Add SplitKit API to query and select the current interval being worked on.

[oota-llvm.git] / lib / CodeGen / RegAllocBase.h

diff --git a/lib/CodeGen/RegAllocBase.h b/lib/CodeGen/RegAllocBase.h
index 8044a192385cadbce826ce852c3a1c58b04f06e3..f431d5a5a026aeec0ec478b0fbb5c3e7ed6578ac 100644 (file)
--- a/lib/CodeGen/RegAllocBase.h
+++ b/lib/CodeGen/RegAllocBase.h
@@ -30,7 +30,7 @@
 // of registers, if a more sophisticated allocator chooses to do that.
 //
 // This framework provides a way to engineer the compile time vs. code
-// quality trade-off without relying a particular theoretical solver.
+// quality trade-off without relying on a particular theoretical solver.
 //
 //===----------------------------------------------------------------------===//
 
@@ -38,6 +38,7 @@
 #define LLVM_CODEGEN_REGALLOCBASE
 
 #include "llvm/ADT/OwningPtr.h"
+#include "LiveIntervalUnion.h"
 
 namespace llvm {
 
@@ -47,16 +48,6 @@ class VirtRegMap;
 class LiveIntervals;
 class Spiller;
 
-// Heuristic that determines the priority of assigning virtual to physical
-// registers. The main impact of the heuristic is expected to be compile time.
-// The default is to simply compare spill weights.
-struct LessSpillWeightPriority
-  : public std::binary_function<LiveInterval,LiveInterval, bool> {
-  bool operator()(const LiveInterval *Left, const LiveInterval *Right) const {
-    return Left->weight < Right->weight;
-  }
-};
-
 // Forward declare a priority queue of live virtual registers. If an
 // implementation needs to prioritize by anything other than spill weight, then
 // this will become an abstract base class with virtual calls to push/get.
@@ -66,20 +57,27 @@ class LiveVirtRegQueue;
 /// be extended to add interesting heuristics.
 ///
 /// Register allocators must override the selectOrSplit() method to implement
-/// live range splitting. LessSpillWeightPriority is provided as a standard
-/// comparator, but we may add an interface to override it if necessary.
+/// live range splitting. They must also override enqueue/dequeue to provide an
+/// assignment order.
 class RegAllocBase {
+  LiveIntervalUnion::Allocator UnionAllocator;
+
+  // Cache tag for PhysReg2LiveUnion entries. Increment whenever virtual
+  // registers may have changed.
+  unsigned UserTag;
+
 protected:
   // Array of LiveIntervalUnions indexed by physical register.
   class LiveUnionArray {
     unsigned NumRegs;
-    OwningArrayPtr<LiveIntervalUnion> Array;
+    LiveIntervalUnion *Array;
   public:
-    LiveUnionArray(): NumRegs(0) {}
+    LiveUnionArray(): NumRegs(0), Array(0) {}
+    ~LiveUnionArray() { clear(); }
 
     unsigned numRegs() const { return NumRegs; }
 
-    void init(unsigned NRegs);
+    void init(LiveIntervalUnion::Allocator &, unsigned NRegs);
 
     void clear();
 
@@ -90,6 +88,7 @@ protected:
   };
 
   const TargetRegisterInfo *TRI;
+  MachineRegisterInfo *MRI;
   VirtRegMap *VRM;
   LiveIntervals *LIS;
   LiveUnionArray PhysReg2LiveUnion;
@@ -98,19 +97,19 @@ protected:
   // query on a new live virtual register.
   OwningArrayPtr<LiveIntervalUnion::Query> Queries;
 
-  RegAllocBase(): TRI(0), VRM(0), LIS(0) {}
+  RegAllocBase(): UserTag(0), TRI(0), MRI(0), VRM(0), LIS(0) {}
 
   virtual ~RegAllocBase() {}
 
   // A RegAlloc pass should call this before allocatePhysRegs.
-  void init(const TargetRegisterInfo &tri, VirtRegMap &vrm, LiveIntervals &lis);
+  void init(VirtRegMap &vrm, LiveIntervals &lis);
 
   // Get an initialized query to check interferences between lvr and preg.  Note
   // that Query::init must be called at least once for each physical register
   // before querying a new live virtual register. This ties Queries and
   // PhysReg2LiveUnion together.
   LiveIntervalUnion::Query &query(LiveInterval &VirtReg, unsigned PhysReg) {
-    Queries[PhysReg].init(&VirtReg, &PhysReg2LiveUnion[PhysReg]);
+    Queries[PhysReg].init(UserTag, &VirtReg, &PhysReg2LiveUnion[PhysReg]);
     return Queries[PhysReg];
   }
 
@@ -125,6 +124,12 @@ protected:
   // Get a temporary reference to a Spiller instance.
   virtual Spiller &spiller() = 0;
 
+  /// enqueue - Add VirtReg to the priority queue of unassigned registers.
+  virtual void enqueue(LiveInterval *LI) = 0;
+
+  /// dequeue - Return the next unassigned register, or NULL.
+  virtual LiveInterval *dequeue() = 0;
+
   // A RegAlloc pass should override this to provide the allocation heuristics.
   // Each call must guarantee forward progess by returning an available PhysReg
   // or new set of split live virtual registers. It is up to the splitter to
@@ -140,19 +145,38 @@ protected:
   // exists, return the interfering register, which may be preg or an alias.
   unsigned checkPhysRegInterference(LiveInterval& VirtReg, unsigned PhysReg);
 
+  /// assign - Assign VirtReg to PhysReg.
+  /// This should not be called from selectOrSplit for the current register.
+  void assign(LiveInterval &VirtReg, unsigned PhysReg);
+
+  /// unassign - Undo a previous assignment of VirtReg to PhysReg.
+  /// This can be invoked from selectOrSplit, but be careful to guarantee that
+  /// allocation is making progress.
+  void unassign(LiveInterval &VirtReg, unsigned PhysReg);
+
   // Helper for spilling all live virtual registers currently unified under preg
   // that interfere with the most recently queried lvr.  Return true if spilling
   // was successful, and append any new spilled/split intervals to splitLVRs.
   bool spillInterferences(LiveInterval &VirtReg, unsigned PhysReg,
                           SmallVectorImpl<LiveInterval*> &SplitVRegs);
 
+  /// addMBBLiveIns - Add physreg liveins to basic blocks.
+  void addMBBLiveIns(MachineFunction *);
+
 #ifndef NDEBUG
   // Verify each LiveIntervalUnion.
   void verify();
 #endif
 
+  // Use this group name for NamedRegionTimer.
+  static const char *TimerGroupName;
+
+public:
+  /// VerifyEnabled - True when -verify-regalloc is given.
+  static bool VerifyEnabled;
+
 private:
-  void seedLiveVirtRegs(LiveVirtRegQueue &VirtRegQ);
+  void seedLiveRegs();
 
   void spillReg(LiveInterval &VirtReg, unsigned PhysReg,
                 SmallVectorImpl<LiveInterval*> &SplitVRegs);