The Indexes Patch.

This introduces a new pass, SlotIndexes, which is responsible for numbering
instructions for register allocation (and other clients). SlotIndexes numbering
is designed to match the existing scheme, so this patch should not cause any
changes in the generated code.

For consistency, and to avoid naming confusion, LiveIndex has been renamed
SlotIndex.

The processImplicitDefs method of the LiveIntervals analysis has been moved
into its own pass so that it can be run prior to SlotIndexes. This was
necessary to match the existing numbering scheme.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85979 91177308-0d34-0410-b5e6-96231b3b80d8

20 files changed, 1862 insertions, 1434 deletions

diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index 05bd173dd2..e31a7f0a25 100644
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -21,221 +21,19 @@
 #ifndef LLVM_CODEGEN_LIVEINTERVAL_H
 #define LLVM_CODEGEN_LIVEINTERVAL_H
 
-#include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/AlignOf.h"
+#include "llvm/CodeGen/SlotIndexes.h"
 #include <cassert>
 #include <climits>
 
 namespace llvm {
+  class LiveIntervals;
   class MachineInstr;
   class MachineRegisterInfo;
   class TargetRegisterInfo;
   class raw_ostream;
-  
-  /// LiveIndex - An opaque wrapper around machine indexes.
-  class LiveIndex {
-    friend class VNInfo;
-    friend class LiveInterval;
-    friend class LiveIntervals;
-    friend struct DenseMapInfo<LiveIndex>;
-
-  public:
-
-    enum Slot { LOAD, USE, DEF, STORE, NUM };
-
-  private:
-
-    unsigned index;
-
-    static const unsigned PHI_BIT = 1 << 31;
-
-  public:
-
-    /// Construct a default LiveIndex pointing to a reserved index.
-    LiveIndex() : index(0) {}
-
-    /// Construct an index from the given index, pointing to the given slot.
-    LiveIndex(LiveIndex m, Slot s)
-      : index((m.index / NUM) * NUM + s) {} 
-    
-    /// Print this index to the given raw_ostream.
-    void print(raw_ostream &os) const;
-
-    /// Compare two LiveIndex objects for equality.
-    bool operator==(LiveIndex other) const {
-      return ((index & ~PHI_BIT) == (other.index & ~PHI_BIT));
-    }
-    /// Compare two LiveIndex objects for inequality.
-    bool operator!=(LiveIndex other) const {
-      return ((index & ~PHI_BIT) != (other.index & ~PHI_BIT));
-    }
-   
-    /// Compare two LiveIndex objects. Return true if the first index
-    /// is strictly lower than the second.
-    bool operator<(LiveIndex other) const {
-      return ((index & ~PHI_BIT) < (other.index & ~PHI_BIT));
-    }
-    /// Compare two LiveIndex objects. Return true if the first index
-    /// is lower than, or equal to, the second.
-    bool operator<=(LiveIndex other) const {
-      return ((index & ~PHI_BIT) <= (other.index & ~PHI_BIT));
-    }
-
-    /// Compare two LiveIndex objects. Return true if the first index
-    /// is greater than the second.
-    bool operator>(LiveIndex other) const {
-      return ((index & ~PHI_BIT) > (other.index & ~PHI_BIT));
-    }
-
-    /// Compare two LiveIndex objects. Return true if the first index
-    /// is greater than, or equal to, the second.
-    bool operator>=(LiveIndex other) const {
-      return ((index & ~PHI_BIT) >= (other.index & ~PHI_BIT));
-    }
-
-    /// Returns true if this index represents a load.
-    bool isLoad() const {
-      return ((index % NUM) == LOAD);
-    }
-
-    /// Returns true if this index represents a use.
-    bool isUse() const {
-      return ((index % NUM) == USE);
-    }
-
-    /// Returns true if this index represents a def.
-    bool isDef() const {
-      return ((index % NUM) == DEF);
-    }
-
-    /// Returns true if this index represents a store.
