/************************************************** * This file includes a data structure to describe * the internal structure of a multiplexer * using a generic graph representation * A Branch is a N:1 MUX in the part of MUX graph * * branch_input --->+ * | * branch_input --->| * |--> branch_out * ... | * | * branch_input --->+ * * A short example of how a two-level MUX is organized by branches * * +-----------+ +--------+ * mux_inputs--->| Branch[0] |--->| | * +-----------+ | | * ... | Branch |---> mux_out * +-----------+ | [N+1] | * mux_inputs--->| Branch[N] |--->| | * +-----------+ +--------+ * *************************************************/ #ifndef MUX_GRAPH_H #define MUX_GRAPH_H #include #include "vtr_vector.h" #include "vtr_range.h" #include "mux_graph_fwd.h" #include "circuit_library.h" class MuxGraph { private: /* data types used only in this class */ enum e_mux_graph_node_type { MUX_INPUT_NODE, MUX_INTERNAL_NODE, MUX_OUTPUT_NODE, NUM_MUX_NODE_TYPES }; public: /* Types and ranges */ typedef vtr::vector::const_iterator node_iterator; typedef vtr::vector::const_iterator edge_iterator; typedef vtr::vector::const_iterator mem_iterator; typedef vtr::Range node_range; typedef vtr::Range edge_range; typedef vtr::Range mem_range; public: /* Public Constructors */ /* Create an object based on a Circuit Model which is MUX */ MuxGraph(const CircuitLibrary& circuit_lib, const CircuitModelId& circuit_model, const size_t& mux_size); private: /* Private Constructors*/ /* Create an empty graph */ MuxGraph(); public: /* Public accessors: Aggregates */ node_range nodes() const; /* Find the non-input nodes */ std::vector non_input_nodes() const; edge_range edges() const; mem_range memories() const; /* Find the number of levels in terms of the multiplexer */ std::vector levels() const; /* Find the actual number of levels in the graph */ std::vector node_levels() const; public: /* Public accessors: Data query */ /* Find the number of inputs in the MUX graph */ size_t num_inputs() const; std::vector inputs() const; /* Find the number of outputs in the MUX graph */ size_t num_outputs() const; std::vector outputs() const; /* Find the edge between two MUX nodes */ std::vector find_edges(const MuxNodeId& from_node, const MuxNodeId& to_node) const; /* Find the number of levels in the MUX graph */ size_t num_levels() const; size_t num_node_levels() const; /* Find the number of SRAMs in the MUX graph */ size_t num_memory_bits() const; /* Find the number of SRAMs at a level in the MUX graph */ size_t num_memory_bits_at_level(const size_t& level) const; /* Find the number of nodes at a given level in the MUX graph */ size_t num_nodes_at_level(const size_t& level) const; /* Find the level of a node */ size_t node_level(const MuxNodeId& node) const; /* Find the index of a node at its level */ size_t node_index_at_level(const MuxNodeId& node) const; /* Find the input edges for a node */ std::vector node_in_edges(const MuxNodeId& node) const; /* Find the input nodes for a edge */ std::vector edge_src_nodes(const MuxEdgeId& edge) const; /* Find the mem that control the edge */ MuxMemId find_edge_mem(const MuxEdgeId& edge) const; /* Identify if the edge is controlled by the inverted output of a mem */ bool is_edge_use_inv_mem(const MuxEdgeId& edge) const; /* Find the sizes of each branch of a MUX */ std::vector branch_sizes() const; /* Find the sizes of each branch of a MUX at a given level */ std::vector branch_sizes(const size_t& level) const; /* Generate MUX graphs for its branches */ MuxGraph subgraph(const MuxNodeId& node) const; std::vector build_mux_branch_graphs() const; /* Get the node id of a given input */ MuxNodeId node_id(const MuxInputId& input_id) const; /* Get the node id of a given output */ MuxNodeId node_id(const MuxOutputId& output_id) const; /* Get the node id w.r.t. the node level and node_index at the level */ MuxNodeId node_id(const size_t& node_level, const size_t& node_index_at_level) const; /* Get the input id of a given node */ MuxInputId input_id(const MuxNodeId& node_id) const; /* Identify if the node is an input of the MUX */ bool is_node_input(const MuxNodeId& node_id) const; /* Get