Structured Fortran - was Re: Self modifying code, lambda calculus

Johnny Billquist bqt at update.uu.se
Wed Sep 23 09:54:49 CDT 2015


On 2015-09-23 16:43, Paul Koning wrote:
>
>> On Sep 23, 2015, at 10:30 AM, Jay Jaeger <cube1 at charter.net> wrote:
>>
>> On 9/23/2015 9:10 AM, Mouse wrote:
>>>> I am 100% certain, for example, that it would be possible to come up
>>>> with a C compiler for a 40K IBM 1410, which is in the set you
>>>> describe.
>>>
>>> Possible?  Sure.  But it would be difficult; you would need to simulate
>>> a binary machine - C has a whole bunch of stuff that is defined to
>>> operate "as if" certain things are stored in binary.
>
> Worse yet, two's complement binary.  At least nowadays.  Which makes me suspect that there had to be some shortcuts taken when C was implemented on the CDC 6000 series.
>
> (Interestingly enough, if you ignore that little detail, it isn't terribly hard to write the skeleton of a 6000 code generator back-end for GCC...)

As far as I can remember, the C standard still do not require that the 
computer uses two complement. So you can actually get away with a C 
compiler that uses one complement. But much actual code will probably 
break, because they make way more assumptions than the standard actually 
provide...

	Johnny



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