CalcSpillWeights: allow overidding the spill weight normalizing function

This will enable the PBQP register allocator to provide its own normalizing function.

No functionnal change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194417 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Arnaud-de-Grandmaison

include/llvm/CodeGen/CalcSpillWeights.h

@@ -43,16 +43,23 @@ namespace llvm {
   /// \brief Calculate auxiliary information for a virtual register such as its
   /// spill weight and allocation hint.
   class VirtRegAuxInfo {
+  public:
+    typedef float (*NormalizingFn)(float, unsigned);
+
+  private:
     MachineFunction &MF;
     LiveIntervals &LIS;
     const MachineLoopInfo &Loops;
     const MachineBlockFrequencyInfo &MBFI;
     DenseMap<unsigned, float> Hint;
+    NormalizingFn normalize;
+
   public:
     VirtRegAuxInfo(MachineFunction &mf, LiveIntervals &lis,
                    const MachineLoopInfo &loops,
-                   const MachineBlockFrequencyInfo &mbfi)
-        : MF(mf), LIS(lis), Loops(loops), MBFI(mbfi) {}
+                   const MachineBlockFrequencyInfo &mbfi,
+                   NormalizingFn norm = normalizeSpillWeight)
+        : MF(mf), LIS(lis), Loops(loops), MBFI(mbfi), normalize(norm) {}
 
     /// \brief (re)compute li's spill weight and allocation hint.
     void calculateSpillWeightAndHint(LiveInterval &li);
@@ -62,7 +69,9 @@ namespace llvm {
   /// live intervals.
   void calculateSpillWeightsAndHints(LiveIntervals &LIS, MachineFunction &MF,
                                      const MachineLoopInfo &MLI,
-                                     const MachineBlockFrequencyInfo &MBFI);
+                                     const MachineBlockFrequencyInfo &MBFI,
+                                     VirtRegAuxInfo::NormalizingFn norm =
+                                         normalizeSpillWeight);
 }
 
 #endif // LLVM_CODEGEN_CALCSPILLWEIGHTS_H

lib/CodeGen/CalcSpillWeights.cpp

@@ -25,12 +25,13 @@ using namespace llvm;
 void llvm::calculateSpillWeightsAndHints(LiveIntervals &LIS,
                            MachineFunction &MF,
                            const MachineLoopInfo &MLI,
-                           const MachineBlockFrequencyInfo &MBFI) {
+                           const MachineBlockFrequencyInfo &MBFI,
+                           VirtRegAuxInfo::NormalizingFn norm) {
   DEBUG(dbgs() << "********** Compute Spill Weights **********\n"
                << "********** Function: " << MF.getName() << '\n');
 
   MachineRegisterInfo &MRI = MF.getRegInfo();
-  VirtRegAuxInfo VRAI(MF, LIS, MLI, MBFI);
+  VirtRegAuxInfo VRAI(MF, LIS, MLI, MBFI, norm);
   for (unsigned i = 0, e = MRI.getNumVirtRegs(); i != e; ++i) {
     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
     if (MRI.reg_nodbg_empty(Reg))
@@ -182,5 +183,5 @@ VirtRegAuxInfo::calculateSpillWeightAndHint(LiveInterval &li) {
   if (isRematerializable(li, LIS, *MF.getTarget().getInstrInfo()))
     totalWeight *= 0.5F;
 
-  li.weight = normalizeSpillWeight(totalWeight, li.getSize());
+  li.weight = normalize(totalWeight, li.getSize());
 }