Bug in floating-point addition: is anyone else seeing this?

[Dave Parker]

On May 21, 7:01 pm, Carl Banks <pavlovevide... at gmail.com> wrote:
> The crucial thing is not to slow down the calculations with useless
> bells and whistles.

Are you running your simulations on a system that does or does not
support the "useless bell and whistle" of correct rounding?  If not,
how do you prevent regression towards 0?

For example, one of the things that caused the PS3 to be in 3rd place
behind the Wii and XBox 360 is that to save a cycle or two, the PS3
cell core does not support rounding of single precision results -- it
truncates them towards 0.  That led to horrible single-pixel errors in
the early demos I saw, which in term helped contribute to game release
delays, which has turned into a major disappointment for Sony.