Robert Dewar wrote:
Russell Shaw wrote:
The original bug was about testing the equality of doubles. I think
that's
just plain mathematically bad. Error bands should be used to test for
"equality", using a band that is in accordance with the minimum precision
specified in the compiler documentation.
That's often taught, but in fact there are many IEEE algorithms where it
makes perfectly good sense to test for absolute equality.
OTOH, maybe the equality operators should discard the excess
precision, so
effectively implementing the error band anyway. Can't say more without
reading
the relevant standards. If the equality operators did this, then it
shouldn't
slow down any non-equality operators or anything else.
But it would, quite unnecessarily, slow down equality.
But isn't equality broken if it doesn't work because of excess precision?
