On Jul 11, 2007, at 9:37 AM, David A. Greene wrote: > On Tuesday 10 July 2007 19:46, Owen Anderson wrote: >> Author: resistor >> Date: Tue Jul 10 19:46:18 2007 >> New Revision: 38517 >> >> URL: http://llvm.org/viewvc/llvm-project?rev=38517&view=rev >> Log: >> Add FastDSE, a new algorithm for doing dead store elimination. This >> algorithm is not as accurate as the current DSE, but it only a >> linear scan >> over each block, rather than quadratic. Eventually (once it has been >> improved somewhat), this will replace the current DSE. > > I hope by "replace" you mean, "will become the new default." Some > of us > are very interested in squeezing out every last possible bit of > performance > and are willing to take a compile time hit to do it. I don't want > to lose the > current DSE implementation.
Right now, the current DSE pass does *very* little, and is extremely expensive. The new FastDSE current misses some cases that the existing DSE pass gets, but Owen is working on completing it. Once done, I'd be very surprised if DSE caught any cases that FastDSE doesn't. If that's the case, we should be able to nuke the old DSE pass. If it's not the case, we'll keep it. -Chris _______________________________________________ llvm-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
