1 files changed, 196 insertions, 22 deletions

diff --git a/include/llvm/CodeGen/MachineInstrBundleIterator.h b/include/llvm/CodeGen/MachineInstrBundleIterator.h
index 45a9a188f90e..2d77cfcae20f 100644
--- a/include/llvm/CodeGen/MachineInstrBundleIterator.h
+++ b/include/llvm/CodeGen/MachineInstrBundleIterator.h
@@ -19,23 +19,126 @@
 
 namespace llvm {
 
+template <class T, bool IsReverse> struct MachineInstrBundleIteratorTraits;
+template <class T> struct MachineInstrBundleIteratorTraits<T, false> {
+  typedef simple_ilist<T, ilist_sentinel_tracking<true>> list_type;
+  typedef typename list_type::iterator instr_iterator;
+  typedef typename list_type::iterator nonconst_instr_iterator;
+  typedef typename list_type::const_iterator const_instr_iterator;
+};
+template <class T> struct MachineInstrBundleIteratorTraits<T, true> {
+  typedef simple_ilist<T, ilist_sentinel_tracking<true>> list_type;
+  typedef typename list_type::reverse_iterator instr_iterator;
+  typedef typename list_type::reverse_iterator nonconst_instr_iterator;
+  typedef typename list_type::const_reverse_iterator const_instr_iterator;
+};
+template <class T> struct MachineInstrBundleIteratorTraits<const T, false> {
+  typedef simple_ilist<T, ilist_sentinel_tracking<true>> list_type;
+  typedef typename list_type::const_iterator instr_iterator;
+  typedef typename list_type::iterator nonconst_instr_iterator;
+  typedef typename list_type::const_iterator const_instr_iterator;
+};
+template <class T> struct MachineInstrBundleIteratorTraits<const T, true> {
+  typedef simple_ilist<T, ilist_sentinel_tracking<true>> list_type;
+  typedef typename list_type::const_reverse_iterator instr_iterator;
+  typedef typename list_type::reverse_iterator nonconst_instr_iterator;
+  typedef typename list_type::const_reverse_iterator const_instr_iterator;
+};
+
+template <bool IsReverse> struct MachineInstrBundleIteratorHelper;
+template <> struct MachineInstrBundleIteratorHelper<false> {
+  /// Get the beginning of the current bundle.
+  template <class Iterator> static Iterator getBundleBegin(Iterator I) {
+    if (!I.isEnd())
+      while (I->isBundledWithPred())
+        --I;
+    return I;
+  }
+
+  /// Get the final node of the current bundle.
+  template <class Iterator> static Iterator getBundleFinal(Iterator I) {
+    if (!I.isEnd())
+      while (I->isBundledWithSucc())
+        ++I;
+    return I;
+  }
+
+  /// Increment forward ilist iterator.
+  template <class Iterator> static void increment(Iterator &I) {
+    I = std::next(getBundleFinal(I));
+  }
+
+  /// Decrement forward ilist iterator.
+  template <class Iterator> static void decrement(Iterator &I) {
+    I = getBundleBegin(std::prev(I));
+  }
+};
+
+template <> struct MachineInstrBundleIteratorHelper<true> {
+  /// Get the beginning of the current bundle.
+  template <class Iterator> static Iterator getBundleBegin(Iterator I) {
+    return MachineInstrBundleIteratorHelper<false>::getBundleBegin(
+               I.getReverse())
+        .getReverse();
+  }
+
+  /// Get the final node of the current bundle.
+  template <class Iterator> static Iterator getBundleFinal(Iterator I) {
+    return MachineInstrBundleIteratorHelper<false>::getBundleFinal(
+               I.getReverse())
+        .getReverse();
+  }
+
+  /// Increment reverse ilist iterator.
+  template <class Iterator> static void increment(Iterator &I) {
+    I = getBundleBegin(std::next(I));
+  }
+
+  /// Decrement reverse ilist iterator.
+  template <class Iterator> static void decrement(Iterator &I) {
+    I = std::prev(getBundleFinal(I));
+  }
+};
+
 /// MachineBasicBlock iterator that automatically skips over MIs that are
 /// inside bundles (i.e. walk top level MIs only).
-template <typename Ty>
-class MachineInstrBundleIterator
-    : public std::iterator<std::bidirectional_iterator_tag, Ty, ptrdiff_t> {
-  typedef ilist_iterator<Ty> instr_iterator;
+template <typename Ty, bool IsReverse = false>
+class MachineInstrBundleIterator : MachineInstrBundleIteratorHelper<IsReverse> {
+  typedef MachineInstrBundleIteratorTraits<Ty, IsReverse> Traits;
+  typedef typename Traits::instr_iterator instr_iterator;
   instr_iterator MII;
 
 public:
-  MachineInstrBundleIterator(instr_iterator MI) : MII(MI) {}
+  typedef typename instr_iterator::value_type value_type;
+  typedef typename instr_iterator::difference_type difference_type;
+  typedef typename instr_iterator::pointer pointer;
+  typedef typename instr_iterator::reference reference;
+  typedef std::bidirectional_iterator_tag iterator_category;
+
+  typedef typename instr_iterator::const_pointer const_pointer;
+  typedef typename instr_iterator::const_reference const_reference;
+
+private:
+  typedef typename Traits::nonconst_instr_iterator nonconst_instr_iterator;
+  typedef typename Traits::const_instr_iterator const_instr_iterator;
+  typedef MachineInstrBundleIterator<
+      typename nonconst_instr_iterator::value_type, IsReverse>
+      nonconst_iterator;
+  typedef MachineInstrBundleIterator<Ty, !IsReverse> reverse_iterator;
 
