From: "Mattias Engdegård" <mattiase@acm.org>
To: Lars Ingebrigtsen <larsi@gnus.org>
Cc: "Vincent Belaïche" <vincent.b.1@hotmail.fr>, 43764@debbugs.gnu.org
Subject: bug#43764: Calc shift right broken
Date: Thu, 8 Oct 2020 14:24:02 +0200 [thread overview]
Message-ID: <4648BF2F-8507-4D39-85F1-1C40C0E8BFC2@acm.org> (raw)
In-Reply-To: <87wo04nnvr.fsf@gnus.org>
6 okt. 2020 kl. 03.28 skrev Lars Ingebrigtsen <larsi@gnus.org>:
> On the other hand, I don't know what people use Calc for here. If
> people are going "I wonder what would happen on a 32-bit machine if I
> were to do this shift operation", then it'd be something else...
Yes, we should be defending the users of Emacs, not Emacs itself.
What about a narrower change: clip the value after shifting right instead of before?
Vincent, would you be happy with the patch below, or do you think a more fundamental change is required?
--- a/lisp/calc/calc-bin.el
+++ b/lisp/calc/calc-bin.el
@@ -375,7 +375,7 @@ calcFunc-lsh
(Math-lessp w n))
0)
((< n 0)
- (math-quotient (math-clip a w) (math-power-of-2 (- n))))
+ (math-clip (math-quotient a (math-power-of-2 (- n))) w))
(t
(math-clip (math-mul a (math-power-of-2 n)) w))))))
next prev parent reply other threads:[~2020-10-08 12:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 15:28 bug#43764: Calc shift right broken Vincent Belaïche
2020-10-02 20:49 ` Mattias Engdegård
2020-10-05 8:12 ` Lars Ingebrigtsen
2020-10-05 10:34 ` Mattias Engdegård
2020-10-06 1:28 ` Lars Ingebrigtsen
2020-10-08 12:24 ` Mattias Engdegård [this message]
2020-10-09 15:29 ` Mattias Engdegård
2020-10-09 15:34 ` Vincent Belaïche
2020-10-10 16:24 ` Mattias Engdegård
2020-10-10 16:31 ` Mattias Engdegård
2020-10-13 9:56 ` Mattias Engdegård
2020-11-04 11:14 ` Vincent Belaïche
2020-11-04 11:54 ` Mattias Engdegård
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