From: Noam Postavsky <npostavs@gmail.com>
To: Pip Cet <pipcet@gmail.com>
Cc: Robert Pluim <rpluim@gmail.com>, Paul Eggert <eggert@cs.ucla.edu>,
Emacs developers <emacs-devel@gnu.org>
Subject: Re: Floating-point constant folding in Emacs byte compiler
Date: Mon, 2 Apr 2018 08:57:30 -0400 [thread overview]
Message-ID: <CAM-tV--e4fp4CE21AsB5xnQYN1YyWUOnX1U8pXGn=OANhLUcbg@mail.gmail.com> (raw)
In-Reply-To: <CAOqdjBfOSJ+aP4OnEBw2njV2H6_PzC87BVbDjazU+2h2PERbdQ@mail.gmail.com>
On 30 March 2018 at 12:26, Pip Cet <pipcet@gmail.com> wrote:
> It's easy to fix this by merging the constvec based on eql rather than
> eq, but that makes the byte compiler inconsistent: with optimization,
> (lambda () (eq 1024.0 1024.0)) will still be false, but without
> optimization, it will turn into bytecode that always returns true.
The byte-compiler is already inconsistent in this way for string literals:
(funcall (byte-compile (lambda ()
(let ((s "one") (s2 "one"))
(eq s s2)))))
;=> t
(funcall (lambda ()
(let ((s "one") (s2 "one"))
(eq s s2))))
;=> nil
Although surprisingly:
(funcall (byte-compile (lambda ()
(eq "one" "one"))))
;=> nil
next prev parent reply other threads:[~2018-04-02 12:57 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-22 23:04 Floating-point constant folding in Emacs byte compiler Paul Eggert
2018-03-23 1:26 ` Stefan Monnier
2018-03-23 5:22 ` Paul Eggert
2018-03-23 8:24 ` Eli Zaretskii
2018-03-23 20:00 ` Paul Eggert
2018-03-23 8:15 ` Eli Zaretskii
2018-03-23 20:52 ` Pip Cet
2018-03-24 6:25 ` Eli Zaretskii
2018-03-26 9:39 ` Robert Pluim
2018-03-26 15:13 ` Eli Zaretskii
2018-03-26 15:57 ` Robert Pluim
2018-03-26 16:02 ` Eli Zaretskii
2018-03-26 18:23 ` Pip Cet
2018-03-26 18:29 ` Eli Zaretskii
2018-03-27 0:28 ` Paul Eggert
2018-03-27 23:28 ` Paul Eggert
2018-03-30 16:26 ` Pip Cet
2018-03-30 16:31 ` Noam Postavsky
2018-03-30 16:39 ` Paul Eggert
2018-04-02 10:56 ` Pip Cet
2018-04-02 11:22 ` Eli Zaretskii
2018-04-02 11:42 ` Pip Cet
2018-04-02 12:50 ` Eli Zaretskii
2018-04-02 14:50 ` Stefan Monnier
2018-04-02 15:02 ` Pip Cet
2018-04-02 12:57 ` Noam Postavsky [this message]
2018-04-02 13:30 ` Eli Zaretskii
2018-04-02 14:48 ` Stefan Monnier
2018-04-02 19:20 ` Paul Eggert
2018-04-02 19:39 ` Pip Cet
2018-04-02 19:58 ` Eli Zaretskii
2018-04-02 20:55 ` Pip Cet
[not found] ` <<83y3i568i0.fsf@gnu.org>
2018-04-02 13:37 ` Drew Adams
2018-04-02 14:05 ` Eli Zaretskii
2018-04-02 14:54 ` Pip Cet
2018-04-02 15:02 ` Drew Adams
2018-03-26 17:52 ` Stefan Monnier
2018-03-26 18:30 ` Eli Zaretskii
2018-03-27 0:08 ` Paul Eggert
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