the output id of a given node */ MuxOutputId output_id(const MuxNodeId& node_id) const; /* Identify if the node is an output of the MUX */ bool is_node_output(const MuxNodeId& node_id) const; /* Decode memory bits based on an input id and an output id * This function will start from the input node * and do a forward propagation until reaching the output node */ std::vector decode_memory_bits(const MuxInputId& input_id, const MuxOutputId& output_id) const; /* Find the input node that the memory bits will route an output node to * This function backward propagate from the output node to an input node * assuming the memory bits are applied * Note: This function is mainly used for decoding LUT MUXes */ MuxInputId find_input_node_driven_by_output_node(const std::map& memory_bits, const MuxOutputId& output_id) const; private: /* Private mutators : basic operations */ /* Add a unconfigured node to the MuxGraph */ MuxNodeId add_node(const enum e_mux_graph_node_type& node_type); /* Add a edge connecting two nodes */ MuxEdgeId add_edge(const MuxNodeId& from_node, const MuxNodeId& to_node); /* Add a memory bit to the MuxGraph */ MuxMemId add_mem(); /* Configure the level of a memory */ void set_mem_level(const MuxMemId& mem, const size_t& level); /* Link an edge to a mem */ void set_edge_mem_id(const MuxEdgeId& edge, const MuxMemId& mem); private: /* Private mutators : graph builders */ void build_multilevel_mux_graph(const size_t& mux_size, const size_t& num_levels, const size_t& num_inputs_per_branch, const CircuitModelId& pgl_model) ; /* Build the graph for a given one-level multiplexer implementation */ void build_onelevel_mux_graph(const size_t& mux_size, const CircuitModelId& pgl_model) ; /* Build the graph for a given multiplexer model */ void build_mux_graph(const CircuitLibrary& circuit_lib, const CircuitModelId& circuit_model, const size_t& mux_size); /* Convert some internal node to outputs according to fracturable LUT circuit design specifications */ void add_fracturable_outputs(const CircuitLibrary& circuit_lib, const CircuitModelId& circuit_model); /* Build fast node lookup */ void build_node_lookup(); /* Build fast mem lookup */ void build_mem_lookup(); private: /* Private validators */ /* valid ids */ bool valid_node_id(const MuxNodeId& node) const; bool valid_edge_id(const MuxEdgeId& edge) const; bool valid_mem_id(const MuxMemId& mem) const; bool valid_input_id(const MuxInputId& input_id) const; bool valid_output_id(const MuxOutputId& output_id) const; bool valid_level(const size_t& level) const; /* validate/invalidate node lookup */ bool valid_node_lookup() const; void invalidate_node_lookup(); void invalidate_mem_lookup(); /* validate graph */ bool valid_mux_graph() const; private: /* Internal data */ vtr::vector node_ids_; /* Unique ids for each node */ vtr::vector node_types_; /* type of each node, input/output/internal */ vtr::vector node_input_ids_; /* Unique ids for each node as an input of the MUX */ vtr::vector node_output_ids_; /* Unique ids for each node as an input of the MUX */ vtr::vector node_levels_; /* at which level, each node belongs to */ vtr::vector node_ids_at_level_; /* the index at the level that each node belongs to */ vtr::vector> node_in_edges_; /* ids of incoming edges to each node */ vtr::vector> node_out_edges_; /* ids of outgoing edges from each node */ vtr::vector edge_ids_; /* Unique ids for each edge */ vtr::vector> edge_src_nodes_; /* source nodes drive this edge */ vtr::vector> edge_sink_nodes_; /* sink nodes this edge drives */ vtr::vector edge_models_; /* type of each edge: tgate/pass-gate */ vtr::vector edge_mem_ids_; /* ids of memory bit that control the edge */ vtr::vector edge_inv_mem_; /* if the edge is controlled by an inverted output of a memory bit */ vtr::vector mem_ids_; /* ids of configuration memories */ vtr::vector mem_levels_; /* ids of configuration memories */ /* fast look-up */ typedef std::vector>> NodeLookup; mutable NodeLookup node_lookup_; /* [num_levels][num_types][num_nodes_per_level] */ typedef std::vector> MemLookup; mutable MemLookup mem_lookup_; /* [num_levels][num_mems_per_level] */ }; #endif