerate included makes sense.

geocar•1y ago

> My understanding is that APL permits mutable state and side effects ... If you're modifying the contents of an array in-place, I don't think it's reasonable to consider that functional.

      a←'hello'
      a[1]←'c'

This does _not_ modify the array in-place. It's actually the same as:

     a←'hello'
     a←'c'@1⊢a

which is more obviously functional. It is easy to convince yourself of this:

      a←'hello'
      b←a
      b[1]←'j'
      a,b

returns 'hellojello' and not 'jellojello'.

teleforce•1y ago

Notice that all the all the languages mentioned depends on the external BLAS library for example OpenBLAS for performance.

D language have excellent support functional and array features with parallel support. On top that not known to others it has high performance native BLAS kind of library with ergonomic and intuitiveness similar to python [1].

[1] Numeric age for D: Mir GLAS is faster than OpenBLAS and Eigen (2016):

http://blog.mir.dlang.io/glas/benchmark/openblas/2016/09/23/...

zfnmxt•1y ago

> Notice that all the all the languages mentioned depends on the external BLAS library for example OpenBLAS for performance.

That's incorrect. Futhark doesn't even have linear algebra primitives---everything has to be done in terms of map/reduce/etc: https://github.com/diku-dk/linalg/blob/master/lib/github.com...

tomsmeding•1y ago

The same holds for Accelerate, and I'm fairly sure also SaC and APL. DaCe even gets a special mention in the paper in section 10.5 stating that they specifically _do_ use BLAS bindings.

joe_the_user•1y ago

"Notice that all the all the languages mentioned depends on the external BLAS library". I didn't notice this 'cause I don't think it's true. For example, it highly implausible that APL[1] would depend on BLAS[2] considering APL predates BLAS by 5-10 years ("developed in the sixties" versus "between 1971 and 1973"). I don't think Futhark uses BLAS either but in modern stupidity, this currently two hour old parent has taken over Google results so it's hard to find references.

[1] https://en.wikipedia.org/wiki/APL_(programming_language)

[2] https://en.wikipedia.org/wiki/Basic_Linear_Algebra_Subprogra...

DrNosferatu•1y ago

Matlab supposedly is “portable APL”.

DrNosferatu•1y ago

the man who invented MATLAB, Cleve Moler said: [I’ve] always seen MATLAB as “portable APL”. [1]

…why the downvoting?

[1] - https://computinged.wordpress.com/2012/06/14/matlab-and-apl-...

beagle3•1y ago

I didn't downvote, but ... as someone who used both, this statement seems nonsensical.

APL is mathematical notation that is also executable. It is all about putting a mathematical algorithm in a succinct, terse way.

MATLAB is a clunky Fortran-like language that does simple 2D matrix stuff reasonably terse (though not remotely as terse as APL), and does everything else horribly awkwardly and verbosely.

Modern MATLAB might be comparable to 1960s APL, but original MATLAB was most certainly not, and even modern MATLAB isn't comparable to modern APL (and its successors such as BQN and K)

devlovstad•1y ago

I took a course on massively parallel programming taught by one of the authors of this paper that extensively used Futhark and CUDA. While I have not used any of these languages since, I have used JAX[1] quite a lot, where the learnings from this course have been quite helpful. Many people will end up writing code for GPUs through different levels of abstraction, but those who are able to reason about the semantics through functional primitives might have an easier time understanding what's happening under the hood.

vanderZwan•1y ago

I think the intended footnote was accidentally left out. Were you talking about this Python library?

https://docs.jax.dev/en/latest/index.html

tough•1y ago

There's a JAX for AI/LM too

https://github.com/jax-ml/jax

but yeah no idea which the OP meant

zfnmxt•1y ago

> I took a course on massively parallel programming taught by one of the authors of this paper that extensively used Futhark and CUDA.

PMPH? :)

It's time to talk about my writerdeck

On The <dl> (2021)

Texas woman arrested for Facebook post about town water quality

Reverse engineering circuitry in a Spacelab computer from 1980

Hengefinder: Finding When the Sun Aligns with Your Street

We made our filesystem 47× faster by deleting it

My two-part desk setup

Green card seekers must leave U.S. to apply, Trump administration says

z386: An Open-Source 80386 Built Around Original Microcode

80386 Microcode Disassembled

PHP's Oddities

SpaceX launches Starship v3 rocket

Making Deep Learning Go Brrrr from First Principles (2022)

Italy Cancels Boeing Pegasus Order, Shifting to Airbus A330 MRTT

The Art of Money Getting

Project Glasswing: An Initial Update

- -dangerously-skip-reading-code

Kindle loyalists scramble as Amazon turns page on old e-readers

Reflections on Building Forum Software

sp.h: Fixing C by giving it a high quality, ultra portable standard library

Why Japanese companies do so many different things

Oura says it gets government demands for user data

Evaluating Spec CPU2026

Highest Random Weight in Elixir

Shipping a laptop to a refugee camp in Uganda

Lisp in Vim (2019)

Rubish: A Unix shell written in pure Ruby

Solving the “Zork” Mystery

Electrobun 2.0 will be decoupled from Bun due to the Rust rewrite

Improving C# Memory Safety

It's time to talk about my writerdeck

On The <dl> (2021)

Texas woman arrested for Facebook post about town water quality

Reverse engineering circuitry in a Spacelab computer from 1980

Hengefinder: Finding When the Sun Aligns with Your Street

We made our filesystem 47× faster by deleting it

My two-part desk setup

Green card seekers must leave U.S. to apply, Trump administration says

z386: An Open-Source 80386 Built Around Original Microcode

80386 Microcode Disassembled

PHP's Oddities

SpaceX launches Starship v3 rocket

Making Deep Learning Go Brrrr from First Principles (2022)

Italy Cancels Boeing Pegasus Order, Shifting to Airbus A330 MRTT

The Art of Money Getting

Project Glasswing: An Initial Update

- -dangerously-skip-reading-code

Kindle loyalists scramble as Amazon turns page on old e-readers

Reflections on Building Forum Software

sp.h: Fixing C by giving it a high quality, ultra portable standard library

Why Japanese companies do so many different things

Oura says it gets government demands for user data

Evaluating Spec CPU2026

Highest Random Weight in Elixir

Shipping a laptop to a refugee camp in Uganda

Lisp in Vim (2019)

Rubish: A Unix shell written in pure Ruby

Solving the “Zork” Mystery

Electrobun 2.0 will be decoupled from Bun due to the Rust rewrite

Improving C# Memory Safety

Comparing Parallel Functional Array Languages: Programming and Performance

Comments