path: root/2025/info/juicemacs-after.md

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<div class="transcript transcript-mainVideo"><a name="juicemacs-mainVideo-transcript"></a><h1>Transcript</h1>

[[!template text="""Hello! This is Kana!""" start="00:00:01.200" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And today I'll be talking about""" start="00:00:02.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""<b>J</b>ust-<b>I</b>n-<b>T</b>ime compilation, or JIT,""" start="00:00:04.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for Emacs Lisp,""" start="00:00:06.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""based on my work-in-progress Emacs clone, Juicemacs.""" start="00:00:07.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Juicemacs aims to explore a few things""" start="00:00:11.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that I've been wondering about for a while.""" start="00:00:13.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For exmaple, what if we had better or even""" start="00:00:15.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""transparent concurrency in ELisp?""" start="00:00:18.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Or, can we have a concurrent GUI?""" start="00:00:21.323" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""One that does not block, or is blocked by Lisp code?""" start="00:00:23.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And finally what can JIT compilation do for ELisp?""" start="00:00:26.883" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Will it provide better performance?""" start="00:00:31.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, a main problem with explorations""" start="00:00:34.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in Emacs clones is that,""" start="00:00:37.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Emacs is a whole universe.""" start="00:00:38.723" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And that means, to make these explorations""" start="00:00:40.963" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""meaningful for Emacs users,""" start="00:00:43.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we need to cover a lot of Emacs features,""" start="00:00:45.483" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""before we can ever begin.""" start="00:00:47.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For example, one of the features of Emacs is that,""" start="00:00:50.643" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it supports a lot of encodings.""" start="00:00:54.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Let's look at this string: it can be encoded""" start="00:00:56.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in both Unicode and Shift-JIS, a Japanese encoding system.""" start="00:00:59.268" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But currently, Unicode does not have""" start="00:01:03.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""an official mapping for this &quot;ki&quot; (﨑) character.""" start="00:01:07.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So when we map from Shift-JIS to Unicode,""" start="00:01:09.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in most programming languages,""" start="00:01:12.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""you end up with something like this:""" start="00:01:14.523" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it's a replacement character.""" start="00:01:16.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But in Emacs, it actually extends""" start="00:01:19.243" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the Unicode range by threefold,""" start="00:01:22.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and uses the extra range to losslessly""" start="00:01:23.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""support characters like this.""" start="00:01:26.834" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So if you want to support this feature,""" start="00:01:29.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that basically rules out all string""" start="00:01:32.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""libraries with Unicode assumptions.""" start="00:01:34.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For another, you need to support""" start="00:01:37.843" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the regular expressions in Emacs,""" start="00:01:40.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which are, really irregular.""" start="00:01:41.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For example, it supports asserting""" start="00:01:45.123" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""about the user cursor position.""" start="00:01:46.901" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And it also uses some character tables,""" start="00:01:49.503" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that can be modified from Lisp code,""" start="00:01:52.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to determine to case mappings.""" start="00:01:53.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And all that makes it really hard, or even""" start="00:01:56.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""impossible to use any existing regexp libraries.""" start="00:01:59.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Also, you need a functional garbage collector.""" start="00:02:05.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""You need threading primitives, because""" start="00:02:07.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Emacs has already had some threading support.""" start="00:02:09.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And you might want the performance of your clone""" start="00:02:12.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to match Emacs, even with its native compilation enabled.""" start="00:02:14.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Not to mention you also need a GUI for an editor.""" start="00:02:19.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And so on.""" start="00:02:21.501" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For Juicemacs, building on Java and""" start="00:02:23.643" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""a compiler framework called Truffle,""" start="00:02:25.634" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""helps in getting better performance;""" start="00:02:27.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and by choosing a language with a good GC,""" start="00:02:30.603" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we can actually focus more on the challenges above.""" start="00:02:32.934" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Currently, Juicemacs has implemented three out of,""" start="00:02:38.163" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""at least four of the interpreters in Emacs.""" start="00:02:41.434" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""One for lisp code, one for bytecode,""" start="00:02:44.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and one for regular expressions,""" start="00:02:46.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""all of them JIT-capable.""" start="00:02:48.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Other than these, Emacs also has around""" start="00:02:51.003" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""two thousand built-in functions in C code.""" start="00:02:53.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And Juicemacs has around""" start="00:02:56.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""four hundred of them implemented.""" start="00:02:57.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It's not that many, but it is surprisingly enough""" start="00:02:59.