Revert [Dominators][CodeGen] Clean up MachineDominators

This reverts r373101 (git commit 72c57ec3e6b320c31274dadb888dc16772b8e7b6)

llvm-svn: 373117

1 files changed, 13 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MachineDominators.cpp b/llvm/lib/CodeGen/MachineDominators.cpp
index a7d7b6e66a0..1dfba8638c2 100644
--- a/llvm/lib/CodeGen/MachineDominators.cpp
+++ b/llvm/lib/CodeGen/MachineDominators.cpp
@@ -64,11 +64,21 @@ void MachineDominatorTree::releaseMemory() {
 }
 
 void MachineDominatorTree::verifyAnalysis() const {
-  if (DT && VerifyMachineDomInfo)
-    if (!DT->verify(DomTreeT::VerificationLevel::Basic)) {
-      errs() << "MachineDominatorTree verification failed\n";
+  if (DT && VerifyMachineDomInfo) {
+    MachineFunction &F = *getRoot()->getParent();
+
+    DomTreeBase<MachineBasicBlock> OtherDT;
+    OtherDT.recalculate(F);
+    if (getRootNode()->getBlock() != OtherDT.getRootNode()->getBlock() ||
+        DT->compare(OtherDT)) {
+      errs() << "MachineDominatorTree for function " << F.getName()
+            << " is not up to date!\nComputed:\n";
+      DT->print(errs());
+      errs() << "\nActual:\n";
+      OtherDT.print(errs());
       abort();
     }
+  }
 }
 
 void MachineDominatorTree::print(raw_ostream &OS, const Module*) const {