Merge pull request #641 from litghost/initial_lookahead

Initial lookahead for FPGA interchange.

1 files changed, 68 insertions, 0 deletions

diff --git a/fpga_interchange/cost_map.h b/fpga_interchange/cost_map.h
new file mode 100644
index 00000000..e57a1027
--- /dev/null
+++ b/fpga_interchange/cost_map.h
@@ -0,0 +1,68 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  Symbiflow Authors
+ *
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef COST_MAP_H
+#define COST_MAP_H
+
+#include <boost/multi_array.hpp>
+#include <mutex>
+
+#include "hash_table.h"
+#include "lookahead.capnp.h"
+#include "nextpnr_namespaces.h"
+#include "nextpnr_types.h"
+#include "type_wire.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+struct Context;
+
+class CostMap
+{
+  public:
+    delay_t get_delay(const Context *ctx, WireId src, WireId dst) const;
+    void set_cost_map(const Context *ctx, const TypeWirePair &wire_pair,
+                      const HashTables::HashMap<std::pair<int32_t, int32_t>, delay_t> &delays);
+
+    void from_reader(lookahead_storage::CostMap::Reader reader);
+    void to_builder(lookahead_storage::CostMap::Builder builder) const;
+
+  private:
+    struct CostMapEntry
+    {
+        boost::multi_array<delay_t, 2> data;
+        std::pair<int32_t, int32_t> offset;
+        delay_t penalty;
+    };
+
+    std::mutex cost_map_mutex_;
+    HashTables::HashMap<TypeWirePair, CostMapEntry> cost_map_;
+
+    void fill_holes(const Context *ctx, const TypeWirePair &wire_pair, boost::multi_array<delay_t, 2> &matrix,
+                    delay_t delay_penality);
+
+    std::pair<delay_t, int> get_nearby_cost_entry(const boost::multi_array<delay_t, 2> &matrix, int cx, int cy,
+                                                  const ArcBounds &bounds);
+    delay_t get_penalty(const boost::multi_array<delay_t, 2> &matrix) const;
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif /* COST_MAP_H */