who ever performed bit logic on large negative integer?

Stephan Rudlof sr at evolgo.de
Sat Jan 26 15:28:04 UTC 2008

On 26.01.2008 16:07, Paolo Bonzini wrote:
>> There should be a comment somewhere (Integer class comment?) 
>> explicitly stating, that you cannot rely on two complement semantics 
>> for LargeNegativeIntegers regarding bit logic (bit logic restricted to 
>> positive Integers is correct).
> That's absurd IMHO.

It's just warning of the current limitations.

>> I fear, changing the fundamental design decision to use magnitude 
>> representation for LargeNegativeIntegers - e.g. by introducing some 
>> kind of two complement representation - would imply a lot of work...

> It is possible to work out bitwise ops on magnitude representation, by 
> computing the two's complement representation on the fly in the 
> primitives or in the fallback Smalltalk code.

OK, another - better - way to go: should be much less work than changing the representation.


> Paolo

Stephan Rudlof (sr at evolgo.de)
   "Genius doesn't work on an assembly line basis.
    You can't simply say, 'Today I will be brilliant.'"
    -- Kirk, "The Ultimate Computer", stardate 4731.3

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