Red Hat Bugzilla – Bug 1250
No DOCUMENTED way to control math function floating exceptions
Last modified: 2008-05-01 11:37:49 EDT
The sources for the library libm do not appear to be
included on the SRPM disk.
Asking what rpm /lib/libm.[whatever] is in or
/usr/lib/libm.[whatever] is in says that libm is not in any
Behaviour on BAD ARGUMENTS is different Intel/Alpha.
Intel will give NaN for log(-2.0) while Alpha gives a
There does not seem to be any DOCUMENTED way to control
the error behaviour of Specail functions (trig, exponential,
log, etc) as there is on Other OS, where you can ask for
an error messate, something like a NaN or Inf and continue,
or a Floating Exception. There appear to be SOME error
messages in the library as determined by strings() but
no indication of how to get them rather than Floating
Exceptions (no reference from the trig/exp/log man pages)
Here's what rpm returns:
bash$ rpm -qf /lib/libm-2.0.7.so
The ldconfig generated symlink is not owned by any package.
There is currently no documentation of flaoting exceptions.
There are differences in handling of floating point exceptions
depending on cpu, compiler flags, and libraries that are used
The best way that I can think of to find out how to understand the
behavior of floating point is to look at the source code of
a large package like gsl (Gnu Scientific Library), octave or