Re: Optimization of cascading recursions in "C" compilers?

From	Ben Bacarisse <ben@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: Optimization of cascading recursions in "C" compilers?
Date	2025-10-03 15:09 +0100
Organization	A noiseless patient Spider
Message-ID	<87frc0qdp0.fsf@bsb.me.uk> (permalink)
References	(3 earlier) <87ikgzm1pi.fsf@bsb.me.uk> <10bjmop$g97d$1@dont-email.me> <10bjn7b$gd6u$1@dont-email.me> <87ldluqj3r.fsf@bsb.me.uk> <10bkrad$p55p$1@dont-email.me>

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Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:

> On 02.10.2025 01:48, Ben Bacarisse wrote:
>> Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
>>> On 01.10.2025 19:01, Janis Papanagnou wrote:
>>>>
>>>> It's expansion, redundancy removal, compression, sub-function matching;
>>>> actually this is described (e.g.) in: Bauer, Wössner (Springer, 1981),
>>>> in ed. 1984 on page 301. (I won't type it all in here for the post but
>>>> if you're interested I can scan the page it and provide a link.)
>
> http://volatile.gridbug.de/fib_bw.pdf
>
>>> See also: Partsch, "Specification and Transformation of Programs"
>>> (Springer, 1990), pages 280ff and 304, with even more formalized
>>> rules (here as well shown based on 'fib' as example).
>
> http://volatile.gridbug.de/fib_p.pdf

That's about memo-ization, which is not the transformation I was asking
about.

>> I no longer have access to an academic library :-(  Could you write out
>> the code in the stages that took you from fib1 to fib2?
>
> It's in document fib_bw.pdf (the first link; in German).

My German is bad, but the big step seems to be annotated "it is obvious
that...".  It may be obvious in this case, but there is no hint at what
formal rule is being applied, or why one would apply it.

I think I just had a more mechanistic approach in mind when you said
"formally refactored".

Thanks for clearing up what transformations you had in mind.

-- 
Ben.

Thread

Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-09-30 17:54 +0200
  Re: Optimization of cascading recursions in "C" compilers? David Brown <david.brown@hesbynett.no> - 2025-09-30 18:04 +0200
    Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-01 00:15 +0200
  Re: Optimization of cascading recursions in "C" compilers? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-09-30 16:12 +0000
    Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-01 00:07 +0200
      Re: Optimization of cascading recursions in "C" compilers? Ben Bacarisse <ben@bsb.me.uk> - 2025-10-01 10:05 +0100
        Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-01 19:01 +0200
          Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-01 19:08 +0200
            Re: Optimization of cascading recursions in "C" compilers? Ben Bacarisse <ben@bsb.me.uk> - 2025-10-02 00:48 +0100
              Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-02 05:25 +0200
                Re: Optimization of cascading recursions in "C" compilers? Ben Bacarisse <ben@bsb.me.uk> - 2025-10-03 15:09 +0100
                Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-03 16:47 +0200
    Re: Optimization of cascading recursions in "C" compilers? bart <bc@freeuk.com> - 2025-10-01 00:02 +0100
      Re: Optimization of cascading recursions in "C" compilers? antispam@fricas.org (Waldek Hebisch) - 2025-10-01 01:22 +0000
    Re: Optimization of cascading recursions in "C" compilers? Rosario19 <Ros@invalid.invalid> - 2025-10-23 00:37 +0200
      Re: Optimization of cascading recursions in "C" compilers? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-22 23:36 +0000
        Re: Optimization of cascading recursions in "C" compilers? Rosario19 <Ros@invalid.invalid> - 2025-10-24 09:53 +0200
          Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-24 15:36 +0200
            Re: Optimization of cascading recursions in "C" compilers? Michael S <already5chosen@yahoo.com> - 2025-10-24 17:35 +0300
              Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-24 17:22 +0200
                Re: Optimization of cascading recursions in "C" compilers? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-24 17:14 +0000
                Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-24 20:31 +0200
                Re: Optimization of cascading recursions in "C" compilers? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-24 23:59 +0000
                Re: Optimization of cascading recursions in "C" compilers? James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-10-27 05:48 -0400
                Re: Optimization of cascading recursions in "C" compilers? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-27 12:52 +0100
                Re: Optimization of cascading recursions in "C" compilers? James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-10-27 14:41 -0400
                Re: Optimization of cascading recursions in "C" compilers? Michael S <already5chosen@yahoo.com> - 2025-10-27 22:33 +0200
                Re: Optimization of cascading recursions in "C" compilers? James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-10-27 16:52 -0400
                Re: Optimization of cascading recursions in "C" compilers? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-27 21:03 +0000
                Re: Optimization of cascading recursions in "C" compilers? antispam@fricas.org (Waldek Hebisch) - 2025-10-28 01:58 +0000

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