/*
* Copyright 2011 Christoph Bumiller
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef __NV50_IR_GRAPH_H__
#define __NV50_IR_GRAPH_H__
#include "codegen/nv50_ir_util.h"
#include <vector>
namespace nv50_ir {
#define ITER_NODE(x) reinterpret_cast<Graph::Node *>((x).get())
#define ITER_EDGE(x) reinterpret_cast<Graph::Edge *>((x).get())
// A connected graph.
class Graph
{
public:
class Node;
class Edge
{
public:
enum Type
{
UNKNOWN,
TREE,
FORWARD,
BACK,
CROSS, // e.g. loop break
DUMMY
};
Edge(Node *dst, Node *src, Type kind);
~Edge() { unlink(); }
inline Node *getOrigin() const { return origin; }
inline Node *getTarget() const { return target; }
inline Type getType() const { return type; }
const char *typeStr() const;
private:
Node *origin;
Node *target;
Type type;
Edge *next[2]; // next edge outgoing/incident from/to origin/target
Edge *prev[2];
void unlink();
friend class Graph;
};
class EdgeIterator : public Iterator
{
public:
EdgeIterator() : e(0), t(0), d(0), rev(false) { }
EdgeIterator(Graph::Edge *first, int dir, bool reverse)
: d(dir), rev(reverse)
{
t = e = ((rev && first) ? first->prev[d] : first);
}
virtual void next()
{
Graph::Edge *n = (rev ? e->prev[d] : e->next[d]);
e = (n == t ? NULL : n);
}
virtual bool end() const { return !e; }
virtual void *get() const { return e; }
inline Node *getNode() const { assert(e); return d ?
e->origin : e->target; }
inline Edge *getEdge() const { return e; }
inline Edge::Type getType() { return e ? e->getType() : Edge::UNKNOWN; }
private:
Graph::Edge *e;
Graph::Edge *t;
int d;
bool rev;
};
class Node
{
public:
Node(void *);
~Node() { cut(); }
void attach(Node *, Edge::Type);
bool detach(Node *);
void cut();
inline EdgeIterator outgoing(bool reverse = false) const;
inline EdgeIterator incident(bool reverse = false) const;
inline Node *parent() const; // returns NULL if count(incident edges) != 1
bool reachableBy(const Node *node, const Node *term) const;
inline bool visit(int);
inline int getSequence() const;
inline int incidentCountFwd() const; // count of incident non-back edges
inline int incidentCount() const { return inCount; }
inline int outgoingCount() const { return outCount; }
Graph *getGraph() const { return graph; }
void *data;
private:
Edge *in;
Edge *out;
Graph *graph;
int visited;
int16_t inCount;
int16_t outCount;
public:
int tag; // for temporary use
friend class Graph;
};
public:
Graph();
~Graph(); // does *not* free the nodes (make it an option ?)
inline Node *getRoot() const { return root; }
inline unsigned int getSize() const { return size; }
inline int nextSequence();
void insert(Node *node); // attach to or set as root
IteratorRef iteratorDFS(bool preorder = true);
IteratorRef iteratorCFG();
// safe iterators are unaffected by changes to the *edges* of the graph
IteratorRef safeIteratorDFS(bool preorder = true);
IteratorRef safeIteratorCFG();
void classifyEdges();
// @weights: indexed by Node::tag
int findLightestPathWeight(Node *, Node *, const std::vector<int>& weights);
private:
void classifyDFS(Node *, int&);
private:
Node *root;
unsigned int size;
int sequence;
};
int Graph::nextSequence()
{
return ++sequence;
}
Graph::Node *Graph::Node::parent() const
{
if (inCount != 1)
return NULL;
assert(in);
return in->origin;
}
bool Graph::Node::visit(int v)
{
if (visited == v)
return false;
visited = v;
return true;
}
int Graph::Node::getSequence() const
{
return visited;
}
Graph::EdgeIterator Graph::Node::outgoing(bool reverse) const
{
return EdgeIterator(out, 0, reverse);
}
Graph::EdgeIterator Graph::Node::incident(bool reverse) const
{
return EdgeIterator(in, 1, reverse);
}
int Graph::Node::incidentCountFwd() const
{
int n = 0;
for (EdgeIterator ei = incident(); !ei.end(); ei.next())
if (ei.getType() != Edge::BACK)
++n;
return n;
}
} // namespace nv50_ir
#endif // __NV50_IR_GRAPH_H__