Re: Moving VAX into 21 century :-)

[Paul Koning <paulkoning%comcast.net@localhost>]

> On Aug 28, 2019, at 1:00 PM, John Wilson <wilson%dbit.com@localhost> wrote:
> 
> ...
> REALLY dumb question:  does GCC run on VMS?  Definitely want to keep the
> usual calling convention around as an option if so.

Yes, for some definition of "run".  The code generation has some bugs and some seem to like to break GCC specifically, but that could be fixed.  The other problem is that GCC is an extreme case of the "Virtual Disease"; it is moderately fast on today's computers but insanely slow on machines of the VAX performance class.

> Also:  agree about not needing a FP, other than as a convenience for
> debugging.  Even Small-C (the only compiler I ever truly understood)
> got that right -- at any point you always know how much you've messed up
> the SP, and [original] K&R pretty much explicitly says that the only thing
> a "goto" into a block (from above) promises to do is fix the SP to where it
> would have been if you'd gotten there honestly (initializers be damned).
> Which sounds like it's saying the exact same thing.

GCC, and I assume other compilers, have a "omit frame pointer" option for most targets (often the default).  However, even so you sometimes need an actual frame pointer; the most obvious example is a function that contains calls to "alloca".

	paul