Remove DebugLabelFolder pass. It is not used by dwarf writer anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89790 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineModuleInfo.h

@@ -135,9 +135,6 @@ class MachineModuleInfo : public ImmutablePass {
   /// llvm.compiler.used.
   SmallPtrSet<const Function *, 32> UsedFunctions;
 
-  /// UsedDbgLabels - labels are used by debug info entries.
-  SmallSet<unsigned, 8> UsedDbgLabels;
-
   bool CallsEHReturn;
   bool CallsUnwindInit;
  
@@ -232,19 +229,6 @@ public:
     return LabelID ? LabelIDList[LabelID - 1] : 0;
   }
 
-  /// isDbgLabelUsed - Return true if label with LabelID is used by
-  /// DwarfWriter.
-  bool isDbgLabelUsed(unsigned LabelID) {
-    return UsedDbgLabels.count(LabelID);
-  }
-  
-  /// RecordUsedDbgLabel - Mark label with LabelID as used. This is used
-  /// by DwarfWriter to inform DebugLabelFolder that certain labels are
-  /// not to be deleted.
-  void RecordUsedDbgLabel(unsigned LabelID) {
-    UsedDbgLabels.insert(LabelID);
-  }
-
   /// getFrameMoves - Returns a reference to a list of moves done in the current
   /// function's prologue.  Used to construct frame maps for debug and exception
   /// handling comsumers.

include/llvm/CodeGen/Passes.h

@@ -136,11 +136,6 @@ namespace llvm {
   /// headers to target specific alignment boundary.
   FunctionPass *createCodePlacementOptPass();
 
-  /// DebugLabelFoldingPass - This pass prunes out redundant debug labels.  This
-  /// allows a debug emitter to determine if the range of two labels is empty,
-  /// by seeing if the labels map to the same reduced label.
-  FunctionPass *createDebugLabelFoldingPass();
-
   /// getRegisterAllocator - This creates an instance of the register allocator
   /// for the Sparc.
   FunctionPass *getRegisterAllocator(TargetMachine &T);

lib/CodeGen/LLVMTargetMachine.cpp

@@ -349,10 +349,6 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
   if (PrintGCInfo)
     PM.add(createGCInfoPrinter(errs()));
 
-  // Fold redundant debug labels.
-  PM.add(createDebugLabelFoldingPass());
-  printAndVerify(PM, "After DebugLabelFolding");
-
   if (OptLevel != CodeGenOpt::None && !DisableCodePlace) {
     PM.add(createCodePlacementOptPass());
     printAndVerify(PM, "After CodePlacementOpt");

lib/CodeGen/MachineModuleInfo.cpp

@@ -293,75 +293,3 @@ unsigned MachineModuleInfo::getPersonalityIndex() const {
   return 0;
 }
 
-//===----------------------------------------------------------------------===//
-/// DebugLabelFolding pass - This pass prunes out redundant labels.  This allows
-/// a info consumer to determine if the range of two labels is empty, by seeing
-/// if the labels map to the same reduced label.
-
-namespace llvm {
-
-struct DebugLabelFolder : public MachineFunctionPass {
-  static char ID;
-  DebugLabelFolder() : MachineFunctionPass(&ID) {}
-
-  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-    AU.setPreservesCFG();
-    AU.addPreservedID(MachineLoopInfoID);
-    AU.addPreservedID(MachineDominatorsID);
-    MachineFunctionPass::getAnalysisUsage(AU);
-  }
-
-  virtual bool runOnMachineFunction(MachineFunction &MF);
-  virtual const char *getPassName() const { return "Label Folder"; }
-};
-
-char DebugLabelFolder::ID = 0;
-
-bool DebugLabelFolder::runOnMachineFunction(MachineFunction &MF) {
-  // Get machine module info.
-  MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
-  if (!MMI) return false;
-
-  // Track if change is made.
-  bool MadeChange = false;
-  // No prior label to begin.
-  unsigned PriorLabel = 0;
-
-  // Iterate through basic blocks.
-  for (MachineFunction::iterator BB = MF.begin(), E = MF.end();
-       BB != E; ++BB) {
-    // Iterate through instructions.
-    for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
-      // Is it a label.
-      if (I->isDebugLabel() && !MMI->isDbgLabelUsed(I->getOperand(0).getImm())){
-        // The label ID # is always operand #0, an immediate.
-        unsigned NextLabel = I->getOperand(0).getImm();
-
-        // If there was an immediate prior label.
-        if (PriorLabel) {
-          // Remap the current label to prior label.
-          MMI->RemapLabel(NextLabel, PriorLabel);
-          // Delete the current label.
-          I = BB->erase(I);
-          // Indicate a change has been made.
-          MadeChange = true;
-          continue;
-        } else {
-          // Start a new round.
-          PriorLabel = NextLabel;
-        }
-       } else {
-        // No consecutive labels.
-        PriorLabel = 0;
-      }
-
-      ++I;
-    }
-  }
-
-  return MadeChange;
-}
-
-FunctionPass *createDebugLabelFoldingPass() { return new DebugLabelFolder(); }
-
-}