-    bool isStore() const {
-      return ((index % NUM) == STORE);
-    }
-
-    /// Returns the slot for this LiveIndex.
-    Slot getSlot() const {
-      return static_cast<Slot>(index % NUM);
-    }
-
-    /// Returns true if this index represents a non-PHI use/def.
-    bool isNonPHIIndex() const {
-      return ((index & PHI_BIT) == 0);
-    }
-
-    /// Returns true if this index represents a PHI use/def.
-    bool isPHIIndex() const {
-      return ((index & PHI_BIT) == PHI_BIT);
-    }
-
-  private:
-
-    /// Construct an index from the given index, with its PHI kill marker set.
-    LiveIndex(bool phi, LiveIndex o) : index(o.index) {
-      if (phi)
-        index |= PHI_BIT;
-      else
-        index &= ~PHI_BIT;
-    }
-
-    explicit LiveIndex(unsigned idx)
-      : index(idx & ~PHI_BIT) {}
-
-    LiveIndex(bool phi, unsigned idx)
-      : index(idx & ~PHI_BIT) {
-      if (phi)
-        index |= PHI_BIT;
-    }
-
-    LiveIndex(bool phi, unsigned idx, Slot slot)
-      : index(((idx / NUM) * NUM + slot) & ~PHI_BIT) {
-      if (phi)
-        index |= PHI_BIT;
-    }
-    
-    LiveIndex nextSlot_() const {
-      assert((index & PHI_BIT) == ((index + 1) & PHI_BIT) &&
-             "Index out of bounds.");
-      return LiveIndex(index + 1);
-    }
-
-    LiveIndex nextIndex_() const {
-      assert((index & PHI_BIT) == ((index + NUM) & PHI_BIT) &&
-             "Index out of bounds.");
-      return LiveIndex(index + NUM);
-    }
-
-    LiveIndex prevSlot_() const {
-      assert((index & PHI_BIT) == ((index - 1) & PHI_BIT) &&
-             "Index out of bounds.");
-      return LiveIndex(index - 1);
-    }
-
-    LiveIndex prevIndex_() const {
-      assert((index & PHI_BIT) == ((index - NUM) & PHI_BIT) &&
-             "Index out of bounds.");
-      return LiveIndex(index - NUM);
-    }
-
-    int distance(LiveIndex other) const {
-      return (other.index & ~PHI_BIT) - (index & ~PHI_BIT);
-    }
-
-    /// Returns an unsigned number suitable as an index into a
-    /// vector over all instructions.
-    unsigned getVecIndex() const {
-      return (index & ~PHI_BIT) / NUM;
-    }
-
-    /// Scale this index by the given factor.
-    LiveIndex scale(unsigned factor) const {
-      unsigned i = (index & ~PHI_BIT) / NUM,
-               o = (index % ~PHI_BIT) % NUM;
-      assert(index <= (~0U & ~PHI_BIT) / (factor * NUM) &&
-             "Rescaled interval would overflow");
-      return LiveIndex(i * NUM * factor, o);
-    }
-
-    static LiveIndex emptyKey() {
-      return LiveIndex(true, 0x7fffffff);
-    }
-
-    static LiveIndex tombstoneKey() {
-      return LiveIndex(true, 0x7ffffffe);
-    }
-
-    static unsigned getHashValue(const LiveIndex &v) {
-      return v.index * 37;
-    }
-
-  };
-
-  inline raw_ostream& operator<<(raw_ostream &os, LiveIndex mi) {
-    mi.print(os);
-    return os;
-  }
-
-  /// Densemap specialization for LiveIndex.
-  template <>
-  struct DenseMapInfo<LiveIndex> {
-    static inline LiveIndex getEmptyKey() {
-      return LiveIndex::emptyKey();
-    }
-    static inline LiveIndex getTombstoneKey() {
-      return LiveIndex::tombstoneKey();
-    }
-    static inline unsigned getHashValue(const LiveIndex &v) {
-      return LiveIndex::getHashValue(v);
-    }
-    static inline bool isEqual(const LiveIndex &LHS,
-                               const LiveIndex &RHS) {
-      return (LHS == RHS);
-    }
-    static inline bool isPod() { return true; }
-  };
-
 
   /// VNInfo - Value Number Information.
   /// This class holds information about a machine level values, including
@@ -270,23 +68,25 @@ namespace llvm {
 
   public:
 
-    typedef SmallVector<LiveIndex, 4> KillSet;
+    typedef SmallVector<SlotIndex, 4> KillSet;
 
