IR: Give 'DI' prefix to debug info metadata
[oota-llvm.git] / include / llvm / CodeGen / RegAllocPBQP.h
index 9a5bd9fdbe1b56d567d30a977a7e930e0f9fe86e..6046e46547b207a71db1462436609b9276c33355 100644 (file)
 #define LLVM_CODEGEN_REGALLOCPBQP_H
 
 #include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/PBQPRAConstraint.h"
 #include "llvm/CodeGen/PBQP/CostAllocator.h"
 #include "llvm/CodeGen/PBQP/ReductionRules.h"
+#include "llvm/CodeGen/PBQPRAConstraint.h"
 #include "llvm/Support/ErrorHandling.h"
 
 namespace llvm {
+
+class raw_ostream;
+
 namespace PBQP {
 namespace RegAlloc {
 
@@ -137,7 +140,7 @@ private:
   typedef ValuePool<AllowedRegVector> AllowedRegVecPool;
 public:
 
-  typedef typename AllowedRegVecPool::PoolRef AllowedRegVecRef;
+  typedef AllowedRegVecPool::PoolRef AllowedRegVecRef;
 
   GraphMetadata(MachineFunction &MF,
                 LiveIntervals &LIS,
@@ -177,23 +180,38 @@ class NodeMetadata {
 public:
   typedef RegAlloc::AllowedRegVector AllowedRegVector;
 
-  typedef enum { Unprocessed,
-                 OptimallyReducible,
-                 ConservativelyAllocatable,
-                 NotProvablyAllocatable } ReductionState;
+  // The node's reduction state. The order in this enum is important,
+  // as it is assumed nodes can only progress up (i.e. towards being
+  // optimally reducible) when reducing the graph.
+  typedef enum {
+    Unprocessed,
+    NotProvablyAllocatable,
+    ConservativelyAllocatable,
+    OptimallyReducible
+  } ReductionState;
 
   NodeMetadata()
     : RS(Unprocessed), NumOpts(0), DeniedOpts(0), OptUnsafeEdges(nullptr),
-      VReg(0) {}
+      VReg(0)
+#ifndef NDEBUG
+      , everConservativelyAllocatable(false)
+#endif
+      {}
 
   // FIXME: Re-implementing default behavior to work around MSVC. Remove once
   // MSVC synthesizes move constructors properly.
   NodeMetadata(const NodeMetadata &Other)
     : RS(Other.RS), NumOpts(Other.NumOpts), DeniedOpts(Other.DeniedOpts),
       OptUnsafeEdges(new unsigned[NumOpts]), VReg(Other.VReg),
-      AllowedRegs(Other.AllowedRegs) {
-    std::copy(&Other.OptUnsafeEdges[0], &Other.OptUnsafeEdges[NumOpts],
-              &OptUnsafeEdges[0]);
+      AllowedRegs(Other.AllowedRegs)
+#ifndef NDEBUG
+      , everConservativelyAllocatable(Other.everConservativelyAllocatable)
+#endif
+  {
+    if (NumOpts > 0) {
+      std::copy(&Other.OptUnsafeEdges[0], &Other.OptUnsafeEdges[NumOpts],
+                &OptUnsafeEdges[0]);
+    }
   }
 
   // FIXME: Re-implementing default behavior to work around MSVC. Remove once
@@ -201,7 +219,11 @@ public:
   NodeMetadata(NodeMetadata &&Other)
     : RS(Other.RS), NumOpts(Other.NumOpts), DeniedOpts(Other.DeniedOpts),
       OptUnsafeEdges(std::move(Other.OptUnsafeEdges)), VReg(Other.VReg),
-      AllowedRegs(std::move(Other.AllowedRegs)) {}
+      AllowedRegs(std::move(Other.AllowedRegs))
+#ifndef NDEBUG
+      , everConservativelyAllocatable(Other.everConservativelyAllocatable)
+#endif
+  {}
 
