This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: SSA value numbering doing better than GCSE?


	I do not know about this specific example, but GCC's GCSE pass
currently is hobbled.  The implementation is fine, but it does not have
enough of the dependency information to apply the optimization in all
valid instances.  I would not be surprised if the SSA pass itself is
constructing or maintaining more of the dependency information necessary
to allow the optimization to proceed in cases which GCSE currently thinks
it cannot apply them. 

David


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]