1 files changed, 207 insertions, 0 deletions
diff --git a/lib/Analysis/IPA/CallGraphSCCPass.cpp b/lib/Analysis/IPA/CallGraphSCCPass.cpp
new file mode 100644
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--- /dev/null
+++ b/lib/Analysis/IPA/CallGraphSCCPass.cpp
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+//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CallGraphSCCPass class, which is used for passes
+// which are implemented as bottom-up traversals on the call graph.  Because
+// there may be cycles in the call graph, passes of this type operate on the
+// call-graph in SCC order: that is, they process function bottom-up, except for
+// recursive functions, which they process all at once.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CallGraphSCCPass.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/PassManagers.h"
+#include "llvm/Function.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// CGPassManager
+//
+/// CGPassManager manages FPPassManagers and CalLGraphSCCPasses.
+
+namespace {
+
+class CGPassManager : public ModulePass, public PMDataManager {
+
+public:
+  static char ID;
+  explicit CGPassManager(int Depth) 
+    : ModulePass(&ID), PMDataManager(Depth) { }
+
+  /// run - Execute all of the passes scheduled for execution.  Keep track of
+  /// whether any of the passes modifies the module, and if so, return true.
+  bool runOnModule(Module &M);
+
+  bool doInitialization(CallGraph &CG);
+  bool doFinalization(CallGraph &CG);
+
+  /// Pass Manager itself does not invalidate any analysis info.
+  void getAnalysisUsage(AnalysisUsage &Info) const {
+    // CGPassManager walks SCC and it needs CallGraph.
+    Info.addRequired<CallGraph>();
+    Info.setPreservesAll();
+  }
+
+  virtual const char *getPassName() const {
+    return "CallGraph Pass Manager";
+  }
+
+  // Print passes managed by this manager
+  void dumpPassStructure(unsigned Offset) {
+    llvm::cerr << std::string(Offset*2, ' ') << "Call Graph SCC Pass Manager\n";
+    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+      Pass *P = getContainedPass(Index);
+      P->dumpPassStructure(Offset + 1);
+      dumpLastUses(P, Offset+1);
+    }
+  }
+
+  Pass *getContainedPass(unsigned N) {
+    assert ( N < PassVector.size() && "Pass number out of range!");
+    Pass *FP = static_cast<Pass *>(PassVector[N]);
+    return FP;
+  }
+
+  virtual PassManagerType getPassManagerType() const { 
+    return PMT_CallGraphPassManager; 
+  }
+};
+
+}
+
+char CGPassManager::ID = 0;
+/// run - Execute all of the passes scheduled for execution.  Keep track of
+/// whether any of the passes modifies the module, and if so, return true.
+bool CGPassManager::runOnModule(Module &M) {
+  CallGraph &CG = getAnalysis<CallGraph>();
+  bool Changed = doInitialization(CG);
+
+  // Walk SCC
+  for (scc_iterator<CallGraph*> I = scc_begin(&CG), E = scc_end(&CG);
+       I != E; ++I) {
+
+    // Run all passes on current SCC
+    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+      Pass *P = getContainedPass(Index);
+
+      dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, "");
+      dumpRequiredSet(P);
+
+      initializeAnalysisImpl(P);
+
+      StartPassTimer(P);
+      if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P))
+        Changed |= CGSP->runOnSCC(*I);   // TODO : What if CG is changed ?
+      else {
+        FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
+        assert (FPP && "Invalid CGPassManager member");
+
+        // Run pass P on all functions current SCC
+        std::vector<CallGraphNode*> &SCC = *I;
+        for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
+          Function *F = SCC[i]->getFunction();
+          if (F) {
+            dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getNameStart());
+            Changed |= FPP->runOnFunction(*F);
+          }
+        }
+      }
+      StopPassTimer(P);
+
+      if (Changed)
+        dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
+      dumpPreservedSet(P);
+
+      verifyPreservedAnalysis(P);      
+      removeNotPreservedAnalysis(P);
+      recordAvailableAnalysis(P);
+      removeDeadPasses(P, "", ON_CG_MSG);
+    }
+  }
+  Changed |= doFinalization(CG);
+  return Changed;
+}
+
+/// Initialize CG
+bool CGPassManager::doInitialization(CallGraph &CG) {
+  bool Changed = false;
+  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {  
+    Pass *P = getContainedPass(Index);
+    if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P)) {
+      Changed |= CGSP->doInitialization(CG);
+    } else {
+      FPPassManager *FP = dynamic_cast<FPPassManager *>(P);
+      assert (FP && "Invalid CGPassManager member");
+      Changed |= FP->doInitialization(CG.getModule());
+    }
+  }
+  return Changed;
+}
+
+/// Finalize CG
+bool CGPassManager::doFinalization(CallGraph &CG) {
+  bool Changed = false;
+  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {  
+    Pass *P = getContainedPass(Index);
+    if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P)) {
+      Changed |= CGSP->doFinalization(CG);
+    } else {
+      FPPassManager *FP = dynamic_cast<FPPassManager *>(P);
+      assert (FP && "Invalid CGPassManager member");
+      Changed |= FP->doFinalization(CG.getModule());
+    }
+  }
+  return Changed;
+}
+
+/// Assign pass manager to manage this pass.
+void CallGraphSCCPass::assignPassManager(PMStack &PMS,
+                                         PassManagerType PreferredType) {
+  // Find CGPassManager 
+  while (!PMS.empty() &&
+         PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
+    PMS.pop();
+
+  assert (!PMS.empty() && "Unable to handle Call Graph Pass");
+  CGPassManager *CGP = dynamic_cast<CGPassManager *>(PMS.top());
+
+  // Create new Call Graph SCC Pass Manager if it does not exist. 
+  if (!CGP) {
+
+    assert (!PMS.empty() && "Unable to create Call Graph Pass Manager");
+    PMDataManager *PMD = PMS.top();
+
+    // [1] Create new Call Graph Pass Manager
+    CGP = new CGPassManager(PMD->getDepth() + 1);
+
+    // [2] Set up new manager's top level manager
+    PMTopLevelManager *TPM = PMD->getTopLevelManager();
+    TPM->addIndirectPassManager(CGP);
+
+    // [3] Assign manager to manage this new manager. This may create
+    // and push new managers into PMS
+    Pass *P = dynamic_cast<Pass *>(CGP);
+    TPM->schedulePass(P);
+
+    // [4] Push new manager into PMS
+    PMS.push(CGP);
+  }
+
+  CGP->add(this);
+}
+
+/// getAnalysisUsage - For this class, we declare that we require and preserve
+/// the call graph.  If the derived class implements this method, it should
+/// always explicitly call the implementation here.
+void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<CallGraph>();
+  AU.addPreserved<CallGraph>();
+}