Re: Motion P1788/M007.01_NaI: Discussion period begins
On 2009-08-09 20:58:48 -0700, Dan Zuras Intervals wrote:
> For 1788, even more than for 754, behaving different
> from one platform to another would be a disaster.
This will be unavoidable, because first, most languages allow compilers
to generate code that behaves differently on different platforms (and
even on a single platform, the results can depend on optimization
options, and in general users prefer that than getting slow code).
And in particular, if IEEE754 is supported, you may get different
results.
BTW, concerning IEEE 754, Java tended to require a same behavior on
the various platforms, meaning that on some platforms, the code would
not be as efficient as it could be. Java has been much criticized for
this choice, and now Java is allowed to be less strict on the
reproducibility.
> It destroys the central theme of assuring the customer that
> the results are correct.
Getting different results doesn't mean that some are incorrect.
And conversely, getting a single result across various platforms
doesn't mean that the result is correct.
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.org/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/>
Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)