X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FAnalysis%2FLoopInfo.cpp;h=559f6768060ec0e67931df6dab793dc6d01216e3;hp=ff5e2fa9dc659ac51cf16473cde7c1340c9d3247;hb=44a95e06cc0bb3a2d617fe94235aee92b1951910;hpb=a59cbb2043c08f3cfb8fb379f0d336e21e070be8

diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index ff5e2fa9dc6..559f6768060 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 was developed by the LLVM research group and 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
@@ -8,124 +15,42 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
 #include "llvm/Analysis/Dominators.h"
-#include "llvm/Support/CFG.h"
 #include "llvm/Assembly/Writer.h"
-#include "Support/DepthFirstIterator.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include <algorithm>
+#include <ostream>
+using namespace llvm;
 
-static RegisterAnalysis<LoopInfo>
-X("loops", "Natural Loop Construction");
-AnalysisID LoopInfo::ID = X;
+char LoopInfo::ID = 0;
+static RegisterPass<LoopInfo>
+X("loops", "Natural Loop Construction", true);
 
 //===----------------------------------------------------------------------===//
 // Loop implementation
 //
-bool Loop::contains(const BasicBlock *BB) const {
-  return find(Blocks.begin(), Blocks.end(), BB) != Blocks.end();
-}
-
-void Loop::print(std::ostream &OS) const {
-  OS << std::string(getLoopDepth()*2, ' ') << "Loop Containing: ";
 
-  for (unsigned i = 0; i < getBlocks().size(); ++i) {
-    if (i) OS << ",";
-    WriteAsOperand(OS, (const Value*)getBlocks()[i]);
-  }
-  OS << "\n";
-
-  std::copy(getSubLoops().begin(), getSubLoops().end(),
-            std::ostream_iterator<const Loop*>(OS, "\n"));
-}
+/// getNumBackEdges - Calculate the number of back edges to the loop header.
+///
 
 //===----------------------------------------------------------------------===//
 // LoopInfo implementation
 //
-
 bool LoopInfo::runOnFunction(Function &) {
   releaseMemory();
-  Calculate(getAnalysis<DominatorSet>());    // Update
+  LI->Calculate(getAnalysis<DominatorTree>());    // Update
   return false;
 }
 
-void LoopInfo::releaseMemory() {
-  for (std::vector<Loop*>::iterator I = TopLevelLoops.begin(),
-         E = TopLevelLoops.end(); I != E; ++I)
-    delete *I;   // Delete all of the loops...
-
-  BBMap.clear();                             // Reset internal state of analysis
-  TopLevelLoops.clear();
-}
-
-
-void LoopInfo::Calculate(const DominatorSet &DS) {
-  BasicBlock *RootNode = DS.getRoot();
-
-  for (df_iterator<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 LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
-  AU.addRequired(DominatorSet::ID);
-  AU.addProvided(ID);
-}
-
-void LoopInfo::print(std::ostream &OS) const {
-  std::copy(getTopLevelLoops().begin(), getTopLevelLoops().end(),
-            std::ostream_iterator<const Loop*>(OS, "\n"));
+  AU.addRequired<DominatorTree>();
 }
 
-Loop *LoopInfo::ConsiderForLoop(BasicBlock *BB, const DominatorSet &DS) {
-  if (BBMap.find(BB) != BBMap.end()) return 0;   // Havn't processed this node?
-
-  std::vector<BasicBlock *> TodoStack;
-
-  // Scan the predecessors of BB, checking to see if BB dominates any of
-  // them.
-  for (pred_iterator I = pred_begin(BB), E = pred_end(BB); 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
-    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(), pred_begin(X), pred_end(X));
-    }
-  }
-
-  // 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<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;
-}
+// Ensure this file gets linked when LoopInfo.h is used.
+DEFINING_FILE_FOR(LoopInfo)