Merge pull request #82 from YosysHQ/ecp5_carry

Adding ECP5 carry support

3 files changed, 91 insertions, 0 deletions

diff --git a/common/chain_utils.h b/common/chain_utils.h
new file mode 100644
index 00000000..b783e30b
--- /dev/null
+++ b/common/chain_utils.h
@@ -0,0 +1,68 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *
+ *  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 CHAIN_UTILS_H
+#define CHAIN_UTILS_H
+
+#include "nextpnr.h"
+#include "util.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+struct CellChain
+{
+    std::vector<CellInfo *> cells;
+};
+
+// Generic chain finder
+template <typename F1, typename F2, typename F3>
+std::vector<CellChain> find_chains(const Context *ctx, F1 cell_type_predicate, F2 get_previous, F3 get_next,
+                                   size_t min_length = 2)
+{
+    std::set<IdString> chained;
+    std::vector<CellChain> chains;
+    for (auto cell : sorted(ctx->cells)) {
+        if (chained.find(cell.first) != chained.end())
+            continue;
+        CellInfo *ci = cell.second;
+        if (cell_type_predicate(ctx, ci)) {
+            CellInfo *start = ci;
+            CellInfo *prev_start = ci;
+            while (prev_start != nullptr) {
+                start = prev_start;
+                prev_start = get_previous(ctx, start);
+            }
+            CellChain chain;
+            CellInfo *end = start;
+            while (end != nullptr) {
+                chain.cells.push_back(end);
+                end = get_next(ctx, end);
+            }
+            if (chain.cells.size() >= min_length) {
+                chains.push_back(chain);
+                for (auto c : chain.cells)
+                    chained.insert(c->name);
+            }
+        }
+    }
+    return chains;
+}
+
+NEXTPNR_NAMESPACE_END
+#endif
diff --git a/common/design_utils.cc b/common/design_utils.cc
index 21c9dcc4..7ad7f749 100644
--- a/common/design_utils.cc
+++ b/common/design_utils.cc
@@ -73,4 +73,24 @@ void print_utilisation(const Context *ctx)
     log_break();
 }
 
+// Connect a net to a port
+void connect_port(const Context *ctx, NetInfo *net, CellInfo *cell, IdString port_name)
+{
+    PortInfo &port = cell->ports.at(port_name);
+    NPNR_ASSERT(port.net == nullptr);
+    port.net = net;
+    if (port.type == PORT_OUT) {
+        NPNR_ASSERT(net->driver.cell == nullptr);
+        net->driver.cell = cell;
+        net->driver.port = port_name;
+    } else if (port.type == PORT_IN) {
+        PortRef user;
+        user.cell = cell;
+        user.port = port_name;
+        net->users.push_back(user);
+    } else {
+        NPNR_ASSERT_FALSE("invalid port type for connect_port");
+    }
+}
+
 NEXTPNR_NAMESPACE_END
diff --git a/common/design_utils.h b/common/design_utils.h
index 95975179..ccf2463b 100644
--- a/common/design_utils.h
+++ b/common/design_utils.h
@@ -82,6 +82,9 @@ template <typename F1> CellInfo *net_driven_by(const Context *ctx, const NetInfo
     }
 }
 
+// Connect a net to a port
+void connect_port(const Context *ctx, NetInfo *net, CellInfo *cell, IdString port_name);
+
 void print_utilisation(const Context *ctx);
 
 NEXTPNR_NAMESPACE_END