X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FLoopInfo.cpp;h=275331b03a58f952f0298d7dde3fc7ec54fb4559;hb=b169426272b85ce28a9a56d13154e61b158fc47a;hp=876161d34fc9199555a353ee2a4ef25ab59adf65;hpb=221d688a5ef21a22c2368c9fff0e92d7966c95e5;p=oota-llvm.git

diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index 876161d34fc..275331b03a5 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -1,4 +1,11 @@
-//===- LoopInfo.cpp - Natural Loop Calculator -------------------------------=//
+//===- LoopInfo.cpp - Natural Loop Calculator -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
 //
 // This file defines the LoopInfo class that is used to identify natural loops
 // and determine the loop depth of various nodes of the CFG.  Note that the
@@ -8,98 +15,36 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
 #include "llvm/Analysis/Dominators.h"
+#include "llvm/Assembly/Writer.h"
 #include "llvm/Support/CFG.h"
-#include "Support/DepthFirstIterator.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include <algorithm>
+#include <ostream>
+using namespace llvm;
 
-AnalysisID cfg::LoopInfo::ID(AnalysisID::create<cfg::LoopInfo>());
+char LoopInfo::ID = 0;
+static RegisterPass<LoopInfo>
+X("loops", "Natural Loop Construction", true, true);
 
 //===----------------------------------------------------------------------===//
-// cfg::Loop implementation
+// Loop implementation
 //
-bool cfg::Loop::contains(const BasicBlock *BB) const {
-  return find(Blocks.begin(), Blocks.end(), BB) != Blocks.end();
-}
-
 
 //===----------------------------------------------------------------------===//
-// cfg::LoopInfo implementation
+// LoopInfo implementation
 //
-bool cfg::LoopInfo::runOnMethod(Method *M) {
-  BBMap.clear();                             // Reset internal state of analysis
-  TopLevelLoops.clear();
-  Calculate(getAnalysis<DominatorSet>());    // Update
+bool LoopInfo::runOnFunction(Function &) {
+  releaseMemory();
+  LI->Calculate(getAnalysis<DominatorTree>().getBase());    // Update
   return false;
 }
 
-void cfg::LoopInfo::Calculate(const DominatorSet &DS) {
-  const BasicBlock *RootNode = DS.getRoot();
-
-  for (df_iterator<const BasicBlock*> NI = df_begin(RootNode),
-	 NE = df_end(RootNode); NI != NE; ++NI)
-    if (Loop *L = ConsiderForLoop(*NI, DS))
-      TopLevelLoops.push_back(L);
-
-  for (unsigned i = 0; i < TopLevelLoops.size(); ++i)
-    TopLevelLoops[i]->setLoopDepth(1);
-}
-
-void cfg::LoopInfo::getAnalysisUsageInfo(Pass::AnalysisSet &Required,
-                                         Pass::AnalysisSet &Destroyed,
-                                         Pass::AnalysisSet &Provided) {
-  Required.push_back(DominatorSet::ID);
-  Provided.push_back(ID);
-}
-
-
-cfg::Loop *cfg::LoopInfo::ConsiderForLoop(const BasicBlock *BB,
-					  const DominatorSet &DS) {
-  if (BBMap.find(BB) != BBMap.end()) return 0;   // Havn't processed this node?
-
-  std::vector<const BasicBlock *> TodoStack;
-
-  // Scan the predecessors of BB, checking to see if BB dominates any of
-  // them.
-  for (BasicBlock::pred_const_iterator I = BB->pred_begin(),
-	 E = BB->pred_end(); I != E; ++I)
-    if (DS.dominates(BB, *I))   // If BB dominates it's predecessor...
-      TodoStack.push_back(*I);
-
-  if (TodoStack.empty()) return 0;  // Doesn't dominate any predecessors...
-
-  // Create a new loop to represent this basic block...
-  Loop *L = new Loop(BB);
-  BBMap[BB] = L;
-
-  while (!TodoStack.empty()) {  // Process all the nodes in the loop
-    const BasicBlock *X = TodoStack.back();
-    TodoStack.pop_back();
-
-    if (!L->contains(X)) {                  // As of yet unprocessed??
-      L->Blocks.push_back(X);
-
-      // Add all of the predecessors of X to the end of the work stack...
-      TodoStack.insert(TodoStack.end(), X->pred_begin(), X->pred_end());
-    }
-  }
-
-  // Add the basic blocks that comprise this loop to the BBMap so that this
-  // loop can be found for them.  Also check subsidary basic blocks to see if
-  // they start subloops of their own.
-  //
-  for (std::vector<const BasicBlock*>::reverse_iterator I = L->Blocks.rbegin(),
-	 E = L->Blocks.rend(); I != E; ++I) {
-
-    // Check to see if this block starts a new loop
-    if (Loop *NewLoop = ConsiderForLoop(*I, DS)) {
-      L->SubLoops.push_back(NewLoop);
-      NewLoop->ParentLoop = L;
-    }
-  
-    if (BBMap.find(*I) == BBMap.end())
-      BBMap.insert(std::make_pair(*I, L));
-  }
-
-  return L;
+void LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<DominatorTree>();
 }