CGAL users discussion list

[Sylvain Pion <>]

Le 31/07/10 17:59, Bernhard Kornberger a écrit :
> I'd like to run a CGAL'ed program in Valgrind. As I know already from
> the past, this does not work very well. Are any compiler-switches or
> Valgrind-options known to overcome the problems? I use gcc (4.4.3) and
> CGAL3.6.0 on 64bit Linux:
>
> terminate called after throwing an instance of 'CGAL::Assertion_exception'
> what(): CGAL ERROR: assertion violation!
> Expr: -CGAL_IA_MUL(-1.1, 10.1) != CGAL_IA_MUL(1.1, 10.1)
> File: /opt/CGAL360/include/CGAL/Interval_nt.h
> Line: 158
> Explanation: Wrong rounding: did you forget the -frounding-math option
> if you use GCC?
>
> ...where -frounding-math is used, and the program works flawlessly
> outside Valgrind.

Hi Bernhard,

Valgrind doesn't handle the FPU rounding modes.  So, under valgrind,
the interval arithmetic of CGAL becomes unreliable (so the Filtered_kernel
and the higher levels using it as well).

I don't think that there is any workaround.  Depending on what you
are trying to debug, you can maybe use a non-degenerate data set,
and use a non robust kernel.  Or use some slow multiprecision kernel
with no interval filtering.

--
Sylvain