Re: [Boost-users] numeric/interval overflow & test_float

From: Guillaume Melquiond (guillaume.melquiond_at_[hidden])
Date: 2005-08-12 13:45:14

Le jeudi 11 août 2005 à 07:29 -0600, Steven Solie a écrit :
 
> What I'm wondering now is what math functions the failed tests are
> executing from the C library? Perhaps there is a boundary condition
> that a math function is not handling correctly or something.

As a matter of fact, no (math) function from the C library is called for
the overflow test. We are simply using the floating-point unit of the
processor to do multiplications.

> Since these tests don't fail on another PowerPC based system I think
> the problem lies with my platform but I need help narrowing it down
> a bit more.

At this stage, I can only envision three possibilities:

1. The compilation goes somewhat wrongly. Could you verify that the body
of the header file boost/numeric/detail/ppc_rounding_control.hpp is
really compiled?

2. The program does not rely on the floating-point unit. Perhaps there
is some software floating-point emulation in effect?

3. The operating system messes with the floating-point unit behind your
back.

Unfortunately they all seem quite far-fetched to me, and I am a bit lost
as to why it fails on your computer. Sorry for not being able to help
more.

Guillaume