[tree-ssa] Patch ping

[Zdenek Dvorak]

> On Wed, 2003-12-03 at 12:44, Zdenek Dvorak wrote:
> > Hello,
> > 
> > > So this is never called on a block with just one incoming edge and a
> > > back edge?
> > 
> > no; it is used to split loops with shared headers, which is exactly when
> > there are more back edges comming into the loop header.
> > 
> 
> Sorry, maybe Im being dense :-)
> 
> if you have one incoming edge and 2 back edges?

sorry, I should say it more clearly -- back edges are always
kept pointing to the newly created block (dummy); just the entry edges
of the loop are redirected back to bb.

Zdenek