[Vm-dev] positive32BitValueOf: fail with LargePositiveInteger
leves at elte.hu
Sun Oct 10 15:08:42 UTC 2010
On Sun, 10 Oct 2010, David T. Lewis wrote:
> On Sun, Oct 10, 2010 at 03:24:35AM +0200, Levente Uzonyi wrote:
>> On Fri, 8 Oct 2010, David T. Lewis wrote:
>>> On Fri, Oct 08, 2010 at 07:12:13PM +0200, Mariano Martinez Peck wrote:
>>>> So....I don't understand...how can I have a LargePositiveInteger but that
>>>> less than 32 bits? Wouldn't that be a SmallInteger?
>>> SmallInteger maxVal hex ==> '16r3FFFFFFF'.
>>> The largest positive two-compliment integer that fits into 32 bits is
>>> 16rEFFFFFFF, so any Integer in the range 16r4000000 through 16rEFFFFFFF
>>> is a LargePositiveInteger that can fit into a signed 32-bit C int.
>>> Thus the number of LargePositiveInteger values that fit into a 32-bit
>>> twos-compliment representation is (16r4000000 to: 16rEFFFFFFF) size ==>
>>> Note that a SmallInteger is represented internally as a 31-bit value,
>>> which accounts for the difference. It's a bit confusing when you are used
>>> to thinking of 32-bit int values.
>> Shouldn't those 16rEFFFFFFF's be 167FFFFFF?
> Umm, yes of course. Sorry about that.
I missed an F too. It's 167FFFFFFF.
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