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Groups > comp.sys.raspberry-pi > #25425 > unrolled thread

AI and decompilation?

Started bygareth evans <headstone255@yahoo.com>
First post2021-01-04 11:00 +0000
Last post2021-02-12 15:40 +0000
Articles 20 on this page of 157 — 28 participants

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Contents

  AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-04 11:00 +0000
    Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-04 11:42 +0000
    Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-04 13:08 +0000
      Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-04 17:51 +0000
        Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-04 21:57 +0000
          Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-04 22:23 +0000
            Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-04 23:09 +0000
          Re: AI and decompilation? Dan Espen <dan1espen@gmail.com> - 2021-01-04 17:50 -0500
            Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-04 23:00 +0000
              Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-04 16:59 -0700
              Re: AI and decompilation? J. Clarke <jclarke.873638@gmail.com> - 2021-01-04 20:42 -0500
                Re: AI and decompilation? Dan Espen <dan1espen@gmail.com> - 2021-01-04 20:59 -0500
              Re: AI and decompilation? Dan Espen <dan1espen@gmail.com> - 2021-01-04 20:55 -0500
                Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-05 10:38 +0000
                  Re: AI and decompilation? Bob Eager <news0073@eager.cx> - 2021-01-05 12:46 +0000
                    Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-05 13:43 +0000
                      Re: AI and decompilation? Bob Eager <news0073@eager.cx> - 2021-01-05 14:23 +0000
                    Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 15:22 +0000
                  Re: AI and decompilation? Dan Espen <dan1espen@gmail.com> - 2021-01-05 09:05 -0500
              Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-05 10:51 +0000
                Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-05 11:52 +0000
                Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 12:06 +0000
                Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-05 20:12 +0000
            Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 11:45 +0000
              Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-05 14:25 -0700
          Re: AI and decompilation? J. Clarke <jclarke.873638@gmail.com> - 2021-01-04 20:38 -0500
            Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 11:54 +0000
            Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-05 14:06 -0700
              Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 22:52 +0000
          Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-05 10:29 +0000
    Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-04 11:05 -0500
      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-04 17:07 +0000
        Re: AI and decompilation? scott@slp53.sl.home (Scott Lurndal) - 2021-01-04 17:52 +0000
          Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-05 10:28 +0000
            Re: AI and decompilation? Thomas Koenig <tkoenig@netcologne.de> - 2021-01-05 13:06 +0000
              Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-05 13:41 +0000
              Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 15:30 +0000
                Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-05 16:42 +0000
                  Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-05 20:12 +0000
                    Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 20:20 +0000
                      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-05 22:23 +0000
                        Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-06 00:14 +0000
                          Re: AI and decompilation? Eli the Bearded <*@eli.users.panix.com> - 2021-01-06 02:17 +0000
                            Re: AI and decompilation? Björn Lundin <b.f.lundin@gmail.com> - 2021-01-08 14:39 +0100
                              Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-08 15:07 +0000
                                Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-08 15:56 +0000
                                Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-08 15:35 +0000
                              Re: AI and decompilation? Eli the Bearded <*@eli.users.panix.com> - 2021-01-08 20:02 +0000
                                Re: AI and decompilation? Björn Lundin <b.f.lundin@gmail.com> - 2021-01-10 15:12 +0100
                        Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 09:36 +0000
                          Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 10:43 +0000
                            Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 18:09 +0000
                              Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 18:29 +0000
                                Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 18:37 +0000
                                  Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 21:03 +0000
                                  Re: AI and decompilation? Björn Lundin <b.f.lundin@gmail.com> - 2021-01-08 14:45 +0100
                                    Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-08 18:06 +0000
                                      Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-08 18:44 +0000
                                        Re: AI and decompilation? A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-09 03:02 +0000
                                      Re: AI and decompilation? A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-09 02:58 +0000
                              Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-06 18:35 +0000
                                Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 18:39 +0000
                                  Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-06 19:03 +0000
                                    Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 19:08 +0000
                                      Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-06 19:19 +0000
                                        Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-07 04:07 +0000
                                          Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-07 12:59 +0000
                                          Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-08 21:41 -0500
                                          Re: AI and decompilation? Pancho <Pancho.Dontmaileme@outlook.com> - 2021-01-09 12:25 +0000
                                            Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-09 12:46 +0000
                                              Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 15:49 +0000
                                                Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-09 18:33 +0000
                                                  Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 19:20 +0000
                                                    Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-09 21:05 +0000
                                                      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 23:19 +0000
                                                        Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-10 12:17 +0000
                                                    Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-09 16:54 -0500
                                                      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 23:48 +0000
                                                        Re: AI and decompilation? A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-10 02:00 +0000