   // FIXME: Re-implementing default behavior to work around MSVC. Remove once
   // MSVC synthesizes move constructors properly.
@@ -214,6 +236,9 @@ public:
               OptUnsafeEdges.get());
     VReg = Other.VReg;
     AllowedRegs = Other.AllowedRegs;
+#ifndef NDEBUG
+    everConservativelyAllocatable = Other.everConservativelyAllocatable;
+#endif
     return *this;
   }
 
@@ -226,6 +251,9 @@ public:
     OptUnsafeEdges = std::move(Other.OptUnsafeEdges);
     VReg = Other.VReg;
     AllowedRegs = std::move(Other.AllowedRegs);
+#ifndef NDEBUG
+    everConservativelyAllocatable = Other.everConservativelyAllocatable;
+#endif
     return *this;
   }
 
@@ -243,10 +271,21 @@ public:
   }
 
   ReductionState getReductionState() const { return RS; }
-  void setReductionState(ReductionState RS) { this->RS = RS; }
+  void setReductionState(ReductionState RS) {
+    assert(RS >= this->RS && "A node's reduction state can not be downgraded");
+    this->RS = RS;
+
+#ifndef NDEBUG
+    // Remember this state to assert later that a non-infinite register
+    // option was available.
+    if (RS == ConservativelyAllocatable)
+      everConservativelyAllocatable = true;
+#endif
+  }
+
 
   void handleAddEdge(const MatrixMetadata& MD, bool Transpose) {
-    DeniedOpts += Transpose ? MD.getWorstCol() : MD.getWorstRow();
+    DeniedOpts += Transpose ? MD.getWorstRow() : MD.getWorstCol();
     const bool* UnsafeOpts =
       Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
     for (unsigned i = 0; i < NumOpts; ++i)
@@ -254,7 +293,7 @@ public:
   }
 
   void handleRemoveEdge(const MatrixMetadata& MD, bool Transpose) {
-    DeniedOpts -= Transpose ? MD.getWorstCol() : MD.getWorstRow();
+    DeniedOpts -= Transpose ? MD.getWorstRow() : MD.getWorstCol();
     const bool* UnsafeOpts =
       Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
     for (unsigned i = 0; i < NumOpts; ++i)
@@ -267,6 +306,12 @@ public:
        &OptUnsafeEdges[NumOpts]);
   }
 
+#ifndef NDEBUG
+  bool wasConservativelyAllocatable() const {
+    return everConservativelyAllocatable;
+  }
+#endif
+
 private:
   ReductionState RS;
   unsigned NumOpts;
@@ -274,6 +319,10 @@ private:
   std::unique_ptr<unsigned[]> OptUnsafeEdges;
   unsigned VReg;
   GraphMetadata::AllowedRegVecRef AllowedRegs;
+
+#ifndef NDEBUG
+  bool everConservativelyAllocatable;
+#endif
 };
 
 class RegAllocSolverImpl {
@@ -307,6 +356,8 @@ public:
   }
 
   void handleAddNode(NodeId NId) {
+    assert(G.getNodeCosts(NId).getLength() > 1 &&
+           "PBQP Graph should not contain single or zero-option nodes");
     G.getNodeMetadata(NId).setup(G.getNodeCosts(NId));
   }
   void handleRemoveNode(NodeId NId) {}
@@ -326,15 +377,7 @@ public:
     NodeMetadata& NMd = G.getNodeMetadata(NId);
     const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
     NMd.handleRemoveEdge(MMd, NId == G.getEdgeNode2Id(EId));
-    if (G.getNodeDegree(NId) == 3) {
-      // This node is becoming optimally reducible.
-      moveToOptimallyReducibleNodes(NId);
-    } else if (NMd.getReductionState() ==
-               NodeMetadata::NotProvablyAllocatable &&
-               NMd.isConservativelyAllocatable()) {
-      // This node just became conservatively allocatable.
-      moveToConservativelyAllocatableNodes(NId);
-    }
+    promote(NId, NMd);
   }
 
   void handleReconnectEdge(EdgeId EId, NodeId NId) {
@@ -343,20 +386,44 @@ public:
     NMd.handleAddEdge(MMd, NId == G.getEdgeNode2Id(EId));
   }
 