     /// The ID number of this value.
     unsigned id;
     
     /// The index of the defining instruction (if isDefAccurate() returns true).
-    LiveIndex def;
+    SlotIndex def;
 
     KillSet kills;
 
-    VNInfo()
-      : flags(IS_UNUSED), id(~1U) { cr.copy = 0; }
+    /*
+    VNInfo(LiveIntervals &li_)
+      : defflags(IS_UNUSED), id(~1U) { cr.copy = 0; }
+    */
 
     /// VNInfo constructor.
     /// d is presumed to point to the actual defining instr. If it doesn't
     /// setIsDefAccurate(false) should be called after construction.
-    VNInfo(unsigned i, LiveIndex d, MachineInstr *c)
+    VNInfo(unsigned i, SlotIndex d, MachineInstr *c)
       : flags(IS_DEF_ACCURATE), id(i), def(d) { cr.copy = c; }
 
     /// VNInfo construtor, copies values from orig, except for the value number.
@@ -377,7 +177,7 @@ namespace llvm {
     }
 
     /// Returns true if the given index is a kill of this value.
-    bool isKill(LiveIndex k) const {
+    bool isKill(SlotIndex k) const {
       KillSet::const_iterator
         i = std::lower_bound(kills.begin(), kills.end(), k);
       return (i != kills.end() && *i == k);
@@ -385,7 +185,7 @@ namespace llvm {
 
     /// addKill - Add a kill instruction index to the specified value
     /// number.
-    void addKill(LiveIndex k) {
+    void addKill(SlotIndex k) {
       if (kills.empty()) {
         kills.push_back(k);
       } else {
@@ -397,7 +197,7 @@ namespace llvm {
 
     /// Remove the specified kill index from this value's kills list.
     /// Returns true if the value was present, otherwise returns false.
-    bool removeKill(LiveIndex k) {
+    bool removeKill(SlotIndex k) {
       KillSet::iterator i = std::lower_bound(kills.begin(), kills.end(), k);
       if (i != kills.end() && *i == k) {
         kills.erase(i);
@@ -407,7 +207,7 @@ namespace llvm {
     }
 
     /// Remove all kills in the range [s, e).
-    void removeKills(LiveIndex s, LiveIndex e) {
+    void removeKills(SlotIndex s, SlotIndex e) {
       KillSet::iterator
         si = std::lower_bound(kills.begin(), kills.end(), s),
         se = std::upper_bound(kills.begin(), kills.end(), e);
@@ -421,11 +221,11 @@ namespace llvm {
   /// program, with an inclusive start point and an exclusive end point.
   /// These ranges are rendered as [start,end).
   struct LiveRange {
-    LiveIndex start;  // Start point of the interval (inclusive)
-    LiveIndex end;    // End point of the interval (exclusive)
+    SlotIndex start;  // Start point of the interval (inclusive)
+    SlotIndex end;    // End point of the interval (exclusive)
     VNInfo *valno;   // identifier for the value contained in this interval.
 
-    LiveRange(LiveIndex S, LiveIndex E, VNInfo *V)
+    LiveRange(SlotIndex S, SlotIndex E, VNInfo *V)
       : start(S), end(E), valno(V) {
 
       assert(S < E && "Cannot create empty or backwards range");
@@ -433,13 +233,13 @@ namespace llvm {
 
     /// contains - Return true if the index is covered by this range.
     ///
-    bool contains(LiveIndex I) const {
+    bool contains(SlotIndex I) const {
       return start <= I && I < end;
     }
 
     /// containsRange - Return true if the given range, [S, E), is covered by
     /// this range. 
-    bool containsRange(LiveIndex S, LiveIndex E) const {
+    bool containsRange(SlotIndex S, SlotIndex E) const {
       assert((S < E) && "Backwards interval?");
       return (start <= S && S < end) && (start < E && E <= end);
     }
@@ -461,11 +261,11 @@ namespace llvm {
   raw_ostream& operator<<(raw_ostream& os, const LiveRange &LR);
 
 
-  inline bool operator<(LiveIndex V, const LiveRange &LR) {
+  inline bool operator<(SlotIndex V, const LiveRange &LR) {
     return V < LR.start;
   }
 