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to bootstrap Emacs and run""" start="00:03:03.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the portable dumper, or pdump, in short.""" start="00:03:05.201" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Let's have a try.""" start="00:03:08.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""""" start="00:03:11.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So this is the binary produced by Java native image.""" start="00:03:11.803" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And it's loading all the files""" start="00:03:15.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""needed for bootstrapping.""" start="00:03:17.168" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Then it dumps the memory to a file to""" start="00:03:18.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""be loaded later, giving us fast startup.""" start="00:03:22.234" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""As we can see here, it throws some frame errors""" start="00:03:25.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""because Juicemacs doesn't have an editor UI""" start="00:03:28.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or functional frames yet.""" start="00:03:31.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But otherwise, it can already run""" start="00:03:33.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""quite some lisp code.""" start="00:03:35.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For example, this code uses the benchmark library""" start="00:03:36.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to measure the performance of this Fibonacci function.""" start="00:03:40.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And we can see here, the JIT engine is""" start="00:03:44.503" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""already kicking in and makes the execution faster.""" start="00:03:47.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""In addition to that, with a bit of workaround,""" start="00:03:51.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Juicemacs can also run some of the ERT,""" start="00:03:53.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or, <b>E</b>macs <b>R</b>egression <b>T</b>est suite, that comes with Emacs.""" start="00:03:56.468" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So... Yes, there are a bunch of test failures,""" start="00:04:01.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which means we are not that compatible""" start="00:04:05.923" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""with Emacs and need more work.""" start="00:04:07.934" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But the whole testing procedure runs fine,""" start="00:04:09.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and it has proper stack traces,""" start="00:04:12.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which is quite useful for debugging Juicemacs.""" start="00:04:14.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So with that, a rather functional JIT runtime,""" start="00:04:17.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""let's now try look into today's topic, JIT compilation for ELisp.""" start="00:04:21.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, you probably know that Emacs has supported""" start="00:04:26.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""native-compilation, or nativecomp in short, for some time now.""" start="00:04:28.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It mainly uses GCC to compile Lisp code""" start="00:04:32.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""into native code, ahead of time.""" start="00:04:35.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And during runtime, Emacs loads those compiled files,""" start="00:04:37.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and gets the performance of native code.""" start="00:04:41.434" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, for example, for installed packages,""" start="00:04:44.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we might want to compile them when we""" start="00:04:47.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""actually use them instead of ahead of time.""" start="00:04:49.060" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And Emacs supports this through""" start="00:04:51.923" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""this <i>native-comp-jit-compilation</i> flag.""" start="00:04:53.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""What it does is, during runtime, Emacs sends""" start="00:04:55.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""loaded files to external Emacs worker processes,""" start="00:04:59.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which will then compile those files asynchronously.""" start="00:05:03.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And when the compilation is done,""" start="00:05:07.003" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the current Emacs session will load the compiled code back""" start="00:05:09.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and improves its performance, on the fly.""" start="00:05:11.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""When you look at this procedure, however, it is,""" start="00:05:16.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""ahead-of-time compilation, done at runtime.""" start="00:05:18.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And it is what current Emacs calls JIT compilation.""" start="00:05:21.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But if you look at some other JIT engines,""" start="00:05:25.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""you'll see much more complex architectures.""" start="00:05:27.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, take luaJIT for an example,""" start="00:05:31.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in addition to this red line here,""" start="00:05:34.234" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which leads us from an interpreted state""" start="00:05:36.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to a compiled native state,""" start="00:05:38.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which is also what Emacs does,""" start="00:05:40.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""LuaJIT also supports going from""" start="00:05:42.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""a compiled state back to its interpreter.""" start="00:05:44.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And this process is called &quot;deoptimization&quot;.""" start="00:05:47.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""In contrast to its name, deoptimization here actually""" start="00:05:51.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""enables a huge category of JIT optimizations.""" start="00:05:55.301" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""They are called speculation.""" start="00:05:58.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Basically, with speculation, the compiler""" start="00:06:01.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""can use runtime statistics to speculate,""" start="00:06:04.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to make bolder assumptions in the compiled code.""" start="00:06:07.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And when the assumptions are invalidated,""" start="00:06:11.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the runtime deoptimizes the code, updates statistics,""" start="00:06:14.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and then recompile the code based on new assumptions,""" start="00:06:18.