Does C implement the first C compiler itself?

[lovecreatesbea...]

K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

[Christopher Layne]

lovecreatesbea. [e-mail] wrote:

K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

Put some deductive reasoning/logic into it.

[Roberto Waltman]

Christopher Layne wrote:

>lovecreatesbea [e-mail] wrote:

>K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

Read "The Development of the C Language" at Dennis Ritchie home page (
http://cm.bell-labs.com/who/dmr )

>Put some deductive reasoning/logic into it.

[OT] That may lead you to logically correct, but nevertheless false
conclusions. The first version of an Algol-like system programming
language for Burroughs mainframes (B5000?) was written in itself.
It was "hand compiled" into assembler to get the first running
version, and it was self-sustained from there.
Roberto Waltman

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[Christopher Layne]

Roberto Waltman wrote:

[OT] That may lead you to logically correct, but nevertheless false
conclusions. The first version of an Algol-like system programming
language for Burroughs mainframes (B5000?) was written in itself.
It was "hand compiled" into assembler to get the first running
version, and it was self-sustained from there.

You just contradicted yourself. That was my point.

The first version was written in another language.

[Dave Hansen]

On Feb 14, 10:09 am, Christopher Layne <[e-mail] dizedwrote:

Roberto Waltman wrote:

[OT] That may lead you to logically correct, but nevertheless false
conclusions. The first version of an Algol-like system programming
language for Burroughs mainframes (B5000?) was written in itself.
It was "hand compiled" into assembler to get the first running
version, and it was self-sustained from there.

You just contradicted yourself. That was my point.

The first version was written in another language.

Not so.

The compiler was _written_ in the target language. It was
_translated_ to assembly.

This is a very common process referred to as "bootstrapp ing" a
compiler. It's a very useful exercise, in that it proves (or
disproves) the utility of the language with a non-trivial application,
and provides an immediate base of test code. Compilers tend to
require a wide range of algorithmic techniques and a variety of data
structures. If your language can implement a compiler, it's likely to
be useful for most other tasks as well.

Though these days, the intermediate language would more likely be C
than assembly, the process is essentially unchanged.

I guess you could argue that the first version of the compiler was
wetware writ by the finger of God, but that probably isn't very
helpful.

Regards,

-=Dave

[David T. Ashley]

"lovecreatesbea [e-mail]" <lo************ ***@gmail.comwr ote in message
news:11******** *************@k 78g2000cwa.goog legroups.com...

K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

Surprisingly, I understand the thought process behind this frivolous
question.

Here is another related question:

If one has the C source code for an optimizing compiler, the compiles the
compiler, creating a new compiler, and repeats this process over many
iterations, will the compiler executable get smaller and smaller each time?

(This is no more and no less frivolous than the original.)
--
David T. Ashley (dt*@e3ft.com)
http://www.e3ft.com (Consulting Home Page)
http://www.dtashley.com (Personal Home Page)
http://gpl.e3ft.com (GPL Publications and Projects)

[Chris McDonald]

"David T. Ashley" <dt*@e3ft.comwr ites:

>If one has the C source code for an optimizing compiler, the compiles the
compiler, creating a new compiler, and repeats this process over many
iterations, will the compiler executable get smaller and smaller each time?

But there's no guarantees that there's optimizations to be made...

--
Chris.

[santosh]

lovecreatesbea. [e-mail] wrote:

K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

You may be interested in the following link:

<http://cm.bell-labs.com/cm/cs/who/dmr/chist.html>

[Keith Thompson]

"David T. Ashley" <dt*@e3ft.comwr ites:

"lovecreatesbea [e-mail]" <lo************ ***@gmail.comwr ote in message
news:11******** *************@k 78g2000cwa.goog legroups.com...

>K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

Surprisingly, I understand the thought process behind this frivolous
question.

Here is another related question:

If one has the C source code for an optimizing compiler, the compiles the
compiler, creating a new compiler, and repeats this process over many
iterations, will the compiler executable get smaller and smaller each time?

No. An optimizer (if it's working properly) makes the target code run
more quickly; it doesn't change its behavior.

Suppose you have C sources for two C compilers, compiler1 and
compiler2. compiler1 includes a very clever optimizer; compiler2
doesn't. Use compiler2 to compile itself, yielding compiler2a.exe,
which compiles slowly. Use compiler1 to compile compiler2, yielding
compiler2b.exe, which compiles more quickly. But compiler2a.exe and
compiler2b.exe work the same way; the code they generate is identical.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Roberto Waltman]

"David T. Ashley" wrote:

>"lovecreatesbe [e-mail]" wrote in message

>K&R says the following in the preface to the first edition,

"... the C compiler, and ... are written in C."

I'm wondering, does it say even the first / original C compiler was
written in C?

Surprisingly , I understand the thought process behind this frivolous
question.

Why frivolous?

>Here is another related question:

If one has the C source code for an optimizing compiler, the compiles the
compiler, creating a new compiler, and repeats this process over many
iterations, will the compiler executable get smaller and smaller each time?

[OT] No, (at least not as worded) A simple test that every
self-compiling compiler should pass, is that when compiling its own
sources it should produce exact duplicates of itself.

If you then change the sources improving the optimization algorithms,
the compiler should produce a faster and/or smaller version of itself
reaching again a steady state after a few iterations.

To expect the cycle to continue for ever is akin to expect a file
compression algorithm to always reduce a file's size, which leads to
the conclusion that all files can be compressed into a single bit.

I could not find a reference now, but I recall reading about Niklaus
Wirth using this process to evaluate optimizations for his Pascal
compilers.

An optimization that would result in a faster or smaller compiler was
integrated in the code, but increasing the complexity of the compiler
with additional optimization steps that could improve code in some
marginal cases, but would not have a significant effect in the Pascal
compiler itself, was not considered a worthwhile trade-off.

Roberto Waltman

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