-  inline bool operator<(const LiveRange &LR, LiveIndex V) {
+  inline bool operator<(const LiveRange &LR, SlotIndex V) {
     return LR.start < V;
   }
 
@@ -522,7 +322,7 @@ namespace llvm {
     /// end of the interval.  If no LiveRange contains this position, but the
     /// position is in a hole, this method returns an iterator pointing the the
     /// LiveRange immediately after the hole.
-    iterator advanceTo(iterator I, LiveIndex Pos) {
+    iterator advanceTo(iterator I, SlotIndex Pos) {
       if (Pos >= endIndex())
         return end();
       while (I->end <= Pos) ++I;
@@ -569,7 +369,7 @@ namespace llvm {
 
     /// getNextValue - Create a new value number and return it.  MIIdx specifies
     /// the instruction that defines the value number.
-    VNInfo *getNextValue(LiveIndex def, MachineInstr *CopyMI,
+    VNInfo *getNextValue(SlotIndex def, MachineInstr *CopyMI,
                          bool isDefAccurate, BumpPtrAllocator &VNInfoAllocator){
       VNInfo *VNI =
         static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
@@ -625,13 +425,15 @@ namespace llvm {
     /// current interval, but are defined in the Clobbers interval, mark them
     /// used with an unknown definition value. Caller must pass in reference to
     /// VNInfoAllocator since it will create a new val#.
-    void MergeInClobberRanges(const LiveInterval &Clobbers,
+    void MergeInClobberRanges(LiveIntervals &li_,
+                              const LiveInterval &Clobbers,
                               BumpPtrAllocator &VNInfoAllocator);
 
     /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
     /// single LiveRange only.
-    void MergeInClobberRange(LiveIndex Start,
-                             LiveIndex End,
+    void MergeInClobberRange(LiveIntervals &li_,
+                             SlotIndex Start,
+                             SlotIndex End,
                              BumpPtrAllocator &VNInfoAllocator);
 
     /// MergeValueInAsValue - Merge all of the live ranges of a specific val#
@@ -657,56 +459,54 @@ namespace llvm {
     bool empty() const { return ranges.empty(); }
 
     /// beginIndex - Return the lowest numbered slot covered by interval.
-    LiveIndex beginIndex() const {
-      if (empty())
-        return LiveIndex();
+    SlotIndex beginIndex() const {
+      assert(!empty() && "Call to beginIndex() on empty interval.");
       return ranges.front().start;
     }
 
     /// endNumber - return the maximum point of the interval of the whole,
     /// exclusive.
-    LiveIndex endIndex() const {
-      if (empty())
-        return LiveIndex();
+    SlotIndex endIndex() const {
+      assert(!empty() && "Call to endIndex() on empty interval.");
       return ranges.back().end;
     }
 
-    bool expiredAt(LiveIndex index) const {
+    bool expiredAt(SlotIndex index) const {
       return index >= endIndex();
     }
 
-    bool liveAt(LiveIndex index) const;
+    bool liveAt(SlotIndex index) const;
 
     // liveBeforeAndAt - Check if the interval is live at the index and the
     // index just before it. If index is liveAt, check if it starts a new live
     // range.If it does, then check if the previous live range ends at index-1.
-    bool liveBeforeAndAt(LiveIndex index) const;
+    bool liveBeforeAndAt(SlotIndex index) const;
 
     /// getLiveRangeContaining - Return the live range that contains the
     /// specified index, or null if there is none.
-    const LiveRange *getLiveRangeContaining(LiveIndex Idx) const {
+    const LiveRange *getLiveRangeContaining(SlotIndex Idx) const {
       const_iterator I = FindLiveRangeContaining(Idx);
       return I == end() ? 0 : &*I;
     }
 
     /// getLiveRangeContaining - Return the live range that contains the
     /// specified index, or null if there is none.
-    LiveRange *getLiveRangeContaining(LiveIndex Idx) {
+    LiveRange *getLiveRangeContaining(SlotIndex Idx) {
       iterator I = FindLiveRangeContaining(Idx);
       return I == end() ? 0 : &*I;
     }
 
     /// FindLiveRangeContaining - Return an iterator to the live range that
     /// contains the specified index, or end() if there is none.
-    const_iterator FindLiveRangeContaining(LiveIndex Idx) const;
+    const_iterator FindLiveRangeContaining(SlotIndex Idx) const;
 