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and that will make the code more performant.""" start="00:06:21.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Let's look at an example.""" start="00:06:24.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, here is a really simple function,""" start="00:06:28.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that adds one to the input number.""" start="00:06:30.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But in Emacs, it is not that simple,""" start="00:06:33.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""because Emacs has three categories of numbers,""" start="00:06:36.168" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that is, fix numbers, or machine-word-sized integers,""" start="00:06:38.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""floating numbers, and big integers.""" start="00:06:42.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And when we compile this, we need""" start="00:06:45.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to handle all three cases.""" start="00:06:47.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And if we analyze the code produced by Emacs,""" start="00:06:49.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""as is shown by this gray graph here,""" start="00:06:52.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we can see that it has, two paths:""" start="00:06:54.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""One fast path, that does fast fix number addition;""" start="00:06:58.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and one for slow paths, that calls out""" start="00:07:01.503" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to an external plus-one function,""" start="00:07:03.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to handle floating number and big integers.""" start="00:07:06.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Now, if we pass integers into this function,""" start="00:07:09.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it's pretty fast because it's on the fast path.""" start="00:07:13.168" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, if we pass in a floating number,""" start="00:07:16.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""then it has to go through the slow path,""" start="00:07:19.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""doing an extra function call, which is slow.""" start="00:07:21.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""What speculation might help here is that,""" start="00:07:25.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it can have flexible fast paths.""" start="00:07:28.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""When we pass a floating number into this function,""" start="00:07:31.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which currently has only fixnumbers on the fast path,""" start="00:07:34.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it also has to go through the slow path.""" start="00:07:37.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But the difference is that, a speculative runtime can""" start="00:07:40.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""deoptimize and recompile the code to adapt to this.""" start="00:07:44.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And when it recompiles, it might add""" start="00:07:47.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""floating number onto the fast path,""" start="00:07:50.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and now floating number operations are also fast.""" start="00:07:52.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And this kind of speculation is why""" start="00:07:55.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""speculative runtime can be really fast.""" start="00:07:58.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Let's take a look at some benchmarks.""" start="00:08:03.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""They're obtained with the <i>elisp-benchmarks</i> library on ELPA.""" start="00:08:05.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""The blue line here is for nativecomp,""" start="00:08:09.523" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and these blue areas mean that nativecomp is slower.""" start="00:08:12.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And, likewise, green areas mean that""" start="00:08:16.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Juicemacs is slower.""" start="00:08:19.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""At a glance, the two (or four)""" start="00:08:20.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""actually seems somehow on par, to me.""" start="00:08:22.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But, let's take a closer look at some of them.""" start="00:08:25.243" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, the first few benchmarks are the classic,""" start="00:08:30.483" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Fibonacci benchmarks.""" start="00:08:32.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""We know that, the series is formed by""" start="00:08:34.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""adding the previous two numbers in the series.""" start="00:08:36.934" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And looking at this expression here,""" start="00:08:39.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Fibonacci benchmarks are quite intensive""" start="00:08:41.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in number additions, subtractions,""" start="00:08:44.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and function calls, if you use recursions.""" start="00:08:46.801" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And it is exactly why""" start="00:08:49.203" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Fibonacci series is a good benchmark.""" start="00:08:51.001" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And looking at the results here... wow.""" start="00:08:54.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Emacs nativecomp executes instantaneously.""" start="00:08:57.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It's a total defeat for Juicemacs, seemingly.""" start="00:08:59.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Now, if you're into benchmarks, you know something is wrong here:""" start="00:09:04.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we are comparing the different things.""" start="00:09:08.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So let's look under the hood""" start="00:09:11.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and disassemble the function""" start="00:09:14.201" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""with this convenient Emacs command""" start="00:09:15.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""called <i>disassemble</i>...""" start="00:09:17.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And these two lines of code is what we got.""" start="00:09:19.163" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, we already can see""" start="00:09:23.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""what's going on here:""" start="00:09:24.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""GCC sees Fibonacci is a pure function,""" start="00:09:26.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""because it returns the same value""" start="00:09:30.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for the same arguments,""" start="00:09:31.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""so GCC chooses to do the computation""" start="00:09:33.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""at compile time""" start="00:09:35.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and inserts the final number directly""" start="00:09:36.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""into the compiled code.""" start="00:09:39.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It is actually great!""" start="00:09:41.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Because it shows that nativecomp""" start="00:09:43.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""knows about pure functions,""" start="00:09:45.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and can do all kinds of things""" start="00:09:47.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""like removing or constant-folding them.""" start="00:09:48.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And Juicemacs just does not do that.""" start="00:09:51.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, we are also concerned about""" start="00:09:54.503" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the things we mentioned earlier:""" start="00:09:57.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the performance of number additions,""" start="00:09:59.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or function calls.""" start="00:10:00.901" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, in order to let the benchmarks""" start="00:10:03.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""show some extra things,""" start="00:10:05.634" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we need to modify it a bit...""" start="00:10:06.963" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""by simply making things non-constant.""" start="00:10:08.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""With that, Emacs gets much slower now.""" start="00:10:11.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And again, let's look what's""" start="00:10:15.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""happening behind these numbers.""" start="00:10:17.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Similarly, with the <i>disassemble</i> command,""" start="00:10:21.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we can look into the assembly.""" start="00:10:23.501" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And again, we can already see""" start="00:10:25.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""what's happening here.""" start="00:10:28.020" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, Juicemacs, due to its speculation nature,""" start="00:10:29.403" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""supports fast paths for all three kind of numbers.""" start="00:10:32.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, currently, Emacs nativecomp""" start="00:10:35.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""does not have any fast path""" start="00:10:39.234" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for the operations here like additions,""" start="00:10:41.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or subtractions, or comparisons,""" start="00:10:43.434" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which is exactly what""" start="00:10:45.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Fibonacci benchmarks are measuring.""" start="00:10:48.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Emacs, at this time, has to call some generic,""" start="00:10:51.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""external functions for them, and this is slow.""" start="00:10:53.801" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But is nativecomp really that slow?""" start="00:11:00.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, I also ran the same benchmark""" start="00:11:03.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in Common Lisp, with SBCL.""" start="00:11:04.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And nativecomp is already fast,""" start="00:11:07.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""compared to untyped SBCL.""" start="00:11:09.001" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It's because SBCL also emits call instructions""" start="00:11:11.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""when it comes to no type info.""" start="00:11:15.501" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, once we declare the types,""" start="00:11:18.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""SBCL is able to compile a fast path for fix numbers,""" start="00:11:21.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which makes its performance on par""" start="00:11:25.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""with speculative JIT engines (that is, Juicemacs),""" start="00:11:27.468" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""because, now both of us are now on fast paths.""" start="00:11:30.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Additionally, if we are bold enough""" start="00:11:36.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to pass this safety zero flag to SBCL,""" start="00:11:38.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it will remove all the slow paths""" start="00:11:41.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and type checks,""" start="00:11:43.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and its performance is close""" start="00:11:45.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to what you get with C.""" start="00:11:46.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Well, probably we don't want safety zero""" start="00:11:48.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""most of the time.""" start="00:11:51.300" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But even then, if nativecomp were to""" start="00:11:52.163" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""get fast paths for more constructs,""" start="00:11:55.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""there certainly is quite""" start="00:11:57.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""some room for performance improvement.""" start="00:11:59.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Let's look at some more benchmarks.""" start="00:12:04.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For example, for this inclist,""" start="00:12:06.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or increment-list, benchmark,""" start="00:12:08.934" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Juicemacs is really slow here. Partly,""" start="00:12:11.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it comes from the cost of Java boxing integers.""" start="00:12:14.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""On the other hand, for Emacs nativecomp,""" start="00:12:17.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for this particular benchmark,""" start="00:12:20.301" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it actually has fast paths""" start="00:12:22.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for all of the operations.""" start="00:12:23.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And that's why it can be so fast,""" start="00:12:25.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and that also proves the nativecomp""" start="00:12:27.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""has a lot potential for improvement.""" start="00:12:30.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""There is another benchmark here""" start="00:12:33.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that use advices.""" start="00:12:35.834" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So Emacs Lisp supports using""" start="00:12:38.