Index: llvm/trunk/include/llvm/IR/CFG.h
===================================================================
--- llvm/trunk/include/llvm/IR/CFG.h
+++ llvm/trunk/include/llvm/IR/CFG.h
@@ -1,4 +1,4 @@
-//===- CFG.h - Process LLVM structures as graphs ----------------*- C++ -*-===//
+//===- CFG.h ----------------------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -6,10 +6,15 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This file defines specializations of GraphTraits that allow Function and
-// BasicBlock graphs to be treated as proper graphs for generic algorithms.
-//
+/// \file
+///
+/// This file provides various utilities for inspecting and working with the
+/// control flow graph in LLVM IR. This includes generic facilities for
+/// iterating successors and predecessors of basic blocks, the successors of
+/// specific terminator instructions, etc. It also defines specializations of
+/// GraphTraits that allow Function and BasicBlock graphs to be treated as
+/// proper graphs for generic algorithms.
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_IR_CFG_H
@@ -118,16 +123,144 @@
 }
 
 //===----------------------------------------------------------------------===//
-// BasicBlock succ_iterator helpers
+// Instruction and BasicBlock succ_iterator helpers
 //===----------------------------------------------------------------------===//
 
-using succ_iterator =
-    TerminatorInst::SuccIterator<TerminatorInst *, BasicBlock>;
-using succ_const_iterator =
-    TerminatorInst::SuccIterator<const TerminatorInst *, const BasicBlock>;
+template <class InstructionT, class BlockT>
+class SuccIterator
+    : public iterator_facade_base<SuccIterator<InstructionT, BlockT>,
+                                  std::random_access_iterator_tag, BlockT, int,
+                                  BlockT *, BlockT *> {
+public:
+  using difference_type = int;
+  using pointer = BlockT *;
+  using reference = BlockT *;
+
+private:
+  InstructionT *Inst;
+  int Idx;
+  using Self = SuccIterator<InstructionT, BlockT>;
+
+  inline bool index_is_valid(int Idx) {
+    // Note that we specially support the index of zero being valid even in the
+    // face of a null instruction.
+    return Idx >= 0 && (Idx == 0 || Idx <= (int)Inst->getNumSuccessors());
+  }
+
+  /// Proxy object to allow write access in operator[]
+  class SuccessorProxy {
+    Self It;
+
+  public:
+    explicit SuccessorProxy(const Self &It) : It(It) {}
+
+    SuccessorProxy(const SuccessorProxy &) = default;
+
+    SuccessorProxy &operator=(SuccessorProxy RHS) {
+      *this = reference(RHS);
+      return *this;
+    }
+
+    SuccessorProxy &operator=(reference RHS) {
+      It.Inst->setSuccessor(It.Idx, RHS);
+      return *this;
+    }
+
+    operator reference() const { return *It; }
+  };
+
+public:
+  // begin iterator
+  explicit inline SuccIterator(InstructionT *Inst) : Inst(Inst), Idx(0) {}
+  // end iterator
+  inline SuccIterator(InstructionT *Inst, bool) : Inst(Inst) {
+    if (Inst)
+      Idx = Inst->getNumSuccessors();
+    else
+      // Inst == NULL happens, if a basic block is not fully constructed and
+      // consequently getTerminator() returns NULL. In this case we construct
+      // a SuccIterator which describes a basic block that has zero
+      // successors.
+      // Defining SuccIterator for incomplete and malformed CFGs is especially
+      // useful for debugging.
+      Idx = 0;
+  }
+
+  /// This is used to interface between code that wants to
+  /// operate on terminator instructions directly.
+  int getSuccessorIndex() const { return Idx; }
+
+  inline bool operator==(const Self &x) const { return Idx == x.Idx; }
+
+  inline BlockT *operator*() const { return Inst->getSuccessor(Idx); }
+
+  // We use the basic block pointer directly for operator->.
+  inline BlockT *operator->() const { return operator*(); }
+
+  inline bool operator<(const Self &RHS) const {
+    assert(Inst == RHS.Inst && "Cannot compare iterators of different blocks!");
+    return Idx < RHS.Idx;
+  }
+
+  int operator-(const Self &RHS) const {
+    assert(Inst == RHS.Inst && "Cannot compare iterators of different blocks!");
+    return Idx - RHS.Idx;
+  }
+
+  inline Self &operator+=(int RHS) {
+    int NewIdx = Idx + RHS;
+    assert(index_is_valid(NewIdx) && "Iterator index out of bound");
+    Idx = NewIdx;
+    return *this;
+  }
+
+  inline Self &operator-=(int RHS) { return operator+=(-RHS); }
+
+  // Specially implement the [] operation using a proxy object to support
+  // assignment.
+  inline SuccessorProxy operator[](int Offset) {
+    Self TmpIt = *this;
+    TmpIt += Offset;
+    return SuccessorProxy(TmpIt);
+  }
+
+  /// Get the source BlockT of this iterator.
+  inline BlockT *getSource() {
+    assert(Inst && "Source not available, if basic block was malformed");
+    return Inst->getParent();
+  }
+};
+
+template <typename T, typename U> struct isPodLike<SuccIterator<T, U>> {
+  static const bool value = isPodLike<T>::value;
+};
+
+using succ_iterator = SuccIterator<Instruction, BasicBlock>;
+using succ_const_iterator = SuccIterator<const Instruction, const BasicBlock>;
 using succ_range = iterator_range<succ_iterator>;
 using succ_const_range = iterator_range<succ_const_iterator>;
 
