diff --git a/llvm/lib/CodeGen/MachineDominators.cpp b/llvm/lib/CodeGen/MachineDominators.cpp
index 3f04bb0..be6778a 100644
--- a/llvm/lib/CodeGen/MachineDominators.cpp
+++ b/llvm/lib/CodeGen/MachineDominators.cpp
@@ -15,9 +15,20 @@
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/ADT/SmallBitVector.h"
+#include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
 
+// FIXME: Always verify dominfo if expensive checking is enabled.
+#ifdef EXPENSIVE_CHECKS
+static bool VerifyMachineDomInfo = false;
+#else
+static bool VerifyMachineDomInfo = false;
+#endif
+static cl::opt<bool, true> VerifyMachineDomInfoX(
+    "verify-machine-dom-info", cl::location(VerifyMachineDomInfo),
+    cl::desc("Verify machine dominator info (time consuming)"));
+
 namespace llvm {
 template class DomTreeNodeBase<MachineBasicBlock>;
 template class DominatorTreeBase<MachineBasicBlock>;
@@ -57,6 +68,11 @@
   DT->releaseMemory();
 }
 
+void MachineDominatorTree::verifyAnalysis() const {
+  if (VerifyMachineDomInfo)
+    verifyDomTree();
+}
+
 void MachineDominatorTree::print(raw_ostream &OS, const Module*) const {
   DT->print(OS);
 }
@@ -125,3 +141,17 @@
   NewBBs.clear();
   CriticalEdgesToSplit.clear();
 }
+
+void MachineDominatorTree::verifyDomTree() const {
+  MachineFunction &F = *getRoot()->getParent();
+
+  MachineDominatorTree OtherDT;
+  OtherDT.DT->recalculate(F);
+  if (compare(OtherDT)) {
+    errs() << "MachineDominatorTree is not up to date!\nComputed:\n";
+    print(errs(), nullptr);
+    errs() << "\nActual:\n";
+    OtherDT.print(errs(), nullptr);
+    abort();
+  }
+}