On Fri, 2007-08-17 at 12:01 -0400, Kenneth Zadeck wrote: > > In any case IRA can not use UREC because UREC is needed before IRA > > calculates reg class info and the reg class info is needed for > > calculation of UREC. If you manage to use LIVE instead of UREC, it > > would permit to use LIVE also in IRA instead of LR. But I can not say > > can we use LIVE instead of UREC because I don't know the > > df-infrastructure well yet. > > > we should talk. I am avail today. i am leaving on vacation tomorrow > for a week. > > Even if this patch does not get in this round, you should consider it as > a starting point for building the interference graph for ira. > > it does not use urec and a big part of the patch is just getting rid of > urec, It does a backwards scan using the live at bottom set as the > starting point for the scan. > This is the most accurate you can get so there really is no reason not > to use it since it is also no more expensive than any weaker technique.
It is the standard way of doing things. Out-Of-SSA has always used live range info from the bottom up for its conflict graph. I'm marginally suprised it is calculated any other way... Andrew