                                                Re: AI and decompilation? druck <news@druck.org.uk> - 2021-01-09 18:36 +0000
                                                  Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 19:28 +0000
                                                    Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-10 12:15 +0000
                                                      Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-10 12:33 +0000
                                                        Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-10 13:18 +0000
                                                          Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-10 14:01 +0000
                                                          Re: AI and decompilation? TimS <timstreater@greenbee.net> - 2021-01-10 15:14 +0000
                                                        Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-10 13:59 +0000
                                                          Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-10 14:46 +0000
                                                            Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-10 15:34 +0000
                                                          Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-10 15:05 +0000
                                                            Re: AI and decompilation? Axel Berger <Spam@Berger-Odenthal.De> - 2021-01-10 17:28 +0100
                                                              Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-11 17:25 +0000
                                                        Re: AI and decompilation? TimS <timstreater@greenbee.net> - 2021-01-10 15:13 +0000
                                                          Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-10 15:35 +0000
                                                          Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-10 15:35 +0000
                                                            Re: AI and decompilation? TimS <timstreater@greenbee.net> - 2021-01-10 17:23 +0000
                                                              Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-10 18:17 +0000
                                                              Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-11 03:44 +0000
                                                                Re: AI and decompilation? TimS <timstreater@greenbee.net> - 2021-01-11 11:00 +0000
                                                            Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-11 03:36 +0000
                                  Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-01-06 21:34 +0000
                              Re: AI and decompilation? druck <news@druck.org.uk> - 2021-01-06 18:37 +0000
                      Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-08 21:09 -0500
                    Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-06 09:32 +0000
                      Re: AI and decompilation? Björn Lundin <b.f.lundin@gmail.com> - 2021-01-08 14:56 +0100
              Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-05 14:25 -0700
              Re: AI and decompilation? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2021-01-06 14:17 +0200
                Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-06 12:42 +0000
                  Re: AI and decompilation? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2021-01-06 16:42 +0200
                  Re: AI and decompilation? "Kerr-Mudd,John" <notsaying@127.0.0.1> - 2021-01-08 09:48 +0000
                    Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-08 10:27 +0000
                Re: AI and decompilation? usenet@only.tnx (Questor) - 2021-01-08 21:40 +0000
            Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-05 14:06 -0700
              Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-05 22:27 +0000
                Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-06 00:14 +0000
                  Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 08:25 +0000
                    Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-08 21:52 -0500
                      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-09 15:37 +0000
                      Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-10 06:40 -0700
                Re: AI and decompilation? scott@slp53.sl.home (Scott Lurndal) - 2021-01-06 15:15 +0000
                  Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 16:09 +0000
                    Re: AI and decompilation? scott@slp53.sl.home (Scott Lurndal) - 2021-01-06 17:07 +0000
                      Re: AI and decompilation? Martin Gregorie <martin@mydomain.invalid> - 2021-01-06 17:38 +0000
            Re: AI and decompilation? druck <news@druck.org.uk> - 2021-01-05 21:20 +0000
      Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-04 17:47 +0000
      Re: AI and decompilation? Dan Espen <dan1espen@gmail.com> - 2021-01-04 14:18 -0500
        Re: AI and decompilation? Peter Flass <peter_flass@yahoo.com> - 2021-01-04 16:54 -0700
      Re: AI and decompilation? Theo <theom+news@chiark.greenend.org.uk> - 2021-01-04 23:01 +0000
    Re: AI and decompilation? Eli the Bearded <*@eli.users.panix.com> - 2021-01-04 20:11 +0000
    Re: AI and decompilation? Richard Kettlewell <invalid@invalid.invalid> - 2021-01-05 09:07 +0000
      Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-05 09:47 +0000
        Re: AI and decompilation? Richard Kettlewell <invalid@invalid.invalid> - 2021-01-05 11:13 +0000
          Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 12:12 +0000
            Re: AI and decompilation? Richard Kettlewell <invalid@invalid.invalid> - 2021-01-05 13:39 +0000
              Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 15:32 +0000
                Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 15:40 +0000
            Re: AI and decompilation? scott@slp53.sl.home (Scott Lurndal) - 2021-01-05 16:02 +0000
          Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-05 18:27 +0000
          Re: AI and decompilation? Vir Campestris <vir.campestris@invalid.invalid> - 2021-01-05 21:15 +0000
            Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 22:54 +0000
      Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 11:56 +0000
        Re: AI and decompilation? A. Dumas <alexandre@dumas.fr.invalid> - 2021-01-05 14:11 +0000
          Re: AI and decompilation? Bob Eager <news0073@eager.cx> - 2021-01-05 14:22 +0000
          Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 15:35 +0000
            Re: AI and decompilation? Ahem A Rivet's Shot <steveo@eircom.net> - 2021-01-05 18:47 +0000
              Re: AI and decompilation? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2021-01-05 20:15 +0000
      Re: AI and decompilation? J. Clarke <jclarke.873638@gmail.com> - 2021-01-05 07:32 -0500
      Re: AI and decompilation? scott@slp53.sl.home (Scott Lurndal) - 2021-01-05 16:00 +0000
    Re: AI and decompilation? Adrian Caspersz <email@here.invalid> - 2021-01-05 11:26 +0000
      Re: AI and decompilation? Thomas Koenig <tkoenig@netcologne.de> - 2021-01-05 13:07 +0000
        Re: AI and decompilation? The Natural Philosopher <tnp@invalid.invalid> - 2021-01-05 13:42 +0000
        Re: AI and decompilation? Eli the Bearded <*@eli.users.panix.com> - 2021-01-05 18:31 +0000
    Re: AI and decompilation? "K. Krause" <klemens.krause@gmx.net> - 2021-01-05 16:01 +0100
    Re: AI and decompilation? druck <news@druck.org.uk> - 2021-01-05 20:51 +0000
      Re: AI and decompilation? gareth evans <headstone255@yahoo.com> - 2021-01-05 22:51 +0000
        Re: AI and decompilation? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2021-01-08 22:23 -0500
    Re: AI and decompilation? Andy Burns <usenet@andyburns.uk> - 2021-02-12 15:40 +0000

Page 7 of 8 — ← Prev page 1 2 3 4 5 6 [7] 8  Next page →


#25549

FromMartin Gregorie <martin@mydomain.invalid>
Date2021-01-06 16:09 +0000
Message-ID<rt4nc4$f8a$2@dont-email.me>
In reply to#25546
On Wed, 06 Jan 2021 15:15:36 +0000, Scott Lurndal wrote:

> Martin Gregorie <martin@mydomain.invalid> writes:
>>On Tue, 05 Jan 2021 14:06:57 -0700, Peter Flass wrote:
>>
>>> You shouldn’t need declarations in C unless you’re using one of those
>>> new-fangled compilers that requires them. Old code should still be
>>> supported, though.
>>>
>>Last time I tried it, (about 2 months ago), the current GNU C compiler
>>accepts the old K&R C first edition procedure declaration syntax. I wish
>>more compilers worked this way.
> 
> It will not, however, accept the original V6 C "a =+ b" ambiguous
> syntax, so older code may still need to be edited before compilation
> with a modern compiler.

I don't *think* I've ever written that or even seen it in valid code. 


-- 
--  
Martin    | martin at
Gregorie  | gregorie dot org

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#25553

Fromscott@slp53.sl.home (Scott Lurndal)
Date2021-01-06 17:07 +0000
Message-ID<r7mJH.9680$cj2.60@fx29.iad>
In reply to#25549
Martin Gregorie <martin@mydomain.invalid> writes:
>On Wed, 06 Jan 2021 15:15:36 +0000, Scott Lurndal wrote:
>
>> Martin Gregorie <martin@mydomain.invalid> writes:
>>>On Tue, 05 Jan 2021 14:06:57 -0700, Peter Flass wrote:
>>>
>>>> You shouldn’t need declarations in C unless you’re using one of those
>>>> new-fangled compilers that requires them. Old code should still be
>>>> supported, though.
>>>>
>>>Last time I tried it, (about 2 months ago), the current GNU C compiler
>>>accepts the old K&R C first edition procedure declaration syntax. I wish
>>>more compilers worked this way.
>> 
>> It will not, however, accept the original V6 C "a =+ b" ambiguous
>> syntax, so older code may still need to be edited before compilation
>> with a modern compiler.
>
>I don't *think* I've ever written that or even seen it in valid code. 
>

From the V6 C compiler source:

        /*
         * The hash table locations of the keywords
         * are marked; if an identifier hashes to one of
         * these locations, it is looked up in in the keyword
         * table first.
         */
        for (ip=kwtab; (sp = ip->kwname); ip++) {
                i = 0;
                while (*sp)
                        i =+ *sp++;
                hshtab[i%hshsiz].hflag = FKEYW;
        }

Note also that in that version of the compiler, MOS
(member of structure) names were global and could be
used with any pointer regardless of type.

