[VPlan] Move graph traits (NFC).

[fhahn]

Summary

By defining the graph traits right after the VPBlockBase definitions, we
can make use of them earlier in the file.

[merge_guards_bot]

Build result: pass - 60325 tests passed, 0 failed and 732 were skipped.

Log files: console-log.txt, CMakeCache.txt

llvm/lib/Transforms/Vectorize/VPlan.h

public:
   /// instances of output IR corresponding to its VPBlockBases.
   bool isReplicator() const { return IsReplicator; }
 
   /// The method which generates the output IR instructions that correspond to
   /// this VPRegionBlock, thereby "executing" the VPlan.
   void execute(struct VPTransformState *State) override;
 };
 
+//===----------------------------------------------------------------------===//
+// GraphTraits specializations for VPlan Hierarchical Control-Flow Graphs     //
+//===----------------------------------------------------------------------===//
+
+// The following set of template specializations implement GraphTraits to treat
+// any VPBlockBase as a node in a graph of VPBlockBases. It's important to note
+// that VPBlockBase traits don't recurse into VPRegioBlocks, i.e., if the
+// VPBlockBase is a VPRegionBlock, this specialization provides access to its
+// successors/predecessors but not to the blocks inside the region.
+
+template <> struct GraphTraits<VPBlockBase *> {
+  using NodeRef = VPBlockBase *;
+  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::iterator;
+
+  static NodeRef getEntryNode(NodeRef N) { return N; }
+
+  static inline ChildIteratorType child_begin(NodeRef N) {
+    return N->getSuccessors().begin();
+  }
+
+  static inline ChildIteratorType child_end(NodeRef N) {
+    return N->getSuccessors().end();
+  }
+};
+
+template <> struct GraphTraits<const VPBlockBase *> {
+  using NodeRef = const VPBlockBase *;
+  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::const_iterator;
+
+  static NodeRef getEntryNode(NodeRef N) { return N; }
+
+  static inline ChildIteratorType child_begin(NodeRef N) {
+    return N->getSuccessors().begin();
+  }
+
+  static inline ChildIteratorType child_end(NodeRef N) {
+    return N->getSuccessors().end();
+  }
+};
+
+// Inverse order specialization for VPBasicBlocks. Predecessors are used instead
+// of successors for the inverse traversal.
+template <> struct GraphTraits<Inverse<VPBlockBase *>> {
+  using NodeRef = VPBlockBase *;
+  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::iterator;
+
+  static NodeRef getEntryNode(Inverse<NodeRef> B) { return B.Graph; }
+
+  static inline ChildIteratorType child_begin(NodeRef N) {
+    return N->getPredecessors().begin();
+  }
+
+  static inline ChildIteratorType child_end(NodeRef N) {
+    return N->getPredecessors().end();
+  }
+};
+
+// The following set of template specializations implement GraphTraits to
+// treat VPRegionBlock as a graph and recurse inside its nodes. It's important
+// to note that the blocks inside the VPRegionBlock are treated as VPBlockBases
+// (i.e., no dyn_cast is performed, VPBlockBases specialization is used), so
+// there won't be automatic recursion into other VPBlockBases that turn to be
+// VPRegionBlocks.
+
+template <>
+struct GraphTraits<VPRegionBlock *> : public GraphTraits<VPBlockBase *> {
+  using GraphRef = VPRegionBlock *;
+  using nodes_iterator = df_iterator<NodeRef>;
+
+  static NodeRef getEntryNode(GraphRef N) { return N->getEntry(); }
+
+  static nodes_iterator nodes_begin(GraphRef N) {
+    return nodes_iterator::begin(N->getEntry());
+  }
+
+  static nodes_iterator nodes_end(GraphRef N) {
+    // df_iterator::end() returns an empty iterator so the node used doesn't
+    // matter.
+    return nodes_iterator::end(N);
+  }
+};
+
+template <>
+struct GraphTraits<const VPRegionBlock *>
+    : public GraphTraits<const VPBlockBase *> {
+  using GraphRef = const VPRegionBlock *;
+  using nodes_iterator = df_iterator<NodeRef>;
+
+  static NodeRef getEntryNode(GraphRef N) { return N->getEntry(); }
+
+  static nodes_iterator nodes_begin(GraphRef N) {
+    return nodes_iterator::begin(N->getEntry());
+  }
+
+  static nodes_iterator nodes_end(GraphRef N) {
+    // df_iterator::end() returns an empty iterator so the node used doesn't
+    // matter.
+    return nodes_iterator::end(N);
+  }
+};
+
+template <>
+struct GraphTraits<Inverse<VPRegionBlock *>>
+    : public GraphTraits<Inverse<VPBlockBase *>> {
+  using GraphRef = VPRegionBlock *;
+  using nodes_iterator = df_iterator<NodeRef>;
+
+  static NodeRef getEntryNode(Inverse<GraphRef> N) {
+    return N.Graph->getExit();
+  }
+
+  static nodes_iterator nodes_begin(GraphRef N) {
+    return nodes_iterator::begin(N->getExit());
+  }
+
+  static nodes_iterator nodes_end(GraphRef N) {
+    // df_iterator::end() returns an empty iterator so the node used doesn't
+    // matter.
+    return nodes_iterator::end(N);
+  }
+};
+
 /// VPlan models a candidate for vectorization, encoding various decisions take
 /// to produce efficient output IR, including which branches, basic-blocks and
 /// output IR instructions to generate, and their cost. VPlan holds a
 /// Hierarchical-CFG of VPBasicBlocks and VPRegionBlocks rooted at an Entry
 /// VPBlock.
 class VPlan {
   friend class VPlanPrinter;
 

