5 files changed, 206 insertions, 13 deletions
diff --git a/llvm/include/llvm/Analysis/DominatorInternals.h b/llvm/include/llvm/Analysis/DominatorInternals.h
index 5ecb3481445..8cea96d3560 100644
--- a/llvm/include/llvm/Analysis/DominatorInternals.h
+++ b/llvm/include/llvm/Analysis/DominatorInternals.h
@@ -262,29 +262,17 @@ void Calculate(DominatorTreeBase<typename GraphTraits<NodeT>::NodeType>& DT,
                                                                      DT.Info[W];
 
     // Step #2: Calculate the semidominators of all vertices
-    bool HasChildOutsideDFS = false;
 
     // initialize the semi dominator to point to the parent node
     WInfo.Semi = WInfo.Parent;
     for (typename GraphTraits<Inverse<NodeT> >::ChildIteratorType CI =
          GraphTraits<Inverse<NodeT> >::child_begin(W),
-         E = GraphTraits<Inverse<NodeT> >::child_end(W); CI != E; ++CI) {
+         E = GraphTraits<Inverse<NodeT> >::child_end(W); CI != E; ++CI)
       if (DT.Info.count(*CI)) {  // Only if this predecessor is reachable!
         unsigned SemiU = DT.Info[Eval<GraphT>(DT, *CI)].Semi;
         if (SemiU < WInfo.Semi)
           WInfo.Semi = SemiU;
       }
-      else {
-        // if the child has no DFS number it is not post-dominated by any exit, 
-        // and so is the current block.
-        HasChildOutsideDFS = true;
-      }
-    }
-
-    // if some child has no DFS number it is not post-dominated by any exit, 
-    // and so is the current block.
-    if (DT.isPostDominator() && HasChildOutsideDFS)
-      WInfo.Semi = 0;
 
     DT.Info[DT.Vertex[WInfo.Semi]].Bucket.push_back(W);
 
diff --git a/llvm/test/Analysis/PostDominators/pr6047_a.ll b/llvm/test/Analysis/PostDominators/pr6047_a.ll
new file mode 100644
index 00000000000..ec1455b46fe
--- /dev/null
+++ b/llvm/test/Analysis/PostDominators/pr6047_a.ll
@@ -0,0 +1,15 @@
+; RUN: opt < %s -postdomtree -analyze | FileCheck %s
+define internal void @f() {
+entry:
+  br i1 undef, label %bb35, label %bb3.i
+
+bb3.i:
+  br label %bb3.i
+
+bb35.loopexit3:
+  br label %bb35
+
+bb35:
+  ret void
+}
+; CHECK: [3] %entry
diff --git a/llvm/test/Analysis/PostDominators/pr6047_b.ll b/llvm/test/Analysis/PostDominators/pr6047_b.ll
new file mode 100644
index 00000000000..7bd2c86b737
--- /dev/null
+++ b/llvm/test/Analysis/PostDominators/pr6047_b.ll
@@ -0,0 +1,19 @@
+; RUN: opt < %s -postdomtree -analyze | FileCheck %s
+define internal void @f() {
+entry:
+  br i1 undef, label %a, label %bb3.i
+
+a:
+  br i1 undef, label %bb35, label %bb3.i
+
+bb3.i:
+  br label %bb3.i
+
+
+bb35.loopexit3:
+  br label %bb35
+
+bb35:
+  ret void
+}
+; CHECK: [4] %entry
diff --git a/llvm/test/Analysis/PostDominators/pr6047_c.ll b/llvm/test/Analysis/PostDominators/pr6047_c.ll
new file mode 100644
index 00000000000..08c9551f156
--- /dev/null
+++ b/llvm/test/Analysis/PostDominators/pr6047_c.ll
@@ -0,0 +1,147 @@
+; RUN: opt < %s -postdomtree -analyze | FileCheck %s
+define internal void @f() {
+entry:
+  br i1 undef, label %bb35, label %bb3.i
+
+bb3.i:
+  br label %bb3.i
+
+bb:
+  br label %bb35
+
+bb.i:
+  br label %bb35
+
+_float32_unpack.exit:
+  br label %bb35
+
+bb.i5:
+  br label %bb35
+
+_float32_unpack.exit8:
+  br label %bb35
+
+bb32.preheader:
+  br label %bb35
+
+bb3:
+  br label %bb35
+
+bb3.split.us:
+  br label %bb35
+
+bb.i4.us:
+  br label %bb35
+
+bb7.i.us:
+  br label %bb35
+
+bb.i4.us.backedge:
+  br label %bb35
+
+bb1.i.us:
+  br label %bb35
+
+bb6.i.us:
+  br label %bb35
+
+bb4.i.us:
+  br label %bb35
+
+bb8.i.us:
+  br label %bb35
+
+bb3.i.loopexit.us:
+  br label %bb35
+
+bb.nph21:
+  br label %bb35
+
+bb4:
+  br label %bb35
+
+bb5:
+  br label %bb35
+
+bb14.preheader:
+  br label %bb35
+
+bb.nph18:
+  br label %bb35
+
+bb8.us.preheader:
+  br label %bb35
+
+bb8.preheader:
+  br label %bb35
+
+bb8.us:
+  br label %bb35
+
+bb8:
+  br label %bb35
+
+bb15.loopexit:
+  br label %bb35
+
+bb15.loopexit2:
+  br label %bb35
+
+bb15:
+  br label %bb35
+
+bb16:
+  br label %bb35
+
+bb17.loopexit.split:
+  br label %bb35
+
+bb.nph14:
+  br label %bb35
+
+bb19:
+  br label %bb35
+
+bb20:
+  br label %bb35
+
+bb29.preheader:
+  br label %bb35
+
+bb.nph:
+  br label %bb35
+
+bb23.us.preheader:
+  br label %bb35
+
+bb23.preheader:
+  br label %bb35
+
+bb23.us:
+  br label %bb35
+
+bb23:
+  br label %bb35
+
+bb30.loopexit:
+  br label %bb35
+
+bb30.loopexit1:
+  br label %bb35
+
+bb30:
+  br label %bb35
+
+bb31:
+  br label %bb35
+
+bb35.loopexit:
+  br label %bb35
+
+bb35.loopexit3:
+  br label %bb35
+
+bb35:
+  ret void
+}
+; CHECK: [3] %entry
diff --git a/llvm/test/Analysis/PostDominators/pr6047_d.ll b/llvm/test/Analysis/PostDominators/pr6047_d.ll
new file mode 100644
index 00000000000..4cfa88029ae
--- /dev/null
+++ b/llvm/test/Analysis/PostDominators/pr6047_d.ll
@@ -0,0 +1,24 @@
+; RUN: opt < %s -postdomtree -analyze | FileCheck %s
+define internal void @f() {
+entry:
+  br i1 1, label %a, label %b
+
+a:
+br label %c
+
+b:
+br label %c
+
+c:
+  br i1 undef, label %bb35, label %bb3.i
+
+bb3.i:
+  br label %bb3.i
+
+bb35.loopexit3:
+  br label %bb35
+
+bb35:
+  ret void
+}
+; CHECK: [4] %entry