<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - PhiMovesPass in register allocator broken" href="https://bugs.freedesktop.org/show_bug.cgi?id=90887#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - PhiMovesPass in register allocator broken" href="https://bugs.freedesktop.org/show_bug.cgi?id=90887">bug 90887</a> from <a class="email" href="mailto:imirkin@alum.mit.edu" title="Ilia Mirkin <imirkin@alum.mit.edu>"> Ilia Mirkin</a> <pre>(In reply to jr from <a href="show_bug.cgi?id=90887#c4">comment #4</a>) > I've been thinking a little about a better way to fix this inbound edge > ordering dependency. Unfortunately it seems that unless there is a way to > efficiently recompute the information there always will be an invariant that > has to be respected by graph transformations (and which attach and detach > simply cannot guarantee on their own). The way that LLVM deals with this is that the source actually contains a reference to the inbound bb as well. That way you can do whatever you want with the edges, each src of a phi node knows which bb it's coming from. It'd be a bit of a pain to introduce here... my strategy so far has been to hold my nose and just fix things up as they come, which I guess is what you've done as well. I need to look at this logic very carefully though. The fact that we were previously adding a FORWARD edge and aren't anymore is a bit worrying -- the meaning of those things is explained somewhere btw -- TREE == part of the MST; FORWARD/etc are various other edges.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>