+inline succ_iterator succ_begin(Instruction *I) { return succ_iterator(I); }
+inline succ_const_iterator succ_begin(const Instruction *I) {
+  return succ_const_iterator(I);
+}
+inline succ_iterator succ_end(Instruction *I) { return succ_iterator(I, true); }
+inline succ_const_iterator succ_end(const Instruction *I) {
+  return succ_const_iterator(I, true);
+}
+inline bool succ_empty(const Instruction *I) {
+  return succ_begin(I) == succ_end(I);
+}
+inline unsigned succ_size(const Instruction *I) {
+  return std::distance(succ_begin(I), succ_end(I));
+}
+inline succ_range successors(Instruction *I) {
+  return succ_range(succ_begin(I), succ_end(I));
+}
+inline succ_const_range successors(const Instruction *I) {
+  return succ_const_range(succ_begin(I), succ_end(I));
+}
+
 inline succ_iterator succ_begin(BasicBlock *BB) {
   return succ_iterator(BB->getTerminator());
 }
@@ -153,11 +286,6 @@
   return succ_const_range(succ_begin(BB), succ_end(BB));
 }
 
-template <typename T, typename U>
-struct isPodLike<TerminatorInst::SuccIterator<T, U>> {
-  static const bool value = isPodLike<T>::value;
-};
-
 //===--------------------------------------------------------------------===//
 // GraphTraits specializations for basic block graphs (CFGs)
 //===--------------------------------------------------------------------===//
Index: llvm/trunk/include/llvm/IR/InstrTypes.h
===================================================================
--- llvm/trunk/include/llvm/IR/InstrTypes.h
+++ llvm/trunk/include/llvm/IR/InstrTypes.h
@@ -64,15 +64,6 @@
     : Instruction(Ty, iType, Ops, NumOps, InsertAtEnd) {}
 
