As I went searching high and low for P6 opcodes, I kept coming across people from Intel saying that there were only two new opcodes in the P6. So I tried and I tried to count up the opcodes that I know about, to see if 1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 = 2. No matter how I tried to accumulate it, CMOV + FCMOVB + FCMOVE + FCMOVBE + FCMOVU + FCMOVNB + FCMOVNE + FCMOVNBE + FCMOVNU + FCOMI + FCOMIP + FUCOMI + FUCOMIP + RDPMC + INT01 + SALC + UD2 didn't add up to 2. Now I see the FDIV bug in a completely different way.
Most people never knew that the Pentium Processor was going to implement 36-bit addressing, and 2-Mbyte pages. As far as I know, these features were implemented in beta silicon, but scrapped for production. Well, they're back on the Pentium Pro Processor, with some other page mode extensions.
The CPUID instruction has grown by 50% on the Pentium Pro Processor. It has added a third level of reporting. At the end of this link, you will be able to download Intel's AP-485 which explains CPUID on the new Pentium Pro Processor (P6).