[TUHS] PDP-11 legacy, C, and modern architectures

Paul Winalski paul.winalski at gmail.com
Thu Jun 28 01:30:47 AEST 2018


What Clem said.  Chisnall is right about C having been designed for a
sequential-programming world.  That's why Fortran (with array and
other parallel/vector operations built in) rules in the HPTC parallel
programming space.  But I don't buy most of his arguments.  Making
parallel programming easy and natural has been an unsolved problem
during my entire 30+ year career in designing software development
tools.  It's still an unsolved problem.  Modern compiler technology
helps to find the hidden parallelism in algorithms expressed
sequentially, but I think the fundamental problem is that most human
beings have great difficulty conceptualizing parallel algorithms.
It's also always been true that to get maximum performance you have to
somehow get close to the specific hardware you're using--either by
explicitly programming for it, or by having a compiler do that for
you.

Note also that there have been extensions to C/C++ to support
parallelism.  Cilk, for example.

-Paul W.



More information about the TUHS mailing list