Java Numerics

[Samuel A. Figueroa]

Jerome Coonen writes (the first fragment is a quote from David Hough):
  > >> the performance penalties for adhering to Java's model are not
  > >> overwhelming and could be reduced further with a few modifications
  > >> in the next revisions of those architectures.
  >The inner product example of my original note showed that memory traffic
  >nearly doubled for compiled x86 code forced to adhere to Java's model.
  >Given that this penalty is suffered by users whose processors dominate
  >the market by orders of magnitude, one might expect this to be of more
  >than "not overwhelming" concern.

Actually, the inner product example showed code that doesn't quite conform
to Java's language specification in the case of underflow.  (If underflow
occurs [or more accurately, if the result is in the range of double precision
denormals], simply storing the result to memory and reloading may lead to
double rounding.)  If underflow cannot be ruled out, then performance on a
Pentium slows down by at least by a factor of ten for addition, subtraction,
and multiplication.

Sam Figueroa