Re: fancy instructions, Continuations

It appears that MitchAlsup1 <mitchalsup@aol.com> said:

applications for which computers are normally used. Thus, the IBM
System/360 was general-purpose since it had string manipulation
instructions and decimal arithmetic in addition to floating-point and
binary integer arithmetic.

>
I think that history shows that those string facilities were, at best,
overkill. None of the RISC machines had any of that and were faster
and at least as general purpose as 360.
>
Especially the COBOL stuff like EDIT and EDIT-and-MARK.

They made sense at the time when memories were small and CPUs were slow.
Decimal arithmetic and pack/unpack and EDMK do exactly what every RPG
and Cobol program did, simple arithmetic on columns of numbers, and print
them in pretty formats.  Sure, you can do all that with libraries, but
on a 4K or 8K machine, every byte was precious, and putting the libraries
in microcode made sense.

These days z still has them all, but I'm sure they're all in millicode,
subroutines in the hardware subset of the instruction set that implement
the rest of it.

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