 public:
-  /// Return the number of successors that this terminator has.
-  unsigned getNumSuccessors() const;
-
-  /// Return the specified successor.
-  BasicBlock *getSuccessor(unsigned idx) const;
-
-  /// Update the specified successor to point at the provided block.
-  void setSuccessor(unsigned idx, BasicBlock *B);
-
   // Methods for support type inquiry through isa, cast, and dyn_cast:
   static bool classof(const Instruction *I) {
     return I->isTerminator();
@@ -94,183 +85,6 @@
       return false;
     }
   }
-
-  //===--------------------------------------------------------------------===//
-  // succ_iterator definition
-  //===--------------------------------------------------------------------===//
-
-  template <class Term, class BB> // Successor Iterator
-  class SuccIterator : public std::iterator<std::random_access_iterator_tag, BB,
-                                            int, BB *, BB *> {
-    using super =
-        std::iterator<std::random_access_iterator_tag, BB, int, BB *, BB *>;
-
-  public:
-    using pointer = typename super::pointer;
-    using reference = typename super::reference;
-
-  private:
-    Term TermInst;
-    unsigned idx;
-    using Self = SuccIterator<Term, BB>;
-
-    inline bool index_is_valid(unsigned idx) {
-      return idx < TermInst->getNumSuccessors();
-    }
-
-    /// Proxy object to allow write access in operator[]
-    class SuccessorProxy {
-      Self it;
-
-    public:
-      explicit SuccessorProxy(const Self &it) : it(it) {}
-
-      SuccessorProxy(const SuccessorProxy &) = default;
-
-      SuccessorProxy &operator=(SuccessorProxy r) {
-        *this = reference(r);
-        return *this;
-      }
-
-      SuccessorProxy &operator=(reference r) {
-        it.TermInst->setSuccessor(it.idx, r);
-        return *this;
-      }
-
-      operator reference() const { return *it; }
-    };
-
-  public:
-    // begin iterator
-    explicit inline SuccIterator(Term T) : TermInst(T), idx(0) {}
-    // end iterator
-    inline SuccIterator(Term T, bool) : TermInst(T) {
-      if (TermInst)
-        idx = TermInst->getNumSuccessors();
-      else
-        // Term == NULL happens, if a basic block is not fully constructed and
-        // consequently getTerminator() returns NULL. In this case we construct
-        // a SuccIterator which describes a basic block that has zero
-        // successors.
-        // Defining SuccIterator for incomplete and malformed CFGs is especially
-        // useful for debugging.
-        idx = 0;
-    }
-
-    /// This is used to interface between code that wants to
-    /// operate on terminator instructions directly.
-    unsigned getSuccessorIndex() const { return idx; }
-
-    inline bool operator==(const Self &x) const { return idx == x.idx; }
-    inline bool operator!=(const Self &x) const { return !operator==(x); }
-
-    inline reference operator*() const { return TermInst->getSuccessor(idx); }
-    inline pointer operator->() const { return operator*(); }
-
-    inline Self &operator++() {
-      ++idx;
-      return *this;
-    } // Preincrement
-
-    inline Self operator++(int) { // Postincrement
-      Self tmp = *this;
-      ++*this;
-      return tmp;
-    }
-
-    inline Self &operator--() {
-      --idx;
-      return *this;
-    }                             // Predecrement
-    inline Self operator--(int) { // Postdecrement
-      Self tmp = *this;
-      --*this;
-      return tmp;
-    }
-
-    inline bool operator<(const Self &x) const {
-      assert(TermInst == x.TermInst &&
-             "Cannot compare iterators of different blocks!");
-      return idx < x.idx;
-    }
-
-    inline bool operator<=(const Self &x) const {
-      assert(TermInst == x.TermInst &&
-             "Cannot compare iterators of different blocks!");
-      return idx <= x.idx;
-    }
-    inline bool operator>=(const Self &x) const {
-      assert(TermInst == x.TermInst &&
-             "Cannot compare iterators of different blocks!");
-      return idx >= x.idx;
-    }
-
-    inline bool operator>(const Self &x) const {
-      assert(TermInst == x.TermInst &&
-             "Cannot compare iterators of different blocks!");
-      return idx > x.idx;
-    }
-
-    inline Self &operator+=(int Right) {
-      unsigned new_idx = idx + Right;
-      assert(index_is_valid(new_idx) && "Iterator index out of bound");
-      idx = new_idx;
-      return *this;
-    }
-
-    inline Self operator+(int Right) const {
-      Self tmp = *this;
-      tmp += Right;
-      return tmp;
-    }
-
-    inline Self &operator-=(int Right) { return operator+=(-Right); }
-
-    inline Self operator-(int Right) const { return operator+(-Right); }
-
-    inline int operator-(const Self &x) const {
-      assert(TermInst == x.TermInst &&
-             "Cannot work on iterators of different blocks!");
-      int distance = idx - x.idx;
-      return distance;
-    }
-
-    inline SuccessorProxy operator[](int offset) {
-      Self tmp = *this;
-      tmp += offset;
-      return SuccessorProxy(tmp);
-    }
-
-    /// Get the source BB of this iterator.
-    inline BB *getSource() {
-      assert(TermInst && "Source not available, if basic block was malformed");
-      return TermInst->getParent();
-    }
-  };
-
-  using succ_iterator = SuccIterator<TerminatorInst *, BasicBlock>;
-  using succ_const_iterator =
-      SuccIterator<const TerminatorInst *, const BasicBlock>;
-  using succ_range = iterator_range<succ_iterator>;
-  using succ_const_range = iterator_range<succ_const_iterator>;
-
-private:
-  inline succ_iterator succ_begin() { return succ_iterator(this); }
-  inline succ_const_iterator succ_begin() const {
-    return succ_const_iterator(this);
-  }
-  inline succ_iterator succ_end() { return succ_iterator(this, true); }
-  inline succ_const_iterator succ_end() const {
-    return succ_const_iterator(this, true);
-  }
-
-public:
-  inline succ_range successors() {
-    return succ_range(succ_begin(), succ_end());
-  }
-  inline succ_const_range successors() const {
-    return succ_const_range(succ_begin(), succ_end());
-  }
 };
 
