[Bug-mit-scheme] [bug #27513] Gambit's arithmetic puts us to shame

[Taylor R. Campbell]

URL:
  <http://savannah.gnu.org/bugs/?27513>

                 Summary: Gambit's arithmetic puts us to shame
                 Project: MIT/GNU Scheme
            Submitted by: riastradh
            Submitted on: Thu 24 Sep 2009 05:20:59 GMT
                Category: None
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Suboptimal behavior
                  Status: None
                 Privacy: Public
             Assigned to: riastradh
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                Keywords: 

    _______________________________________________________

Details:

(expt 27 2/3)
;Value: 8.999999999999998

(expt (expt 2 2000) 3/2000)
;The object
114813069527425452423283320117768198402231770208869520047764273682576626139237031385665948631650626991844596463898746277344711896086305533142593135616665318539129989145312280000688779148240044871428926990063486244781615463646388363947317026040466353970904996558162398808944629605623311649536164221970332681344168908984458505602379484807914058900934776500429002716706625830522008132236281291761267883317206598995396418127021779858404042159853183251540889433902091920554957783589672039160081957216630582755380425583726015528348786419432054508915275783882625175435528800822842770817965453762184851149029376,
passed as the first argument to integer->flonum, is not in the correct range.

(integer-shift-left (expt 2 50) -1)
;Hardware trap SIGBUS

Gambit gives:

> (expt 27 2/3)
9
> (expt (expt 2 2000) 3/2000)
8
> (arithmetic-shift (expt 2 50) -1)
562949953421312




    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?27513>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/