 }
 
 inline raw_ostream &operator<<(raw_ostream &OS, VPlan &Plan) {
   VPlanPrinter Printer(OS, Plan);
   Printer.dump();
   return OS;
 }
 
-//===----------------------------------------------------------------------===//
-// GraphTraits specializations for VPlan Hierarchical Control-Flow Graphs     //
-//===----------------------------------------------------------------------===//
-
-// The following set of template specializations implement GraphTraits to treat
-// any VPBlockBase as a node in a graph of VPBlockBases. It's important to note
-// that VPBlockBase traits don't recurse into VPRegioBlocks, i.e., if the
-// VPBlockBase is a VPRegionBlock, this specialization provides access to its
-// successors/predecessors but not to the blocks inside the region.
-
-template <> struct GraphTraits<VPBlockBase *> {
-  using NodeRef = VPBlockBase *;
-  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::iterator;
-
-  static NodeRef getEntryNode(NodeRef N) { return N; }
-
-  static inline ChildIteratorType child_begin(NodeRef N) {
-    return N->getSuccessors().begin();
-  }
-
-  static inline ChildIteratorType child_end(NodeRef N) {
-    return N->getSuccessors().end();
-  }
-};
-
-template <> struct GraphTraits<const VPBlockBase *> {
-  using NodeRef = const VPBlockBase *;
-  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::const_iterator;
-
-  static NodeRef getEntryNode(NodeRef N) { return N; }
-
-  static inline ChildIteratorType child_begin(NodeRef N) {
-    return N->getSuccessors().begin();
-  }
-
-  static inline ChildIteratorType child_end(NodeRef N) {
-    return N->getSuccessors().end();
-  }
-};
-
-// Inverse order specialization for VPBasicBlocks. Predecessors are used instead
-// of successors for the inverse traversal.
-template <> struct GraphTraits<Inverse<VPBlockBase *>> {
-  using NodeRef = VPBlockBase *;
-  using ChildIteratorType = SmallVectorImpl<VPBlockBase *>::iterator;
-
-  static NodeRef getEntryNode(Inverse<NodeRef> B) { return B.Graph; }
-
-  static inline ChildIteratorType child_begin(NodeRef N) {
-    return N->getPredecessors().begin();
-  }
-
-  static inline ChildIteratorType child_end(NodeRef N) {
-    return N->getPredecessors().end();
-  }
-};
-
-// The following set of template specializations implement GraphTraits to
-// treat VPRegionBlock as a graph and recurse inside its nodes. It's important
-// to note that the blocks inside the VPRegionBlock are treated as VPBlockBases
-// (i.e., no dyn_cast is performed, VPBlockBases specialization is used), so
-// there won't be automatic recursion into other VPBlockBases that turn to be
-// VPRegionBlocks.
-
-template <>
-struct GraphTraits<VPRegionBlock *> : public GraphTraits<VPBlockBase *> {
-  using GraphRef = VPRegionBlock *;
-  using nodes_iterator = df_iterator<NodeRef>;
-
-  static NodeRef getEntryNode(GraphRef N) { return N->getEntry(); }
-
-  static nodes_iterator nodes_begin(GraphRef N) {
-    return nodes_iterator::begin(N->getEntry());
-  }
-
-  static nodes_iterator nodes_end(GraphRef N) {
-    // df_iterator::end() returns an empty iterator so the node used doesn't
-    // matter.
-    return nodes_iterator::end(N);
-  }
-};
-
-template <>
-struct GraphTraits<const VPRegionBlock *>
-    : public GraphTraits<const VPBlockBase *> {
-  using GraphRef = const VPRegionBlock *;
-  using nodes_iterator = df_iterator<NodeRef>;
-
-  static NodeRef getEntryNode(GraphRef N) { return N->getEntry(); }
-
-  static nodes_iterator nodes_begin(GraphRef N) {
-    return nodes_iterator::begin(N->getEntry());
-  }
-
-  static nodes_iterator nodes_end(GraphRef N) {
-    // df_iterator::end() returns an empty iterator so the node used doesn't
-    // matter.
-    return nodes_iterator::end(N);
-  }
-};
-
-template <>
-struct GraphTraits<Inverse<VPRegionBlock *>>
-    : public GraphTraits<Inverse<VPBlockBase *>> {
-  using GraphRef = VPRegionBlock *;
-  using nodes_iterator = df_iterator<NodeRef>;
-
-  static NodeRef getEntryNode(Inverse<GraphRef> N) {
-    return N.Graph->getExit();
-  }
-
-  static nodes_iterator nodes_begin(GraphRef N) {
-    return nodes_iterator::begin(N->getExit());
-  }
-
-  static nodes_iterator nodes_end(GraphRef N) {
-    // df_iterator::end() returns an empty iterator so the node used doesn't
-    // matter.
-    return nodes_iterator::end(N);
-  }
-};
 
 //===----------------------------------------------------------------------===//
 // VPlan Utilities
 //===----------------------------------------------------------------------===//
 
 /// Class that provides utilities for VPBlockBases in VPlan.
 class VPBlockUtils {
 public: