This would make it more efficient to remove the redundant Phi nodes or insert new Phi nodes for SSA, besides providing a cleaner BasicBlock structure.
Created attachment 130254 [details]
Created attachment 130255 [details]
This is performance neutral. See attached.
Comment on attachment 130254 [details]
I like this a lot! R=me.
Landed as http://trac.webkit.org/changeset/110008