Revert "CalculateSpillWeights does not need to be a pass"

Temporarily revert my previous commit until I understand why it breaks 3 target tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194272 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 11 deletions

diff --git a/include/llvm/CodeGen/CalcSpillWeights.h b/include/llvm/CodeGen/CalcSpillWeights.h
index 00d9c6a..c8ec764 100644
--- a/include/llvm/CodeGen/CalcSpillWeights.h
+++ b/include/llvm/CodeGen/CalcSpillWeights.h
@@ -21,9 +21,7 @@ namespace llvm {
   class MachineBlockFrequencyInfo;
   class MachineLoopInfo;
 
-  /// \brief Normalize the spill weight of a live interval
-  ///
-  /// The spill weight of a live interval is computed as:
+  /// normalizeSpillWeight - The spill weight of a live interval is computed as:
   ///
   ///   (sum(use freq) + sum(def freq)) / (K + size)
   ///
@@ -40,8 +38,8 @@ namespace llvm {
     return UseDefFreq / (Size + 25*SlotIndex::InstrDist);
   }
 
-  /// \brief Calculate auxiliary information for a virtual register such as its
-  /// spill weight and allocation hint.
+  /// VirtRegAuxInfo - Calculate auxiliary information for a virtual
+  /// register such as its spill weight and allocation hint.
   class VirtRegAuxInfo {
     MachineFunction &MF;
     LiveIntervals &LIS;
@@ -54,16 +52,29 @@ namespace llvm {
                    const MachineBlockFrequencyInfo &mbfi)
         : MF(mf), LIS(lis), Loops(loops), MBFI(mbfi) {}
 
-    /// \brief (re)compute li's spill weight and allocation hint.
+    /// CalculateWeightAndHint - (re)compute li's spill weight and allocation
+    /// hint.
     void CalculateWeightAndHint(LiveInterval &li);
   };
 
-  /// \brief Compute spill weights and allocation hints for all virtual register
+  /// CalculateSpillWeights - Compute spill weights for all virtual register
   /// live intervals.
-  void calculateSpillWeights(LiveIntervals &LIS,
-                             MachineFunction &MF,
-                             const MachineLoopInfo &MLI,
-                             const MachineBlockFrequencyInfo &MBFI);
+  class CalculateSpillWeights : public MachineFunctionPass {
+  public:
+    static char ID;
+
+    CalculateSpillWeights() : MachineFunctionPass(ID) {
+      initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
+    }
+
+    virtual void getAnalysisUsage(AnalysisUsage &au) const;
+
+    virtual bool runOnMachineFunction(MachineFunction &fn);
+
+  private:
+    /// Returns true if the given live interval is zero length.
+    bool isZeroLengthInterval(LiveInterval *li) const;
+  };
 
 }