Add SplitKit API to query and select the current interval being worked on.

[oota-llvm.git] / lib / CodeGen / SplitKit.h

diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index d735f1070b9b057f36e7aa06085627a3e025bbf4..fab56f70d9bac15a3364c78cc0f2350f79fd9674 100644 (file)
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -12,6 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IndexedMap.h"
@@ -50,17 +51,9 @@ public:
   const MachineLoopInfo &Loops;
   const TargetInstrInfo &TII;
 
-  // Instructions using the the current register.
-  typedef SmallPtrSet<const MachineInstr*, 16> InstrPtrSet;
-  InstrPtrSet UsingInstrs;
-
   // Sorted slot indexes of using instructions.
   SmallVector<SlotIndex, 8> UseSlots;
 
-  // The number of instructions using CurLI in each basic block.
-  typedef DenseMap<const MachineBasicBlock*, unsigned> BlockCountMap;
-  BlockCountMap UsingBlocks;
-
   /// Additional information about basic blocks where the current variable is
   /// live. Such a block will look like one of these templates:
   ///
@@ -77,32 +70,38 @@ public:
     SlotIndex LastUse;    ///< Last instr using current reg.
     SlotIndex Kill;       ///< Interval end point inside block.
     SlotIndex Def;        ///< Interval start point inside block.
-    /// Last possible point for splitting live ranges.
-    SlotIndex LastSplitPoint;
-    bool Uses;            ///< Current reg has uses or defs in block.
     bool LiveThrough;     ///< Live in whole block (Templ 5. or 6. above).
     bool LiveIn;          ///< Current reg is live in.
     bool LiveOut;         ///< Current reg is live out.
   };
 
-  /// Basic blocks where var is live. This array is parallel to
-  /// SpillConstraints.
-  SmallVector<BlockInfo, 8> LiveBlocks;
-
 private:
   // Current live interval.
   const LiveInterval *CurLI;
 
+  /// LastSplitPoint - Last legal split point in each basic block in the current
+  /// function. The first entry is the first terminator, the second entry is the
+  /// last valid split point for a variable that is live in to a landing pad
+  /// successor.
+  SmallVector<std::pair<SlotIndex, SlotIndex>, 8> LastSplitPoint;
+
+  /// UseBlocks - Blocks where CurLI has uses.
+  SmallVector<BlockInfo, 8> UseBlocks;
+
+  /// ThroughBlocks - Block numbers where CurLI is live through without uses.
+  BitVector ThroughBlocks;
+
+  /// NumThroughBlocks - Number of live-through blocks.
+  unsigned NumThroughBlocks;
+
+  SlotIndex computeLastSplitPoint(unsigned Num);
+
   // Sumarize statistics by counting instructions using CurLI.
   void analyzeUses();
 
   /// calcLiveBlockInfo - Compute per-block information about CurLI.
   bool calcLiveBlockInfo();
 
-  /// canAnalyzeBranch - Return true if MBB ends in a branch that can be
-  /// analyzed.
-  bool canAnalyzeBranch(const MachineBasicBlock *MBB);
-
 public:
   SplitAnalysis(const VirtRegMap &vrm, const LiveIntervals &lis,
                 const MachineLoopInfo &mli);
@@ -118,9 +117,14 @@ public:
   /// getParent - Return the last analyzed interval.
   const LiveInterval &getParent() const { return *CurLI; }
 
-  /// hasUses - Return true if MBB has any uses of CurLI.
-  bool hasUses(const MachineBasicBlock *MBB) const {
-    return UsingBlocks.lookup(MBB);
+  /// getLastSplitPoint - Return that base index of the last valid split point
+  /// in the basic block numbered Num.
+  SlotIndex getLastSplitPoint(unsigned Num) {
+    // Inline the common simple case.
+    if (LastSplitPoint[Num].first.isValid() &&
+        !LastSplitPoint[Num].second.isValid())
+      return LastSplitPoint[Num].first;
+    return computeLastSplitPoint(Num);
   }
 
   /// isOriginalEndpoint - Return true if the original live range was killed or
@@ -130,10 +134,17 @@ public:
   /// splitting.
   bool isOriginalEndpoint(SlotIndex Idx) const;
 
-  typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
+  /// getUseBlocks - Return an array of BlockInfo objects for the basic blocks
+  /// where CurLI has uses.
+  ArrayRef<BlockInfo> getUseBlocks() { return UseBlocks; }
 
-  // Print a set of blocks with use counts.
-  void print(const BlockPtrSet&, raw_ostream&) const;
+  /// getNumThroughBlocks - Return the number of through blocks.
+  unsigned getNumThroughBlocks() const { return NumThroughBlocks; }
+
+  /// isThroughBlock - Return true if CurLI is live through MBB without uses.
+  bool isThroughBlock(unsigned MBB) const { return ThroughBlocks.test(MBB); }
+
+  typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
 
   /// getMultiUseBlocks - Add basic blocks to Blocks that may benefit from
   /// having CurLI split to a new live interval. Return true if Blocks can be
@@ -272,7 +283,15 @@ public:
   void reset(LiveRangeEdit&);
 
   /// Create a new virtual register and live interval.
-  void openIntv();
+  /// Return the interval index, starting from 1. Interval index 0 is the
+  /// implicit complement interval.
+  unsigned openIntv();
+
+  /// currentIntv - Return the current interval index.
+  unsigned currentIntv() const { return OpenIdx; }
+
+  /// selectIntv - Select a previously opened interval index.
+  void selectIntv(unsigned Idx);
 
   /// enterIntvBefore - Enter the open interval before the instruction at Idx.
   /// If the parent interval is not live before Idx, a COPY is not inserted.