3 files changed, 41 insertions, 1 deletions
diff --git a/include/llvm/CodeGen/CalcSpillWeights.h b/include/llvm/CodeGen/CalcSpillWeights.h
index e5273c5..99703a1 100644
--- a/include/llvm/CodeGen/CalcSpillWeights.h
+++ b/include/llvm/CodeGen/CalcSpillWeights.h
@@ -12,10 +12,35 @@
 #define LLVM_CODEGEN_CALCSPILLWEIGHTS_H
 
 #include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/ADT/DenseMap.h"
 
 namespace llvm {
 
   class LiveInterval;
+  class LiveIntervals;
+  class MachineLoopInfo;
+
+  /// VirtRegAuxInfo - Calculate auxiliary information for a virtual
+  /// register such as its spill weight and allocation hint.
+  class VirtRegAuxInfo {
+    MachineFunction &mf_;
+    LiveIntervals &lis_;
+    MachineLoopInfo &loops_;
+    DenseMap<unsigned, float> hint_;
+  public:
+    VirtRegAuxInfo(MachineFunction &mf, LiveIntervals &lis,
+                   MachineLoopInfo &loops) :
+      mf_(mf), lis_(lis), loops_(loops) {}
+
+    /// CalculateRegClass - recompute the register class for li from its uses.
+    /// Since the register class can affect the allocation hint, this function
+    /// should be called before CalculateWeightAndHint if both are called.
+    void CalculateRegClass(LiveInterval &li);
+
+    /// CalculateWeightAndHint - (re)compute li's spill weight and allocation
+    /// hint.
+    void CalculateWeightAndHint(LiveInterval &li);
+  };
 
   /// CalculateSpillWeights - Compute spill weights for all virtual register
   /// live intervals.
@@ -27,7 +52,7 @@ namespace llvm {
 
     virtual void getAnalysisUsage(AnalysisUsage &au) const;
 
-    virtual bool runOnMachineFunction(MachineFunction &fn);    
+    virtual bool runOnMachineFunction(MachineFunction &fn);
 
   private:
     /// Returns true if the given live interval is zero length.
diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index 0c92b85..f0e068b 100644
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -520,6 +520,15 @@ namespace llvm {
     ///
     unsigned getSize() const;
 
+    /// Returns true if the live interval is zero length, i.e. no live ranges
+    /// span instructions. It doesn't pay to spill such an interval.
+    bool isZeroLength() const {
+      for (const_iterator i = begin(), e = end(); i != e; ++i)
+        if (i->end.getPrevIndex() > i->start)
+          return false;
+      return true;
+    }
+
     /// isSpillable - Can this interval be spilled?
     bool isSpillable() const {
       return weight != HUGE_VALF;
diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index b154bf1..04477ac 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -105,6 +105,12 @@ namespace llvm {
       return r2iMap_.count(reg);
     }
 
+    /// isAllocatable - is the physical register reg allocatable in the current
+    /// function?
+    bool isAllocatable(unsigned reg) const {
+      return allocatableRegs_.test(reg);
+    }
+
     /// 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.