Re: [PATCH] Fix spelling of ones' complement.

[Koning, Paul via Gcc-patches]

> On Nov 16, 2021, at 2:03 AM, Aldy Hernandez via Gcc-patches 
> <gcc-patches@gcc.gnu.org> wrote:
> 
> On Tue, Nov 16, 2021, 03:20 Marek Polacek via Gcc-patches <
> gcc-patches@gcc.gnu.org> wrote:
> 
>> On Tue, Nov 16, 2021 at 02:01:47AM +0000, Koning, Paul via Gcc-patches
>> wrote:
>>> 
>>> 
>>>> On Nov 15, 2021, at 8:48 PM, Marek Polacek via Gcc-patches <
>> gcc-patches@gcc.gnu.org> wrote:
>>>> 
>>>> Nitpicking time.  It's spelled "ones' complement" rather than "one's
>>>> complement".
>>> 
>>> Is that so?  I see Wikipedia claims it is, but there are no sources for
>> that claim.  (There is an assertion that it is "discussed at length on the
>> talk page" of an article about number representation, but in fact there is
>> no discussion there at all.)
>>> 
>>> I have never seen this spelling before, and I very much doubt its
>> validity.  For one thing, why then have "two's complement"?  For another,
>> to pick one random authority, J.E. Thornton in "Design of a computer -- the
>> Control Data 6600" refers to "one's complement" to describe the well known
>> mode used by that machine and its relatives.
>> 
>> Knuth, The Art of Computer Programming Volume 2, page 203-4:
>> 
>> "A two's complement number is complemented with respect to a single
>> power of 2, while a ones' complement number is complemented with respect
>> to a long sequence of 1s."
>> 
> 
> I think you get to do a drop mike when you pull out Knuth.
> 
> :-)

If that were the only source, sure.  But with authoritative sources for both 
terms (with the ones I quoted being the earlier ones) at the very least there 
is an argument that both terms are used.  

Some more: DEC PDP-1 handbook (April 1960), page 9: "Negative numbers are 
represented as the 1's complement of the positive numbers."

Univac 1107 CPU manual, page 2-6: "Next, the adder subtracts the one's 
complement..."

CDC 160 programming manual (1963), page 2-1: "All arithmetic is binary, one's 
complement notation".

Incidentally, these are the four of the five machines cited by the Wikipedia 
article.