#pragma once #include #include #include 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 nodes_map; std::unordered_map 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 TORCH_API findPatternMatches(const Graph& pattern, Graph& graph); } // namespace jit } // namespace torch