Move DependenceGraph.* to lib/Analysis/DataStructure

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14452 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 255 insertions, 0 deletions

diff --git a/lib/Analysis/DataStructure/DependenceGraph.h b/lib/Analysis/DataStructure/DependenceGraph.h
new file mode 100644
index 0000000000..679ecd7d13
--- /dev/null
+++ b/lib/Analysis/DataStructure/DependenceGraph.h
@@ -0,0 +1,255 @@
+//===- DependenceGraph.h - Dependence graph for a function ------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file provides an explicit representation for the dependence graph
+// of a function, with one node per instruction and one edge per dependence.
+// Dependences include both data and control dependences.
+// 
+// Each dep. graph node (class DepGraphNode) keeps lists of incoming and
+// outgoing dependence edges.
+// 
+// Each dep. graph edge (class Dependence) keeps a pointer to one end-point
+// of the dependence.  This saves space and is important because dep. graphs
+// can grow quickly.  It works just fine because the standard idiom is to
+// start with a known node and enumerate the dependences to or from that node.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DEPENDENCEGRAPH_H
+#define LLVM_ANALYSIS_DEPENDENCEGRAPH_H
+
+#include "Support/hash_map"
+#include <cassert>
+#include <iosfwd>
+#include <utility>
+#include <vector>
+
+namespace llvm {
+
+class Instruction;
+class Function;
+class Dependence;
+class DepGraphNode;
+class DependenceGraph;
+
+//----------------------------------------------------------------------------
+/// enum DependenceType - The standard data dependence types
+///
+enum DependenceType {
+  NoDependence       = 0x0,
+  TrueDependence     = 0x1,
+  AntiDependence     = 0x2,
+  OutputDependence   = 0x4,
+  ControlDependence  = 0x8,         // from a terminator to some other instr.
+  IncomingFlag       = 0x10         // is this an incoming or outgoing dep?
+};
+
+//----------------------------------------------------------------------------
+/// Dependence Class - A representation of a simple (non-loop-related)
+/// dependence.
+///
+class Dependence {
+  DepGraphNode*   toOrFromNode;
+  unsigned char  depType;
+
+public:
+  Dependence(DepGraphNode* toOrFromN, DependenceType type, bool isIncoming)
+    : toOrFromNode(toOrFromN),
+      depType(type | (isIncoming? IncomingFlag : 0x0)) { }
+
+  Dependence(const Dependence& D) : toOrFromNode(D.toOrFromNode),
+      depType(D.depType) { }
+
+  bool operator==(const Dependence& D) const {
+    return toOrFromNode == D.toOrFromNode && depType == D.depType;
+  }
+
+  /// Get information about the type of dependence.
+  /// 
+  unsigned getDepType() const {
+    return depType;
+  }
+
+  /// Get source or sink depending on what type of node this is!
+  /// 
+  DepGraphNode* getSrc() {
+    assert(depType & IncomingFlag); return toOrFromNode;
+  }
+  const DepGraphNode* getSrc() const {
+    assert(depType & IncomingFlag); return toOrFromNode;
+  }
+
+  DepGraphNode* getSink() {
+    assert(! (depType & IncomingFlag)); return toOrFromNode;
+  }
+  const DepGraphNode* getSink() const {
+    assert(! (depType & IncomingFlag)); return toOrFromNode;
+  }
+
+  /// Debugging support methods
+  /// 
+  void print(std::ostream &O) const;
+
+  // Default constructor: Do not use directly except for graph builder code
+  // 
+  Dependence() : toOrFromNode(NULL), depType(NoDependence) { }
+};
+
+#ifdef SUPPORTING_LOOP_DEPENDENCES
+struct LoopDependence: public Dependence {
+  DependenceDirection dir;
+  int                 distance;
+  short               level;
+  LoopInfo*           enclosingLoop;
+};
+#endif
+
+
+//----------------------------------------------------------------------------
+/// DepGraphNode Class - A representation of a single node in a dependence
+/// graph, corresponding to a single instruction.
