<div dir="auto"><div>Speeding up compile times would be excellent! Do you have benchmarks? Estimates?<div dir="auto"><br></div><div dir="auto">ZuriHac is coming up, and I want to devote my participation time to improving ghc's usability, one way or another. Improving compile times would be the best usability boon I can think of. If there is promise in this project, I'd like to learn about any way I could help out.</div><br><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, 9 May 2019, 15.54 james faure, <<a href="mailto:james.faure@epitech.eu">james.faure@epitech.eu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black;background-color:rgb(255,255,255)">
<span style="margin:0px">Hello,</span><br>
</div>
<div style="margin:0px;font-size:15px;font-family:"Segoe UI","Segoe UI Web (West European)","Segoe UI",-apple-system,system-ui,Roboto,"Helvetica Neue",sans-serif;color:rgb(32,31,30);background-color:rgb(255,255,255)">
<div style="margin:0px">
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
I want to introduce the STG backend I am currently working on:</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
<a href="https://github.com/jfaure/lfvm-stg" rel="noopener noreferrer noreferrer" style="margin:0px" target="_blank">https://github.com/jfaure/lfvm-stg</a></div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
I'd love to see how much interest there is for this, to receive any comments, and find out if I've missed anything !</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
<br>
</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
The goal is to massively speed up compilation times and generate faster and clearer code, and in that respect I am already quite successful. Llvm is very well suited for encoding a (lazy) functional language, however t<span style="margin:0px;background-color:white">he
evaluation mechanism is</span><span> </span>very different to ghc's stg, there is notably no continuation passing nor result registers. In LFVM, all non constant let bindings are given an llvm function. I believe this approach is more natural, the llvm more
accurately reflects the source code and we get proper stack traces in a debugger.</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
<br>
</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
Status:</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
The project is barely a month old, and I'm working to support everything ghc's code generation supports.</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
The STG is heavily based on the one found in ghc and, at this time and as far as I can tell, supports<span style="margin:0px"> everything except multithreading, a gc and lazy evaluation. The current idea I think is very promising is to use an inferred pi calculus
to elegantly implement all 3 missing parts at once.</span></div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
<br>
</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
Pi calculus [1] (process calculus) In the STG</div>
<div style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;color:black">
<ul>
<li>Multithreading occurs for arguments of functions with >1 arity</li><li>Perfect garbage collection is quite probably possible<span style="margin:0px;background-color:white"><span style="margin:0px"> </span>[2]</span>, where allocation creates a new pi name, and its uses are modeled by pi calculus communication</li><li>Perfect Lazy evaluation (in the sense that the wrapper and associated wrapped type overhead is coerced away after the first evaluation) is possible in the pi calculus and closely linked the gc model. I intend to make strict evaluation the default, If you
want lazy (for MonadFix or infinite lists or whatever), you must request it.</li></ul>
<div style="margin:0px">[1]: <a href="https://en.wikipedia.org/wiki/%CE%A0-calculus" rel="noopener noreferrer noreferrer" style="margin:0px" target="_blank">https://en.wikipedia.org/wiki/%CE%A0-calculus</a></div>
</div>
<div style="margin:0px">[2]: <a href="https://www.researchgate.net/publication/228514964_Resources_garbage-collection_and_the_pi-calculus" rel="noopener noreferrer noreferrer" style="margin:0px;font-size:12pt;font-family:Calibri,Arial,Helvetica,sans-serif;text-align:left;background-color:white" target="_blank">https://www.researchgate.net/publication/228514964_Resources_garbage-collection_and_the_pi-calculus</a><br>
</div>
<div style="margin:0px"><br>
</div>
<div style="margin:0px"><span style="margin:0px;font-family:Calibri,Arial,Helvetica,sans-serif;color:black;background-color:white">James Faure (Discord: J4#0303)</span></div>
</div>
</div>
<br>
</div>
</div>
_______________________________________________<br>
Haskell-Cafe mailing list<br>
To (un)subscribe, modify options or view archives go to:<br>
<a href="http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe" rel="noreferrer noreferrer" target="_blank">http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe</a><br>
Only members subscribed via the mailman list are allowed to post.</blockquote></div></div></div>