path: root/include/llvm/CodeGen/MachineBasicBlock.h

//===-- llvm/CodeGen/MachineBasicBlock.h ------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Collect the sequence of machine instructions for a basic block.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
#define LLVM_CODEGEN_MACHINEBASICBLOCK_H

#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/ADT/GraphTraits.h"

namespace llvm {

class Pass;
class BasicBlock;
class MachineFunction;
class MCSymbol;
class SlotIndexes;
class StringRef;
class raw_ostream;

template <>
struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> {
private:
  mutable ilist_half_node<MachineInstr> Sentinel;

  // this is only set by the MachineBasicBlock owning the LiveList
  friend class MachineBasicBlock;
  MachineBasicBlock* Parent;

public:
  MachineInstr *createSentinel() const {
    return static_cast<MachineInstr*>(&Sentinel);
  }
  void destroySentinel(MachineInstr *) const {}

  MachineInstr *provideInitialHead() const { return createSentinel(); }
  MachineInstr *ensureHead(MachineInstr*) const { return createSentinel(); }
  static void noteHead(MachineInstr*, MachineInstr*) {}

  void addNodeToList(MachineInstr* N);
  void removeNodeFromList(MachineInstr* N);
  void transferNodesFromList(ilist_traits &SrcTraits,
                             ilist_iterator<MachineInstr> first,
                             ilist_iterator<MachineInstr> last);
  void deleteNode(MachineInstr *N);
private:
  void createNode(const MachineInstr &);
};

class MachineBasicBlock : public ilist_node<MachineBasicBlock> {
  typedef ilist<MachineInstr> Instructions;
  Instructions Insts;
  const BasicBlock *BB;
  int Number;
  MachineFunction *xParent;
  
  /// Predecessors/Successors - Keep track of the predecessor / successor
  /// basicblocks.
  std::vector<MachineBasicBlock *> Predecessors;
  std::vector<MachineBasicBlock *> Successors;

  /// LiveIns - Keep track of the physical registers that are livein of
  /// the basicblock.
  std::vector<unsigned> LiveIns;

  /// Alignment - Alignment of the basic block. Zero if the basic block does
  /// not need to be aligned.
  unsigned Alignment;
  
  /// IsLandingPad - Indicate that this basic block is entered via an
  /// exception handler.
  bool IsLandingPad;

  /// AddressTaken - Indicate that this basic block is potentially the
  /// target of an indirect branch.
  bool AddressTaken;

  // Intrusive list support
  MachineBasicBlock() {}

  explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb);

  ~MachineBasicBlock();

  // MachineBasicBlocks are allocated and owned by MachineFunction.
  friend class MachineFunction;

public:
  /// getBasicBlock - Return the LLVM basic block that this instance
  /// corresponded to originally. Note that this may be NULL if this instance
  /// does not correspond directly to an LLVM basic block.
  ///
  const BasicBlock *getBasicBlock() const { return BB; }

  /// getName - Return the name of the corresponding LLVM basic block, or
  /// "(null)".
  StringRef getName() const;

  /// hasAddressTaken - Test whether this block is potentially the target
  /// of an indirect branch.
  bool hasAddressTaken() const { return AddressTaken; }

  /// setHasAddressTaken - Set this block to reflect that it potentially
  /// is the target of an indirect branch.
  void setHasAddressTaken() { AddressTaken = true; }

  /// getParent - Return the MachineFunction containing this basic block.
  ///
  const MachineFunction *getParent() const { return xParent; }
  MachineFunction *getParent() { return xParent; }

  typedef Instructions::iterator                              iterator;
  typedef Instructions::const_iterator                  const_iterator;
  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
  typedef std::reverse_iterator<iterator>             reverse_iterator;

  unsigned size() const { return (unsigned)Insts.size(); }
  bool empty() const { return Insts.empty(); }

  MachineInstr& front() { return Insts.front(); }
  MachineInstr& back()  { return Insts.back(); }
  const MachineInstr& front() const { return Insts.front(); }
  const MachineInstr& back()  const { return Insts.back(); }

  iterator                begin()       { return Insts.begin();  }
  const_iterator          begin() const { return Insts.begin();  }
  iterator                  end()       { return Insts.end();    }
  const_iterator            end() const { return Insts.end();    }
  reverse_iterator       rbegin()       { return Insts.rbegin(); }
  const_reverse_iterator rbegin() const { return Insts.rbegin(); }
  reverse_iterator       rend  ()       { return Insts.rend();   }
  const_reverse_iterator rend  () const { return Insts.rend();   }

  // Machine-CFG iterators
  typedef std::vector<MachineBasicBlock *>::iterator       pred_iterator;
  typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
  typedef std::vector<MachineBasicBlock *>::iterator       succ_iterator;
  typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
  typedef std::vector<MachineBasicBlock *>::reverse_iterator
                                                         pred_reverse_iterator;
  typedef std::vector<MachineBasicBlock *>::const_reverse_iterator
                                                   const_pred_reverse_iterator;
  typedef std::vector<MachineBasicBlock *>::reverse_iterator
                                                         succ_reverse_iterator;
  typedef std::vector<MachineBasicBlock *>::const_reverse_iterator
                                                   const_succ_reverse_iterator;

  pred_iterator        pred_begin()       { return Predecessors.begin(); }
  const_pred_iterator  pred_begin() const { return Predecessors.begin(); }
  pred_iterator        pred_end()         { return Predecessors.end();   }
  const_pred_iterator  pred_end()   const { return Predecessors.end();   }
  pred_reverse_iterator        pred_rbegin()
                                          { return Predecessors.rbegin();}
  const_pred_reverse_iterator  pred_rbegin() const
                                          { return Predecessors.rbegin();}
  pred_reverse_iterator        pred_rend()
                                          { return Predecessors.rend();  }
  const_pred_reverse_iterator  pred_rend()   const
                                          { return Predecessors.rend();  }
  unsigned             pred_size()  const {
    return (unsigned)Predecessors.size();
  }
  bool                 pred_empty() const { return Predecessors.empty(); }
  succ_iterator        succ_begin()       { return Successors.begin();   }
  const_succ_iterator  succ_begin() const { return Successors.begin();   }
  succ_iterator        succ_end()         { return Successors.end();     }
  const_succ_iterator  succ_end()   const { return Successors.end();     }
  succ_reverse_iterator        succ_rbegin()
                                          { return Successors.rbegin();  }
  const_succ_reverse_iterator  succ_rbegin() const
                                          { return Successors.rbegin();  }
  succ_reverse_iterator        succ_rend()
                                          { return Successors.rend();    }
  const_succ_reverse_iterator  succ_rend()   const
                                          { return Successors.rend();    }
  unsigned             succ_size()  const {
    return (unsigned)Successors.size();
  }
  bool                 succ_empty() const { return Successors.empty();   }

  // LiveIn management methods.

  /// addLiveIn - Add the specified register as a live in.  Note that it
  /// is an error to add the same register to the same set more than once.
  void addLiveIn(unsigned Reg)  { LiveIns.push_back(Reg); }

  /// removeLiveIn - Remove the specified register from the live in set.
  ///
  void removeLiveIn(unsigned Reg);

  /// isLiveIn - Return true if the specified register is in the live in set.
  ///
  bool isLiveIn(unsigned Reg) const;

  // Iteration support for live in sets.  These sets are kept in sorted
  // order by their register number.
  typedef std::vector<unsigned>::const_iterator livein_iterator;
  livein_iterator livein_begin() const { return