Pi in the Pentium: reverse-engineering the constants in its floating-point unit

392 · Ken Shirriff · Jan. 5, 2025, 5:32 p.m.
Summary
This blog post presents a detailed examination of the Intel Pentium's floating-point unit, focusing on its implementation of polynomial approximations for calculating transcendental functions. Through reverse-engineering the chip's constant ROM, the author reveals how these approximations outperform traditional Taylor series methods, a topic useful for developers interested in computer architecture and optimization techniques.