vendor/llvm/llvm-trunk-r321017

1 files changed, 36 insertions, 10 deletions

diff --git a/include/llvm/CodeGen/CalcSpillWeights.h b/include/llvm/CodeGen/CalcSpillWeights.h
index 17c9415a81cbd..d9e8206408a78 100644
--- a/include/llvm/CodeGen/CalcSpillWeights.h
+++ b/include/llvm/CodeGen/CalcSpillWeights.h
@@ -1,4 +1,4 @@
-//===---------------- lib/CodeGen/CalcSpillWeights.h ------------*- C++ -*-===//
+//===- lib/CodeGen/CalcSpillWeights.h ---------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-
 #ifndef LLVM_CODEGEN_CALCSPILLWEIGHTS_H
 #define LLVM_CODEGEN_CALCSPILLWEIGHTS_H
 
@@ -16,11 +15,12 @@
 
 namespace llvm {
 
-  class LiveInterval;
-  class LiveIntervals;
-  class MachineBlockFrequencyInfo;
-  class MachineLoopInfo;
-  class VirtRegMap;
+class LiveInterval;
+class LiveIntervals;
+class MachineBlockFrequencyInfo;
+class MachineFunction;
+class MachineLoopInfo;
+class VirtRegMap;
 
   /// \brief Normalize the spill weight of a live interval
   ///
@@ -32,7 +32,6 @@ namespace llvm {
   ///                   per function call. Derived from block frequencies.
   /// @param Size       Size of live interval as returnexd by getSize()
   /// @param NumInstr   Number of instructions using this live interval
-  ///
   static inline float normalizeSpillWeight(float UseDefFreq, unsigned Size,
                                            unsigned NumInstr) {
     // The constant 25 instructions is added to avoid depending too much on
@@ -47,7 +46,7 @@ namespace llvm {
   /// spill weight and allocation hint.
   class VirtRegAuxInfo {
   public:
-    typedef float (*NormalizingFn)(float, unsigned, unsigned);
+    using NormalizingFn = float (*)(float, unsigned, unsigned);
 
   private:
     MachineFunction &MF;
@@ -67,6 +66,32 @@ namespace llvm {
 
     /// \brief (re)compute li's spill weight and allocation hint.
     void calculateSpillWeightAndHint(LiveInterval &li);
+
+    /// \brief Compute future expected spill weight of a split artifact of li
+    /// that will span between start and end slot indexes.
+    /// \param li     The live interval to be split.
+    /// \param start  The expected begining of the split artifact. Instructions
+    ///               before start will not affect the weight.
+    /// \param end    The expected end of the split artifact. Instructions
+    ///               after end will not affect the weight.
+    /// \return The expected spill weight of the split artifact. Returns
+    /// negative weight for unspillable li.
+    float futureWeight(LiveInterval &li, SlotIndex start, SlotIndex end);
+
+    /// \brief Helper function for weight calculations.
+    /// (Re)compute li's spill weight and allocation hint, or, for non null
+    /// start and end - compute future expected spill weight of a split
+    /// artifact of li that will span between start and end slot indexes.
+    /// \param li     The live interval for which to compute the weight.
+    /// \param start  The expected begining of the split artifact. Instructions
+    ///               before start will not affect the weight. Relevant for
+    ///               weight calculation of future split artifact.
+    /// \param end    The expected end of the split artifact. Instructions
+    ///               after end will not affect the weight. Relevant for
+    ///               weight calculation of future split artifact.
+    /// \return The spill weight. Returns negative weight for unspillable li.
+    float weightCalcHelper(LiveInterval &li, SlotIndex *start = nullptr,
+                           SlotIndex *end = nullptr);
   };
 
   /// \brief Compute spill weights and allocation hints for all virtual register
@@ -77,6 +102,7 @@ namespace llvm {
                                      const MachineBlockFrequencyInfo &MBFI,
                                      VirtRegAuxInfo::NormalizingFn norm =
                                          normalizeSpillWeight);
-}
+
+} // end namespace llvm
 
 #endif // LLVM_CODEGEN_CALCSPILLWEIGHTS_H