Only recalculate DFS Numbers if invalid. Invalidate DFS numbers on reset. Add unit...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234933 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Support/GenericDomTree.h b/include/llvm/Support/GenericDomTree.h
index 5d11766ef44a52f7634bf6115bd23b7fb909e521..63678bb98bb10fc9b5253b4a94d37ef8b46ea63b 100644 (file)
--- a/include/llvm/Support/GenericDomTree.h
+++ b/include/llvm/Support/GenericDomTree.h
@@ -243,6 +243,8 @@ protected:
     this->Roots.clear();
     Vertex.clear();
     RootNode = nullptr;
+    DFSInfoValid = false;
+    SlowQueries = 0;
   }
 
   // NewBB is split and now it has one successor. Update dominator tree to
@@ -663,6 +665,12 @@ public:
   /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
   /// dominator tree in dfs order.
   void updateDFSNumbers() const {
+
+    if (DFSInfoValid) {
+      SlowQueries = 0;
+      return;
+    }
+
     unsigned DFSNum = 0;
 
     SmallVector<std::pair<const DomTreeNodeBase<NodeT> *,

diff --git a/unittests/IR/DominatorTreeTest.cpp b/unittests/IR/DominatorTreeTest.cpp
index 287a944845432d6c900b170d420ed00fd8cf1364..6a5838e693acf50758d04c371e60618e8fe9df73 100644 (file)
--- a/unittests/IR/DominatorTreeTest.cpp
+++ b/unittests/IR/DominatorTreeTest.cpp
@@ -10,6 +10,7 @@
 #include "llvm/IR/Dominators.h"
 #include "llvm/Analysis/PostDominators.h"
 #include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
@@ -174,6 +175,33 @@ namespace llvm {
         EXPECT_EQ(DominatedBBs.size(), 0UL);
         EXPECT_EQ(PostDominatedBBs.size(), 0UL);
 
+        // Check DFS Numbers before
+        EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
+        EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 7UL);
+        EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
+        EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 2UL);
+        EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 5UL);
+        EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 6UL);
+        EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 3UL);
+        EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 4UL);
+
+        // Reattach block 3 to block 1 and recalculate
+        BB1->getTerminator()->eraseFromParent();
+        BranchInst::Create(BB4, BB3, ConstantInt::getTrue(F.getContext()), BB1);
+        DT->recalculate(F);
+
+        // Check DFS Numbers after
+        EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
+        EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 9UL);
+        EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
+        EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 4UL);
+        EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 7UL);
+        EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 8UL);
+        EXPECT_EQ(DT->getNode(BB3)->getDFSNumIn(), 2UL);
+        EXPECT_EQ(DT->getNode(BB3)->getDFSNumOut(), 3UL);
+        EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 5UL);
+        EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 6UL);
+
         return false;
       }
       void getAnalysisUsage(AnalysisUsage &AU) const override {