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""advices to override functions""" start="00:12:40.501" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""by wrapping the original function, and an advice""" start="00:12:42.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""function, two of them, inside a glue function.""" start="00:12:44.834" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And in this benchmark, we advice the Fibonacci function""" start="00:12:47.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to cache the first ten entries to speed up computation,""" start="00:12:51.468" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""as can be seen in the speed-up in the Juicemacs results.""" start="00:12:54.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""However, it seems that nativecomp does not yet""" start="00:13:00.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""compile glue functions, and that makes advices slower.""" start="00:13:02.901" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""With these benchmarks, let's discuss this big question:""" start="00:13:08.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Should GNU Emacs adopt speculative JIT compilation?""" start="00:13:12.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Well, the hidden question is actually,""" start="00:13:16.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""is it worth it?""" start="00:13:18.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And, my personal answer is, maybe not.""" start="00:13:21.323" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""The first reason is that, slow paths, like, floating numbers,""" start="00:13:24.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""are actually not that frequent in Emacs.""" start="00:13:28.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And optimizing for fast paths like fix numbers""" start="00:13:31.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""can already get us very good performance already.""" start="00:13:34.101" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And the second or main reason is that,""" start="00:13:38.083" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""speculative JIT is very hard.""" start="00:13:40.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""LuaJIT, for example, took a genius to build.""" start="00:13:43.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Even with the help of GCC, we need to hand-write""" start="00:13:46.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""all those fast path or slow path or switching logic.""" start="00:13:50.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""We need to find a way to deoptimize, which requires""" start="00:13:54.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""mapping machine registers back to interpreter stack.""" start="00:13:58.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And also, speculation needs runtime info,""" start="00:14:01.903" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which also costs us extra memory.""" start="00:14:04.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Moreover, as is shown by some benchmarks above,""" start="00:14:07.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""there's some low-hanging fruits in nativecomp that""" start="00:14:10.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""might get us better performance with relatively lower effort.""" start="00:14:13.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Compared to this, a JIT engine is a huge, huge undertaking.""" start="00:14:17.443" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But, for Juicemacs, the JIT engine comes a lot cheaper,""" start="00:14:22.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""because, we are cheating by building on""" start="00:14:26.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""an existing compiler framework called Truffle.""" start="00:14:29.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Truffle is a meta-compiler framework,""" start="00:14:33.543" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which means that it lets you write""" start="00:14:35.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""an interpreter, add required annotations,""" start="00:14:37.634" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and it will automatically turn the""" start="00:14:40.203" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""interpreter into a JIT runtime.""" start="00:14:42.501" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So for example, here is a typical bytecode interpreter.""" start="00:14:45.743" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""After you add the required annotations,""" start="00:14:49.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Truffle will know that,""" start="00:14:51.234" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the bytecode here is constant, and it should""" start="00:14:52.623" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""unroll this loop here, to inline all those bytecode.""" start="00:14:55.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And then, when Truffle""" start="00:14:59.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""compiles the code, it knows that:""" start="00:15:00.468" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""the first loop here does: x plus one,""" start="00:15:02.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and the second does: return.""" start="00:15:05.234" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And then it will compile all that into,""" start="00:15:07.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""return x plus 1,""" start="00:15:09.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which is exactly what we would expect""" start="00:15:11.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""when compiling this pseudo code.""" start="00:15:14.068" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Building on that, we can also easily implement speculation,""" start="00:15:17.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""by using this <i>transferToInterpreterAndInvalidate</i> function""" start="00:15:21.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""provided by Truffle.""" start="00:15:24.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And Truffle will automatically turn that""" start="00:15:26.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""into deoptimization.""" start="00:15:28.534" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Now, for example, when this add function""" start="00:15:30.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""is supplied with, two floating numbers.""" start="00:15:32.701" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""It will go through the slow path here,""" start="00:15:35.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which might lead to a compiled slow path,""" start="00:15:38.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or deoptimization.""" start="00:15:40.961" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And going this deoptimization way,""" start="00:15:43.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""it can then update the runtime stats.""" start="00:15:45.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And now, when the code is compiled again,""" start="00:15:48.323" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Truffle will know,""" start="00:15:50.401" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that these compilation stats, suggests that,""" start="00:15:51.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""we have floating numbers.""" start="00:15:54.101" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And this floating point addition branch will""" start="00:15:55.