timing: Data structures for STA rewrite

Signed-off-by: gatecat <gatecat@ds0.me>

common/timing.h

@@ -24,6 +24,128 @@
 
 NEXTPNR_NAMESPACE_BEGIN
 
+struct CellPortKey
+{
+    IdString cell, port;
+    struct Hash
+    {
+        inline std::size_t operator()(const CellPortKey &arg) const noexcept
+        {
+            std::size_t seed = std::hash<IdString>()(arg.cell);
+            seed ^= std::hash<IdString>()(arg.port) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+            return seed;
+        }
+    };
+    inline bool operator==(const CellPortKey &other) const { return (cell == other.cell) && (port == other.port); }
+};
+
+struct NetPortKey
+{
+    IdString net;
+    size_t idx;
+    static const size_t DRIVER_IDX = std::numeric_limits<size_t>::max();
+
+    inline bool is_driver() const { return (idx == DRIVER_IDX); }
+    inline size_t user_idx() const
+    {
+        NPNR_ASSERT(idx != DRIVER_IDX);
+        return idx;
+    }
+
+    struct Hash
+    {
+        std::size_t operator()(const NetPortKey &arg) const noexcept
+        {
+            std::size_t seed = std::hash<IdString>()(arg.net);
+            seed ^= std::hash<size_t>()(arg.idx) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+            return seed;
+        }
+    };
+    inline bool operator==(const NetPortKey &other) const { return (net == other.net) && (idx == other.idx); }
+};
+
+struct ClockDomainKey
+{
+    IdString clock;
+    ClockEdge edge;
+    // probably also need something here to deal with constraints
+    inline bool is_async() const { return clock == IdString(); }
+
+    struct Hash
+    {
+        std::size_t operator()(const ClockDomainKey &arg) const noexcept
+        {
+            std::size_t seed = std::hash<IdString>()(arg.clock);
+            seed ^= std::hash<int>()(int(arg.edge)) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+            return seed;
+        }
+    };
+    inline bool operator==(const ClockDomainKey &other) const { return (clock == other.clock) && (edge == other.edge); }
+};
+
+struct TimingAnalyser
+{
+  public:
+    TimingAnalyser(Context *ctx) : ctx(ctx){};
+
+  private:
+    // To avoid storing the domain tag structure (which could get large when considering more complex constrained tag
+    // cases), assign each domain an ID and use that instead
+    typedef int domain_id_t;
+    // An arrival or required time entry. Stores both the min/max delays; and the traversal to reach them for critical
+    // path reporting
+    struct ArrivReqTime
+    {
+        DelayPair value;
+        CellPortKey bwd_min, bwd_max;
+        int path_length;
+    };
+    // Data per port-domain tuple
+    struct PortDomainData
+    {
+        ArrivReqTime arrival, required;
+        delay_t setup_slack = std::numeric_limits<delay_t>::max(), hold_slack = std::numeric_limits<delay_t>::max();
+        delay_t budget = std::numeric_limits<delay_t>::max();
+        int max_path_length = 0;
+        float criticality = 0;
+    };
+
+    // A cell timing arc, used to cache cell timings and reduce the number of potentially-expensive Arch API calls
+    struct CellArc
+    {
+        enum ArcType
+        {
+            COMBINATIONAL,
+            SETUP,
+            HOLD,
+            CLK_TO_Q
+        } type;
+        IdString other_port;
+        DelayQuad value;
+        // Clock polarity, not used for combinational arcs
+        ClockEdge edge;
+    };
+
+    // Timing data for every cell port
+    struct PerPort
+    {
+        CellPortKey cell_port;
+        NetPortKey net_port;
+        // per domain timings
+        std::unordered_map<domain_id_t, PortDomainData> domains;
+        // cell timing arcs to (outputs)/from (inputs)  from this port
+        std::vector<CellArc> cell_arcs;
+        // routing delay into this port (input ports only)
+        DelayPair route_delay;
+    };
+
+    std::unordered_map<CellPortKey, PerPort, CellPortKey::Hash> ports;
+    std::unordered_map<ClockDomainKey, domain_id_t, ClockDomainKey::Hash> domain_to_id;
+    std::vector<ClockDomainKey> id_to_domain;
+
+    Context *ctx;
+};
+
 // Evenly redistribute the total path slack amongst all sinks on each path
 void assign_budget(Context *ctx, bool quiet = false);