Floating Point Problem

[Tim Prince]

Ron Young wrote:
>   Why would a program give me a output of all NaNs on my Pentium 4 and my
> Athlon64 , but not on my Pentium 3.
>  I used flags -O3 -ffast-math -mfpmath=sse on all machines. The Intel
> compiler 7.1 runs this program fine.
> 
> How can I trace this problem down?
> 
I'm sure you're expecting some of the usual advice, such as check for 
uninitialized data, read the FAQs, etc.  If those are the only flags you 
used, it doesn't make a great deal of sense, unless you trying to trip 
up the compiler.  -mfpmath=sse without a -march= flag might be a way to 
do that, and there aren't many choices for -march which would be 
compatible both with P-III and with sse.