Floating Point

I'm unemployed right now and I go to job interviews once in a while. One time, the company was doing another AI thing, having to do with verifying that training computations were doing something useful, and not just "dumping a stream of floating point numbers".

Until now I didn't think of it, but apparently AI is all in FP. And it reminded me how I worked in a CPU design place, where they had a group focused on FP. Those guys were doing FP since the days of transistor. They migrated their designs, generation by generation, through TTL, ECL, Bi-CMOS, CMOS. When I heard from them last, they were tinkering with "deep sub-micron".

One remarkable part about their thing was that because they started out in transistors, their FPU didn't have any microcode. It was all in hardware. Even divisions! Just a bunch of counters that sequenced whatever necessary.

For a long time during the reign of x86, the group was somewhat de-prioritized, because many microprocessors at the time treated FP performance as an afterthought. A number of desktop CPUs shipped with no hardware FP at all. But look how the tables have turned. I honestly hope that it was not too late and AI has become a boon for the successors of my past colleagues.