[DomTree] verifyDomTree to unconditionally perform DT verification

I folded the check for the flag -verify-dom-info into the only caller
where I think it is supposed to be checked: verifyAnalysis.  (The idea
of the flag is to enable this expensive verification in
verifyPreservedAnalysis.)

I'm assuming that when manually scheduling the verification pass
with -passes=verify<domtree>, we do want to perform the verification.

llvm-svn: 236575

llvm/lib/IR/Dominators.cpp

@@ -282,9 +282,6 @@ bool DominatorTree::isReachableFromEntry(const Use &U) const {
 }
 
 void DominatorTree::verifyDomTree() const {
-  if (!VerifyDomInfo)
-    return;
-
   Function &F = *getRoot()->getParent();
 
   DominatorTree OtherDT;
@@ -350,7 +347,10 @@ bool DominatorTreeWrapperPass::runOnFunction(Function &F) {
   return false;
 }
 
-void DominatorTreeWrapperPass::verifyAnalysis() const { DT.verifyDomTree(); }
+void DominatorTreeWrapperPass::verifyAnalysis() const {
+    if (VerifyDomInfo)
+      DT.verifyDomTree();
+}
 
 void DominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
   DT.print(OS);

llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp

@@ -455,10 +455,9 @@ static Instruction *findLocationForEntrySafepoint(Function &F,
   // Note: SplitBlock modifies the DT.  Simply passing a Pass (which is a
   // module pass) is not enough.
   DT.recalculate(F);
-#ifndef NDEBUG
+
   // SplitBlock updates the DT
-  DT.verifyDomTree();
-#endif
+  DEBUG(DT.verifyDomTree());
 
   return BB->getTerminator();
 }