[TUHS] Re: Software written in B

[Sebastien F4GRX <f4grx@f4grx.net>]

Hi,

Wow, this is amazing.

For my information, where are the initialization values for the 
ctab[128] vector coming from?

Do you still have the version that generates a tree before codegen?

I know that generating code while parsing is possible for stack based 
machines, this is also how Crenshaw describes it in its document (but 
for 68k).

I decided not to do it for my own compiler, so that I can write multiple 
code generators.

Sebastien

Le 23/06/2023 à 12:59, Angelo Papenhoff a écrit :
> Another update: I have worked quite a bit on my compiler
> the last couple of days and have managed to make it produce the same
> code as those in the binaries (compared the intermediate code by eye).
> There were a few mistakes, the files have been updated.
>
> I removed some features that I figured were not in ken's original
> compiler and most importantly changed it to generate RPN code directly
> instead of parsing an expression into a tree and generating code from
> that, which ken confirmed was how it worked.
> I'm still not entirely happy with the result (the build() function seems
> a bit kludgy), but at least it seems to produce something accurate.
> Unfortunately I have no idea what the intermediate would have looked
> like, so the output of this is purely my fantasy.
> I will also have to adjust my take on ba now due to the changes.
>
> For anyone interested, this is my WIP version of bc.b:
> https://gist.github.com/aap/6df9b4c53c63592437d97dadab533649
>
> aap
>
> On 17/06/23, Angelo Papenhoff wrote:
>> Update: I'm now done with the first pass of this.
>> I reversed all the programs and successfully ran them through my
>> compiler (i haven't assembled or linked anything though).
>> http://squoze.net/B/programs/
>>
>> To check for correctness, the files should of course be compiled,
>> assembled and linked again. Unfortunately my compiler currently
>> does not generate quite the same code as the original one. I will
>> have to work on this.
>> Most importantly & and | are only bitwise operators in the version
>> of B that compiled these programs, but some other differences (like
>> the fixup chain and the way strings are stored) exist too.
>>
>> It would be nice to have a fully working B system on v1/v2 UNIX again,
>> with everything built from source, we can even reconstruct different
>> versions of the runtime (and perhaps standard library). So far the
>> PDP-11 version of my B system has only run on v6 and 2.11BSD.
>>
>> best,
>> aap
>>
>> On 14/06/23, Angelo Papenhoff wrote:
>>> I will hopefully continue with this in the next time (if, goto, mail and
>>> glob are left).