On Wed, Sep 05, 2012 at 11:07:17AM +0200, Richard Guenther wrote:
> > But that's not a problem with inlining, that's a problem with allowing
> > things to happen out of order (for some definition of things and
> > order) - which in my understanding -Og is going to tie down.
>
> Yes, the goal is definitely to avoid the jumping back and forth
> on source lines you can see when debugging optimized programs.
>
> Btw, the patch only lies the foundation for all the goals that
> accumulated in this thread to be eventually fulfilled. I only
> tried to collect the minimal set of optimizations that do not
> automatically defeat any of them ;)
The jumping back and forth could be fixed by limiting scheduling only to
insns with the same locus with -Og or something similar (if doing scheduling
at all). Of course the fewer gimple passes that reorder stmts the better
too. Guess some inlining ought to be allowed, but e.g. IPA cloning should
be definitely disabled.
Jakub