https://github.com/mortdeus/legacy-cc/blob/master/last1120c/c00.c

This makes it difficult to build the original V6 c compiler using
a modern compiler :-)

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#25555

FromMartin Gregorie <martin@mydomain.invalid>
Date2021-01-06 17:38 +0000
Message-ID<rt4sj7$f8a$4@dont-email.me>
In reply to#25553
On Wed, 06 Jan 2021 17:07:35 +0000, Scott Lurndal wrote:

> Martin Gregorie <martin@mydomain.invalid> writes:
>>On Wed, 06 Jan 2021 15:15:36 +0000, Scott Lurndal wrote:
>>
>>> Martin Gregorie <martin@mydomain.invalid> writes:
>>>>On Tue, 05 Jan 2021 14:06:57 -0700, Peter Flass wrote:
>>>>
>>>>> You shouldn’t need declarations in C unless you’re using one of
>>>>> those new-fangled compilers that requires them. Old code should
>>>>> still be supported, though.
>>>>>
>>>>Last time I tried it, (about 2 months ago), the current GNU C compiler
>>>>accepts the old K&R C first edition procedure declaration syntax. I
>>>>wish more compilers worked this way.
>>> 
>>> It will not, however, accept the original V6 C "a =+ b" ambiguous
>>> syntax, so older code may still need to be edited before compilation
>>> with a modern compiler.
>>
>>I don't *think* I've ever written that or even seen it in valid code.
>>
>>
> From the V6 C compiler source:
> 
>         /*
>          * The hash table locations of the keywords * are marked; if an
>          identifier hashes to one of * these locations, it is looked up
>          in in the keyword * table first.
>          */
>         for (ip=kwtab; (sp = ip->kwname); ip++) {
>                 i = 0;
>                 while (*sp)
>                         i =+ *sp++;
>                 hshtab[i%hshsiz].hflag = FKEYW;
>         }
> 
> Note also that in that version of the compiler, MOS (member of
> structure) names were global and could be used with any pointer
> regardless of type.
> 
> https://github.com/mortdeus/legacy-cc/blob/master/last1120c/c00.c
> 
> This makes it difficult to build the original V6 c compiler using a
> modern compiler :-)

Quite!




-- 
--  
Martin    | martin at
Gregorie  | gregorie dot org

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#25504

Fromdruck <news@druck.org.uk>
Date2021-01-05 21:20 +0000
Message-ID<rt2l7m$cll$1@dont-email.me>
In reply to#25460
On 05/01/2021 10:28, The Natural Philosopher wrote:
> Yes. I am certain that certain compilers and certain languages leave a 
> fingerprint, Always THAT resister, used to do THAT job, always that 
> particular sequence of assembly to mimic that high level construct.

They certainly do, I wrote !ARMalyser to analyse RISC OS executables and 
to aid the conversion from the old 26 bit ARM mode to modern Aarch32. It 
was very obvious if Norcroft C, GCC or handwritten assembly had been 
used by looking at any chunk of the code, not just the obvious file headers.

> I think it is up to a limited point entirely possible to make an AI that 
> could replace  machine code with editable and compilable  source code.
> But there will always be the Problem Of Induction. Many many possible 
> constructs in source using an infinite number of random variable and 
> function  names, could compile to the same object code. And there is no 
> way to reinstate the comments either, so it becomes an exercise 
> ultimately in hand editing and reinstating the comments manually - 
> almost as big a job as writing from scratch.

I was not attempting to turn the executable in to a high level language, 
but to give the user as much help understanding the assembler code as 
possible, to aid the conversion.

At the lowest level identifying what was code and what was data, easy in 
well defined executable formats produced by compilers, but hard in 
handwritten assembler, which had often used every trick in the book to 
squeeze out performance on a 8MHz ARM2 with 512MB of RAM.

The next step was using knowledge of the Standard C Library functions 
and SWI APIs to annotate the registers passed and returned from the APIs 
and where those registers contain static addresses, the data blocks they 
point to.

To allow code to be modified with additional instructions to recreate 
flag preserving behaviour of the 26 bit code (in the few cases it is 
actually necessary) and data added to make the larger 32 bit file 
headers, all code and data addresses are identified and converted in to 
labels.

ARMalyser outputs in the standard Object Assembler syntax so it can be 
reassembled to produce an identical executable, and subsequently 
modified. It can also add syntax colouring in various formats such as 
XML, HTML/CSS for viewing.

