Andrew MacLeod wrote: > 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 > > this is gcc, get a life.
bottom up is the way i was taught when i was a small child playing with compilers with training wheels. Gcc always seemed weird because you need reg_dead and reg_unused notes. Note that my patch does not use reg_dead or unused notes. kenny