Re: Math Functions: Basic building blocks...

From: Eric Ford (eford_at_[hidden])
Date: 2001-09-13 14:37:32

> > As for nan, according to the GNU C library manual, ISO C99 provide
> > fpclassify, isnan, isinf, etc..  What's the shortcoming of this
> > method?  
> 
> Do you have access to the real code for this _ can only find
> MACRO names, not the actual MACRO.

it's in my my /usr/include/math.h.  Unfortunately, the macros just are
wrappers so that it calls the right internal functions depending on
the argument type (by making use of sizeof's, obviously a template
would be better for allowing for user defined types).  The code for
the internal functions is surely avaliable (just find a source tarball
for a recent version of glibc (mine is glibc-devel-2.2.2-10)). 
Unfortunately, it's probably useless.  I think the relevant question
is how common is fpclassify isnan and isinf support in compilers such
as MS's?