If you were in marketing you could say the code which does this is 'AI', 
but its really a huge chunk of tangled heuristics, which works well most 
of the time, but occasionally miss-identifies code or data. Its a bit 
too eager to identify code, due to the tricks assembler programmers 
used, if I ripped all that out and only worked on compiler generated 
executables, it would be a lot more reliable.

---druck

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#25439

Fromgareth evans <headstone255@yahoo.com>
Date2021-01-04 17:47 +0000
Message-ID<rsvkb2$2s5$1@dont-email.me>
In reply to#25436
On 04/01/2021 16:05, Dennis Lee Bieber wrote:
> 	Actually, I think the use of disassemblers et al has fallen away.
> Modern processors have so many peephole optimizations and out-of-order
> execution streams that converting an executable back to assembly source is
> almost meaningless -- and getting back to a high-level language is near
> impossible. One would have to be an expert at the assembly for a processor
> to have any chance of understanding the result.
>
>

AF6VN DE G4SDW

But we Radio Hams thrive on such low level technicalities!  :-)

73.

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#25443

FromDan Espen <dan1espen@gmail.com>
Date2021-01-04 14:18 -0500
Message-ID<rsvpmo$bfb$1@dont-email.me>
In reply to#25436
Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:

> On Mon, 4 Jan 2021 11:00:29 +0000, gareth evans <headstone255@yahoo.com>
> declaimed the following:
>
>>Thinking back to my first job, nearly 50 years ago now,
>>when I had to dis-assemble DEC's paper tape BASIC
>>interpreter in order to enhance it, I guess that
>>dis-assemblers and decompilers must now be ten-a-penny,
>>especially for programs running under Windows where
>>the structure of Windows programs is well-known with
>>an assumption that C was the source language?
>>
> 	Actually, I think the use of disassemblers et al has fallen away.
> Modern processors have so many peephole optimizations and out-of-order
> execution streams that converting an executable back to assembly source is
> almost meaningless -- and getting back to a high-level language is near
> impossible. One would have to be an expert at the assembly for a processor
> to have any chance of understanding the result.

Well, in my last job I often used disassemblers.
IBM z/OS.
Very useful for understanding IBM code.

I can't see what out of order execution has to do with a disassembler.
You disassemble executables.

Since I understand Assembler, I certainly got meaning out of it
even if the original was an optimized HLL.  You can see what services
are being called.

-- 
Dan Espen

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#25451

FromPeter Flass <peter_flass@yahoo.com>
Date2021-01-04 16:54 -0700
Message-ID<189325689.631496758.708516.peter_flass-yahoo.com@news.eternal-september.org>
In reply to#25443
Dan Espen <dan1espen@gmail.com> wrote:
> Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:
> 
>> On Mon, 4 Jan 2021 11:00:29 +0000, gareth evans <headstone255@yahoo.com>
>> declaimed the following:
>> 
>>> Thinking back to my first job, nearly 50 years ago now,
>>> when I had to dis-assemble DEC's paper tape BASIC
>>> interpreter in order to enhance it, I guess that
>>> dis-assemblers and decompilers must now be ten-a-penny,
>>> especially for programs running under Windows where
>>> the structure of Windows programs is well-known with
>>> an assumption that C was the source language?
>>> 
>> Actually, I think the use of disassemblers et al has fallen away.
>> Modern processors have so many peephole optimizations and out-of-order
>> execution streams that converting an executable back to assembly source is
>> almost meaningless -- and getting back to a high-level language is near
>> impossible. One would have to be an expert at the assembly for a processor
>> to have any chance of understanding the result.
> 
> Well, in my last job I often used disassemblers.
> IBM z/OS.
> Very useful for understanding IBM code.

I was going to say that disassemblers for IBM seem to work fairly well.
I’ve used them a few times.

> 
> I can't see what out of order execution has to do with a disassembler.
> You disassemble executables.
> 
> Since I understand Assembler, I certainly got meaning out of it
> even if the original was an optimized HLL.  You can see what services
> are being called.
> 

I think, for example, that one disassembler might recognize the SVC
number.i think it put the macro name in as a comment (LINK, GETMAIN, etc.)


-- 
Pete

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#25449

FromTheo <theom+news@chiark.greenend.org.uk>
Date2021-01-04 23:01 +0000
Message-ID<Xjr*mEo-x@news.chiark.greenend.org.uk>
In reply to#25436
Dennis Lee Bieber <wlfraed@ix.netcom.com> wrote:
>         Actually, I think the use of disassemblers et al has fallen away.
> Modern processors have so many peephole optimizations and out-of-order
> execution streams that converting an executable back to assembly source is
> almost meaningless -- and getting back to a high-level language is near
> impossible. One would have to be an expert at the assembly for a processor
> to have any chance of understanding the result.

Apple essentially do this for their Rosetta 2 x86-to-ARM converter.  They
take existing x86 executables, which are likely generated by their Xcode
LLVM compiler.  They convert the assembly back into LLVM's intermediate
representation, which is the idealised-assembly representation most of the
compiler stages work on.  Then they push that IR through the regular ARM
LLVM backend, including optimiser stages, to produce 64-bit ARM executables.

It's not a language intended for humans to read, but it's high enough for
the compiler stages to work on.  Doing it this way avoids having to emulate
any ARM instructions.

Theo

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#25444

FromEli the Bearded <*@eli.users.panix.com>
Date2021-01-04 20:11 +0000
Message-ID<eli$2101041456@qaz.wtf>
In reply to#25425
In comp.sys.raspberry-pi, gareth evans  <headstone255@yahoo.com> wrote:
> But I wonder if Artificial Intelligence could, after
> being fed with numerous instruction sets, take a
> block of binary, and analyse its source without
> any prior knowledge of the instruction set?

I suspect AI could be trained to do that, perhaps better than being
trained to read English. Not sure if anyone has ever tried.

> I am particularly interested in the Binary Blob
> provided for Raspberry Pi computers, with a view to
> getting detailed knowledge of the video processors
> employed therein.

The info-sec people use disassemblers all the time, and don't limit
themselves to compiled from C and intended for Windows binaries. They
try to extract passwords and locate flaws in firmware for all sorts
of internet-connected things. I recall Cybergibbons creating some
tutorials in November or December. It was linked from his twitter
account, but I didn't pay that close attention to where it was. A
quick look at his blog and youtube didn't find them, but he's got a
robust web presence.

Elijah
------
have you searched if anyone else has reversed engineered it already?

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#25458

FromRichard Kettlewell <invalid@invalid.invalid>
Date2021-01-05 09:07 +0000
Message-ID<87k0srah12.fsf@LkoBDZeT.terraraq.uk>
In reply to#25425
gareth evans <headstone255@yahoo.com> writes:
> Thinking back to my first job, nearly 50 years ago now,
> when I had to dis-assemble DEC's paper tape BASIC
> interpreter in order to enhance it, I guess that
> dis-assemblers and decompilers must now be ten-a-penny,
> especially for programs running under Windows where
> the structure of Windows programs is well-known with
> an assumption that C was the source language?
>
> But I wonder if Artificial Intelligence could, after
> being fed with numerous instruction sets, take a
> block of binary, and analyse its source without
> any prior knowledge of the instruction set?
>
> I am particularly interested in the Binary Blob
> provided for Raspberry Pi computers, with a view to
> getting detailed knowledge of the video processors
> employed therein.

Why would you do that instead of reading a reference manual for the
target architecture?

-- 
https://www.greenend.org.uk/rjk/

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#25459

FromAhem A Rivet's Shot <steveo@eircom.net>
Date2021-01-05 09:47 +0000
Message-ID<20210105094747.a0b43d4f7d1719b1e7cb7869@eircom.net>
In reply to#25458
On Tue, 05 Jan 2021 09:07:21 +0000
Richard Kettlewell <invalid@invalid.invalid> wrote:

> gareth evans <headstone255@yahoo.com> writes:

> > I am particularly interested in the Binary Blob
> > provided for Raspberry Pi computers, with a view to
> > getting detailed knowledge of the video processors
> > employed therein.
> 
> Why would you do that instead of reading a reference manual for the
> target architecture?

	The documentation for the GPU on the RPi has not been published, he
seeks to reverse engineer it from the binary code that implements a
published API on it.

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
C:\>WIN                                     | A better way to focus the sun
The computer obeys and wins.                |    licences available see
You lose and Bill collects.                 |    http://www.sohara.org/

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#25464

FromRichard Kettlewell <invalid@invalid.invalid>
Date2021-01-05 11:13 +0000
Message-ID<87eeizab7k.fsf@LkoBDZeT.terraraq.uk>
In reply to#25459
Ahem A Rivet's Shot <steveo@eircom.net> writes:
> Richard Kettlewell <invalid@invalid.invalid> wrote:
>> gareth evans <headstone255@yahoo.com> writes:
>>> I am particularly interested in the Binary Blob
>>> provided for Raspberry Pi computers, with a view to
>>> getting detailed knowledge of the video processors
>>> employed therein.
>> 
>> Why would you do that instead of reading a reference manual for the
>> target architecture?
>
> 	The documentation for the GPU on the RPi has not been published,
> he seeks to reverse engineer it from the binary code that implements a
> published API on it.

