The disturbing myth of Eiffel portability

[cjames3@ibm.net (The Rt Rev'd Colin James III, KOTM 1/96)]

It is common knowledge that the same ANSI C source code when compiled by
different ANSI C compilers produces executables which when run yield
different, inconsistent floating point results.  

This is due to the fact that the runtime floating point packages of ANSI C
compilers vary as to word size and are not required to conform to strict
standards, other than weasel words, as are Ada compilers.

Eiffel emits ANSI C code.

Therefore Eiffel is in fact not truly portable and can in fact yield
different numerical results according to platform.

That begs the following question:  how can the largest Eiffel project of
over 700,000 lines of code (the CALfp bank's derivatives' program) expect
to be taken seriously if the source code when compiled on different
platforms could produce inconsistent and erroneous results.  

In other words, the reason that banks generally have learned to avoid C due
to floating point problems is not solved at all but rather propagated and
worsened by the questionable strategic decision to adopt Eiffel.  That fact
may of course explain why no other famous banks with both US _and_ European
computer operations have jumped on the Eiffel bandwagon and predictably
would not, such as the perfect example of CitiCorp which had the first GE
bank computers about 1962.

Don Knuth tried to get around the floating point problem in the 1960's by
suggesting in Volumes 1 and 2 of his opus to use scaled integers.  It's too
bad that the immature project weenies choose not to read that classic
anymore these days and thus don't know the meaning of integer math.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Re-usable, patented financial software for business and banks 
Colin James III, Principal Scientist     www.cec-services.com
CEC Services, LLC, 1613 Morning Dr, Loveland, CO   80538-4410
Telephone lines:  Voice 970.622.0466; Facsimile: 970.622.0177
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~