[LLVMdev] PassManager Dependence Question

[David Greene]

On Friday 19 September 2008 17:26, Devang Patel wrote:
> On Sep 19, 2008, at 3:11 PM, David Greene wrote:
> > Let's say I have an analysis pass that's dependent on another
> > analysis pass
> > (getAnalysisUsage does the appropraite things).
> >
> > So Pass Y depends on Pass X.
> >
> > If some transformation pass depends on Pass Y and Pass Y has not been
> > invalidated by another other pass BUT Pass X _has_ been invalidated
> > by some
> > other pass, what happens?
> >
> > I can imagine two likely paths in the current implementation of
> > PassManager:
> >
> > 1. Pass Y is not re-run because it is considered up-to-date
> >
> > 2. Pass Y is re-run after Pass X because Pass X is out-of-date
> >
> > Which one of these happens?
>
> 1) will happen.

Ok, that's bad for me.  Is there some way to query whether a Pass is 
up-to-date?

                                                       -Dave