There’s Only Four Billion Floats—So Test Them All!
Bruce Dawson (via Hacker News):
A few months ago I saw a blog post touting fancy new SSE3 functions for implementing vector floor, ceil, and round functions. There was the inevitable proud proclaiming of impressive performance and correctness. However the ceil function gave the wrong answer for many numbers it was supposed to handle, including odd-ball numbers like ‘one’.