The sandsifter audits x86 processors for hidden instructions and 
hardware bugs, by systematically generating machine code to search
through a processor's instruction set, and monitoring execution for
anomalies. Sandsifter has uncovered secret processor instructions from
every major vendor; ubiquitous software bugs in disassemblers,
assemblers, and emulators; flaws in enterprise hypervisors; and both
benign and security-critical hardware bugs in x86 chips.

WWW: https://github.com/xoreaxeaxeax/sandsifter