Embedded in Academia

Formal verification isn’t some sort of magic pixie dust that we sprinkle over a computer system to make it better. Real formal verification involves a lot of the same kind of difficult, nasty,...

https://blog.regehr.org/archives/2124

Compilers can be improved over time, but this is a slow process. “Proebsting’s Law” is an old joke which suggested that advances in compiler optimization will double the speed of a computat...

https://blog.regehr.org/archives/2578

In its original form, a peephole optimization applied to a collection of instructions located close together in a program. For example, in a register transfer language we might find this sequence...

https://blog.regehr.org/archives/2485

An optimizing compiler traditionally has three main parts: a frontend that translates a source language into an intermediate representation (IR), a “middle end” that rewrites IR into better ...

https://blog.regehr.org/archives/2265

Mutation-based fuzzing is based on the idea that new, bug-triggering inputs can often be created by randomly modifying existing, non-bug-triggering inputs. For example, if we wanted to find bugs...

https://blog.regehr.org/archives/2148

The spinlock is the most basic mutual exclusion primitive provided by a multiprocessor operating system. Spinlocks need to protect against preemption on the current CPU (typically by disabling in...

https://blog.regehr.org/archives/2173

Test-case reduction is more or less a necessity when debugging failures of complex programs such as compilers. Automated test-case reduction is useful not only because it allows developers to avo...

https://blog.regehr.org/archives/2109

NB: This piece is not about responsible disclosure of security issues. For almost as long as people have written code, we have also worked to create methods for finding software defects. Much mor...

https://blog.regehr.org/archives/2037

Let’s talk about these functions: unsigned add(unsigned x) { return x + x; } unsigned shift(unsigned x) { return x << 1; } From the point of view of the C and C++ abstract machines, their beha...

https://blog.regehr.org/archives/1837

Years ago my friend Derek heard that the Jarbidge Wilderness — a remote, mountainous area along the Idaho-Nevada border — is one of the least-visited wilderness areas in the USA, and we’ve ...

https://blog.regehr.org/archives/1832