[LLVMdev] how to track down a kernel miscompilation?

[Andrew Lenharth]

On Mon, Nov 24, 2008 at 10:51 AM, John Regehr <regehr at cs.utah.edu> wrote:
>> 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.

Yes, the rash of volatile bug fixes made getting 2.6 working much much
easier than getting 2.4 originally was.  Unfortunately I am in the
middle of prepping a paper so I can't track down the current
instcombine bug, but I've posted a building and working kernel should
other people want to play with llvm compiled linux kernels.

Andrew