[MacRuby-devel] [MacRuby] #748: 32bit Number Limit and Conversion

[MacRuby]

#748: 32bit Number Limit and Conversion
-----------------------------+----------------------------------------------
 Reporter:  lp@…             |       Owner:  lsansonetti@…        
     Type:  defect           |      Status:  new                  
 Priority:  major            |   Milestone:  MacRuby 0.7          
Component:  MacRuby          |    Keywords:  32bit number         
-----------------------------+----------------------------------------------
Description changed by martinlagardette@…:

Old description:

> there seems to be a bug in the 32bit release of 0.6 with numbers
>
> arch -arch i386 macirb --simple-prompt
> >> 0x44485250
> # reality check
> => 1145590352
> >> NSNumber.numberWithInt(0x44485250)                              # then
> see all 32 NSNumber are weird...
> => 71848528
> >> NSNumber.numberWithFloat(0x44485250)
> => 1145590272.0
> >> NSNumber.numberWithInt(1145590352)
> => 71848528
> >> NSNumber.numberWithFloat(1145590352)
> => 1145590272.0
>
> versus:
>
> arch -arch x86_64 macirb --simple-prompt
> >> 0x44485250
> # reality check
> => 1145590352
> >> NSNumber.numberWithInt(0x44485250)
> => 1145590352
> >> NSNumber.numberWithFloat(0x44485250)
> => 1145590400.0
> >> NSNumber.numberWithInt(1145590352)
> => 1145590352
> >> NSNumber.numberWithFloat(1145590352.0)                      # this is
> weird again...
> => 1145590400.0
>
> to look a bit further, the bug turning point seems to be here for the
> 32bit release:
>
> >> NSNumber.numberWithInt(536870910)
> => 536870910
> >> NSNumber.numberWithInt(536870911)
> => 536870911
> >> NSNumber.numberWithInt(536870912)
> => -536870912
> >> NSNumber.numberWithInt(536870913)
> => -536870911
>
> and here in the 64 bit:
>
> >> NSNumber.numberWithInt(2147483646)
> => 2147483646
> >> NSNumber.numberWithInt(2147483647)
> => 2147483647
> >> NSNumber.numberWithInt(2147483648)
> => -2147483648
> >> NSNumber.numberWithInt(2147483649)
> => -2147483647
>

> also an other detail:
>
> 32bit turning point:
> >> 536870911 / 16
> => 33554431
>
> 64bit turning point:
> >> 2147483647 / 64
> => 33554431

New description:

 there seems to be a bug in the 32bit release of 0.6 with numbers

 {{{
 arch -arch i386 macirb --simple-prompt
 >> 0x44485250                         # reality check
 => 1145590352
 >> NSNumber.numberWithInt(0x44485250) # then see all 32 NSNumber are
 weird...
 => 71848528
 >> NSNumber.numberWithFloat(0x44485250)
 => 1145590272.0
 >> NSNumber.numberWithInt(1145590352)
 => 71848528
 >> NSNumber.numberWithFloat(1145590352)
 => 1145590272.0
 }}}
 versus:
 {{{
 arch -arch x86_64 macirb --simple-prompt
 >> 0x44485250                             # reality check
 => 1145590352
 >> NSNumber.numberWithInt(0x44485250)
 => 1145590352
 >> NSNumber.numberWithFloat(0x44485250)
 => 1145590400.0
 >> NSNumber.numberWithInt(1145590352)
 => 1145590352
 >> NSNumber.numberWithFloat(1145590352.0) # this is weird again...
 => 1145590400.0
 }}}
 to look a bit further, the bug turning point seems to be here for the
 32bit release:
 {{{
 >> NSNumber.numberWithInt(536870910)
 => 536870910
 >> NSNumber.numberWithInt(536870911)
 => 536870911
 >> NSNumber.numberWithInt(536870912)
 => -536870912
 >> NSNumber.numberWithInt(536870913)
 => -536870911
 }}}
 and here in the 64 bit:
 {{{
 >> NSNumber.numberWithInt(2147483646)
 => 2147483646
 >> NSNumber.numberWithInt(2147483647)
 => 2147483647
 >> NSNumber.numberWithInt(2147483648)
 => -2147483648
 >> NSNumber.numberWithInt(2147483649)
 => -2147483647
 }}}

 also an other detail:
 {{{
 32bit turning point:
 >> 536870911 / 16
 => 33554431

 64bit turning point:
 >> 2147483647 / 64
 => 33554431
 }}}

--

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Ticket URL: <http://www.macruby.org/trac/ticket/748#comment:1>
MacRuby <http://macruby.org/>