     /// FindLiveRangeContaining - Return an iterator to the live range that
     /// contains the specified index, or end() if there is none.
-    iterator FindLiveRangeContaining(LiveIndex Idx);
+    iterator FindLiveRangeContaining(SlotIndex Idx);
 
     /// findDefinedVNInfo - Find the by the specified
     /// index (register interval) or defined 
-    VNInfo *findDefinedVNInfoForRegInt(LiveIndex Idx) const;
+    VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
 
     /// findDefinedVNInfo - Find the VNInfo that's defined by the specified
     /// register (stack inteval only).
@@ -721,7 +521,7 @@ namespace llvm {
 
     /// overlaps - Return true if the live interval overlaps a range specified
     /// by [Start, End).
-    bool overlaps(LiveIndex Start, LiveIndex End) const;
+    bool overlaps(SlotIndex Start, SlotIndex End) const;
 
     /// overlapsFrom - Return true if the intersection of the two live intervals
     /// is not empty.  The specified iterator is a hint that we can begin
@@ -738,18 +538,19 @@ namespace llvm {
     /// join - Join two live intervals (this, and other) together.  This applies
     /// mappings to the value numbers in the LHS/RHS intervals as specified.  If
     /// the intervals are not joinable, this aborts.
-    void join(LiveInterval &Other, const int *ValNoAssignments,
+    void join(LiveInterval &Other,
+              const int *ValNoAssignments,
               const int *RHSValNoAssignments,
               SmallVector<VNInfo*, 16> &NewVNInfo,
               MachineRegisterInfo *MRI);
 
     /// isInOneLiveRange - Return true if the range specified is entirely in the
     /// a single LiveRange of the live interval.
-    bool isInOneLiveRange(LiveIndex Start, LiveIndex End);
+    bool isInOneLiveRange(SlotIndex Start, SlotIndex End);
 
     /// removeRange - Remove the specified range from this interval.  Note that
     /// the range must be a single LiveRange in its entirety.
-    void removeRange(LiveIndex Start, LiveIndex End,
+    void removeRange(SlotIndex Start, SlotIndex End,
                      bool RemoveDeadValNo = false);
 
     void removeRange(LiveRange LR, bool RemoveDeadValNo = false) {
@@ -773,8 +574,8 @@ namespace llvm {
     void ComputeJoinedWeight(const LiveInterval &Other);
 
     bool operator<(const LiveInterval& other) const {
-      const LiveIndex &thisIndex = beginIndex();
-      const LiveIndex &otherIndex = other.beginIndex();
+      const SlotIndex &thisIndex = beginIndex();
+      const SlotIndex &otherIndex = other.beginIndex();
       return (thisIndex < otherIndex ||
               (thisIndex == otherIndex && reg < other.reg));
     }
@@ -785,8 +586,9 @@ namespace llvm {
   private:
 
     Ranges::iterator addRangeFrom(LiveRange LR, Ranges::iterator From);
-    void extendIntervalEndTo(Ranges::iterator I, LiveIndex NewEnd);
-    Ranges::iterator extendIntervalStartTo(Ranges::iterator I, LiveIndex NewStr);
+    void extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd);
+    Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
+
     LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
 
   };
diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 511db6db10..efb4a03d88 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -23,12 +23,14 @@
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Allocator.h"
 #include <cmath>
+#include <iterator>
 
 namespace llvm {
 
@@ -40,21 +42,6 @@ namespace llvm {
   class TargetInstrInfo;
   class TargetRegisterClass;
   class VirtRegMap;
-  typedef std::pair<LiveIndex, MachineBasicBlock*> IdxMBBPair;
-
-  inline bool operator<(LiveIndex V, const IdxMBBPair &IM) {
-    return V < IM.first;
-  }
-
-  inline bool operator<(const IdxMBBPair &IM, LiveIndex V) {
-    return IM.first < V;
-  }
-
-  struct Idx2MBBCompare {
-    bool operator()(const IdxMBBPair &LHS, const IdxMBBPair &RHS) const {
-      return LHS.first < RHS.first;
-    }
-  };
   
   class LiveIntervals : public MachineFunctionPass {
     MachineFunction* mf_;
@@ -64,33 +51,15 @@ namespace llvm {
     const TargetInstrInfo* tii_;
     AliasAnalysis *aa_;
     LiveVariables* lv_;
+    SlotIndexes* indexes_;
 
