From: "Bernd Oppolzer" <[email protected]>
Sent: Tuesday, February 06, 2018 1:23 AM


Am 05.02.2018 um 14:42 schrieb Gord Tomlin:

And, BTW, the historic facts are simply wrong:

IBM had a C compiler for MVS (and VM, I believe) long before there were
string instructions on z/Arch.

MVC, CLC, MVCL, CLCL, MVO, MVN, ED, EDMK, TR, TRT
are all string instructions. Most of these were available in 1965 with the
S/360.  Long before C.

The implementation of strcpy etc. was slow
in those early days, but some companies (including the ones I worked for)
anyway used C on the mainframe, to take some advantage of the fact that
business critical software like (in our case) insurance math had to be developed
only once and could be deployed to different platforms (mainframe for
back office applications and servers and laptops for the insurance agencies).

The strcpy etc. implementation by microcode came later, when customer
pressure on IBM to support C better on the mainframe became higher;
that at least was my impression of IBM's motivation behind that.

More history: Kernighan and Ritchie IMHO had a good knowledge of the
IBM platform and PL/1, for example; one of the first implementations of
C was on S/360. I agree that it is not nice to search for a string terminator
using TRT, for example (given the length limitation of 256), but anyway:
it can be done, and there are other languages with similar "unfriendly"
concepts or problems that have to solved somehow by the compiler writers ...

You should not mix up language and hardware issues in your reasoning ...
better to keep the two topics separate.

Kind regards

Bernd

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