Refactor away tSpill and tRestore pseudos in ARM backend.

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

diff --git a/lib/CodeGen/RegAllocBase.h b/lib/CodeGen/RegAllocBase.h
index 65bec06c712ab54645c7f332b8859eaa2d23609d..031642117efcc69f43e561061ed67b4dccc9b17d 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.
 //
 //===----------------------------------------------------------------------===//
 
@@ -39,7 +39,7 @@
 
 #include "llvm/ADT/OwningPtr.h"
 #include "LiveIntervalUnion.h"
-#include <queue>
+#include "RegisterClassInfo.h"
 
 namespace llvm {
 
@@ -58,10 +58,15 @@ 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 {
@@ -84,30 +89,36 @@ protected:
   };
 
   const TargetRegisterInfo *TRI;
+  MachineRegisterInfo *MRI;
   VirtRegMap *VRM;
   LiveIntervals *LIS;
+  RegisterClassInfo RegClassInfo;
   LiveUnionArray PhysReg2LiveUnion;
 
   // Current queries, one per physreg. They must be reinitialized each time we
   // 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];
   }
 
+  // Invalidate all cached information about virtual registers - live ranges may
+  // have changed.
+  void invalidateVirtRegs() { ++UserTag; }
+
   // The top-level driver. The output is a VirtRegMap that us updated with
   // physical register assignments.
   //
@@ -119,9 +130,11 @@ protected:
   // Get a temporary reference to a Spiller instance.
   virtual Spiller &spiller() = 0;
 
-  // getPriority - Calculate the allocation priority for VirtReg.
-  // Virtual registers with higher priorities are allocated first.
-  virtual float getPriority(LiveInterval *LI) = 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
@@ -138,6 +151,15 @@ 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.
@@ -152,8 +174,15 @@ protected:
   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(std::priority_queue<std::pair<float, unsigned> >&);
+  void seedLiveRegs();
 
   void spillReg(LiveInterval &VirtReg, unsigned PhysReg,
                 SmallVectorImpl<LiveInterval*> &SplitVRegs);