     /// Special pool allocator for VNInfo's (LiveInterval val#).
     ///
     BumpPtrAllocator VNInfoAllocator;
 
-    /// MBB2IdxMap - The indexes of the first and last instructions in the
-    /// specified basic block.
-    std::vector<std::pair<LiveIndex, LiveIndex> > MBB2IdxMap;
-
-    /// Idx2MBBMap - Sorted list of pairs of index of first instruction
-    /// and MBB id.
-    std::vector<IdxMBBPair> Idx2MBBMap;
-
-    /// FunctionSize - The number of instructions present in the function
-    uint64_t FunctionSize;
-
-    typedef DenseMap<const MachineInstr*, LiveIndex> Mi2IndexMap;
-    Mi2IndexMap mi2iMap_;
-
-    typedef std::vector<MachineInstr*> Index2MiMap;
-    Index2MiMap i2miMap_;
-
     typedef DenseMap<unsigned, LiveInterval*> Reg2IntervalMap;
     Reg2IntervalMap r2iMap_;
 
-    DenseMap<MachineBasicBlock*, LiveIndex> terminatorGaps;
-
     /// phiJoinCopies - Copy instructions which are PHI joins.
     SmallVector<MachineInstr*, 16> phiJoinCopies;
 
@@ -100,48 +69,10 @@ namespace llvm {
     /// CloneMIs - A list of clones as result of re-materialization.
     std::vector<MachineInstr*> CloneMIs;
 
-    typedef LiveInterval::InstrSlots InstrSlots;
-
   public:
     static char ID; // Pass identification, replacement for typeid
     LiveIntervals() : MachineFunctionPass(&ID) {}
 
-    LiveIndex getBaseIndex(LiveIndex index) {
-      return LiveIndex(index, LiveIndex::LOAD);
-    }
-    LiveIndex getBoundaryIndex(LiveIndex index) {
-      return LiveIndex(index,
-        (LiveIndex::Slot)(LiveIndex::NUM - 1));
-    }
-    LiveIndex getLoadIndex(LiveIndex index) {
-      return LiveIndex(index, LiveIndex::LOAD);
-    }
-    LiveIndex getUseIndex(LiveIndex index) {
-      return LiveIndex(index, LiveIndex::USE);
-    }
-    LiveIndex getDefIndex(LiveIndex index) {
-      return LiveIndex(index, LiveIndex::DEF);
-    }
-    LiveIndex getStoreIndex(LiveIndex index) {
-      return LiveIndex(index, LiveIndex::STORE);
-    }    
-
-    LiveIndex getNextSlot(LiveIndex m) const {
-      return m.nextSlot_();
-    }
-
-    LiveIndex getNextIndex(LiveIndex m) const {
-      return m.nextIndex_();
-    }
-
-    LiveIndex getPrevSlot(LiveIndex m) const {
-      return m.prevSlot_();
-    }
-
-    LiveIndex getPrevIndex(LiveIndex m) const {
-      return m.prevIndex_();
-    }
-
     static float getSpillWeight(bool isDef, bool isUse, unsigned loopDepth) {
       return (isDef + isUse) * powf(10.0F, (float)loopDepth);
     }
@@ -170,111 +101,18 @@ namespace llvm {
       return r2iMap_.count(reg);
     }
 
-    /// getMBBStartIdx - Return the base index of the first instruction in the
-    /// specified MachineBasicBlock.
-    LiveIndex getMBBStartIdx(MachineBasicBlock *MBB) const {
-      return getMBBStartIdx(MBB->getNumber());
-    }
-    LiveIndex getMBBStartIdx(unsigned MBBNo) const {
-      assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
-      return MBB2IdxMap[MBBNo].first;
-    }
-
-    /// getMBBEndIdx - Return the store index of the last instruction in the
-    /// specified MachineBasicBlock.
-    LiveIndex getMBBEndIdx(MachineBasicBlock *MBB) const {
-      return getMBBEndIdx(MBB->getNumber());
-    }
-    LiveIndex getMBBEndIdx(unsigned MBBNo) const {
-      assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
-      return MBB2IdxMap[MBBNo].second;
-    }
-
     /// getScaledIntervalSize - get the size of an interval in "units,"
     /// where every function is composed of one thousand units.  This
     /// measure scales properly with empty index slots in the function.
     double getScaledIntervalSize(LiveInterval& I) {
-      return (1000.0 / InstrSlots::NUM * I.getSize()) / i2miMap_.size();
+      return (1000.0 * I.getSize()) / indexes_->getIndexesLength();
     }
     
