29 Nov
2021
29 Nov
'21
3:15 a.m.
Rob Pike writes:
Is there a symbiosis between C and the PDP-11
instruction set? The
machine was vital to C and Unix's success, but primarily due to the
availability of a department-sized machine. Was the instruction set a
significant component? Most Unix programmers wrote little to no
assembly, although perhaps more read what came out of the compiler.
But did it matter? Auto-increment and -decrement are often cited in
this story, but they are not that important, really, and were around
well before the PDP-11 made its appearance.
I'm curious to hear arguments on either side.
-rob
Well, might just be my personal experience, but most of the machines
that I had used before the 11 were classic accumulator architectures.
I feel that the 11's pointer architecture combined with autoincrement
and autodecrement was an amazing fit for C. If I remember correctly,
it was very cool to have *p++ = *q++ be a single instruction.
BTW, one thing that I forgot in my earlier post is that I think that
the book also omitted any mention of Creative Commons. The book did
talk about the business of the web and such, and it's my opinion that
CC was an an essential third prong. The machines were one, the software
was another, the third was content and CC was a big enabler.
Jon