[LLVMdev] how to track down a kernel miscompilation?

[John Regehr]

> was wrong.  At the time (~ 1 year ago) it was almost always
> instcombine and almost always volatile related.  Now bugpoint has some
> ways to run the code by some external agent which I haven't
> investigated yet.

People have fixed a ton of bugs (volatile and otherwise) in instcombine 
since then.  I will be very interested to hear what pass ends up being the 
problem here, and what exactly is the code that triggers the bug-- please 
post these when the results are known.

John Regehr