     /// getApproximateInstructionCount - computes an estimate of the number
     /// of instructions in a given LiveInterval.
     unsigned getApproximateInstructionCount(LiveInterval& I) {
       double IntervalPercentage = getScaledIntervalSize(I) / 1000.0;
-      return (unsigned)(IntervalPercentage * FunctionSize);
-    }
-
-    /// getMBBFromIndex - given an index in any instruction of an
-    /// MBB return a pointer the MBB
-    MachineBasicBlock* getMBBFromIndex(LiveIndex index) const {
-      std::vector<IdxMBBPair>::const_iterator I =
-        std::lower_bound(Idx2MBBMap.begin(), Idx2MBBMap.end(), index);
-      // Take the pair containing the index
-      std::vector<IdxMBBPair>::const_iterator J =
-        ((I != Idx2MBBMap.end() && I->first > index) ||
-         (I == Idx2MBBMap.end() && Idx2MBBMap.size()>0)) ? (I-1): I;
-
-      assert(J != Idx2MBBMap.end() && J->first <= index &&
-             index <= getMBBEndIdx(J->second) &&
-             "index does not correspond to an MBB");
-      return J->second;
-    }
-
-    /// getInstructionIndex - returns the base index of instr
-    LiveIndex getInstructionIndex(const MachineInstr* instr) const {
-      Mi2IndexMap::const_iterator it = mi2iMap_.find(instr);
-      assert(it != mi2iMap_.end() && "Invalid instruction!");
-      return it->second;
-    }
-
-    /// getInstructionFromIndex - given an index in any slot of an
-    /// instruction return a pointer the instruction
-    MachineInstr* getInstructionFromIndex(LiveIndex index) const {
-      // convert index to vector index
-      unsigned i = index.getVecIndex();
-      assert(i < i2miMap_.size() &&
-             "index does not correspond to an instruction");
-      return i2miMap_[i];
-    }
-
-    /// hasGapBeforeInstr - Return true if the previous instruction slot,
-    /// i.e. Index - InstrSlots::NUM, is not occupied.
-    bool hasGapBeforeInstr(LiveIndex Index) {
-      Index = getBaseIndex(getPrevIndex(Index));
-      return getInstructionFromIndex(Index) == 0;
-    }
-
-    /// hasGapAfterInstr - Return true if the successive instruction slot,
-    /// i.e. Index + InstrSlots::Num, is not occupied.
-    bool hasGapAfterInstr(LiveIndex Index) {
-      Index = getBaseIndex(getNextIndex(Index));
-      return getInstructionFromIndex(Index) == 0;
-    }
-
-    /// findGapBeforeInstr - Find an empty instruction slot before the
-    /// specified index. If "Furthest" is true, find one that's furthest
-    /// away from the index (but before any index that's occupied).
-    LiveIndex findGapBeforeInstr(LiveIndex Index, bool Furthest = false) {
-      Index = getBaseIndex(getPrevIndex(Index));
-      if (getInstructionFromIndex(Index))
-        return LiveIndex();  // No gap!
-      if (!Furthest)
-        return Index;
-      LiveIndex PrevIndex = getBaseIndex(getPrevIndex(Index));
-      while (getInstructionFromIndex(Index)) {
-        Index = PrevIndex;
-        PrevIndex = getBaseIndex(getPrevIndex(Index));
-      }
-      return Index;
-    }
-
-    /// InsertMachineInstrInMaps - Insert the specified machine instruction
-    /// into the instruction index map at the given index.
-    void InsertMachineInstrInMaps(MachineInstr *MI, LiveIndex Index) {
-      i2miMap_[Index.getVecIndex()] = MI;
-      Mi2IndexMap::iterator it = mi2iMap_.find(MI);
-      assert(it == mi2iMap_.end() && "Already in map!");
-      mi2iMap_[MI] = Index;
+      return (unsigned)(IntervalPercentage * indexes_->getFunctionSize());
     }
 
