#pragma once
|
|
#include <torch/csrc/jit/ir.h>
|
|
#include <unordered_map>
|
#include <vector>
|
|
namespace torch {
|
namespace jit {
|
|
/**
|
* \brief A structure describing a match of a pattern in a graph.
|
*
|
* The structure contains an anchor node, from which the match was found, and
|
* match-maps for nodes and values. A match-map specifies correspondance between
|
* nodes in the pattern graph (match-map keys) with nodes in the actual graph
|
* (match-map values). We keep such maps for both nodes and values.
|
*/
|
struct Match {
|
Node* anchor;
|
std::unordered_map<const Node*, Node*> nodes_map;
|
std::unordered_map<const Value*, Value*> values_map;
|
};
|
|
/**
|
* \brief Find all matches of a \p PATTERN in a \p GRAPH.
|
*
|
* The function returns a vector of match-descriptors (see description of
|
* `struct Match`).
|
*
|
* Matching rules:
|
* - Pattern graph must contain a single block.
|
* - Matched subgraphs do not span across different blocks.
|
* - No uses outside the match are allowed, except for Param and Return nodes.
|
* Basically, we're matching hammocks, not arbitrary subgraphs.
|
* - Pattern graph must return only one value (i.e. it must have a single
|
* node leading to return).
|
* - Nodes that are not used in computation of the return value in the pattern
|
* graph are ignored during matching (IOW, we're essentially performing DCE on
|
* the pattern).
|
* - Pattern graph nodes cannot alias. TODO: the check not implemented yet.
|
* - Aliasing nodes in the graph can not consitute a match (i.e. in all found
|
* matches no nodes in the subgraph alias with each other). TODO: the check not
|
* implemented yet.
|
* - The matcher will not mutate either the pattern graph or the matched graph,
|
* but the latter is taken as non-const so that Match may contain non-const
|
* pointers. This enables clients of this API to use Match to drive mutations.
|
*/
|
std::vector<Match> TORCH_API
|
findPatternMatches(const Graph& pattern, Graph& graph);
|
|
} // namespace jit
|
} // namespace torch
|
