From: "Paul Raulerson" <paul.rauler...@me.com>
Sent: Friday, January 26, 2018 6:48 AM
On Jan 25, 2018, at 06:53, Tom Marchant
<000000a69b48f3bb-dmarc-requ...@listserv.uga.edu> wrote:
On Wed, 24 Jan 2018 22:54:49 -0600, Paul Raulerson wrote:
On Jan 24, 2018, at 10:14 AM, Seymour J Metz wrote:
Like many old sayings, it's worth what you paid for it. The z instruction set includes
operations far more powerful than anything in C, and the lack of a Turing complete macro
language makes C highly inflexible.
I am not sure that really makes sense. What exactly do you feel is “more powerful” about the
zArch instruction set than “anything” in the C language?
You can't find any of the more than 1100 instructions in the z/Architecture instruction set that
are more powerful than any C language constructs?
Nope. Care to share your opinion with more specifics? I looked at string manipulation and standard
math.
Take a look at TRT, TR, ED, EDMK.
PACK and UNPK can do useful things too.
The 50-60 basic instructions, along with the grande counterparts, all are pretty simple and
comparative.
The C language was actually modeled on the PDP-11 instruction set
A very primitive instruction set compared to the current z/Architecture
instruction set.
At the time, both instruction sets were roughly equivalent. Of course, PDP-11 development stopped
about 30 years ago, while IBM HLASM has continued to develop, expand, and gain new capabilities.
As for Macros, well, C macros are generally much simpler than HLASM, though
with good reason.
Yes, it was easier to code.
Um, no. I believe HLASM macros were developed more because the mainframe
compilers
were originally designed as multi pass compilers because of resource
limitations.
Compile this phase, load a tape. Compile another phase, load another tape.
Not on our system /360.
Certainly multi-pass compilers were in use.
Magnetic tapes, when used, were for receiving distribition materials,
and for sending similar stuff to other sites.
And so on... C did not have those same limitations, probably because C is about 10 years younger
than IBM 360 assembler.
Unix at AT&T Bell Labs was originally billed as a text processing system, which it did very well.
But that was kind of a smokescreen to justify the development of Unix and C at Bell because
Multics was going away.
I think it is plain silly to think HLASM is always superior for development purposes to other
languages, including C.
In some cases it is superior - such as when bottom up development is called for. It can even fit
in well in an Agile/SCRUM environment for goodness sake! And, to top it all off, it is great fun
to program in.
But in many cases, other languages are far more efficient to use.It is not a good or bad thing, it
just is.
There are ways to increase the usability of HLASM in those sub-optimal use cases, such as usi
structured macros. But you often find a lot of resistance to things line that from the HLASM
community, and it takes the focus off accomplishing what has to be done and moves it to how to do
it. Square Hole, Round Peg type of thing I think. :)
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