Machine-independent intermediate languages

[Eric S. Raymond]

In article <898 at sword.bellcore.com>, yba at arrow.UUCP (Mark Levine) writes:
> You have built some questionable assumptions into your reality
> check, and need to define your acronyms:

Sorry, I typoed.

> 	MLL -- is this a machine level language?

That 'MLL' should have read 'MIIL'.

> 	MIIL -- is this a machine independent intermediate language,
> 		and if so, at what level of expressive power, and is
> 		it any different than the MLL?  How?

Good question -- in fact, it's precisely the question I was trying to ask
with respect to HLLs. I think more acronym confusion can be best avoided if
I re-pose my three questions with this correction. They are:

	1) What properties distinguish a MIIL from a HLL?

(That is: how do I look at the semantics, performance, and portability of
a set of languages and sort the MIILs from the HLLs?)

	2) Are the portability goals for which MIILs are designed achievable
	   at all, given the diversity of today's architectures?

	3) If the answer to 2 is 'yes', *can those goals be achieved with
	   lower complexity and cost than an HLL compiler?*

The whole debate so far has been about 2). I am trying to suggest that the
critical question is actually 3), that the answer to 3) appears to be 'no',
and that the notion of MIIL is therefore fundamentally rather pointless,
because it distracts us from the *important* questions about designing
portability into HLLs.

> I beleive in such a thing as a MOL, a machine oriented language, and
> in a high level machine oriented language which is portable.  It is
> possible to do MUCH better than C.

Fine. I don't so believe (I've seen too many bizarre architectures) but I have
an open mind. Show me!
-- 
      Eric S. Raymond                     (the mad mastermind of TMN-Netnews)
      UUCP: ...!{uunet,att,rutgers}!snark!eric = eric at snark.UUCP
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