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Boosted by ireneista@irenes.space ("Irenes (many)"):
kenshirriff@oldbytes.space ("Ken Shirriff") wrote:

How do computers calculate complicated trig functions such as tangent? I took a look at Intel's 8087 floating-point chip under the microscope to find out. The chip combines two techniques to evaluate the tan function quickly and accurately: polynomials and an algorithm called CORDIC...

A die photo of the 8087 chip under a microscope shows complex patterns from its transistors and wiring. The middle of the chip holds the microcode ROM, while the bottom half of the chip is the datapath that performs calculations. Zooming in on the datapath shows various functional blocks, which appear as rectangles with different textures. Important functional blocks are labeled: exponent ROM, constant ROM, shifter, adder, registers, and so forth.