
ATLAS has detected that your machine has 3DNow! capability, and ATLAS
can use these instructions to dramatically speed up single precision
operations.  However, 3DNow! does not use IEEE compliant arithmetic;
in particular, it does not handle NaNs or Infinities at all (operations
on them are essentially undefined), and it does not handle overflow or
underflow correctly.  There may be other discrepencies as well.  Therefore,
only enable 3DNow! if you are very sure that these shortcomings in
accuracy do not concern you.  In general, getting the answer very fast
is no substitute for getting the *correct* answer, so just say no if
you are at all unsure.
