[fpc-devel] Re: System 370: Episode 3. Addressing and it's limits Part One!

[Mark Morgan Lloyd]

steve smithers wrote:
>> Mark Morgan Lloyd wrote on Fri, 10 Feb 2012 21:37:52 +0000
> 
>> I'm a bit worried that gas might not support all the arithmetic 
>> operations that appear to be required by your examples, but at the same 
>> time I still feel that Linux is the best initial target. Has anybody 
>> ported a fully-featured IBM macro assembler to Linux?
> 
> To take your points in reverse order:
> 
> Tachyon produce a free HLA compatible assembler.  IBM produce one that
> may or may not be free.  There may be others too.

The Tachyon one looks interesting, although I note that the free variant 
is for non-commercial use only- I hope that doesn't cause anybody any 
problems.

> Yes.  I agree, Linux/390 would seem a logical first step.

Reading around, I note that IBM started supporting IEEE maths with the 
zSeries, not (as I previously thought) with the 390. I think that 
implies that the best initial target would probably by zSeries running 
Linux, with migration to other operating systems etc. following.

> Gas is brain-dead, I wouldn't use it.  It WON'T work for my examples as
> it supports, as far I know, neither USING nor MACROs, let alone the
> doubts you have.

I notice people discussing health warnings associated with the IBM macro 
libraries- emphatically not in the public domain. I've definitely never 
seen these, so if necessary I could be part of a cleanroom 
reimplementation of what's needed.

I suppose there's a possibility that once the dust has settled it would 
be possible to implement a preprocessor to allow gas to serve as a backend.

> Finally, my examples are just that, examples.  It is not a specification
> for a final product, it is a wild theory based on zero knowlege of the
> internals of the compiler.  I can come up with a few others if you
> don't like that one.  In fact, episode 6 may just do that, but it will
> be a while before it appears.

Hopefully I'm not the only person reading your notes with interest.

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]