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

[Andrew MacLeod]

On Wed, 2003-06-11 at 00:04, Diego Novillo wrote:
> 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.
> 
> 

Well, I think that into-ssa copyprop ought to look at the
-ftree-copyprop flag... if that isn't on, I dont think into-ssa ought to
be doing copyprop either...  Same thing with const-prop.  

And I like the flag to disable everything... Helps when tracking down
bugs :-)



Andrew