From: Pip Cet <pipcet@gmail.com>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: "Mattias Engdegård" <mattiase@acm.org>,
"Stefan Monnier" <monnier@iro.umontreal.ca>,
emacs-devel@gnu.org
Subject: Re: Bug#38708: eq vs eql in byte-compiled code
Date: Thu, 2 Jan 2020 12:27:14 +0000 [thread overview]
Message-ID: <CAOqdjBdSZSQoUbe10tx7bc5kqwuC=qG=aYAMOXeNOuEDQtzjfA@mail.gmail.com> (raw)
In-Reply-To: <1e0940ff-e418-bafc-66d3-72b562b2c65b@cs.ucla.edu>
On Thu, Jan 2, 2020 at 7:52 AM Paul Eggert <eggert@cs.ucla.edu> wrote:
> I did that, and surprise! it sped up 'make compile-always' by about 7% on the
> two platforms I tried it on (Fedora 31 and Ubuntu 18.04.3, both x86-64).
For what it's worth, I'm not seeing that effect, and it seems too
large to me to be easily explicable.
I might be mistaken, but our hash tables never shrink, do they? That
sounds like a potential problem to me, particularly for people who
mess about with gc settings; but I haven't been able to produce a
problem in practice with your patch.
> Two or three issues:
>
> * Should we document that eq == eql on bignums, or continue to leave this stuff
> unspecified?
I don't think we should be making any new promises about eq.
> * Should we try hash-consing floats too? Maybe it wouldn't be as slow as we
> thought, for typical computations anyway....
I think the answer is yes here...
> * The attached patch could probably be sped up a bit by supporting sets as well
> as mappings at the low level, since bignum_map is really just a set of bignums.
> Not sure it's worth the effort, though.
if it's also yes here.
next prev parent reply other threads:[~2020-01-02 12:27 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-31 15:07 Bug#38708: eq vs eql in byte-compiled code Pip Cet
2019-12-31 15:51 ` Andrea Corallo
2019-12-31 16:05 ` Mattias Engdegård
2019-12-31 17:38 ` Paul Eggert
2020-01-01 12:38 ` Mattias Engdegård
2020-01-02 8:38 ` Paul Eggert
2020-01-02 17:26 ` Mattias Engdegård
2020-01-04 19:55 ` Stefan Monnier
2020-01-22 10:56 ` Mattias Engdegård
2020-01-25 0:59 ` Paul Eggert
2020-01-01 15:45 ` Stefan Monnier
2020-01-02 7:52 ` Paul Eggert
2020-01-02 12:27 ` Pip Cet [this message]
2020-01-02 23:12 ` Paul Eggert
2020-01-02 13:48 ` Eli Zaretskii
2020-01-04 18:54 ` Stefan Monnier
2020-01-04 19:33 ` Paul Eggert
2020-01-04 19:49 ` Stefan Monnier
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