     /// conflictsWithPhysRegDef - Returns true if the specified register
@@ -288,19 +126,7 @@ namespace llvm {
                                  bool CheckUse,
                                  SmallPtrSet<MachineInstr*,32> &JoinedCopies);
 
-    /// findLiveInMBBs - Given a live range, if the value of the range
-    /// is live in any MBB returns true as well as the list of basic blocks
-    /// in which the value is live.
-    bool findLiveInMBBs(LiveIndex Start, LiveIndex End,
-                        SmallVectorImpl<MachineBasicBlock*> &MBBs) const;
-
-    /// findReachableMBBs - Return a list MBB that can be reached via any
-    /// branch or fallthroughs. Return true if the list is not empty.
-    bool findReachableMBBs(LiveIndex Start, LiveIndex End,
-                        SmallVectorImpl<MachineBasicBlock*> &MBBs) const;
-
     // Interval creation
-
     LiveInterval &getOrCreateInterval(unsigned reg) {
       Reg2IntervalMap::iterator I = r2iMap_.find(reg);
       if (I == r2iMap_.end())
@@ -325,36 +151,75 @@ namespace llvm {
       r2iMap_.erase(I);
     }
 
+    SlotIndex getZeroIndex() const {
+      return indexes_->getZeroIndex();
+    }
+
+    SlotIndex getInvalidIndex() const {
+      return indexes_->getInvalidIndex();
+    }
+
     /// isNotInMIMap - returns true if the specified machine instr has been
     /// removed or was never entered in the map.
-    bool isNotInMIMap(MachineInstr* instr) const {
-      return !mi2iMap_.count(instr);
+    bool isNotInMIMap(const MachineInstr* Instr) const {
+      return !indexes_->hasIndex(Instr);
+    }
+
+    /// Returns the base index of the given instruction.
+    SlotIndex getInstructionIndex(const MachineInstr *instr) const {
+      return indexes_->getInstructionIndex(instr);
+    }
+    
+    /// Returns the instruction associated with the given index.
+    MachineInstr* getInstructionFromIndex(SlotIndex index) const {
+      return indexes_->getInstructionFromIndex(index);
+    }
+
+    /// Return the first index in the given basic block.
+    SlotIndex getMBBStartIdx(const MachineBasicBlock *mbb) const {
+      return indexes_->getMBBStartIdx(mbb);
+    } 
+
+    /// Return the last index in the given basic block.
+    SlotIndex getMBBEndIdx(const MachineBasicBlock *mbb) const {
+      return indexes_->getMBBEndIdx(mbb);
+    } 
+
+    MachineBasicBlock* getMBBFromIndex(SlotIndex index) const {
+      return indexes_->getMBBFromIndex(index);
+    }
+
+    bool hasGapBeforeInstr(SlotIndex index) {
+      return indexes_->hasGapBeforeInstr(index);
+    }
+
+    bool hasGapAfterInstr(SlotIndex index) {
+      return indexes_->hasGapAfterInstr(index);
+    }
+
+    SlotIndex findGapBeforeInstr(SlotIndex index, bool furthest = false) {
+      return indexes_->findGapBeforeInstr(index, furthest);
+    }
+
+    void InsertMachineInstrInMaps(MachineInstr *MI, SlotIndex Index) {
+      indexes_->insertMachineInstrInMaps(MI, Index);
     }
 
-    /// RemoveMachineInstrFromMaps - This marks the specified machine instr as
-    /// deleted.
     void RemoveMachineInstrFromMaps(MachineInstr *MI) {
-      // remove index -> MachineInstr and
-      // MachineInstr -> index mappings
-      Mi2IndexMap::iterator mi2i = mi2iMap_.find(MI);
-      if (mi2i != mi2iMap_.end()) {
-        i2miMap_[mi2i->second.index/InstrSlots::NUM] = 0;
-        mi2iMap_.erase(mi2i);
-      }
+      indexes_->re