[Info-vax] Which programming language would you like to see officially supported on VMS ?

[John Reagan]

On Thursday, August 13, 2020 at 10:57:25 AM UTC-4, Dave Froble wrote:
> On 8/13/2020 8:55 AM, gérard Calliet wrote:
> > Le 20/02/2020 à 03:45, John Reagan a écrit :
> >> I'll need Cmake on OpenVMS to build LLVM on x86.
> > Will we get Cmake and up-to-date LLVM also on itanium ?
> > <
> 
> Gerald,
> 
>  From some of your posts it appears you're interested in seeing VSI 
> continue to develop for VAX, Alpha, and itanic.  If so, then you're 
> going to be disappointed.  All three of those are basically dead 
> products.  x86 is the beginning of the future.
> 
> Without being John, I can still pretty much guarantee you that you will 
> not see LLVM on VAX, Alpha, or itanic from VSI.
> 
> While there are multiple reasons, the main reason is that VSI is 
> leverging x86 work on LLVM for VMS usage.  As far as I know, there is no 
> LLVM already on itanic.  Thus, VSI would have to develop the entire 
> compiler tool chain, and, that just isn't going to happen.
> 
> -- 
> David Froble                       Tel: 724-529-0450
> Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
> DFE Ultralights, Inc.
> 170 Grimplin Road
> Vanderbilt, PA  15486

There USED to be an Itanium target for LLVM but it is long dead and removed from the current tree.  I've never seen reference to a VAX or Alpha target.  It is pretty "easy" to write an LLVM target.  Somebody is trying a 68040 target and I've also seen a joke target for Z-80 (as a cross-compiler only of course).

Since VAX is an operand-rich architecture, doing a VAX target with reasonable code might be tough.  That's why we never did a GEM VAX, we didn't want to deal with an architecture where choice of operands was viewed as an optimization.

On the other hand, Alpha is such a regular ISA, I bet somebody could start with the RiscV target and make an Alpha target.  The bigger challenge is writing Alpha objects.  LLVM's MC layer doesn't know about those formats.  Somebody could try to lift knowledge from an older binutils (respecting GPL copyrights of course) and add that object/debug format.  (Or write a stand-alone tool that would turn an mythical ELF/DWARF Alpha object into a proper EOBJ/DST Alpha object - that sounds fun!)