I was under the impression it was a VideoCore IV, which appears to be
sufficiently documented for GNU toolchain port.

https://docs.broadcom.com/doc/12358545
https://github.com/itszor/vc4-toolchain

-- 
https://www.greenend.org.uk/rjk/

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#25471

Fromgareth evans <headstone255@yahoo.com>
Date2021-01-05 12:12 +0000
Message-ID<rt1l2u$o0a$1@dont-email.me>
In reply to#25464
On 05/01/2021 11:13, Richard Kettlewell wrote:
> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>> Richard Kettlewell <invalid@invalid.invalid> wrote:
>>> gareth evans <headstone255@yahoo.com> writes:
>>>> I am particularly interested in the Binary Blob
>>>> provided for Raspberry Pi computers, with a view to
>>>> getting detailed knowledge of the video processors
>>>> employed therein.
>>>
>>> Why would you do that instead of reading a reference manual for the
>>> target architecture?
>>
>> 	The documentation for the GPU on the RPi has not been published,
>> he seeks to reverse engineer it from the binary code that implements a
>> published API on it.
>
> I was under the impression it was a VideoCore IV, which appears to be
> sufficiently documented for GNU toolchain port.
>
> https://docs.broadcom.com/doc/12358545
> https://github.com/itszor/vc4-toolchain
>

The first of those does not produce anything.

Does the second describe the GPU in some detail and describe
the instruction set such that I might produce my own binary blob
to do something completely different?

Also, AIUI, a different GPU has been incorporated into the
64-bit RPis.

Anyway, thanks for your input.

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#25476

FromRichard Kettlewell <invalid@invalid.invalid>
Date2021-01-05 13:39 +0000
Message-ID<878s97a4g4.fsf@LkoBDZeT.terraraq.uk>
In reply to#25471
gareth evans <headstone255@yahoo.com> writes:
> On 05/01/2021 11:13, Richard Kettlewell wrote:
>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>> 	The documentation for the GPU on the RPi has not been published,
>>> he seeks to reverse engineer it from the binary code that implements a
>>> published API on it.
>>
>> I was under the impression it was a VideoCore IV, which appears to be
>> sufficiently documented for GNU toolchain port.
>>
>> https://docs.broadcom.com/doc/12358545
>> https://github.com/itszor/vc4-toolchain
>
> The first of those does not produce anything.

It’s the VideoCore IV 3D Architecture Reference Guide.

> Does the second describe the GPU in some detail and describe
> the instruction set such that I might produce my own binary blob
> to do something completely different?

It’s a toolchain port.

-- 
https://www.greenend.org.uk/rjk/

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#25487

Fromgareth evans <headstone255@yahoo.com>
Date2021-01-05 15:32 +0000
Message-ID<rt20pq$b2q$2@dont-email.me>
In reply to#25476
On 05/01/2021 13:39, Richard Kettlewell wrote:
> gareth evans <headstone255@yahoo.com> writes:
>> On 05/01/2021 11:13, Richard Kettlewell wrote:
>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>> 	The documentation for the GPU on the RPi has not been published,
>>>> he seeks to reverse engineer it from the binary code that implements a
>>>> published API on it.
>>>
>>> I was under the impression it was a VideoCore IV, which appears to be
>>> sufficiently documented for GNU toolchain port.
>>>
>>> https://docs.broadcom.com/doc/12358545
>>> https://github.com/itszor/vc4-toolchain
>>
>> The first of those does not produce anything.
>
> It’s the VideoCore IV 3D Architecture Reference Guide.

Perhaps not available to the Man On The Clapham Omnibus.

Are you in a privileged position with Broadcom to have
such access?

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#25489

Fromgareth evans <headstone255@yahoo.com>
Date2021-01-05 15:40 +0000
Message-ID<rt219c$di9$2@dont-email.me>
In reply to#25487
On 05/01/2021 15:32, gareth evans wrote:
> On 05/01/2021 13:39, Richard Kettlewell wrote:
>> gareth evans <headstone255@yahoo.com> writes:
>>> On 05/01/2021 11:13, Richard Kettlewell wrote:
>>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>>>     The documentation for the GPU on the RPi has not been published,
>>>>> he seeks to reverse engineer it from the binary code that implements a
>>>>> published API on it.
>>>>
>>>> I was under the impression it was a VideoCore IV, which appears to be
>>>> sufficiently documented for GNU toolchain port.
>>>>
>>>> https://docs.broadcom.com/doc/12358545
>>>> https://github.com/itszor/vc4-toolchain
>>>
>>> The first of those does not produce anything.
>>
>> It’s the VideoCore IV 3D Architecture Reference Guide.
>
> Perhaps not available to the Man On The Clapham Omnibus.
>
> Are you in a privileged position with Broadcom to have
> such access?
>
>

Mea Culpa !!!!!!!!

