Always normalize spill weights, also for intervals created by spilling.

[oota-llvm.git] / include / llvm / CodeGen / LiveIntervalAnalysis.h

diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index d71f960ce6bd5d76fbe9564f66e0625a9e7cd272..294eb25fb23f8f9499e337adf19f1c6930f64d95 100644 (file)
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -60,9 +60,6 @@ namespace llvm {
     typedef DenseMap<unsigned, LiveInterval*> Reg2IntervalMap;
     Reg2IntervalMap r2iMap_;
 
-    /// phiJoinCopies - Copy instructions which are PHI joins.
-    SmallVector<MachineInstr*, 16> phiJoinCopies;
-
     /// allocatableRegs_ - A bit vector of allocatable registers.
     BitVector allocatableRegs_;
 
@@ -77,6 +74,14 @@ namespace llvm {
       return (isDef + isUse) * powf(10.0F, (float)loopDepth);
     }
 
+    // After summing the spill weights of all defs and uses, the final weight
+    // should be normalized, dividing the weight of the interval by its size.
+    // This encourages spilling of intervals that are large and have few uses,
+    // and discourages spilling of small intervals with many uses.
+    void normalizeSpillWeight(LiveInterval &li) {
+      li.weight /= getApproximateInstructionCount(li) + 25;
+    }
+
     typedef Reg2IntervalMap::iterator iterator;
     typedef Reg2IntervalMap::const_iterator const_iterator;
     const_iterator begin() const { return r2iMap_.begin(); }
@@ -115,10 +120,13 @@ namespace llvm {
       return (unsigned)(IntervalPercentage * indexes_->getFunctionSize());
     }
 
-    /// conflictsWithPhysRegDef - Returns true if the specified register
-    /// is defined during the duration of the specified interval.
-    bool conflictsWithPhysRegDef(const LiveInterval &li, VirtRegMap &vrm,
-                                 unsigned reg);
+    /// conflictsWithPhysReg - Returns true if the specified register is used or
+    /// defined during the duration of the specified interval. Copies to and
+    /// from li.reg are allowed. This method is only able to analyze simple
+    /// ranges that stay within a single basic block. Anything else is
+    /// considered a conflict.
+    bool conflictsWithPhysReg(const LiveInterval &li, VirtRegMap &vrm,
+                              unsigned reg);
 
     /// conflictsWithPhysRegRef - Similar to conflictsWithPhysRegRef except
     /// it can check use as well.
@@ -189,20 +197,12 @@ namespace llvm {
       return indexes_->getMBBFromIndex(index);
     }
 
-    bool hasGapBeforeInstr(SlotIndex index) {
-      return indexes_->hasGapBeforeInstr(index);
-    }
-
-    bool hasGapAfterInstr(SlotIndex index) {
-      return indexes_->hasGapAfterInstr(index);
+    SlotIndex getMBBTerminatorGap(const MachineBasicBlock *mbb) {
+      return indexes_->getTerminatorGap(mbb);
     }
 
-    SlotIndex findGapBeforeInstr(SlotIndex index, bool furthest = false) {
-      return indexes_->findGapBeforeInstr(index, furthest);
-    }
-
-    void InsertMachineInstrInMaps(MachineInstr *MI, SlotIndex Index) {
-      indexes_->insertMachineInstrInMaps(MI, Index);
+    SlotIndex InsertMachineInstrInMaps(MachineInstr *MI) {
+      return indexes_->insertMachineInstrInMaps(MI);
     }
 
     void RemoveMachineInstrFromMaps(MachineInstr *MI) {
@@ -219,7 +219,7 @@ namespace llvm {
     }
 
     void renumber() {
-      indexes_->renumber();
+      indexes_->renumberIndexes();
     }
 
     BumpPtrAllocator& getVNInfoAllocator() { return VNInfoAllocator; }
@@ -290,13 +290,6 @@ namespace llvm {
     /// computeIntervals - Compute live intervals.
     void computeIntervals();
 
-    bool isSafeAndProfitableToCoalesce(LiveInterval &DstInt,
-                                       LiveInterval &SrcInt,
-                 SmallVector<MachineInstr*,16> &IdentCopies,
-                 SmallVector<MachineInstr*,16> &OtherCopies);
-
-    void performEarlyCoalescing();
-
     /// handleRegisterDef - update intervals for a register def
     /// (calls handlePhysicalRegisterDef and
     /// handleVirtualRegisterDef)
@@ -424,6 +417,9 @@ namespace llvm {
         DenseMap<unsigned,unsigned> &MBBVRegsMap,
         std::vector<LiveInterval*> &NewLIs);
 
+    // Normalize the spill weight of all the intervals in NewLIs.
+    void normalizeSpillWeights(std::vector<LiveInterval*> &NewLIs);
+
     static LiveInterval* createInterval(unsigned Reg);
 
     void printInstrs(raw_ostream &O) const;