Pentium Calculator

[AeroASM]

Can I just clarify on this division bug?

Code Select Expand


mov eax,2
mov edx,0
mov ecx,1
div ecx


How exactly will eax end up with 1.98342876849685623?

[MichaelW]

The Pentium divide bug I remember was actually an FDIV bug. I think the problem was some missing entries in a lookup table. The attachment is a C program that tests for the bug. IIRC on the one processor I found that had the bug, the return value was incorrect beyond the fifth or sixth decimal place.



[attachment deleted by admin]