> -----Original Message----- > From: Zhigang Gong [mailto:zhigang.g...@linux.intel.com] > Sent: Wednesday, September 23, 2015 9:44 AM > To: Song, Ruiling > Cc: Gong, Zhigang; beignet@lists.freedesktop.org > Subject: Re: [Beignet] [PATCH v2 1/2] GBE: continue to refine interfering > check. > > On Wed, Sep 23, 2015 at 02:33:43AM +0000, Song, Ruiling wrote: > > > > > > > -----Original Message----- > > > From: Beignet [mailto:beignet-boun...@lists.freedesktop.org] On > > > Behalf Of Zhigang Gong > > > Sent: Monday, September 7, 2015 8:20 AM > > > To: beignet@lists.freedesktop.org > > > Cc: Gong, Zhigang > > > Subject: [Beignet] [PATCH v2 1/2] GBE: continue to refine interfering > > > check. > > > > > > More aggresive interfering check, even if both registers are in > > > Livein set or Liveout set, they are still possible not interfering to > > > each other. > > > > > > v2: > > > Liveout interfering check need to take care those BBs which has only > > > one register defined. > > > > > > For example: > > > > > > BBn: > > > ... > > > MOV %r1, %src > > > ... > > > > > > Both %r1 and %r2 are in the BBn's liveout set, but %r2 is not > > > defined or used in BBn. The previous implementation ignore this BB > > > which is incorrect. As %r1 was modified to a different value, it > > > means %r1 could not be replaced with %r2 in this case. > > I thought of another one: (r0, r1 contain different values) > > BB0: > > def r0 > > > > BB1: > > def r1 > > use r1 > > use r0 > > > > How could the algorithm deal with it? > If r1 is a local value in BB1, then it is just ignored in these analysis > including DAG > and liveness. Don't worry about the correctness of this case, as in > gen_reg_allocation we will calculate correct interval for it.
r1 was only defined and used in BB1. Ignored? the interfere() would return false if I call interfere() with r0 and r1 as arguments. But it should return true, as their live-ranges interfere. > If r1 is not a local value of BB1, then it's either in live in of liveout set > of BB1. > Either case, this algorithm could deal it correctly. > > > And looks like the algorithm is converting the "live-range > > interference problem" into "checking the interference in live-In, live-Out > > set". > > Any paper talking on this method? > Actually, most of the paper just talk about to use liveness and DAg > information > to check interference between the phi and phi copy values to determin whether > to coalesce. Not too much details. I just use our liveness information and > DAG to > do the job. > > > > > And for same BB interference (r0, r1 defined and used in same BB), although > we don't need to support it yet, I think if we can put an assert, it would be > better. > Could you describe more detail of this case? local variable or not local > variable? > Are they in live in set or live out set? Not in liveout or livein set. They are only defined and used in same Basic Block. But there live-range interfere. > > Thanks for the comments, > Zhigang Gong. > > > > > Thanks! > > Ruiling > > > > _______________________________________________ > > Beignet mailing list > > Beignet@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/beignet _______________________________________________ Beignet mailing list Beignet@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/beignet
