MI Sched: revert a minor heuristic that snuck in with -misched-vcopy.
I'll fix the heuristic in a general way in a follow-up commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180815 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index 32aedbe..fff6b2b 100644
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -1990,9 +1990,15 @@
return;
// Weak edges are for clustering and other constraints.
+ //
+ // Deferring TryCand here does not change Cand's reason. This is good in the
+ // sense that a bad candidate shouldn't affect a previous candidate's
+ // goodness, but bad in that it is assymetric and depends on queue order.
+ CandReason OrigReason = Cand.Reason;
if (tryLess(getWeakLeft(TryCand.SU, Zone.isTop()),
getWeakLeft(Cand.SU, Zone.isTop()),
TryCand, Cand, Weak)) {
+ Cand.Reason = OrigReason;
return;
}
// Avoid critical resource consumption and balance the schedule.