 //===----------------------------------------------------------------------===//
Index: llvm/trunk/include/llvm/IR/Instruction.h
===================================================================
--- llvm/trunk/include/llvm/IR/Instruction.h
+++ llvm/trunk/include/llvm/IR/Instruction.h
@@ -611,6 +611,16 @@
   /// operands in the corresponding predecessor block.
   bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
 
+  /// Return the number of successors that this instruction has. The instruction
+  /// must be a terminator.
+  unsigned getNumSuccessors() const;
+
+  /// Return the specified successor. This instruction must be a terminator.
+  BasicBlock *getSuccessor(unsigned Idx) const;
+
+  /// Update the specified successor to point at the provided block. This
+  /// instruction must be a terminator.
+  void setSuccessor(unsigned Idx, BasicBlock *BB);
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   static bool classof(const Value *V) {
Index: llvm/trunk/include/llvm/IR/Instructions.h
===================================================================
--- llvm/trunk/include/llvm/IR/Instructions.h
+++ llvm/trunk/include/llvm/IR/Instructions.h
@@ -3354,6 +3354,33 @@
   BranchInst *cloneImpl() const;
 
 public:
+  /// Iterator type that casts an operand to a basic block.
+  ///
+  /// This only makes sense because the successors are stored as adjacent
+  /// operands for branch instructions.
+  struct succ_op_iterator
+      : iterator_adaptor_base<succ_op_iterator, value_op_iterator,
+                              std::random_access_iterator_tag, BasicBlock *,
+                              ptrdiff_t, BasicBlock *, BasicBlock *> {
+    explicit succ_op_iterator(value_op_iterator I) : iterator_adaptor_base(I) {}
+
+    BasicBlock *operator*() const { return cast<BasicBlock>(*I); }
+    BasicBlock *operator->() const { return operator*(); }
+  };
+
+  /// The const version of `succ_op_iterator`.
+  struct const_succ_op_iterator
+      : iterator_adaptor_base<const_succ_op_iterator, const_value_op_iterator,
+                              std::random_access_iterator_tag,
+                              const BasicBlock *, ptrdiff_t, const BasicBlock *,
+                              const BasicBlock *> {
+    explicit const_succ_op_iterator(const_value_op_iterator I)
+        : iterator_adaptor_base(I) {}
+
+    const BasicBlock *operator*() const { return cast<BasicBlock>(*I); }
+    const BasicBlock *operator->() const { return operator*(); }
+  };
+
   static BranchInst *Create(BasicBlock *IfTrue,
                             Instruction *InsertBefore = nullptr) {
     return new(1) BranchInst(IfTrue, InsertBefore);
@@ -3408,6 +3435,18 @@
   /// continues to map correctly to each operand.
   void swapSuccessors();
 
+  iterator_range<succ_op_iterator> successors() {
+    return make_range(
+        succ_op_iterator(std::next(value_op_begin(), isConditional() ? 1 : 0)),
+        succ_op_iterator(value_op_end()));
+  }
+
+  iterator_range<const_succ_op_iterator> successors() const {
+    return make_range(const_succ_op_iterator(
+                          std::next(value_op_begin(), isConditional() ? 1 : 0)),
+                      const_succ_op_iterator(value_op_end()));
+  }
+
   // Methods for support type inquiry through isa, cast, and dyn_cast:
   static bool classof(const Instruction *I) {
     return (I->getOpcode() == Instruction::Br);
@@ -3821,6 +3860,33 @@
   IndirectBrInst *cloneImpl() const;
 
