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Boosted by slightlyoff@toot.cafe ("Alex Russell"):
kenshirriff@oldbytes.space ("Ken Shirriff") wrote:

Intel's Pentium processor (1993). Looking inside the chip , I found a large, complicated circuit just to multiply by 3 (lower right). Why? The Pentium uses a fast technique to multiply 64-bit numbers and it turns out that 3 is a special case. Let's take a closer look at multiplication... 1/N

A die photo of the Pentium processor. Under a microscope, the chip is a tan square with darker rectangular regions and tiny lines. I've removed a metal layer of the chip to make the circuitry more visible. The main functional units are labeled: caches, execution unit, floating point unit, microcode ROM, and so forth. A rectangular circuit in the lower right is highlighted: the times-3 circuit.