------- Comment #33 from dnovillo at redhat dot com 2006-11-09 21:48 ------- Subject: Re: [4.3 Regression] Misscompilation of spec2006 gcc
dberlin at dberlin dot org wrote on 11/09/06 16:28: > Uh, LIM and store sinking are too. Roughly all of our memory > optimizations are. > They are? Really? Can you show me where exactly? > The changes i have to make to PRE (and to the other things) to > account for this is actually to rebuild the non-mem-ssa-factored (IE > the current factored) form out of the chains by seeing what symbols > they really affect. > OK, so how come you were so positive about the new interface? I need to understand what was the great difficulty you ran into that made you change your mind. I need to see a specific example. See, the UD chains you get in mem-ssa are neither incomplete nor wrong. The symbols affected are right there in plain sight, so there is no loss of any information. > For at least all the opts i see us doing, it makes them more or less > useless without doing things (like reexpanding them) first. Because > this is true, I'm not sure it's a good idea at all, which is why i'm > still on the fence. > But you still haven't *shown* me where the hardness or slowness comes in. Granted, the work is still unfinished so we can't really do actual measurements. But I need to understand where the difficulties will be so that I can accomodate the infrastructure. It's obviously not my intent to make things harder to use. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29680