 public:
+  /// Iterator type that casts an operand to a basic block.
+  ///
+  /// This only makes sense because the successors are stored as adjacent
+  /// operands for indirectbr instructions.
+  struct succ_op_iterator
+      : iterator_adaptor_base<succ_op_iterator, value_op_iterator,
+                              std::random_access_iterator_tag, BasicBlock *,
+                              ptrdiff_t, BasicBlock *, BasicBlock *> {
+    explicit succ_op_iterator(value_op_iterator I) : iterator_adaptor_base(I) {}
+
+    BasicBlock *operator*() const { return cast<BasicBlock>(*I); }
+    BasicBlock *operator->() const { return operator*(); }
+  };
+
+  /// The const version of `succ_op_iterator`.
+  struct const_succ_op_iterator
+      : iterator_adaptor_base<const_succ_op_iterator, const_value_op_iterator,
+                              std::random_access_iterator_tag,
+                              const BasicBlock *, ptrdiff_t, const BasicBlock *,
+                              const BasicBlock *> {
+    explicit const_succ_op_iterator(const_value_op_iterator I)
+        : iterator_adaptor_base(I) {}
+
+    const BasicBlock *operator*() const { return cast<BasicBlock>(*I); }
+    const BasicBlock *operator->() const { return operator*(); }
+  };
+
   static IndirectBrInst *Create(Value *Address, unsigned NumDests,
                                 Instruction *InsertBefore = nullptr) {
     return new IndirectBrInst(Address, NumDests, InsertBefore);
@@ -3863,6 +3929,16 @@
     setOperand(i + 1, NewSucc);
   }
 
+  iterator_range<succ_op_iterator> successors() {
+    return make_range(succ_op_iterator(std::next(value_op_begin())),
+                      succ_op_iterator(value_op_end()));
+  }
+
+  iterator_range<const_succ_op_iterator> successors() const {
+    return make_range(const_succ_op_iterator(std::next(value_op_begin())),
+                      const_succ_op_iterator(value_op_end()));
+  }
+
   // Methods for support type inquiry through isa, cast, and dyn_cast:
   static bool classof(const Instruction *I) {
     return I->getOpcode() == Instruction::IndirectBr;
Index: llvm/trunk/lib/Analysis/LoopInfo.cpp
===================================================================
--- llvm/trunk/lib/Analysis/LoopInfo.cpp
+++ llvm/trunk/lib/Analysis/LoopInfo.cpp
@@ -226,7 +226,7 @@
       MDNode *MD = nullptr;
 
       // Check if this terminator branches to the loop header.
-      for (BasicBlock *Successor : TI->successors()) {
+      for (BasicBlock *Successor : successors(TI)) {
         if (Successor == H) {
           MD = TI->getMetadata(LLVMContext::MD_loop);
           break;
@@ -262,7 +262,7 @@
   BasicBlock *H = getHeader();
   for (BasicBlock *BB : this->blocks()) {
     TerminatorInst *TI = BB->getTerminator();
-    for (BasicBlock *Successor : TI->successors()) {
+    for (BasicBlock *Successor : successors(TI)) {
       if (Successor == H)
         TI->setMetadata(LLVMContext::MD_loop, LoopID);
     }
Index: llvm/trunk/lib/Analysis/MemorySSAUpdater.cpp
===================================================================
--- llvm/trunk/lib/Analysis/MemorySSAUpdater.cpp
+++ llvm/trunk/lib/Analysis/MemorySSAUpdater.cpp
@@ -580,7 +580,7 @@
   for (BasicBlock *BB : DeadBlocks) {
     TerminatorInst *TI = BB->getTerminator();
     assert(TI && "Basic block expected to have a terminator instruction");
-    for (BasicBlock *Succ : TI->successors())
+    for (BasicBlock *Succ : successors(TI))
       if (!DeadBlocks.count(Succ))
         if (MemoryPhi *MP = MSSA->getMemoryAccess(Succ)) {
           MP->unorderedDeleteIncomingBlock(BB);
Index: llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -355,7 +355,7 @@
     MIRBuilder.buildBr(TgtBB);
 
   // Link successors.
-  for (const BasicBlock *Succ : BrInst.successors())
+  for (const BasicBlock *Succ : successors(&BrInst))
     CurBB.addSuccessor(&getMBB(*Succ));
   return true;
 }
@@ -415,7 +415,7 @@
 
