[turbofan] split all functions off of LinearScanAllocator which are unrelated to LinearScan

src/compiler/register-allocator.h

Index: src/compiler/register-allocator.h
diff --git a/src/compiler/register-allocator.h b/src/compiler/register-allocator.h
index d62ffb32fca1e0ef101a0838d3e06f692e807f12..47ff02a7ae61924fa4bba696fac997f573917ea0 100644
--- a/src/compiler/register-allocator.h
+++ b/src/compiler/register-allocator.h
@@ -583,7 +583,50 @@ class LiveRangeBuilder final : public ZoneObject {
 };
 
 
-class LinearScanAllocator final : public ZoneObject {
+class RegisterAllocator : public ZoneObject {
+ public:
+  explicit RegisterAllocator(RegisterAllocationData* data);
+
+ protected:
+  RegisterAllocationData* data() const { return data_; }
+  InstructionSequence* code() const { return data()->code(); }
+  Zone* allocation_zone() const { return data()->allocation_zone(); }
+
+  LiveRange* LiveRangeFor(int index) { return data()->LiveRangeFor(index); }
+
+  // Split the given range at the given position.
+  // If range starts at or after the given position then the
+  // original range is returned.
+  // Otherwise returns the live range that starts at pos and contains
+  // all uses from the original range that follow pos. Uses at pos will
+  // still be owned by the original range after splitting.
+  LiveRange* SplitRangeAt(LiveRange* range, LifetimePosition pos);
+
+  // Split the given range in a position from the interval [start, end].
+  LiveRange* SplitBetween(LiveRange* range, LifetimePosition start,
+                          LifetimePosition end);
+
+  // Find a lifetime position in the interval [start, end] which
+  // is optimal for splitting: it is either header of the outermost
+  // loop covered by this interval or the latest possible position.
+  LifetimePosition FindOptimalSplitPos(LifetimePosition start,
+                                       LifetimePosition end);
+
+  void Spill(LiveRange* range);
+
+  // If we are trying to spill a range inside the loop try to
+  // hoist spill position out to the point just before the loop.
+  LifetimePosition FindOptimalSpillingPos(LiveRange* range,
+                                          LifetimePosition pos);
+
+ private:
+  RegisterAllocationData* const data_;
+
+  DISALLOW_COPY_AND_ASSIGN(RegisterAllocator);
+};
+
+
+class LinearScanAllocator final : public RegisterAllocator {
  public:
   LinearScanAllocator(RegisterAllocationData* data, RegisterKind kind,
                       Zone* local_zone);
@@ -592,9 +635,6 @@ class LinearScanAllocator final : public ZoneObject {
   void AllocateRegisters();
 
  private:
-  RegisterAllocationData* data() const { return data_; }
-  InstructionSequence* code() const { return data()->code(); }
-  Zone* allocation_zone() const { return data()->allocation_zone(); }
   int num_registers() const { return num_registers_; }
   const char* RegisterName(int allocation_index) const;
 
@@ -606,8 +646,6 @@ class LinearScanAllocator final : public ZoneObject {
     return inactive_live_ranges_;
   }
 
-  LiveRange* LiveRangeFor(int index) { return data()->LiveRangeFor(index); }
-
   // Helper methods for updating the life range lists.
   void AddToActive(LiveRange* range);
   void AddToInactive(LiveRange* range);
@@ -625,28 +663,6 @@ class LinearScanAllocator final : public ZoneObject {
   bool TryAllocateFreeReg(LiveRange* range);
   void AllocateBlockedReg(LiveRange* range);
 
-  // Live range splitting helpers.
-
-  // Split the given range at the given position.
-  // If range starts at or after the given position then the
-  // original range is returned.
-  // Otherwise returns the live range that starts at pos and contains
-  // all uses from the original range that follow pos. Uses at pos will
-  // still be owned by the original range after splitting.
-  LiveRange* SplitRangeAt(LiveRange* range, LifetimePosition pos);
-
-  // Split the given range in a position from the interval [start, end].
-  LiveRange* SplitBetween(LiveRange* range, LifetimePosition start,
-                          LifetimePosition end);
-
-  // Find a lifetime position in the interval [start, end] which
-  // is optimal for splitting: it is either header of the outermost
-  // loop covered by this interval or the latest possible position.
-  LifetimePosition FindOptimalSplitPos(LifetimePosition start,
-                                       LifetimePosition end);
-
-  void Spill(LiveRange* range);
-
   // Spill the given life range after position pos.
   void SpillAfter(LiveRange* range, LifetimePosition pos);
 
@@ -661,12 +677,6 @@ class LinearScanAllocator final : public ZoneObject {
 
   void SplitAndSpillIntersecting(LiveRange* range);
 
-  // If we are trying to spill a range inside the loop try to
-  // hoist spill position out to the point just before the loop.
-  LifetimePosition FindOptimalSpillingPos(LiveRange* range,
-                                          LifetimePosition pos);
-
-  RegisterAllocationData* const data_;
   const RegisterKind mode_;
   const int num_registers_;