Never insert duplicate edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41169 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/PredicateSimplifier.cpp b/lib/Transforms/Scalar/PredicateSimplifier.cpp
index 972e875..e27bac5 100644
--- a/lib/Transforms/Scalar/PredicateSimplifier.cpp
+++ b/lib/Transforms/Scalar/PredicateSimplifier.cpp
@@ -711,23 +711,27 @@
++J;
}
- if (J != E && J->To == n && J->Subtree->dominates(Subtree)) {
+ if (J != E && J->To == n) {
+ assert(J->Subtree->dominates(Subtree));
+
edge.LV = static_cast<LatticeVal>(J->LV & R);
assert(validPredicate(edge.LV) && "Invalid union of lattice values.");
- if (edge.LV != J->LV) {
- // We have to tighten any edge beneath our update.
- for (iterator K = I; K->To == n; --K) {
- if (K->Subtree->DominatedBy(Subtree)) {
- LatticeVal LV = static_cast<LatticeVal>(K->LV & edge.LV);
- assert(validPredicate(LV) && "Invalid union of lattice values");
- K->LV = LV;
- }
- if (K == B) break;
+ if (edge.LV == J->LV)
+ return; // This update adds nothing new.
+ }
+
+ if (I != B) {
+ // We also have to tighten any edge beneath our update.
+ for (iterator K = I - 1; K->To == n; --K) {
+ if (K->Subtree->DominatedBy(Subtree)) {
+ LatticeVal LV = static_cast<LatticeVal>(K->LV & edge.LV);
+ assert(validPredicate(LV) && "Invalid union of lattice values");
+ K->LV = LV;
}
-
+ if (K == B) break;
}
- }
+ }
// Insert new edge at Subtree if it isn't already there.
if (I == E || I->To != n || Subtree != I->Subtree)