Tracking miscompilations in LLVM using its own unit tests

Hi,

John Regehr & I wrote a blog post on tracking miscompilations in LLVM using
its own unit tests & Alive2.
We have been tracking existing bugs & regressions in LLVM and we wrote a
summary of the remaining issues we are aware of. Some issues are simpler,
other require discussion around IR semantics.

https://blog.regehr.org/archives/1737

Thanks to everybody that has contributed so far in fixing bugs & LangRef.

Nuno

Can you give an example of a bug related to pointer comparisons? As far as I know, pointer icmp is the same as integer icmp, and all transforms are consistent with that. And it would be a serious issue if std::less was broken.

(There are a couple bugs where we can rewrite a pointer with one origin to a pointer with a different origin, but that's not really the same issue.)

-Eli