[debbugs-tracker] bug#14864: closed (bitwise-arithmetic-shift-right is wrong for large shift amounts)

[GNU bug Tracking System]

Your message dated Sun, 14 Jul 2013 14:54:24 -0400
with message-id <address@hidden>
and subject line Re: bug#14864: bitwise-arithmetic-shift-right is wrong for 
large shift amounts
has caused the debbugs.gnu.org bug report #14864,
regarding bitwise-arithmetic-shift-right is wrong for large shift amounts
to be marked as done.

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-- 
14864: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=14864
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--- Begin Message --- Subject: bitwise-arithmetic-shift-right is wrong for large shift amounts Date: Sun, 14 Jul 2013 18:08:55 +0200 User-agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux)

Hello schemers,

bitwise-arithmetic-shift-right from (rnrs) is wrong for ridiculously
large shift amounts:

scheme@(guile-user)> (import (rnrs))
scheme@(guile-user)> (bitwise-arithmetic-shift-right -2 (+ (greatest-fixnum) 1))
$1 = -2

The correct result is -1. Tested on an amd64 system with
guile-2.0.9.20-10454-dirty. Here are a few more failing cases, if it
helps:

(bitwise-arithmetic-shift-right
  -1939573486025768832
  1842615318141600354)
=>
-112898036
; *** failed ***
; expected result: -1

(bitwise-arithmetic-shift-right
  1344211617424411880
  1877595747324902264)
=>
18
; *** failed ***
; expected result: 0

(bitwise-arithmetic-shift-right
  -1152921504606846979
  88553614889043251)
=>
-513
; *** failed ***
; expected result: -1

(bitwise-arithmetic-shift-right
  -870600743868926059
  1508151148)
=>
-49488
; *** failed ***
; expected result: -1

Regards,

-- 
Göran Weinholt <address@hidden>
13             MR. JAKES:  I think our economy was based on
14 industrial process.
15             JUSTICE SCALIA:  It was based on horses, for
16 Pete's sake.

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--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#14864: bitwise-arithmetic-shift-right is wrong for large shift amounts
>
>
>
>
> Date: 
>
> Sun, 14 Jul 2013 14:54:24 -0400
>
>
>
>
> User-agent: 
>
> Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux)
>
>
>
>
> Göran Weinholt <address@hidden> writes:
>
> > bitwise-arithmetic-shift-right from (rnrs) is wrong for ridiculously
> > large shift amounts:
> >
> > scheme@(guile-user)> (import (rnrs))
> > scheme@(guile-user)> (bitwise-arithmetic-shift-right -2 (+ (greatest-fixnum) 
> > 1))
> > $1 = -2
> >
> > The correct result is -1.
>
> Thanks for the report.  Now fixed in stable-2.0.
>
> http://git.savannah.gnu.org/gitweb/?p=guile.git;a=commitdiff;h=7e8166f5bdb526c021c826943aaf050134cccc83
>
>     Mark
>
>
> --- End Message ---