[Info-vax] VAX VMS going forward

[John Reagan]

On Thursday, July 30, 2020 at 7:57:22 AM UTC-4, hb wrote:
> On 7/30/20 2:36 AM, John Reagan wrote:
> > The linker simply won't put static data in a memory region that needs a 64-bit pointer to access it.  Of course, you are welcome to create-and-map-section-64 into 64-bit space and access it as you see fit. 
> 
> I think John wanted to say that the linker can't move static data from
> 32 to 64 bit address space - as it can with code, as long as the PSECT
> is PIC. However, static data can have the ALLOC_64BIT attribute. The
> linker puts static data according to the absence or presence of that
> attribute into 32 or 64 bit address space. I only saw this attribute set
> by FORTRAN - I don't know but doubt that other compilers support it. And
> no, the linker does not accept an option to set that PSECT attribute.

I skipped that on purpose.  Fortran (and only Fortran) has the ability to put a large COMMON block in 64-bit address space.   You can't easily take the address (Fortran's %LOC is 32-bits) or do I/O into it.