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

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Message #31 received at 34781 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Michael Heerdegen <michael_heerdegen <at> web.de>
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 13:33:45 -0700

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?

(An alternative to this annoying most-positive-portable-bignum business
would be to require --with-wide-int on all platforms. :-)

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