The guaranteed alignment of ptr+offset is only the minimum of
[oota-llvm.git] / include / llvm / CodeGen / MachineBasicBlock.h
index 01bbc11519d67172c9209a68593a40288e2ff2d7..df6e5a32a82bc4c5594566ec951cc11be9cf4625 100644 (file)
@@ -1,12 +1,12 @@
 //===-- llvm/CodeGen/MachineBasicBlock.h ------------------------*- C++ -*-===//
-// 
+//
 //                     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.
-// 
+//
 //===----------------------------------------------------------------------===//
-// 
+//
 // Collect the sequence of machine instructions for a basic block.
 //
 //===----------------------------------------------------------------------===//
 #define LLVM_CODEGEN_MACHINEBASICBLOCK_H
 
 #include "llvm/CodeGen/MachineInstr.h"
-#include "Support/ilist"
-#include <iosfwd>
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/ilist"
+#include "llvm/Support/Streams.h"
 
 namespace llvm {
   class MachineFunction;
 
 // ilist_traits
 template <>
-class ilist_traits<MachineInstr> {
+struct ilist_traits<MachineInstr> {
+protected:
   // this is only set by the MachineBasicBlock owning the ilist
   friend class MachineBasicBlock;
   MachineBasicBlock* parent;
@@ -43,7 +45,8 @@ public:
   static void setPrev(MachineInstr* N, MachineInstr* prev) { N->prev = prev; }
   static void setNext(MachineInstr* N, MachineInstr* next) { N->next = next; }
 
-  static MachineInstr* createNode();
+  static MachineInstr* createSentinel();
+  static void destroySentinel(MachineInstr *MI) { delete MI; }
   void addNodeToList(MachineInstr* N);
   void removeNodeFromList(MachineInstr* N);
   void transferNodesFromList(
@@ -55,20 +58,36 @@ public:
 class BasicBlock;
 
 class MachineBasicBlock {
-public:
   typedef ilist<MachineInstr> Instructions;
   Instructions Insts;
   MachineBasicBlock *Prev, *Next;
   const BasicBlock *BB;
+  int Number;
+  MachineFunction *Parent;
+
+  /// 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;
+  
+  /// IsLandingPad - Indicate that this basic block is entered via an
+  /// exception handler.
+  bool IsLandingPad;
+
 public:
-  MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0), BB(bb) {
+  explicit MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0),
+                                                         BB(bb), Number(-1),
+                                                         Parent(0),
+                                                         IsLandingPad(false) {
     Insts.parent = this;
   }
-  ~MachineBasicBlock() {}
-  
+
+  ~MachineBasicBlock();
+
   /// getBasicBlock - Return the LLVM basic block that this instance
   /// corresponded to originally.
   ///
@@ -76,7 +95,8 @@ public:
 
   /// getParent - Return the MachineFunction containing this basic block.
   ///
-  const MachineFunction *getParent() const;
+  const MachineFunction *getParent() const { return Parent; }
+  MachineFunction *getParent() { return Parent; }
 
   typedef ilist<MachineInstr>::iterator                       iterator;
   typedef ilist<MachineInstr>::const_iterator           const_iterator;
@@ -103,70 +123,109 @@ public:
   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 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 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);
+
+  // Iteration support for live in sets.  These sets are kept in sorted
+  // order by their register number.
+  typedef std::vector<unsigned>::iterator       livein_iterator;
+  typedef std::vector<unsigned>::const_iterator const_livein_iterator;
+  livein_iterator       livein_begin()       { return LiveIns.begin(); }
+  const_livein_iterator livein_begin() const { return LiveIns.begin(); }
+  livein_iterator       livein_end()         { return LiveIns.end(); }
+  const_livein_iterator livein_end()   const { return LiveIns.end(); }
+  bool            livein_empty() const { return LiveIns.empty(); }
+
+  /// isLandingPad - Returns true if the block is a landing pad. That is
+  /// this basic block is entered via an exception handler.
+  bool isLandingPad() const { return IsLandingPad; }
+
+  /// setIsLandingPad - Indicates the block is a landing pad.  That is
+  /// this basic block is entered via an exception handler.
+  void setIsLandingPad() { IsLandingPad = true; }
+
+  // Code Layout methods.
+  
+  /// moveBefore/moveAfter - move 'this' block before or after the specified
+  /// block.  This only moves the block, it does not modify the CFG or adjust
+  /// potential fall-throughs at the end of the block.
+  void moveBefore(MachineBasicBlock *NewAfter);
+  void moveAfter(MachineBasicBlock *NewBefore);
   
