Re: floating point exception

[Richard B. Johnson]

On 16 Jan 2002, Christian Thalinger wrote:

> On Wed, 2002-01-16 at 15:32, Zwane Mwaikambo wrote:
> > Can you also reproduce _without_ loading NVdriver, just to make everybody 
> > happy.
> > 
> > Thanks,
> > 	Zwane Mwaikambo
> > 
> 
> Sure, same breakdown. Maybe it's really an dual athlon xp issue as dave
> jones mentioned. But shouldn't this also occur when i trigger a floating
> point exception myself? Is there a way to check which floating point
> exception was raised by the seti client?
> 
> Regards.
> 

Maybe you can run it off from gdb? Or `strace` it to a file? Usually
these things are caused by invalid 'C' runtime libraries, either
corrupt, "installed by just making a sim-link to something that
was presumed to be close to what the application was compiled with",
or an error in mem-mapping.

Another very-real possibility is that somebody used floating-point
within the kernel thus corrupting  the `seti` FPU state. You can
check this out by making a program that does lots of FP calculations,
perhaps the sine of a large number of values. You put the results
into one array. Then you do the exact same thing with the results
put into another array.  Then just `memcmp` the arrays! You run
this in a loop for an hour. If the kernel is mucking with your FPU,
it will certainly show.

Cheers,
Dick Johnson

Penguin : Linux version 2.4.1 on an i686 machine (797.90 BogoMips).

    I was going to compile a list of innovations that could be
    attributed to Microsoft. Once I realized that Ctrl-Alt-Del
    was handled in the BIOS, I found that there aren't any.