   // Link successors.
   MachineBasicBlock &CurBB = MIRBuilder.getMBB();
-  for (const BasicBlock *Succ : BrInst.successors())
+  for (const BasicBlock *Succ : successors(&BrInst))
     CurBB.addSuccessor(&getMBB(*Succ));
 
   return true;
Index: llvm/trunk/lib/IR/BasicBlock.cpp
===================================================================
--- llvm/trunk/lib/IR/BasicBlock.cpp
+++ llvm/trunk/lib/IR/BasicBlock.cpp
@@ -442,7 +442,7 @@
     // Cope with being called on a BasicBlock that doesn't have a terminator
     // yet. Clang's CodeGenFunction::EmitReturnBlock() likes to do this.
     return;
-  for (BasicBlock *Succ : TI->successors()) {
+  for (BasicBlock *Succ : successors(TI)) {
     // N.B. Succ might not be a complete BasicBlock, so don't assume
     // that it ends with a non-phi instruction.
     for (iterator II = Succ->begin(), IE = Succ->end(); II != IE; ++II) {
Index: llvm/trunk/lib/IR/Instruction.cpp
===================================================================
--- llvm/trunk/lib/IR/Instruction.cpp
+++ llvm/trunk/lib/IR/Instruction.cpp
@@ -617,6 +617,42 @@
   }
 }
 
+unsigned Instruction::getNumSuccessors() const {
+  switch (getOpcode()) {
+#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
+  case Instruction::OPC:                                                       \
+    return static_cast<const CLASS *>(this)->getNumSuccessors();
+#include "llvm/IR/Instruction.def"
+  default:
+    break;
+  }
+  llvm_unreachable("not a terminator");
+}
+
+BasicBlock *Instruction::getSuccessor(unsigned idx) const {
+  switch (getOpcode()) {
+#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
+  case Instruction::OPC:                                                       \
+    return static_cast<const CLASS *>(this)->getSuccessor(idx);
+#include "llvm/IR/Instruction.def"
+  default:
+    break;
+  }
+  llvm_unreachable("not a terminator");
+}
+
+void Instruction::setSuccessor(unsigned idx, BasicBlock *B) {
+  switch (getOpcode()) {
+#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
+  case Instruction::OPC:                                                       \
+    return static_cast<CLASS *>(this)->setSuccessor(idx, B);
+#include "llvm/IR/Instruction.def"
+  default:
+    break;
+  }
+  llvm_unreachable("not a terminator");
+}
+
 Instruction *Instruction::cloneImpl() const {
   llvm_unreachable("Subclass of Instruction failed to implement cloneImpl");
 }
Index: llvm/trunk/lib/IR/Instructions.cpp
===================================================================
--- llvm/trunk/lib/IR/Instructions.cpp
+++ llvm/trunk/lib/IR/Instructions.cpp
@@ -72,46 +72,6 @@
 }
 
 //===----------------------------------------------------------------------===//
-//                            TerminatorInst Class
-//===----------------------------------------------------------------------===//
-
-unsigned TerminatorInst::getNumSuccessors() const {
-  switch (getOpcode()) {
-#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
-  case Instruction::OPC:                                                       \
-    return static_cast<const CLASS *>(this)->getNumSuccessors();
-#include "llvm/IR/Instruction.def"
-  default:
-    break;
-  }
-  llvm_unreachable("not a terminator");
-}
-
-BasicBlock *TerminatorInst::getSuccessor(unsigned idx) const {
-  switch (getOpcode()) {
-#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
-  case Instruction::OPC:                                                       \
-    return static_cast<const CLASS *>(this)->getSuccessor(idx);
-#include "llvm/IR/Instruction.def"
-  default:
-    break;
-  }
-  llvm_unreachable("not a terminator");
-}
-
-void TerminatorInst::setSuccessor(unsigned idx, BasicBlock *B) {
-  switch (getOpcode()) {
-#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
-  case Instruction::OPC:                                                       \
-    return static_cast<CLASS *>(this)->setSuccessor(idx, B);
-#include "llvm/IR/Instruction.def"
-  default:
-    break;
-  }
-  llvm_unreachable("not a terminator");
-}
-
-//===----------------------------------------------------------------------===//
 //                              SelectInst Class
 //===----------------------------------------------------------------------===//
 
Index: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3198,7 +3198,7 @@
       }
     }
 
-    for (BasicBlock *SuccBB : TI->successors())
+    for (BasicBlock *SuccBB : successors(TI))
       Worklist.push_back(SuccBB);
   } while (!Worklist.empty());
 
Index: llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp
+++ llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp
@@ -365,7 +365,7 @@
 
