This patch corrects logic in PPCFrameLowering for save and restore of

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

diff --git a/lib/CodeGen/LiveIntervalUnion.h b/lib/CodeGen/LiveIntervalUnion.h
index 7f494474f99e656bcaadecc6e07e0fc2c523538a..cd4e690c3740a197ef33f8cf44c5e80b5c4defce 100644 (file)
--- a/lib/CodeGen/LiveIntervalUnion.h
+++ b/lib/CodeGen/LiveIntervalUnion.h
@@ -20,8 +20,6 @@
 #include "llvm/ADT/IntervalMap.h"
 #include "llvm/CodeGen/LiveInterval.h"
 
-#include <algorithm>
-
 namespace llvm {
 
 class MachineLoopRange;
@@ -59,17 +57,14 @@ public:
   // LiveIntervalUnions share an external allocator.
   typedef LiveSegments::Allocator Allocator;
 
-  class InterferenceResult;
   class Query;
 
 private:
-  const unsigned RepReg;  // representative register number
   unsigned Tag;           // unique tag for current contents.
   LiveSegments Segments;  // union of virtual reg segments
 
 public:
-  LiveIntervalUnion(unsigned r, Allocator &a) : RepReg(r), Tag(0), Segments(a)
-    {}
+  explicit LiveIntervalUnion(Allocator &a) : Tag(0), Segments(a) {}
 
   // Iterate over all segments in the union of live virtual registers ordered
   // by their starting position.
@@ -106,43 +101,13 @@ public:
   void verify(LiveVirtRegBitSet& VisitedVRegs);
 #endif
 
-  /// Cache a single interference test result in the form of two intersecting
-  /// segments. This allows efficiently iterating over the interferences. The
-  /// iteration logic is handled by LiveIntervalUnion::Query which may
-  /// filter interferences depending on the type of query.
-  class InterferenceResult {
-    friend class Query;
-
-    LiveInterval::iterator VirtRegI; // current position in VirtReg
-    SegmentIter LiveUnionI;          // current position in LiveUnion
-
-    // Internal ctor.
-    InterferenceResult(LiveInterval::iterator VRegI, SegmentIter UnionI)
-      : VirtRegI(VRegI), LiveUnionI(UnionI) {}
-
-  public:
-    // Public default ctor.
-    InterferenceResult(): VirtRegI(), LiveUnionI() {}
-
-    /// interference - Return the register that is interfering here.
-    LiveInterval *interference() const { return LiveUnionI.value(); }
-
-    // Note: this interface provides raw access to the iterators because the
-    // result has no way to tell if it's valid to dereference them.
-
-    // Access the VirtReg segment.
-    LiveInterval::iterator virtRegPos() const { return VirtRegI; }
-
-    // Access the LiveUnion segment.
-    const SegmentIter &liveUnionPos() const { return LiveUnionI; }
-  };
-
   /// Query interferences between a single live virtual register and a live
   /// interval union.
   class Query {
     LiveIntervalUnion *LiveUnion;
     LiveInterval *VirtReg;
-    InterferenceResult FirstInterference;
+    LiveInterval::iterator VirtRegI; // current position in VirtReg
+    SegmentIter LiveUnionI;          // current position in LiveUnion
     SmallVector<LiveInterval*,4> InterferingVRegs;
     bool CheckedFirstInterference;
     bool SeenAllInterferences;
@@ -188,7 +153,7 @@ public:
     }
 
     // Does this live virtual register interfere with the union?
-    bool checkInterference() { return isInterference(firstInterference()); }
+    bool checkInterference() { return collectInterferingVRegs(1); }
 
     // Count the virtual registers in this union that interfere with this
     // query's live virtual register, up to maxInterferingRegs.
@@ -215,19 +180,27 @@ public:
   private:
     Query(const Query&);          // DO NOT IMPLEMENT
     void operator=(const Query&); // DO NOT IMPLEMENT
+  };
 
-    // Private interface for queries
-    const InterferenceResult &firstInterference();
-    bool nextInterference(InterferenceResult &IR) const;
-    void findIntersection(InterferenceResult &IR) const;
+  // Array of LiveIntervalUnions.
+  class Array {
+    unsigned Size;
+    LiveIntervalUnion *LIUs;
+  public:
+    Array() : Size(0), LIUs(0) {}
+    ~Array() { clear(); }
 
-    bool isInterference(const InterferenceResult &IR) const {
-      if (IR.VirtRegI != VirtReg->end()) {
-        assert(overlap(*IR.VirtRegI, IR.LiveUnionI) &&
-               "invalid segment iterators");
-        return true;
-      }
-      return false;
+    // Initialize the array to have Size entries.
+    // Reuse an existing allocation if the size matches.
+    void init(LiveIntervalUnion::Allocator&, unsigned Size);
+
+    unsigned size() const { return Size; }
+
+    void clear();
+
+    LiveIntervalUnion& operator[](unsigned idx) {
+      assert(idx <  Size && "idx out of bounds");
+      return LIUs[idx];
     }
   };
 };