Add a verifyAnalysis to LoopInfo, LoopSimplify, and LCSSA form that verify

that these passes are properly preserved.

Fix several transformation passes that claimed to preserve LoopSimplify
form but weren't.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80926 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/LoopInfo.cpp

@@ -300,6 +300,9 @@ bool Loop::isLoopSimplifyForm() const {
 ///
 void
 Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const {
+  assert(isLoopSimplifyForm() &&
+         "getUniqueExitBlocks assumes the loop is in canonical form!");
+
   // Sort the blocks vector so that we can use binary search to do quick
   // lookups.
   SmallVector<BasicBlock *, 128> LoopBBs(block_begin(), block_end());
@@ -371,6 +374,13 @@ bool LoopInfo::runOnFunction(Function &) {
   return false;
 }
 
+void LoopInfo::verifyAnalysis() const {
+  for (iterator I = begin(), E = end(); I != E; ++I) {
+    assert(!(*I)->getParentLoop() && "Top-level loop has a parent!");
+    (*I)->verifyLoop();
+  }
+}
+
 void LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequired<DominatorTree>();