-  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 ();   }
-  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 ();     }
-
   // Machine-CFG mutators
-
+  
   /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
   /// The Predecessors list of succ is automatically updated.
   ///
-  void addSuccessor (MachineBasicBlock *succ) {
-    Successors.push_back (succ);
-    assert (std::find (Successors.begin (), Successors.end (), succ)
-            == Successors.end ()
-            && "Trying to addSuccessor a MBB which is already my successor");
-    succ->addPredecessor (this);
-  }
+  void addSuccessor(MachineBasicBlock *succ);
 
-  /// removeSuccessor - Remove succ from the successors list of this
+  /// removeSuccessor - Remove successor from the successors list of this
   /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
   ///
-  void removeSuccessor (MachineBasicBlock *succ) {
-    succ->removePredecessor (this);
-    std::vector<MachineBasicBlock *>::iterator goner =
-      std::find (Successors.begin(), Successors.end (), succ);
-    assert (goner != Successors.end ()
-            && "Trying to removeSuccessor a MBB which isn't my successor");
-    Successors.erase (goner);
-  }
+  void removeSuccessor(MachineBasicBlock *succ);
 
-  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
-  /// Don't do this unless you know what you're doing, because it doesn't
-  /// update pred's successors list. Use pred->addSuccessor instead.
+  /// removeSuccessor - Remove specified successor from the successors list of
+  /// this MachineBasicBlock. The Predecessors list of succ is automatically
+  /// updated.  Return the iterator to the element after the one removed.
   ///
-  void addPredecessor (MachineBasicBlock *pred) {
-    Predecessors.push_back (pred);
-    assert(std::find (Predecessors.begin (), Predecessors.end (), pred)
-           == Predecessors.end ()
-           && "Trying to addPredecessor a MBB which is already my predecessor");
-  }
-
-  /// removePredecessor - Remove pred as a predecessor of this
-  /// MachineBasicBlock. Don't do this unless you know what you're
-  /// doing, because it doesn't update pred's successors list. Use
-  /// pred->removeSuccessor instead.
-  ///
-  void removePredecessor (MachineBasicBlock *pred) {
-    std::vector<MachineBasicBlock *>::iterator goner =
-      std::find (Predecessors.begin(), Predecessors.end (), pred);
-    assert (goner != Predecessors.end ()
-            && "Trying to removePredecessor a MBB which isn't my predecessor");
-    Predecessors.erase (goner);
-  }
+  succ_iterator removeSuccessor(succ_iterator I);
+  
+  /// isSuccessor - Return true if the specified MBB is a successor of this
+  /// block.
+  bool isSuccessor(MachineBasicBlock *MBB) const;
 
   /// getFirstTerminator - returns an iterator to the first terminator
   /// instruction of this basic block. If a terminator does not exist,
   /// it returns end()
   iterator getFirstTerminator();
 
+  void pop_front() { Insts.pop_front(); }
+  void pop_back() { Insts.pop_back(); }
   void push_back(MachineInstr *MI) { Insts.push_back(MI); }
   template<typename IT>
   void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
@@ -180,17 +239,131 @@ public:
   MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
   void clear()                           { Insts.clear(); }
 
