more on rogue comment: IEEE 754R and Reproducibility

[David Hough 754R work <754r@xxxxxxxxxxx>]

> > > You are introducing a comparable requirement into floating-point,
> > > by demanding reproducibility in parallel codes.

Currently Annex B.3 states 

 "Languages should provide means for programmers to specify reproducible 
results that are identical on all platforms supporting that language and this 
standard, for operations completely specified by this standard"

without explaining much about what that means.    The intent is that languages
should provide means to suppress, when that's desirable,
gratuitous numerical variations among platforms, revolving around 
associativity foremost and intermediate precisions as well, and many other
aspects of secondary importance.      It is not intended to help with
irreproducibility built into the semantics of a particular program running
on any platform (such as multithreading based on dynamic workload). 
Nor is it intended that implementations of the same algorithm in different
languages should produce the same results; I don't see any way to specify
that technically even if it were desirable. 

(And now, looking at Annex B and C, I don't see anything about the default
widenTo method for expression evaluation.    
I would expect it to be language-defined.)

> However, I would agree that it is unreasable to request/demand that
> unrelated changes be coupled to the repeatability mantra. Thus, the
> following would appear unnecessary:
>   4) Identical decimal encodings be used.

It's just possible that the standardized API's for converting decimal encodings
might not be universally implemented efficiently enough to be suitable for
portable code, so as usual people will roll their own... with subsequent
latitude for error which would be less likely to arise if there were only one 
decimal encoding.    So it's one possible unlikely source of error, even
if it's not in the same class as rounding errors.

>   5) Annex material be moved to other clauses.

How many people are aware of the current reproducibility recommendation
in Annex B.3?     How much weight does a "normative"
annex carry that's all "should" and no "shall" anyway?
One would prefer to explain to a reader that the division of normative
and non-normative material into body and annexes followed some logical 
order weightier than a series of frequently-reversed committee votes.