   // Return true when a successor of BB dominates A.
   bool successorDominate(const BasicBlock *BB, const BasicBlock *A) {
-    for (const BasicBlock *Succ : BB->getTerminator()->successors())
+    for (const BasicBlock *Succ : successors(BB))
       if (DT->dominates(Succ, A))
         return true;
 
@@ -584,8 +584,8 @@
     for (auto CHI : C) {
       BasicBlock *Dest = CHI.Dest;
       // Find if all the edges have values flowing out of BB.
-      bool Found = llvm::any_of(TI->successors(), [Dest](const BasicBlock *BB) {
-          return BB == Dest; });
+      bool Found = llvm::any_of(
+          successors(TI), [Dest](const BasicBlock *BB) { return BB == Dest; });
       if (!Found)
         return false;
     }
Index: llvm/trunk/lib/Transforms/Scalar/LoopInterchange.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopInterchange.cpp
+++ llvm/trunk/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -662,7 +662,7 @@
   if (!OuterLoopHeaderBI)
     return false;
 
-  for (BasicBlock *Succ : OuterLoopHeaderBI->successors())
+  for (BasicBlock *Succ : successors(OuterLoopHeaderBI))
     if (Succ != InnerLoopPreHeader && Succ != OuterLoopLatch)
       return false;
 
@@ -1336,7 +1336,7 @@
 static void updateSuccessor(BranchInst *BI, BasicBlock *OldBB,
                             BasicBlock *NewBB,
                             std::vector<DominatorTree::UpdateType> &DTUpdates) {
-  assert(llvm::count_if(BI->successors(),
+  assert(llvm::count_if(successors(BI),
                         [OldBB](BasicBlock *BB) { return BB == OldBB; }) < 2 &&
          "BI must jump to OldBB at most once.");
   for (unsigned i = 0, e = BI->getNumSuccessors(); i < e; ++i) {
Index: llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -59,7 +59,7 @@
   // of their predecessors is going away.
   if (DTU)
     Updates.reserve(BBTerm->getNumSuccessors());
-  for (BasicBlock *Succ : BBTerm->successors()) {
+  for (BasicBlock *Succ : successors(BBTerm)) {
     Succ->removePredecessor(BB);
     if (DTU)
       Updates.push_back({DominatorTree::Delete, BB, Succ});
Index: llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp
+++ llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp
@@ -415,7 +415,7 @@
 
     // Recursively clone any reachable successor blocks.
     const TerminatorInst *TI = BB->getTerminator();
-    for (const BasicBlock *Succ : TI->successors())
+    for (const BasicBlock *Succ : successors(TI))
       ToClone.push_back(Succ);
   }
 
Index: llvm/trunk/lib/Transforms/Utils/Local.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp
@@ -235,7 +235,7 @@
         Updates.reserve(SI->getNumSuccessors() - 1);
 
       // Remove entries from PHI nodes which we no longer branch to...
-      for (BasicBlock *Succ : SI->successors()) {
+      for (BasicBlock *Succ : successors(SI)) {
         // Found case matching a constant operand?
         if (Succ == TheOnlyDest) {
           TheOnlyDest = nullptr; // Don't modify the first branch to TheOnlyDest
Index: llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp
+++ llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp
@@ -375,8 +375,7 @@
   // Along with all the other instructions, we just cloned OrigHeader's
   // terminator into OrigPreHeader. Fix up the PHI nodes in each of OrigHeader's
   // successors by duplicating their incoming values for OrigHeader.
-  TerminatorInst *TI = OrigHeader->getTerminator();
-  for (BasicBlock *SuccBB : TI->successors())
+  for (BasicBlock *SuccBB : successors(OrigHeader))
     for (BasicBlock::iterator BI = SuccBB->begin();
          PHINode *PN = dyn_cast<PHINode>(BI); ++BI)
       PN->addIncoming(PN->getIncomingValueForBlock(OrigHeader), OrigPreheader);
Index: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -3414,7 +3414,7 @@
   BasicBlock *KeepEdge2 = TrueBB != FalseBB ? FalseBB : nullptr;
 
   // Then remove the rest.
-  for (BasicBlock *Succ : OldTerm->successors()) {
+  for (BasicBlock *Succ : successors(OldTerm)) {
     // Make sure only to keep exactly one copy of each edge.
     if (Succ == KeepEdge1)
       KeepEdge1 = nullptr;