+  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
+  /// To), and insert them into this MBB right before 'where'.
+  void splice(iterator where, MachineBasicBlock *Other, iterator From,
+              iterator To) {
+    Insts.splice(where, Other->Insts, From, To);
+  }
+
+  /// ReplaceUsesOfBlockWith - Given a machine basic block that branched to
+  /// 'Old', change the code and CFG so that it branches to 'New' instead.
+  void ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New);
+
+  /// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in
+  /// the CFG to be inserted.  If we have proven that MBB can only branch to
+  /// DestA and DestB, remove any other MBB successors from the CFG. DestA and
+  /// DestB can be null. Besides DestA and DestB, retain other edges leading
+  /// to LandingPads (currently there can be only one; we don't check or require
+  /// that here). Note it is possible that DestA and/or DestB are LandingPads.
+  bool CorrectExtraCFGEdges(MachineBasicBlock *DestA,
+                            MachineBasicBlock *DestB,
+                            bool isCond);
+
   // Debugging methods.
   void dump() const;
   void print(std::ostream &OS) const;
+  void print(std::ostream *OS) const { if (OS) print(*OS); }
+
+  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
+  /// level, unless they're not in a MachineFunction yet, in which case this
+  /// will return -1.
+  ///
+  int getNumber() const { return Number; }
+  void setNumber(int N) { Number = N; }
 
 private:   // Methods used to maintain doubly linked list of blocks...
-  friend class ilist_traits<MachineBasicBlock>;
+  friend struct ilist_traits<MachineBasicBlock>;
 
   MachineBasicBlock *getPrev() const { return Prev; }
   MachineBasicBlock *getNext() const { return Next; }
   void setPrev(MachineBasicBlock *P) { Prev = P; }
   void setNext(MachineBasicBlock *N) { Next = N; }
+
+  // Machine-CFG mutators
+
+  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
+  /// Don't do this unless you know what you're doing, because it doesn't
+  /// update pred's successors list. Use pred->addSuccessor instead.
+  ///
+  void addPredecessor(MachineBasicBlock *pred);
+
+  /// removePredecessor - Remove pred as a predecessor of this
+  /// MachineBasicBlock. Don't do this unless you know what you're
+  /// doing, because it doesn't update pred's successors list. Use
+  /// pred->removeSuccessor instead.
+  ///
+  void removePredecessor(MachineBasicBlock *pred);
+};
+
+std::ostream& operator<<(std::ostream &OS, const MachineBasicBlock &MBB);
+
+//===--------------------------------------------------------------------===//
+// GraphTraits specializations for machine basic block graphs (machine-CFGs)
+//===--------------------------------------------------------------------===//
+
+// Provide specializations of GraphTraits to be able to treat a
+// MachineFunction as a graph of MachineBasicBlocks...
+//
+
+template <> struct GraphTraits<MachineBasicBlock *> {
+  typedef MachineBasicBlock NodeType;
+  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
+
+  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
+  static inline ChildIteratorType child_begin(NodeType *N) {
+    return N->succ_begin();
+  }
+  static inline ChildIteratorType child_end(NodeType *N) {
+    return N->succ_end();
+  }
+};
+
+template <> struct GraphTraits<const MachineBasicBlock *> {
+  typedef const MachineBasicBlock NodeType;
+  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
+
+  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
+  static inline ChildIteratorType child_begin(NodeType *N) {
+    return N->succ_begin();
+  }
+  static inline ChildIteratorType child_end(NodeType *N) {
+    return N->succ_end();
+  }
+};
+
+// Provide specializations of GraphTraits to be able to treat a
+// MachineFunction as a graph of MachineBasicBlocks... and to walk it
+// in inverse order.  Inverse order for a function is considered
+// to be when traversing the predecessor edges of a MBB
+// instead of the successor edges.
+//
+template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
+  typedef MachineBasicBlock NodeType;
+  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
+  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
+    return G.Graph;
+  }
+  static inline ChildIteratorType child_begin(NodeType *N) {
+    return N->pred_begin();
+  }
+  static inline ChildIteratorType child_end(NodeType *N) {
+    return N->pred_end();
+  }
+};
+
+template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
+  typedef const MachineBasicBlock NodeType;
+  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
+  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
+    return G.Graph;
+  }
+  static inline ChildIteratorType child_begin(NodeType *N) {
+    return N->pred_begin();
+  }
+  static inline ChildIteratorType child_end(NodeType *N) {
+    return N->pred_end();
+  }
 };
 
 } // End llvm namespace