3 files changed, 36 insertions, 19 deletions

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index b8a0361f7f..7285057210 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -14,16 +14,17 @@
 #ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
 #define LLVM_CODEGEN_MACHINEBASICBLOCK_H
 
-#include <vector>
+#include "llvm/CodeGen/MachineInstr.h"
+#include "Support/ilist"
 
 namespace llvm {
 
 class BasicBlock;
-class MachineInstr;
-template <typename T> struct ilist_traits;
 
 class MachineBasicBlock {
-  std::vector<MachineInstr*> Insts;
+public:
+  typedef ilist<MachineInstr> Instructions;
+  Instructions Insts;
   MachineBasicBlock *Prev, *Next;
   const BasicBlock *BB;
 public:
@@ -35,19 +36,27 @@ public:
   ///
   const BasicBlock *getBasicBlock() const { return BB; }
   
-  typedef std::vector<MachineInstr*>::iterator                iterator;
-  typedef std::vector<MachineInstr*>::const_iterator    const_iterator;
+  typedef ilist<MachineInstr>::iterator                       iterator;
+  typedef ilist<MachineInstr>::const_iterator           const_iterator;
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
   typedef std::reverse_iterator<iterator>             reverse_iterator;
 
   unsigned size() const { return Insts.size(); }
   bool empty() const { return Insts.empty(); }
 
-  MachineInstr * operator[](unsigned i) const { return Insts[i]; }
-  MachineInstr *&operator[](unsigned i)       { return Insts[i]; }
+  const MachineInstr& operator[](unsigned i) const {
+      const_iterator it = Insts.begin();
+      std::advance(it, i);
+      return *it;
+  }
+  MachineInstr& operator[](unsigned i) {
+      iterator it = Insts.begin();
+      std::advance(it, i);
+      return *it;
+  }
 
-  MachineInstr *front() const { return Insts.front(); }
-  MachineInstr *back()  const { return Insts.back(); }
+  MachineInstr& front() { return Insts.front(); }
+  MachineInstr& back()  { return Insts.back(); }
 
   iterator                begin()       { return Insts.begin();  }
   const_iterator          begin() const { return Insts.begin();  }
@@ -64,16 +73,11 @@ public:
   iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
 
   // erase - Remove the specified element or range from the instruction list.
-  // These functions do not delete any instructions removed.
+  // These functions delete any instructions removed.
   //
   iterator erase(iterator I)             { return Insts.erase(I); }
   iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
-
-  MachineInstr *pop_back() {
-    MachineInstr *R = back();
-    Insts.pop_back();
-    return R;
-  }
+  MachineInstr* remove(iterator &I)      { return Insts.remove(I); }
 
 private:   // Methods used to maintain doubly linked list of blocks...
   friend class ilist_traits<MachineBasicBlock>;
diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index 4f255598d3..2c443967ee 100644
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -20,7 +20,6 @@
 
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "Support/Annotation.h"
-#include "Support/ilist"
 
 namespace llvm {
 
diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index ff05631d40..0cc46b0c54 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -28,6 +28,8 @@ class MachineBasicBlock;
 class TargetMachine;
 class GlobalValue;
 
+template <typename T> class ilist_traits;
+
 typedef int MachineOpCode;
 
 //===----------------------------------------------------------------------===//
@@ -353,12 +355,24 @@ class MachineInstr {
   unsigned         opCodeFlags;         // flags modifying instrn behavior
   std::vector<MachineOperand> operands; // the operands
   unsigned numImplicitRefs;             // number of implicit operands
-
+  MachineInstr* prev, *next;            // links for our intrusive list
   // OperandComplete - Return true if it's illegal to add a new operand
   bool OperandsComplete() const;
 
   MachineInstr(const MachineInstr &);  // DO NOT IMPLEMENT
   void operator=(const MachineInstr&); // DO NOT IMPLEMENT
+
+private:
+  // Intrusive list support
+  //
+  friend class ilist_traits<MachineInstr>;
+  MachineInstr() { /* this is for ilist use only to create the sentinel */ }
+  MachineInstr* getPrev() const { return prev; }
+  MachineInstr* getNext() const { return next; }
+
+  void setPrev(MachineInstr* mi) { prev = mi; }
+  void setNext(MachineInstr* mi) { next = mi; }
+
 public:
   MachineInstr(int Opcode, unsigned numOperands);