[Info-vax] C and assembly language, was: Re: WHY IS VSI REQUIRING A HYPERVISOR FOR X86 OPENVMS?

[John Reagan]

On Tuesday, December 22, 2020 at 11:30:10 AM UTC-5, Simon Clubley wrote:
> On 2020-12-21, Wilm Boerhout <wboerhou... at this-gmail.com> wrote: 
> > John Reagan schreef op 21-12-2020 om 02:55: 
> >>
> >> "Much"? I think Clair did a line count/module posting in the last year or so. The Macro-32 contribution was getting pretty low (less than 20%?) However, just the difficult and nasty parts that nobody wants to attempt to rewrite. I'd pay real money to watch somebody try to rewrite the shadow driver out of Macro-32 (pretty much every routine can jump into any other routine in an alternative universe threading scheme). And I've recently had to look at chunks of DECnet IV and even I couldn't make heads-or-tails out of some of the algorithms. 
> >> 
> > 
> > Apropos DECnet IV: a bunch of us in the HECnet alternate universe have 
> > been running pydecnet (that is, DECnet IV written in python from the 
> > original DECnet specifications) for a while now, thanks to Paul Koning's 
> > implementation effort ***bows to Paul*** 
> >
> $ set response/mode=good_natured 
> 
> DECnet Phase IV in Python ??? That's just unnatural. ;-) 
> 
> On a more serious note, I wonder why John was looking at the DECnet 
> Phase IV code. I wonder if something in there found a problem in the 
> new compilers ?
> Simon. 
> 
> -- 
> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP 
> Walking destinations on a map are further away than they appear.
No conspiracies here.  We were looking at the code that did MAC address lookups for MOP loads.  It has some Alpha vs Itanium conditionals.  I was asked by another engineer to explain why the two platforms were different what x86 needs.  The original VAX version pushed routine addresses on the stack and did some "JSB @(SP)+"  along with some hard resets of the SP (think of it as a cheap form of setjmp/longjmp).    You can't do a store into SP on Itanium so the code had to do something else. 

If you want a list of known bugs with the current x86 cross-compilers?  I have that list too.  There are several.  I'm currently working on a linker issue that cropped up with our bootstrapping native compilers to x86.  Our linker doesn't handle code in SHT_GROUP but EH data not in the group.  It ended up trying to apply relocations to non-existent code.  A sanity check was raised.  What else do you want to know?  For C, I have one bug dealing with a #pragma linkage, one with changing "align(page)", and request for a new builtin to read/write the Time Stamp Counter.  There are a few open for Macro-32 and two for BLISS (all worked around with simple edits).