Firefox did not display anything but was quietly downloading the PDF
in the background without me realising!

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#25491

Fromscott@slp53.sl.home (Scott Lurndal)
Date2021-01-05 16:02 +0000
Message-ID<140JH.47697$li2.31337@fx22.iad>
In reply to#25471
gareth evans <headstone255@yahoo.com> writes:
>On 05/01/2021 11:13, Richard Kettlewell wrote:
>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>> Richard Kettlewell <invalid@invalid.invalid> wrote:
>>>> gareth evans <headstone255@yahoo.com> writes:
>>>>> I am particularly interested in the Binary Blob
>>>>> provided for Raspberry Pi computers, with a view to
>>>>> getting detailed knowledge of the video processors
>>>>> employed therein.
>>>>
>>>> Why would you do that instead of reading a reference manual for the
>>>> target architecture?
>>>
>>> 	The documentation for the GPU on the RPi has not been published,
>>> he seeks to reverse engineer it from the binary code that implements a
>>> published API on it.
>>
>> I was under the impression it was a VideoCore IV, which appears to be
>> sufficiently documented for GNU toolchain port.
>>
>> https://docs.broadcom.com/doc/12358545
>> https://github.com/itszor/vc4-toolchain
>>
>
>The first of those does not produce anything.

Except a PDF entitled "VideoCore IV 3d Architecture Reference Guide".

Check your downloads directory.

e.g. 

Fragment shaders are started automatically each time the FEP accumulates a vector of up to four quads (16
pixels) to shade together. The quad input data from the FEP is automatically written into per-thread QPU
registers when the fragment shader is started. The following data is written to these QPU registers, in addition
to the normal PC address, uniforms base address, and uniforms size:

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#25493

FromAhem A Rivet's Shot <steveo@eircom.net>
Date2021-01-05 18:27 +0000
Message-ID<20210105182745.1cd73b52cf71f605f8f29d81@eircom.net>
In reply to#25464
On Tue, 05 Jan 2021 11:13:03 +0000
Richard Kettlewell <invalid@invalid.invalid> wrote:

> I was under the impression it was a VideoCore IV, which appears to be
> sufficiently documented for GNU toolchain port.
> 
> https://docs.broadcom.com/doc/12358545

	Whoah there, that was proprietary and NDS only last time I looked.
Seems Broadcom have been decent while I wasn't looking - good news!

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
C:\>WIN                                     | A better way to focus the sun
The computer obeys and wins.                |    licences available see
You lose and Bill collects.                 |    http://www.sohara.org/

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#25503

FromVir Campestris <vir.campestris@invalid.invalid>
Date2021-01-05 21:15 +0000
Message-ID<rt2kto$7s1$1@dont-email.me>
In reply to#25464
On 05/01/2021 11:13, Richard Kettlewell wrote:
> I was under the impression it was a VideoCore IV, which appears to be
> sufficiently documented for GNU toolchain port.
> 
> https://docs.broadcom.com/doc/12358545
> https://github.com/itszor/vc4-toolchain

I understand that the latest Pi is indeed a VC4.

Be aware that as a SIMD processor it's ... odd. Very odd.

That documentation ties up with what I remember about the device, and I 
wish I'd had it when I was working on it.

Andy

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#25512

Fromgareth evans <headstone255@yahoo.com>
Date2021-01-05 22:54 +0000
Message-ID<rt2qn1$h9p$3@dont-email.me>
In reply to#25503
On 05/01/2021 21:15, Vir Campestris wrote:
> On 05/01/2021 11:13, Richard Kettlewell wrote:
>> I was under the impression it was a VideoCore IV, which appears to be
>> sufficiently documented for GNU toolchain port.
>>
>> https://docs.broadcom.com/doc/12358545
>> https://github.com/itszor/vc4-toolchain
>
> I understand that the latest Pi is indeed a VC4.
>
> Be aware that as a SIMD processor it's ... odd. Very odd.
>
> That documentation ties up with what I remember about the device, and I
> wish I'd had it when I was working on it.
>

You were working on it? What can you tell us?

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