-  void handleSetEdgeCosts(EdgeId EId, const Matrix& NewCosts) {
-    handleRemoveEdge(EId);
-
+  void handleUpdateCosts(EdgeId EId, const Matrix& NewCosts) {
     NodeId N1Id = G.getEdgeNode1Id(EId);
     NodeId N2Id = G.getEdgeNode2Id(EId);
     NodeMetadata& N1Md = G.getNodeMetadata(N1Id);
     NodeMetadata& N2Md = G.getNodeMetadata(N2Id);
+    bool Transpose = N1Id != G.getEdgeNode1Id(EId);
+
+    // Metadata are computed incrementally. First, update them
+    // by removing the old cost.
+    const MatrixMetadata& OldMMd = G.getEdgeCosts(EId).getMetadata();
+    N1Md.handleRemoveEdge(OldMMd, Transpose);
+    N2Md.handleRemoveEdge(OldMMd, !Transpose);
+
+    // And update now the metadata with the new cost.
     const MatrixMetadata& MMd = NewCosts.getMetadata();
-    N1Md.handleAddEdge(MMd, N1Id != G.getEdgeNode1Id(EId));
-    N2Md.handleAddEdge(MMd, N2Id != G.getEdgeNode1Id(EId));
+    N1Md.handleAddEdge(MMd, Transpose);
+    N2Md.handleAddEdge(MMd, !Transpose);
+
+    // As the metadata may have changed with the update, the nodes may have
+    // become ConservativelyAllocatable or OptimallyReducible.
+    promote(N1Id, N1Md);
+    promote(N2Id, N2Md);
   }
 
 private:
 
+  void promote(NodeId NId, NodeMetadata& NMd) {
+    if (G.getNodeDegree(NId) == 3) {
+      // This node is becoming optimally reducible.
+      moveToOptimallyReducibleNodes(NId);
+    } else if (NMd.getReductionState() ==
+               NodeMetadata::NotProvablyAllocatable &&
+               NMd.isConservativelyAllocatable()) {
+      // This node just became conservatively allocatable.
+      moveToConservativelyAllocatableNodes(NId);
+    }
+  }
+
   void removeFromCurrentSet(NodeId NId) {
     switch (G.getNodeMetadata(NId).getReductionState()) {
     case NodeMetadata::Unprocessed: break;
@@ -477,8 +544,10 @@ private:
   public:
     SpillCostComparator(const Graph& G) : G(G) {}
     bool operator()(NodeId N1Id, NodeId N2Id) {
-      PBQPNum N1SC = G.getNodeCosts(N1Id)[0] / G.getNodeDegree(N1Id);
-      PBQPNum N2SC = G.getNodeCosts(N2Id)[0] / G.getNodeDegree(N2Id);
+      PBQPNum N1SC = G.getNodeCosts(N1Id)[0];
+      PBQPNum N2SC = G.getNodeCosts(N2Id)[0];
+      if (N1SC == N2SC)
+        return G.getNodeDegree(N1Id) < G.getNodeDegree(N2Id);
       return N1SC < N2SC;
     }
   private:
@@ -497,6 +566,17 @@ private:
   typedef PBQP::Graph<RegAllocSolverImpl> BaseT;
 public:
   PBQPRAGraph(GraphMetadata Metadata) : BaseT(Metadata) {}
+
+  /// @brief Dump this graph to dbgs().
+  void dump() const;
+
+  /// @brief Dump this graph to an output stream.
+  /// @param OS Output stream to print on.
+  void dump(raw_ostream &OS) const;
+
+  /// @brief Print a representation of this graph in DOT format.
+  /// @param OS Output stream to print on.
+  void printDot(raw_ostream &OS) const;
 };
 
 inline Solution solve(PBQPRAGraph& G) {