GNU bug report logs - #34781
27.0.50; integer in pcase sometimes compared by eq

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Package: emacs;

Reported by: Mattias Engdegård <mattiase <at> acm.org>

Date: Thu, 7 Mar 2019 15:16:02 UTC

Severity: normal

Tags: patch

Found in version 27.0.50

Done: Mattias Engdegård <mattiase <at> acm.org>

Bug is archived. No further changes may be made.

Full log

Message #34 received at 34781 <at> debbugs.gnu.org (full text, mbox):

From: Michael Heerdegen <michael_heerdegen <at> web.de>
To: Paul Eggert <eggert <at> cs.ucla.edu>
Cc: Mattias Engdegård <mattiase <at> acm.org>,
 34781 <at> debbugs.gnu.org
Subject: Re: bug#34781: 27.0.50; integer in pcase sometimes compared by eq
Date: Thu, 28 Mar 2019 22:30:33 +0100

Paul Eggert <eggert <at> cs.ucla.edu> writes:

> On 3/28/19 12:47 PM, Michael Heerdegen wrote:
> > AFAIU the patch only corrects an optimization (use `memq' instead of
> > `member') that doesn't work for bignums.  This can never be harmful.
>
> Isn't it harmful if a 64-bit Emacs decides that the optimization is safe
> for the fixnum 1000000000 and thus generates the faster code, but the
> code is put into an .elc file and then loaded by a 32-bit emacs that
> treats 1000000000 as a bignum?

Ah ok - yes, I guess that would indeed happen.

Michael.
This bug report was last modified 6 years and 53 days ago.

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