An Algorithm that Computes a Lower Bound on the Distance Between a Segment and $Z^2$
Vincent Lefèvre · HAL (Le Centre pour la Communication Scientifique Directe) · 1997
We give a fast algorithm for computing a lower bound on the distance between a straight line and the points of a regular grid. This algorithm is used to find worst cases when trying to round the elementary functions correctly in floating-point arithmetic, which consists in returning the machine number that is the closest (there are other rounding modes) to the exact result.