-  MachineInstrBundleIterator(Ty &MI) : MII(MI) {
+public:
+  MachineInstrBundleIterator(instr_iterator MI) : MII(MI) {
+    assert((!MI.getNodePtr() || MI.isEnd() || !MI->isBundledWithPred()) &&
+           "It's not legal to initialize MachineInstrBundleIterator with a "
+           "bundled MI");
+  }
+
+  MachineInstrBundleIterator(reference MI) : MII(MI) {
     assert(!MI.isBundledWithPred() && "It's not legal to initialize "
                                       "MachineInstrBundleIterator with a "
                                       "bundled MI");
   }
-  MachineInstrBundleIterator(Ty *MI) : MII(MI) {
+  MachineInstrBundleIterator(pointer MI) : MII(MI) {
     // FIXME: This conversion should be explicit.
     assert((!MI || !MI->isBundledWithPred()) && "It's not legal to initialize "
                                                 "MachineInstrBundleIterator "
@@ -43,34 +146,101 @@ public:
   }
   // Template allows conversion from const to nonconst.
   template <class OtherTy>
-  MachineInstrBundleIterator(const MachineInstrBundleIterator<OtherTy> &I)
+  MachineInstrBundleIterator(
+      const MachineInstrBundleIterator<OtherTy, IsReverse> &I,
+      typename std::enable_if<std::is_convertible<OtherTy *, Ty *>::value,
+                              void *>::type = nullptr)
       : MII(I.getInstrIterator()) {}
   MachineInstrBundleIterator() : MII(nullptr) {}
 
-  Ty &operator*() const { return *MII; }
-  Ty *operator->() const { return &operator*(); }
+  /// Get the bundle iterator for the given instruction's bundle.
+  static MachineInstrBundleIterator getAtBundleBegin(instr_iterator MI) {
+    return MachineInstrBundleIteratorHelper<IsReverse>::getBundleBegin(MI);
+  }
+
+  reference operator*() const { return *MII; }
+  pointer operator->() const { return &operator*(); }
+
+  /// Check for null.
+  bool isValid() const { return MII.getNodePtr(); }
 
-  // FIXME: This conversion should be explicit.
-  operator Ty *() const { return MII.getNodePtrUnchecked(); }
+  friend bool operator==(const MachineInstrBundleIterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return L.MII == R.MII;
+  }
+  friend bool operator==(const MachineInstrBundleIterator &L,
+                         const const_instr_iterator &R) {
+    return L.MII == R; // Avoid assertion about validity of R.
+  }
+  friend bool operator==(const const_instr_iterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return L == R.MII; // Avoid assertion about validity of L.
+  }
+  friend bool operator==(const MachineInstrBundleIterator &L,
+                         const nonconst_instr_iterator &R) {
+    return L.MII == R; // Avoid assertion about validity of R.
+  }
+  friend bool operator==(const nonconst_instr_iterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return L == R.MII; // Avoid assertion about validity of L.
+  }
+  friend bool operator==(const MachineInstrBundleIterator &L, const_pointer R) {
+    return L == const_instr_iterator(R); // Avoid assertion about validity of R.
+  }
+  friend bool operator==(const_pointer L, const MachineInstrBundleIterator &R) {
+    return const_instr_iterator(L) == R; // Avoid assertion about validity of L.
+  }
+  friend bool operator==(const MachineInstrBundleIterator &L,
+                         const_reference R) {
+    return L == &R; // Avoid assertion about validity of R.
+  }
+  friend bool operator==(const_reference L,
+                         const MachineInstrBundleIterator &R) {
+    return &L == R; // Avoid assertion about validity of L.
+  }
 
-  bool operator==(const MachineInstrBundleIterator &X) const {
-    return MII == X.MII;
+  friend bool operator!=(const MachineInstrBundleIterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const MachineInstrBundleIterator &L,
+                         const const_instr_iterator &R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const const_instr_iterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const MachineInstrBundleIterator &L,
+                         const nonconst_instr_iterator &R) {
+    return !(L == R);
   }
-  bool operator!=(const MachineInstrBundleIterator &X) const {
-    return !operator==(X);
+  friend bool operator!=(const nonconst_instr_iterator &L,
+                         const MachineInstrBundleIterator &R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const MachineInstrBundleIterator &L, const_pointer R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const_pointer L, const MachineInstrBundleIterator &R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const MachineInstrBundleIterator &L,
+                         const_reference R) {
+    return !(L == R);
+  }
+  friend bool operator!=(const_reference L,
+                         const MachineInstrBundleIterator &R) {
+    return !(L == R);
   }
 
   // Increment and decrement operators...
   MachineInstrBundleIterator &operator--() {
-    do
-      --MII;
-    while (MII->isBundledWithPred());
+    this->decrement(MII);
     return *this;
   }
   MachineInstrBundleIterator &operator++() {
-    while (MII->isBundledWithSucc())
-      ++MII;
-    ++MII;
+    this->increment(MII);
     return *this;
   }
   MachineInstrBundleIterator operator--(int) {
@@ -85,6 +255,10 @@ public:
   }
 
   instr_iterator getInstrIterator() const { return MII; }
+
+  nonconst_iterator getNonConstIterator() const { return MII.getNonConst(); }
+
+  reverse_iterator getReverse() const { return MII.getReverse(); }
 };
 
 } // end namespace llvm