+///
+class DepGraphNode {
+  Instruction*  instr;
+  std::vector<Dependence>  inDeps;
+  std::vector<Dependence>  outDeps;
+  friend class DependenceGraph;
+  
+  typedef std::vector<Dependence>::      iterator       iterator;
+  typedef std::vector<Dependence>::const_iterator const_iterator;
+
+        iterator inDepBegin()        { return inDeps.begin(); }
+  const_iterator inDepBegin()  const { return inDeps.begin(); }
+        iterator inDepEnd()          { return inDeps.end();   }
+  const_iterator inDepEnd()    const { return inDeps.end();   }
+  
+        iterator outDepBegin()       { return outDeps.begin(); }
+  const_iterator outDepBegin() const { return outDeps.begin(); }
+        iterator outDepEnd()         { return outDeps.end();   }
+  const_iterator outDepEnd()   const { return outDeps.end();   }
+
+public:
+  DepGraphNode(Instruction& I) : instr(&I) { }
+
+        Instruction& getInstr()       { return *instr; }
+  const Instruction& getInstr() const { return *instr; }
+
+  /// Debugging support methods
+  /// 
+  void print(std::ostream &O) const;
+};
+
+
+//----------------------------------------------------------------------------
+/// DependenceGraph Class - A representation of a dependence graph for a
+/// procedure. The primary query operation here is to look up a DepGraphNode for
+/// a particular instruction, and then use the in/out dependence iterators
+/// for the node.
+///
+class DependenceGraph {
+  DependenceGraph(const DependenceGraph&); // DO NOT IMPLEMENT
+  void operator=(const DependenceGraph&);  // DO NOT IMPLEMENT
+
+  typedef hash_map<Instruction*, DepGraphNode*> DepNodeMapType;
+  typedef DepNodeMapType::      iterator       map_iterator;
+  typedef DepNodeMapType::const_iterator const_map_iterator;
+
+  DepNodeMapType depNodeMap;
+
+  inline DepGraphNode* getNodeInternal(Instruction& inst,
+                                       bool createIfMissing = false) {
+    map_iterator I = depNodeMap.find(&inst);
+    if (I == depNodeMap.end())
+      return (!createIfMissing)? NULL :
+        depNodeMap.insert(
+            std::make_pair(&inst, new DepGraphNode(inst))).first->second;
+    else
+      return I->second;
+  }
+
+public:
+  typedef std::vector<Dependence>::      iterator       iterator;
+  typedef std::vector<Dependence>::const_iterator const_iterator;
+
+public:
+  DependenceGraph() { }
+  ~DependenceGraph();
+
+  /// Get the graph node for an instruction.  There will be one if and
+  /// only if there are any dependences incident on this instruction.
+  /// If there is none, these methods will return NULL.
+  /// 
+  DepGraphNode* getNode(Instruction& inst, bool createIfMissing = false) {
+    return getNodeInternal(inst, createIfMissing);
+  }
+  const DepGraphNode* getNode(const Instruction& inst) const {
+    return const_cast<DependenceGraph*>(this)
+      ->getNodeInternal(const_cast<Instruction&>(inst));
+  }
+
+  iterator inDepBegin(DepGraphNode& T) {
+    return T.inDeps.begin();
+  }
+  const_iterator inDepBegin (const DepGraphNode& T) const {
+    return T.inDeps.begin();
+  }
+
+  iterator inDepEnd(DepGraphNode& T) {
+    return T.inDeps.end();
+  }
+  const_iterator inDepEnd(const DepGraphNode& T) const {
+    return T.inDeps.end();
+  }
+
+  iterator outDepBegin(DepGraphNode& F) {
+    return F.outDeps.begin();
+  }
+  const_iterator outDepBegin(const DepGraphNode& F) const {
+    return F.outDeps.begin();
+  }
+
+  iterator outDepEnd(DepGraphNode& F) {
+    return F.outDeps.end();
+  }
+  const_iterator outDepEnd(const DepGraphNode& F) const {
+    return F.outDeps.end();
+  }
+
+  /// Debugging support methods
+  /// 
+  void print(const Function& func, std::ostream &O) const;
+
+public:
+  /// AddSimpleDependence - adding and modifying the dependence graph.
+  /// These should to be used only by dependence analysis implementations.
+  ///
+  void AddSimpleDependence(Instruction& fromI, Instruction& toI,
+                           DependenceType depType) {
+    DepGraphNode* fromNode = getNodeInternal(fromI, /*create*/ true);
+    DepGraphNode* toNode   = getNodeInternal(toI,   /*create*/ true);
+    fromNode->outDeps.push_back(Dependence(toNode, depType, false));
+    toNode->  inDeps. push_back(Dependence(fromNode, depType, true));
+  }
+
+#ifdef SUPPORTING_LOOP_DEPENDENCES
+  // This interface is a placeholder to show what information is needed.
+  // It will probably change when it starts being used.
+  void AddLoopDependence(Instruction&  fromI,
+                         Instruction&  toI,
+                         DependenceType      depType,
+                         DependenceDirection dir,
+                         int                 distance,
+                         short               level,
+                         LoopInfo*           enclosingLoop);
+#endif // SUPPORTING_LOOP_DEPENDENCES
+};
+
+} // End llvm namespace
+
+#endif