[PM] Split the LoopInfo object apart from the legacy pass, creating

a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

llvm-svn: 226373

1 files changed, 31 insertions, 27 deletions

diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
index b1f62c4..c200f9f 100644
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -45,11 +45,6 @@ static cl::opt<bool,true>
 VerifyLoopInfoX("verify-loop-info", cl::location(VerifyLoopInfo),
                 cl::desc("Verify loop info (time consuming)"));
 
-char LoopInfo::ID = 0;
-INITIALIZE_PASS_BEGIN(LoopInfo, "loops", "Natural Loop Information", true, true)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_END(LoopInfo, "loops", "Natural Loop Information", true, true)
-
 // Loop identifier metadata name.
 static const char *const LoopMDName = "llvm.loop";
 
@@ -609,15 +604,6 @@ Loop *UnloopUpdater::getNearestLoop(BasicBlock *BB, Loop *BBLoop) {
   return NearLoop;
 }
 
-//===----------------------------------------------------------------------===//
-// LoopInfo implementation
-//
-bool LoopInfo::runOnFunction(Function &) {
-  releaseMemory();
-  LI.Analyze(getAnalysis<DominatorTreeWrapperPass>().getDomTree());
-  return false;
-}
-
 /// updateUnloop - The last backedge has been removed from a loop--now the
 /// "unloop". Find a new parent for the blocks contained within unloop and
 /// update the loop tree. We don't necessarily have valid dominators at this
@@ -680,36 +666,54 @@ void LoopInfo::updateUnloop(Loop *Unloop) {
   }
 }
 
-void LoopInfo::verifyAnalysis() const {
-  // LoopInfo is a FunctionPass, but verifying every loop in the function
-  // each time verifyAnalysis is called is very expensive. The
+//===----------------------------------------------------------------------===//
+// LoopInfo implementation
+//
+
+char LoopInfoWrapperPass::ID = 0;
+INITIALIZE_PASS_BEGIN(LoopInfoWrapperPass, "loops", "Natural Loop Information",
+                      true, true)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_END(LoopInfoWrapperPass, "loops", "Natural Loop Information",
+                    true, true)
+
+bool LoopInfoWrapperPass::runOnFunction(Function &) {
+  releaseMemory();
+  LI.getBase().Analyze(getAnalysis<DominatorTreeWrapperPass>().getDomTree());
+  return false;
+}
+
+void LoopInfoWrapperPass::verifyAnalysis() const {
+  // LoopInfoWrapperPass is a FunctionPass, but verifying every loop in the
+  // function each time verifyAnalysis is called is very expensive. The
   // -verify-loop-info option can enable this. In order to perform some
-  // checking by default, LoopPass has been taught to call verifyLoop
-  // manually during loop pass sequences.
+  // checking by default, LoopPass has been taught to call verifyLoop manually
+  // during loop pass sequences.
 
   if (!VerifyLoopInfo) return;
 
   DenseSet<const Loop*> Loops;
-  for (iterator I = begin(), E = end(); I != E; ++I) {
+  for (LoopInfo::iterator I = LI.begin(), E = LI.end(); I != E; ++I) {
     assert(!(*I)->getParentLoop() && "Top-level loop has a parent!");
     (*I)->verifyLoopNest(&Loops);
   }
 
   // Verify that blocks are mapped to valid loops.
-  for (DenseMap<BasicBlock*, Loop*>::const_iterator I = LI.BBMap.begin(),
-         E = LI.BBMap.end(); I != E; ++I) {
-    assert(Loops.count(I->second) && "orphaned loop");
-    assert(I->second->contains(I->first) && "orphaned block");
+  for (auto &Entry : LI.LI.BBMap) {
+    BasicBlock *BB = Entry.first;
+    Loop *L = Entry.second;
+    assert(Loops.count(L) && "orphaned loop");
+    assert(L->contains(BB) && "orphaned block");
   }
 }
 
-void LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+void LoopInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequired<DominatorTreeWrapperPass>();
 }
 
-void LoopInfo::print(raw_ostream &OS, const Module*) const {
-  LI.print(OS);
+void LoopInfoWrapperPass::print(raw_ostream &OS, const Module *) const {
+  LI.LI.print(OS);
 }
 
 //===----------------------------------------------------------------------===//