I would argue the Intel FDIV bug was one. This stuff gets simulated and synthesized at length, using Cadence, Synopsys and other tools before it sees tapeout.

I would argue the Intel FDIV bug was one. This stuff gets simulated and synthesized at length, using Cadence, Synopsys and other tools before it sees tapeout. https://en.wikipedia.org/wiki/Pentium_FDIV_bug https://en.wikipedia.org/wiki/Pentium_FDIV_bug