Complex numbers in compilers - upcoming GNU Tools Cauldron.

[Toon Moene <toon@moene.org>]

This is going to be an interesting discussion.

In the upcoming GNU Tools Cauldron meeting the representation of complex 
numbers in GCC will be discussed from the following "starting point":

"Complex numbers are used to describe many physical phenomenons and are 
of prime importance in data signal processing. Nevertheless, despite 
being part of the C and C++ standards since C99, they are still not 
completely first class citizens in mainstream compilers."

*This* is from the Fortran 66 Standard (http://moene.org/~toon/f66.pdf - 
a photocopy of the 1966 Standard):

- - - - -

Chapter 4. Data Types:
...
4.2.4 Complex Type.

A complex datum is processor approximation to the value of a complex number.
...

- - - - -

I can recall people complaining about the way complex arithmetic was 
handled by compilers since the late 70s.

This is even obvious in weather forecasting software I have to deal with 
*today* (all written in Fortran). Some models use complex variables to 
encode the "spectral" (wave-decomposed) computations in parts where that 
is useful - others just "degrade" those algorithms to explicitly use reals.

Kind regards,

-- 
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands