Compilation performance comparison of 3.5.0 and TreeSSA trees on MICO sources as requested in: [tree-ssa] Merge status 2004-05-03

[law@redhat.com]

In message < 1083800290.3350.6.camel@localhost.localdomain >, Diego Novillo write
s:
 >On Wed, 2004-05-05 at 19:33, Jan Hubicka wrote:
 >
 >> You need ssa form form DCE.  Going in/out just for DCE might be bit
 >> expensive...
 >> 
 >Well, is it?  You probably don't even need the full out-of-ssa pass.  If
 >at -O0 we only schedule passes the will never create overlapping LRs,
 >you can just drop the SSA_NAMEs on the way out. 
Right.  And DCE certainly doesn't create overlapping lifetimes.


You know, we could actually make the "may create overlapping lifetime" a
property of the optimization passes.  That way we just check the property
at out-of-ssa time, if the property is clear, then we just drop the SSA_NAMES.

jeff