[patch] Remove flow_loop_scan

[Jeffrey A Law]

On Wed, 2005-02-23 at 01:04 +0100, Zdenek Dvorak wrote:
> Hello,
> 
> > > Long term, we would like to keep information about loops up-to-date for most
> > > of optimizations, which would make EDGE_LOOP_EXIT unnecessary.
> > I'm not sure how feasible that is, particularly for jump threading :(
> 
> as long as jump threading does not damage loops (i.e. is a bit careful
> when dealing with edges leading to loop header), this is not a problem
It's careful in the sense that it'll try not to create an irreducible
region.  But jump threading can do things like rotate loops, take a
single multiple block loop and turn it into nested loops.

Jeff