On Mon, Nov 28, 2016 at 11:52:53AM +0100, Jan Hubicka wrote:
> > > IPA-ICF performs some code-generation visible changes from hash table
> > > traversal, where the hash values can be different between -g and -g0
> > > (I bet it hashes DECL_UID in somewhere, perhaps other things).
> >
> > It should not - the hash is stable for LTO streaming.
> > I think ICF merging -g and -g0 function is a valid transform (we could
> > try to pick the body with debug info in it), but it would be nice to
> > understand what is causing the differences?
>
> Actually I think we should understand it - otherwise we will continue seeing
> difference between -g and -g0. At some point we compare easy properties, like
> number of basic blocks and ssa names. Perhaps those are affected by -g?
No, number of bbs and ssa names (and their exact versions) must be identical
with -g/-g0.
I've already checked the patch in because Richard acked it this morning.
But I can debug the hash computation.
Jakub
