[Info-vax] Pascal query

[H Vlems]

On Dec 4, 5:31 pm, "John Reagan" <johnrrea... at earthlink.net> wrote:
> "Ade" <adrian.birk... at blueyonder.co.uk> wrote in message
>
> news:8g9Sm.35746$iT5.28666 at newsfe12.ams2...
>
> > Hi,
>
> > I've had to use Pascal to shift some data around from one set of common
> > memory images on a Vax to the new ones on an Itanium. Anyway, I wrote a
> > quick program to dump the contents into a file which could then be
> > compiled on the Itanium and run to populate the data structures. This
> > program just would not compile. All it consists of is a (hell of a) lot
> > variable:=value; statements. I kept getting insufficient virtual memory
> > errors so I played with the quotas and the page file until I hit a 20gb
> > pagefile and a process pagefile quota of 20,000,000. I then split the
> > results into much smaller chunks to get them to compile.
>
> > There's probably around 1.2 million assignment statements altogether. Can
> > anyone suggest why the program wouldn't compile?
>
> The Pascal compiler (like all the GEM-based compilers) are 32-bit programs.
> They do not use P2 space.  We have too many embedded 32-bit pointers in data
> structures all over the frontends and GEM to safely make changes.
>
> That said, if you have a VERY large program, the compiler will simply run
> out of P0 address space.  The size of the pagefiles or the pagefile quota
> won't help.  When P0 runs out, we're done.
>
> We do make big efforts to reuse heap storage as the compiler is finished
> with it, but we have to keep all the pending instructions in memory so we
> can peephole optimize them, bundle them, write the ELF file, etc.  We looked
> at doing it in "chunks" but even that was going to disturb lots of code.
> Since most programs don't hit the limit, the risk of breaking everybody for
> the reward of letting a few very large programs compile, didn't seem like a
> good thing.
>
> Did it ever compile on Alpha?  Anyway, the program simply requires more
> memory to compile than is available in P0 space.  Breaking them up into
> smaller modules is the correct solution.
>
> John

Just out of curiosity, does the OP have an alternative?
If there's very little program logic and lots of assignments, would
Macro be an option?
Hans