On Fri, 2011-12-02 at 13:46 -0700, Jeff Law wrote: > On 12/02/11 12:27, William J. Schmidt wrote: > > > > > Erm, wait. How are PHIs in different blocks going to have the > > same incoming edges? (I was thinking of control dependence edges, > > but these are just regular control flow incoming edges, right?) So > > this really isn't going to help. > They're not. But if we find an equivalence between phi_1 and phi_2, > then we can replace every reference to phi_2 with phi_1. This is safe > because any reference to phi_2 must be dominated by the assignment to > phi_2 which is in the same block as phi_1. > > So while continuing to have the phis in the available expression table > is not useful beyond the current block, the equivalency created when a > redundant PHI is encountered is useful to keep. > > I may have not made the distinction clearly in prior messages. If > that's what your patch does, then you're golden.
Ah, yes. This is what I'm doing. Sorry for the confusion! And thanks for the clarification. Bill > > Jeff >
