[tree-ssa] Add flag to disable dominator optimizations [patch]

[Diego Novillo]

On Tue, 2003-06-10 at 22:08, Jason Merrill wrote:
> Would it be possible to control copy prop separately from discarding
> redundant statements?  I don't see how the latter can hurt.
> 
It would be more intrusive because it would be more fine-grained.  It
means adding more short-circuit logic to rewrite_and_optimize_stmt.  I'd
rather avoid that, ATM.

It's not clear whether the switch will survive at all.  If we find that
it really helps PRE, then I will re-implement the logic differently. 
The switch doesn't really hurt copy-prop nor const-prop, it merely
leaves more work for those two separate passes.


Diego.