Viaduct API for a hybrid between generic and full-custom arch

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

1 files changed, 82 insertions, 0 deletions

diff --git a/generic/viaduct_helpers.h b/generic/viaduct_helpers.h
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+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  gatecat <gatecat@ds0.me>
+ *
+ *  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 VIADUCT_HELPERS_H
+#define VIADUCT_HELPERS_H
+
+#include "nextpnr_namespaces.h"
+#include "nextpnr_types.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+/*
+Viaduct -- a series of small arches
+
+See viaduct_api.h for more background.
+
+viaduct_helpers provides some features for building up arches using the viaduct API
+*/
+
+// Used to configure various generic pack functions
+struct CellTypePort
+{
+    CellTypePort() : cell_type(), port(){};
+    CellTypePort(IdString cell_type, IdString port) : cell_type(cell_type), port(port){};
+    explicit CellTypePort(const PortRef &net_port)
+            : cell_type(net_port.cell ? net_port.cell->type : IdString()), port(net_port.port){};
+    inline bool operator==(const CellTypePort &other) const
+    {
+        return cell_type == other.cell_type && port == other.port;
+    }
+    inline bool operator!=(const CellTypePort &other) const
+    {
+        return cell_type != other.cell_type || port != other.port;
+    }
+    inline unsigned hash() const { return mkhash(cell_type.hash(), port.hash()); }
+    IdString cell_type, port;
+};
+
+struct ViaductHelpers
+{
+    ViaductHelpers(){};
+    Context *ctx;
+    void init(Context *ctx) { this->ctx = ctx; }
+    // IdStringList components for x and y locations
+    std::vector<IdString> x_ids, y_ids;
+    void resize_ids(int x, int y);
+    // Get an IdStringList for a hierarchical ID
+    // Because this uses an IdStringList with seperate X and Y components; this will be much more efficient than
+    // creating unique strings for each object in each X and Y position
+    IdStringList xy_id(int x, int y, IdString base);
+    IdStringList xy_id(int x, int y, IdStringList base);
+    // Common packing functions
+    // Remove nextpnr-inserted IO buffers; where IO buffer insertion is done in synthesis
+    // expects a set of top-level port types
+    void remove_nextpnr_iobs(const pool<CellTypePort> &top_ports);
+    // Constrain cells with certain port connection patterns together with a fixed z-offset
+    int constrain_cell_pairs(const pool<CellTypePort> &src_ports, const pool<CellTypePort> &sink_ports, int delta_z);
+    // Replace constants with given driving cells
+    void replace_constants(CellTypePort vcc_driver, CellTypePort gnd_driver,
+                           const dict<IdString, Property> &vcc_params = {},
+                           const dict<IdString, Property> &gnd_params = {});
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif