Add dominates/properlyDominates queries to IDom.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29456 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 0 deletions

diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h
index 31b8562f2c..085225505e 100644
--- a/include/llvm/Analysis/Dominators.h
+++ b/include/llvm/Analysis/Dominators.h
@@ -101,7 +101,17 @@ public:
   inline BasicBlock *operator[](BasicBlock *BB) const {
     return get(BB);
   }
+  
+  /// dominates - Return true if A dominates B.
+  ///
+  bool dominates(BasicBlock *A, BasicBlock *B) const;
 
+  /// properlyDominates - Return true if A dominates B and A != B.
+  ///
+  bool properlyDominates(BasicBlock *A, BasicBlock *B) const {
+    return A != B || properlyDominates(A, B);
+  }
+  
   /// get() - Synonym for operator[].
   ///
   inline BasicBlock *get(BasicBlock *BB) const {
diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp
index 35c847f7d6..f079acfdb4 100644
--- a/lib/VMCore/Dominators.cpp
+++ b/lib/VMCore/Dominators.cpp
@@ -211,6 +211,17 @@ bool ImmediateDominators::runOnFunction(Function &F) {
   return false;
 }
 
+/// dominates - Return true if A dominates B.
+///
+bool ImmediateDominatorsBase::dominates(BasicBlock *A, BasicBlock *B) const {
+  assert(A && B && "Null pointers?");
+  
+  // Walk up the dominator tree from B to determine if A dom B.
+  while (A != B && B)
+    B = get(B);
+  return A == B;
+}
+
 void ImmediateDominatorsBase::print(std::ostream &o, const Module* ) const {
   Function *F = getRoots()[0]->getParent();
   for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {