src/gallium/drivers/nv50/codegen/nv50_ir_graph.h

   1 /*
   2  * Copyright 2011 Christoph Bumiller
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  18  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
  19  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #ifndef __NV50_IR_GRAPH_H__
  24 #define __NV50_IR_GRAPH_H__
  25
  26 #include "nv50_ir_util.h"
  27
  28 namespace nv50_ir {
  29
  30 #define ITER_NODE(x) reinterpret_cast<Graph::Node *>((x).get())
  31 #define ITER_EDGE(x) reinterpret_cast<Graph::Edge *>((x).get())
  32
  33 // A connected graph.
  34 class Graph
  35 {
  36 public:
  37    class Node;
  38
  39    class GraphIterator : public Iterator
  40    {
  41    public:
  42       virtual ~GraphIterator() { };
  43    };
  44
  45    class Edge
  46    {
  47    public:
  48       enum Type
  49       {
  50          UNKNOWN,
  51          TREE,
  52          FORWARD,
  53          BACK,
  54          CROSS, // e.g. loop break
  55          DUMMY
  56       };
  57
  58       Edge(Node *dst, Node *src, Type kind);
  59       ~Edge() { unlink(); }
  60
  61       inline Node *getOrigin() const { return origin; }
  62       inline Node *getTarget() const { return target; }
  63
  64       inline Type getType() const { return type; }
  65       const char *typeStr() const;
  66
  67    private:
  68       Node *origin;
  69       Node *target;
  70
  71       Type type;
  72       Edge *next[2]; // next edge outgoing/incident from/to origin/target
  73       Edge *prev[2];
  74
  75       void unlink();
  76
  77       friend class Graph;
  78    };
  79
  80    class EdgeIterator : public Iterator
  81    {
  82    public:
  83       EdgeIterator() : e(0), t(0), d(0), rev(false) { }
  84       EdgeIterator(Graph::Edge *first, int dir, bool reverse)
  85          : d(dir), rev(reverse)
  86       {
  87          t = e = ((rev && first) ? first->prev[d] : first);
  88       }
  89
  90       virtual void next()
  91       {
  92          Graph::Edge *n = (rev ? e->prev[d] : e->next[d]);
  93          e = (n == t ? NULL : n);
  94       }
  95       virtual bool end() const { return !e; }
  96       virtual void *get() const { return e; }
  97
  98       inline Node *getNode() const { assert(e); return d ?
  99                                                    e->origin : e->target; }
 100       inline Edge *getEdge() const { return e; }
 101       inline Edge::Type getType() { return e ? e->getType() : Edge::UNKNOWN; }
 102
 103    private:
 104       Graph::Edge *e;
 105       Graph::Edge *t;
 106       int d;
 107       bool rev;
 108    };
 109
 110    class Node
 111    {
 112    public:
 113       Node(void *);
 114       ~Node() { cut(); }
 115
 116       void attach(Node *, Edge::Type);
 117       bool detach(Node *);
 118       void cut();
 119
 120       inline EdgeIterator outgoing(bool reverse = false) const;
 121       inline EdgeIterator incident(bool reverse = false) const;
 122
 123       inline Node *parent() const; // returns NULL if count(incident edges) != 1
 124
 125       bool reachableBy(Node *node, Node *term);
 126
 127       inline bool visit(int);
 128       inline int  getSequence() const;
 129
 130       inline int incidentCountFwd() const; // count of incident non-back edges
 131       inline int incidentCount() const { return inCount; }
 132       inline int outgoingCount() const { return outCount; }
 133
 134       Graph *getGraph() const { return graph; }
 135
 136       void *data;
 137
 138    private:
 139       Edge *in;
 140       Edge *out;
 141       Graph *graph;
 142
 143       int visited;
 144
 145       int16_t inCount;
 146       int16_t outCount;
 147    public:
 148       int tag; // for temporary use
 149
 150       friend class Graph;
 151    };
 152
 153 public:
 154    Graph();
 155    ~Graph(); // does *not* free the nodes (make it an option ?)
 156
 157    inline Node *getRoot() const { return root; }
 158
 159    inline unsigned int getSize() const { return size; }
 160
 161    inline int nextSequence();
 162
 163    void insert(Node *node); // attach to or set as root
 164
 165    GraphIterator *iteratorDFS(bool preorder = true);
 166    GraphIterator *iteratorCFG();
 167
 168    // safe iterators are unaffected by changes to the *edges* of the graph
 169    GraphIterator *safeIteratorDFS(bool preorder = true);
 170    GraphIterator *safeIteratorCFG();
 171
 172    inline void putIterator(Iterator *); // should be GraphIterator *
 173
 174    void classifyEdges();
 175
 176 private:
 177    void classifyDFS(Node *, int&);
 178
 179 private:
 180    Node *root;
 181    unsigned int size;
 182    int sequence;
 183 };
 184
 185 int Graph::nextSequence()
 186 {
 187    return ++sequence;
 188 }
 189
 190 Graph::Node *Graph::Node::parent() const
 191 {
 192    if (inCount != 1)
 193       return NULL;
 194    assert(in);
 195    return in->origin;
 196 }
 197
 198 bool Graph::Node::visit(int v)
 199 {
 200    if (visited == v)
 201       return false;
 202    visited = v;
 203    return true;
 204 }
 205
 206 int Graph::Node::getSequence() const
 207 {
 208    return visited;
 209 }
 210
 211 void Graph::putIterator(Iterator *iter)
 212 {
 213    delete reinterpret_cast<GraphIterator *>(iter);
 214 }
 215
 216 Graph::EdgeIterator Graph::Node::outgoing(bool reverse) const
 217 {
 218    return EdgeIterator(out, 0, reverse);
 219 }
 220
 221 Graph::EdgeIterator Graph::Node::incident(bool reverse) const
 222 {
 223    return EdgeIterator(in, 1, reverse);
 224 }
 225
 226 int Graph::Node::incidentCountFwd() const
 227 {
 228    int n = 0;
 229    for (EdgeIterator ei = incident(); !ei.end(); ei.next())
 230       if (ei.getType() != Edge::BACK)
 231          ++n;
 232    return n;
 233 }
 234
 235 } // namespace nv50_ir
 236
 237 #endif // __NV50_IR_GRAPH_H__