From: Mark H Weaver <mhw@netris.org>
To: Zefram <zefram@fysh.org>
Cc: 21901-done@debbugs.gnu.org
Subject: bug#21901: bit shift wrong on maximal right shift
Date: Sun, 14 Oct 2018 05:40:51 -0400 [thread overview]
Message-ID: <87pnwcuaqk.fsf@netris.org> (raw)
In-Reply-To: <20151113102203.GL13455@fysh.org> (Zefram's message of "Fri, 13 Nov 2015 10:22:03 +0000")
Zefram <zefram@fysh.org> writes:
> With Guile 2.0.11:
>
> scheme@(guile-user)> (ash 123 (ash -1 63))
> $1 = 123
>
> Correct result would of course be zero. Problem only occurs for
> exactly this shift distance: one bit less produces the right answer.
Nice catch!
It's finally fixed in commit 1990aa916382d0afcebd5315a6d6f555949ff654 on
the stable-2.2 branch. The fix will be in Guile 2.2.5.
Thanks for the report.
Mark
next prev parent reply other threads:[~2018-10-14 9:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-13 10:22 bug#21901: bit shift wrong on maximal right shift Zefram
2016-06-20 16:02 ` Andy Wingo
2018-10-14 9:40 ` Mark H Weaver [this message]
2018-10-20 22:27 ` Mark H Weaver
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