From: Chong Yidong <cyd@stupidchicken.com>
To: Juri Linkov <juri@jurta.org>
Cc: 5754@debbugs.gnu.org
Subject: bug#5754: Bytecomp Arithmetic test failed
Date: Sat, 03 Apr 2010 18:40:59 -0400 [thread overview]
Message-ID: <87iq88ma6c.fsf@stupidchicken.com> (raw)
In-Reply-To: <87ocifjx74.fsf@mail.jurta.org>
> I tried to run some tests in the `test' subdir,
> and `bytecomp-testsuite-run' in `test/bytecomp-testsuite.el' fails
> on one test: (let ((a (expt 2 -1074)) (b 0.125)) (* a 8 b))
> returns 5e-324 when evaluated by interpreter,
> but after byte-compilation returns 0.0
I originally thought this was a regression, because my copy of Emacs
23.1 did not appear to have this problem. On further investigation, it
is not a regression. Emacs 23.1 and before also have the problem.
The key is that if I compile Emacs with CFLAGS="-g", then
(funcall
(byte-compile
(list 'lambda nil
(quote (let ((a (expt 2 -1074)) (b 0.125)) (* a 8 b))))))
returns 0.0. If I compile Emacs with CFLAGS="-g -O2", then it returns
5e-324.
It looks like this may be a compiler bug.
next prev parent reply other threads:[~2010-04-03 22:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-23 7:47 bug#5754: Bytecomp Arithmetic test failed Juri Linkov
2010-03-23 8:38 ` Lennart Borgman
2010-03-23 9:03 ` Juri Linkov
2010-03-23 13:31 ` Lennart Borgman
2010-03-24 22:15 ` Chong Yidong
2010-03-24 22:52 ` Lennart Borgman
2010-03-25 1:15 ` Stefan Monnier
2010-03-25 1:19 ` Lennart Borgman
2010-03-25 7:19 ` Juri Linkov
2010-03-30 16:08 ` Juri Linkov
2010-04-03 22:18 ` Juri Linkov
2010-04-03 22:40 ` Chong Yidong [this message]
2010-04-03 22:54 ` Juri Linkov
2010-04-03 23:31 ` Chong Yidong
2010-04-04 6:25 ` Eli Zaretskii
2010-04-04 8:05 ` Andreas Schwab
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