rounding bug or no bug?

[Abdulaziz Ghuloum]

[61]: ikarus
Ikarus Scheme version 0.0.2patched+ (revision 1333, build 2008-01-06)
Copyright (c) 2006-2007 Abdulaziz Ghuloum

> 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584.0
1.34078079299426e154
> ^D
[62]: larceny
Larceny v0.95 "First Safety" (Nov 8 2007 04:30:20, precise:BSD Unix:unified)
larceny.heap, built on Thu Nov 8 04:39:44 EST 2007

> 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584.0
1.3407807929942597e154

> ^D
[63]: petite
Petite Chez Scheme Version 7.4
Copyright (c) 1985-2007 Cadence Research Systems

> 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584.0
1.3407807929942597e154
>
[64]: mzscheme
Welcome to MzScheme v371 [3m], Copyright (c) 2004-2007 PLT Scheme Inc.
> 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584.0
1.3407807929942597e+154
> ^D
[65]: gsi
Gambit v4.0.1

> 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584.0
1.3407807929942597e154
>

[Abdulaziz Ghuloum (aghuloum)]

Just in case you cannot tell, the exact number is exactly in between the two inexact results:

> (- 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584 (inexact->exact 1.3407807929942597e154))
1488565707357402911845015158554633286356257506687627387456491927921949262056238946972039271861787782268441644249633132407878864135402815488
> (- (inexact->exact 1.34078079299426e154) 13407807929942598588139732355608757972494524375225679733981068131349151486565474898751136354405850399729303719974268319295398132445078977825297784408899584)
1488565707357402911845015158554633286356257506687627387456491927921949262056238946972039271861787782268441644249633132407878864135402815488

[leppie (leppie)]

Maybe I am looking at this wrong, but shouldn't both expressions evaluate to negative numbers in the last post above?

[leppie (leppie)]

Oops, was looking wrong :( Will teach me not just to look at the last numbers, but the whole number!

[Abdulaziz Ghuloum (aghuloum)]

BUG. fixed in revision 1340.

[Abdulaziz Ghuloum (aghuloum)]

This bug report is about to be closed as the fix comitted
previously will be incorporated in the next 0.0.3 release of
Ikarus Scheme, scheduled for January 31, 2008. A release
candidate tarball is available for download from:
http://www.cs.indiana.edu/~aghuloum/ikarus/ikarus-0.0.3-rc1.tar.gz
Please do test it if you have the time and report any issues
you might encounter. Thank you very much for your support.
(Sorry for the duplicates; I'm updating every open bug.)