1's comp

Toby Thain toby at telegraphics.com.au
Sat May 21 22:29:09 CDT 2016

On 2016-05-21 10:56 PM, Jon Elson wrote:
> On 05/21/2016 09:34 PM, Toby Thain wrote:
>> On 2016-05-21 10:26 PM, ben wrote:
>>> On 5/20/2016 7:19 PM, Sean Conner wrote:
>>>>> Hehe, what is a long long? Yes, you are totally right. Still, I assert
>>>>> that C is still the defacto most portable language on Earth. What
>>>>> other
>>>>> language runs on as many OS's and CPUs ? None that I can think of.
>>>>   A long long is at least 64-bits long.
>>> Only if you get rid of char pointers you are portable.
>>> I like 1's compilent because it handles shifting properly.
>>> using 1's compilment unsigned would be 1 bit less in size
>>> not 1 bit more the C standard seems to make it.
>> Don't underestimate the headache of handling two zeroes.
> Right, on the LINC, if you compared positive zero to negative zero, it
> would not set the equals flag!
> I have no idea how many tests had to be put in the code for that, but
> anyplace where the two values could be zero, you had to check for that
> special case.

The Grishman book[1] gave me the impression that this was challenging on 
the CDC 6x00 as well.

[1] http://ygdes.com/CDC/Grishman_CDC6000AsmLangPgmg.pdf


> Jon

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