From: "T.V Raman" <raman@google.com>
To: Tom Tromey <tom@tromey.com>
Cc: emacs-devel@gnu.org
Subject: Re: Emacs Lisp JIT Compiler
Date: Mon, 13 Aug 2018 06:50:03 -0700 [thread overview]
Message-ID: <p91va8e74vo.fsf@google.com> (raw)
In-Reply-To: <87va8ej4o1.fsf@tromey.com> (Tom Tromey's message of "Sun, 12 Aug 2018 22:01:34 -0600")
Tom Tromey <tom@tromey.com> writes:
Will it work with adviced functions?> Hi. I've written a JIT compiler for Emacs Lisp, and I'd like to check
> it in.
>
> This JIT is based on GNU libjit, like some other attempts that have come
> before it. However, this one is somewhat faster than those, primarily
> because it does all stack manipulations at compile time, not runtime.
>
> In some simple benchmarks, it is about 3x faster than the bytecode
> interpreter.
>
> I have only tested this on x86-64. Whether or not the JIT works on a
> given platform is primarily up to libjit. (I suspect the JIT won't work
> on x86 with --with-wide-int; but that is something I could fix.)
>
> I currently have the JIT set up to always compile all eligible functions
> (that is, just byte-compiled, lexically-bound functions). It's robust
> enough that, as far as I can tell, everything works fine in this mode.
> It would be possible to have it be a bit lazier, say only compile after
> 100 invocations, or something like that.
>
> Aside from the possible --with-wide-int thing, there are two bugs I know
> of.
>
> First, libjit never frees functions. So, if a function is JIT-compiled
> and then redefined, the old JIT code will linger. It's possible to fix
> this with a custom allocator and a libjit patch (that I sent but that
> hasn't been checked in yet).
>
> Second, I haven't gotten around to emulating the "quitcounter" behavior
> in the bytecode interpreter. This seems straightforward.
>
>
> This version of the compiler is pretty basic. It just compiles each
> bytecode to more or less the obvious thing. I have some plans to make
> the calling convention a bit less expensive, and to allow for inlining.
>
> Note that this change does not involve any semantic changes to Emacs Lisp.
> Also, if libjit is unavailable, the JIT is simply disabled.
>
> Tom
>
--
next prev parent reply other threads:[~2018-08-13 13:50 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 4:01 Emacs Lisp JIT Compiler Tom Tromey
2018-08-13 5:37 ` Paul Eggert
2018-08-13 15:15 ` Tom Tromey
2018-08-14 0:16 ` Tom Tromey
2018-08-14 20:11 ` Daniel Colascione
2018-08-14 20:55 ` Paul Eggert
2018-08-14 21:03 ` Daniel Colascione
2018-08-14 22:38 ` Paul Eggert
2018-08-15 16:41 ` Eli Zaretskii
2018-08-15 17:16 ` Paul Eggert
2018-08-15 17:47 ` Eli Zaretskii
2018-08-16 0:29 ` Tom Tromey
2018-08-16 13:26 ` Eli Zaretskii
2018-08-16 15:43 ` Daniel Colascione
2018-08-16 16:22 ` Andreas Schwab
2018-08-19 18:17 ` Tom Tromey
2018-08-19 19:00 ` Eli Zaretskii
2018-08-19 19:16 ` Tom Tromey
2018-08-19 20:23 ` Stefan Monnier
2018-08-18 10:10 ` Steinar Bang
2018-08-18 11:31 ` Eli Zaretskii
2018-08-19 10:00 ` Robert Pluim
2018-08-19 15:01 ` Eli Zaretskii
2018-08-19 15:26 ` Tom Tromey
2018-08-23 0:47 ` Tom Tromey
2018-08-23 16:48 ` Eli Zaretskii
2018-08-24 17:54 ` Tom Tromey
2018-08-24 20:23 ` Eli Zaretskii
2018-08-24 21:03 ` Tom Tromey
2018-08-25 6:51 ` Eli Zaretskii
2018-09-10 11:03 ` Ergus
2018-09-10 11:15 ` Robert Pluim
2018-09-10 11:53 ` Tom Tromey
2018-09-12 13:37 ` Robert Pluim
2018-09-13 4:32 ` Tom Tromey
2018-08-16 0:03 ` Tom Tromey
2018-08-16 2:45 ` Eli Zaretskii
2018-08-16 18:07 ` Eli Zaretskii
2018-08-13 13:50 ` T.V Raman [this message]
2018-08-13 15:18 ` Tom Tromey
2018-08-13 15:23 ` T.V Raman
2018-08-13 15:15 ` Eli Zaretskii
2018-08-20 21:54 ` John Wiegley
2018-08-13 23:31 ` Richard Stallman
2018-08-13 23:51 ` Tom Tromey
2018-08-16 2:42 ` Richard Stallman
2018-08-15 0:21 ` Clément Pit-Claudel
2018-08-16 0:32 ` Tom Tromey
2018-08-16 2:14 ` Clément Pit-Claudel
-- strict thread matches above, loose matches on Subject: below --
2016-12-11 17:37 Nickolas Lloyd
2016-12-12 6:07 ` John Wiegley
2016-12-12 11:51 ` Nickolas Lloyd
2016-12-12 16:45 ` John Wiegley
2016-12-23 17:22 ` Nickolas Lloyd
2016-12-13 22:24 ` Johan Bockgård
2016-12-05 18:16 Burton Samograd
2016-12-05 18:40 ` Eli Zaretskii
2016-12-05 19:32 ` Daniel Colascione
2016-12-05 21:03 ` Burton Samograd
2016-12-06 15:54 ` Lluís
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