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Re: Is MIX utterly silly?

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"Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> writes:

> On 20.08.2019 14:49, David Brown wrote:

[...]

>> [...] But MIX was a big mistake.  IMHO, of course.
>
> It was a child of its time.

Nothing is ever immune to that, but the purpose of MIX was precisely not
to be a child of its time.  ``My books focus on timeless truths.''

--8<---------------cut here---------------start------------->8---
Why have a machine language?

Many readers are no doubt thinking, ``Why does Knuth replace MIX by
another machine instead of just sticking to a high-level programming
language? Hardly anybody uses assemblers these days.''

Such people are entitled to their opinions, and they need not bother
reading the machine-language parts of my books. But the reasons for
machine language that I gave in the preface to Volume 1, written in the
early 1960s, remain valid today:

    One of the principal goals of my books is to show how high-level
    constructions are actually implemented in machines, not simply to
    show how they are applied. I explain coroutine linkage, tree
    structures, random number generation, high-precision arithmetic,
    radix conversion, packing of data, combinatorial searching,
    recursion, etc., from the ground up.  The programs needed in my
    books are generally so short that their main points can be grasped
    easily.  People who are more than casually interested in computers
    should have at least some idea of what the underlying hardware is
    like. Otherwise the programs they write will be pretty weird.
    Machine language is necessary in any case, as output of many of the
    software programs I describe.  Expressing basic methods like
    algorithms for sorting and searching in machine language makes it
    possible to carry out meaningful studies of the effects of cache and
    RAM size and other hardware characteristics (memory speed,
    pipelining, multiple issue, lookaside buffers, the size of cache
    blocks, etc.) when comparing different schemes.

Moreover, if I did use a high-level language, what language should it
be? In the 1960s I would probably have chosen Algol W; in the 1970s, I
would then have had to rewrite my books using Pascal; in the 1980s, I
would surely have changed everything to C; in the 1990s, I would have
had to switch to C++ and then probably to Java. In the 2000s, yet
another language will no doubt be de rigueur. I cannot afford the time
to rewrite my books as languages go in and out of fashion; languages
aren't the point of my books, the point is rather what you can do in
your favorite language. My books focus on timeless truths.

Therefore I will continue to use English as the high-level language in
TAOCP, and I will continue to use a low-level language to indicate how
machines actually compute. Readers who only want to see algorithms that
are already packaged in a plug-in way, using a trendy language, should
buy other people's books.

The good news is that programming for RISC machines is pleasant and
simple, when the RISC machine has a nice clean design. So I need not
dwell on arcane, fiddly little details that distract from the main
points. In this respect MMIX will be significantly better than MIX.

Source:
https://www-cs-faculty.stanford.edu/~knuth/mmix.html
--8<---------------cut here---------------end--------------->8---

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Is MIX utterly silly? Peter Percival <peterxpercival@hotmail.com> - 2019-08-19 22:52 +0100
  Re: Is MIX utterly silly? Robert Wessel <robertwessel2@yahoo.com> - 2019-08-19 21:14 -0500
    Re: Is MIX utterly silly? Peter Percival <peterxpercival@hotmail.com> - 2019-08-20 13:15 +0100
      Re: Is MIX utterly silly? David Brown <david.brown@hesbynett.no> - 2019-08-20 14:49 +0200
        Re: Is MIX utterly silly? "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2019-08-21 07:35 +0200
          Re: Is MIX utterly silly? David Brown <david.brown@hesbynett.no> - 2019-08-21 14:08 +0200
            Re: Is MIX utterly silly? "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2019-08-21 17:10 +0200
              Re: Is MIX utterly silly? David Brown <david.brown@hesbynett.no> - 2019-08-22 15:11 +0200
          Re: Is MIX utterly silly? Louis Valence <lvalence@example.com> - 2019-08-23 17:13 -0300
            Re: Is MIX utterly silly? Peter Percival <peterxpercival@hotmail.com> - 2019-08-24 20:53 +0100
              Re: Is MIX utterly silly? luser droog <mijoryx@yahoo.com> - 2019-09-08 12:50 -0700
      Re: Is MIX utterly silly? Louis Valence <lvalence@example.com> - 2019-08-23 17:01 -0300

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