Comment 5 for bug 128479

I think the user who submitted this bug is unaware of the ieee() function.

Use ieee(0) to make division by zero an error.
Use ieee(1) to be warned when dividing by zero.
Use ieee(2) to silently allow division by zero.

If division by zero is not an error x/0 yeilds:
%nan if x=0
%inf if x>0
-%inf if x<0