Reference RegionPass to stop it being eliminated.

[oota-llvm.git] / include / llvm / CodeGen / MachineBasicBlock.h

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index cc651ca77b7756c63f390738bff34d9e018c8c56..bb7abdbd0160c6a33daa32b81cbbcffe9d146c08 100644 (file)
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -19,6 +19,7 @@
 
 namespace llvm {
 
+class Pass;
 class BasicBlock;
 class MachineFunction;
 class MCSymbol;
@@ -258,6 +259,11 @@ public:
   /// machine basic block (i.e., copies all the successors fromMBB and
   /// remove all the successors from fromMBB).
   void transferSuccessors(MachineBasicBlock *fromMBB);
+
+  /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as
+  /// in transferSuccessors, and update PHI operands in the successor blocks
+  /// which refer to fromMBB to refer to this.
+  void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB);
   
   /// isSuccessor - Return true if the specified MBB is a successor of this
   /// block.
@@ -276,17 +282,35 @@ public:
   /// branch to do so (e.g., a table jump).  True is a conservative answer.
   bool canFallThrough();
 
+  /// Returns a pointer to the first instructon in this block that is not a 
+  /// PHINode instruction. When adding instruction to the beginning of the
+  /// basic block, they should be added before the returned value, not before
+  /// the first instruction, which might be PHI.
+  /// Returns end() is there's no non-PHI instruction.
+  iterator getFirstNonPHI();
+
   /// getFirstTerminator - returns an iterator to the first terminator
   /// instruction of this basic block. If a terminator does not exist,
   /// it returns end()
   iterator getFirstTerminator();
 
+  /// SplitCriticalEdge - Split the critical edge from this block to the
+  /// given successor block, and return the newly created block, or null
+  /// if splitting is not possible.
+  ///
+  /// This function updates LiveVariables, MachineDominatorTree, and
+  /// MachineLoopInfo, as applicable.
+  MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P);
+
   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); }
   iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
+  iterator insertAfter(iterator I, MachineInstr *M) { 
+    return Insts.insertAfter(I, M); 
+  }
 
   // erase - Remove the specified element or range from the instruction list.
   // These functions delete any instructions removed.