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""then be incorporated into the fast path.""" start="00:15:58.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""To put it into Java code...""" start="00:16:02.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Most operations are just as simple as this.""" start="00:16:06.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And it supports fast paths for integers,""" start="00:16:08.823" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""floating numbers, and big integers.""" start="00:16:11.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And the simplicity of this not only saves us work,""" start="00:16:14.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""but also enables Juicemacs to explore more things more rapidly.""" start="00:16:17.134" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And actually, I have done some silly explorations.""" start="00:16:22.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For example, I tried to constant-fold more things.""" start="00:16:26.583" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Many of us have an Emacs config that stays""" start="00:16:30.303" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""largely unchanged, at least during one Emacs session.""" start="00:16:32.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And that means many of the global variables""" start="00:16:36.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in ELisp are constant.""" start="00:16:39.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And with speculation, we can""" start="00:16:42.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""speculate about the stable ones,""" start="00:16:44.601" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and try to inline them as constants.""" start="00:16:46.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And this might improve performance,""" start="00:16:49.663" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or maybe not?""" start="00:16:51.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Because, we will need a full editor""" start="00:16:53.183" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to get real world data.""" start="00:16:55.368" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""I also tried changing cons lists to be backed""" start="00:16:58.223" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""by some arrays, because, maybe arrays are faster, I guess?""" start="00:17:01.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But in the end, <i>setcdr</i> requires some kind of indirection,""" start="00:17:05.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and that actually makes the performance worse.""" start="00:17:09.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And for regular expressions,""" start="00:17:12.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""I also tried borrowing techniques from PCRE JIT,""" start="00:17:14.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""which is quite fast in itself, but it is""" start="00:17:18.023" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""unfortunately unsupported by Java Truffle runtime.""" start="00:17:20.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""So, looking at these, well,""" start="00:17:24.263" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""explorations can fail, certainly.""" start="00:17:27.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But, with Truffle and Java, these,""" start="00:17:30.343" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""for now, are not that hard to implement,""" start="00:17:32.801" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and also very often, they teach us something""" start="00:17:34.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""in return, whether or not they fail.""" start="00:17:37.668" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Finally, let's talk about some explorations""" start="00:17:42.463" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""that we might get into in the future.""" start="00:17:45.334" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For the JIT engine, for example,""" start="00:17:47.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""currently I'm looking into the implementation of""" start="00:17:49.783" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""nativecomp to maybe reuse some of its optimizations.""" start="00:17:52.634" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""For the GUI, I'm very very slowly working on one.""" start="00:17:56.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""If it ever completes, I have one thing""" start="00:18:01.423" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""I'm really looking forward to implementing.""" start="00:18:03.734" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""That is, inlining widgets, or even""" start="00:18:06.703" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""other buffers, directly into a buffer.""" start="00:18:08.901" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Well, it's because, people sometimes complain""" start="00:18:11.863" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""about Emacs's GUI capabilities,""" start="00:18:13.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But I personally think that supporting inlining,""" start="00:18:16.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""like a whole buffer inside another buffer as a rectangle,""" start="00:18:19.768" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""could get us very far in layout abilities.""" start="00:18:23.143" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And this approach should also""" start="00:18:26.983" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""be compatible with terminals.""" start="00:18:28.568" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And I really want to see how this idea""" start="00:18:30.943" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""plays out with Juicemacs.""" start="00:18:32.934" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And of course, there's Lisp concurrency.""" start="00:18:36.103" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And currently i'm thinking of a JavaScript-like,""" start="00:18:39.063" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""transparent, single-thread model, using Java's virtual threads.""" start="00:18:42.168" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""But anyway, if you are interested in JIT compilation,""" start="00:18:46.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Truffle, or anything above,""" start="00:18:49.968" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""or maybe you have your own ideas,""" start="00:18:51.763" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""you are very welcome to reach out!""" start="00:18:53.868" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Juicemacs does need to implement many more built-in functions,""" start="00:18:56.383" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""and any help would be very appreciated.""" start="00:19:00.034" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""And I promise, it can be a very fun playground""" start="00:19:03.163" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""to learn about Emacs and do crazy things.""" start="00:19:05.801" video="mainVideo-juicemacs" id="subtitle"]]
[[!template text="""Thank you!""" start="00:19:08.443" video="mainVideo-juicemacs" id="subtitle"]]

</div>Questions or comments? Please e-mail [kana@iroiro.party](mailto:kana@iroiro.party?subject=Comment%20for%20EmacsConf%202023%20juicemacs%3A%20Juicemacs%3A%20exploring%20speculative%20JIT%20compilation%20for%20ELisp%20in%20Java)


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