[Info-vax] NaT consumption faults with COBOL?

[Bob Gezelter]

On Nov 17, 6:59 pm, "John Reagan" <johnrrea... at earthlink.net> wrote:
> "Jim Duff" <spam.t... at 127.0.0.1> wrote in message
>
> news:49dbt6-ddk.ln1 at SendSpamHere.ORG...
>
>
>
> > All,
>
> > I'm currently seeing some NaT consumption faults on straight COBOL code
> > compiled with HP COBOL V2.9-1453 on OpenVMS IA64 V8.3-1H1.  The compiler
> > is invoked with the following qualifiers:
>
> > /ansi/tie/standard=v3/reserved=noxopen/check=(all,nodec)/convert=leading
>
> > Looking up the NATFAULT error, we have (in part):
>
> > "A NaT value can be generated by a user program using an I64 feature
> > called control speculation. However, compiler-generated code should
> > never take a NaT fault."
>
> > Based on this, a call was logged with HP, and they came back with "This
> > is a function of the memory load on your machine."
>
> > This doesn't ring right with me.  Has anyone else seen anything similar?
> > Any known issues around this area?
>
> That wasn't the most helpful answer you received.
>
> I haven't seen any NaT consumption faults with COBOL code.  There was some
> bugs in the GEM code generator that might expose incoming NaT that just
> happen to be sitting around in registers.  We only saw them in C and BLISS
> code.  However, my memory says they should be fixed in the GEM inside of
> COBOL V2.9 regardless.
>
> Is this easily reproducable?  Most NaT consumption faults I've seen are
> random and hard to pin down.
>
> You should submit a case against the COBOL compiler and provide a reproducer
> if possible.  If not, the team would certainly want to know enough info to
> track it back to the COBOL source line that tripped across the NaT (so .MAP
> files, /LIST/MACH files, etc.).  We need that to figure out which code
> pattern needs NaT safety checking.  As the message said, no
> compiler-generated code should take a NaT fault (including Macro-32).  You
> should only be able to get a NaT fault if you write in Itanium assembly and
> aim at your foot.
>
> GEM itself does not use the NaT feature of Itanium, but the C++ compiler
> does (which is how NaT show up from time to time).
>
> I can explain in more detail if folks are interested (and you have a strong
> gag reflex).
>
> John

John,

With all due respect, don't you mean "do NOT have a strong gag
reflex" (I presume you meant "strong stomach").

- Bob ("Strong Stomach") Gezelter, http://www.rlgsc.com