On Tue, Jan 5, 2010 at 9:46 AM, Eric Fisher <joefoxr...@gmail.com> wrote: > Hi, > > I found that sometimes -fno-tree-dominator-opts will bring a big speed > promotion. This is because that pass_dominator tries to thread jumps. > But sometimes this will cause that the loop's exit bb does not > dominator its latch bb again. Then pass_complete_unroll is unable to > know the exact number of loop iteration and will not unroll the loop > completely again > > Any comments?
Do you have a testcase for this? Please file a bugreport then. Jump threading should avoid breaking canonical loop forms. Thanks, Richard. > Thanks, > Eric. >
