1 files changed, 65 insertions, 0 deletions
diff --git a/common/constraints.h b/common/constraints.h
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index 00000000..dfb108f8
--- /dev/null
+++ b/common/constraints.h
@@ -0,0 +1,65 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  The 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 CONSTRAINTS_H
+#define CONSTRAINTS_H
+
+#ifndef NEXTPNR_H
+#error Include after "nextpnr.h" only.
+#endif
+
+#include "exclusive_state_groups.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+template <size_t StateCount, typename StateType = int8_t, typename CountType = uint8_t> struct Constraints
+{
+    using ConstraintStateType = StateType;
+    using ConstraintCountType = CountType;
+
+    enum ConstraintType
+    {
+        CONSTRAINT_TAG_IMPLIES = 0,
+        CONSTRAINT_TAG_REQUIRES = 1,
+    };
+
+    template <typename StateRange> struct Constraint
+    {
+        virtual size_t tag() const = 0;
+        virtual ConstraintType constraint_type() const = 0;
+        virtual StateType state() const = 0;
+        virtual StateRange states() const = 0;
+    };
+
+    typedef ExclusiveStateGroup<StateCount, StateType, CountType> TagState;
+    std::unordered_map<uint32_t, std::vector<typename TagState::Definition>> definitions;
+
+    template <typename ConstraintRange> void bindBel(TagState *tags, const ConstraintRange constraints);
+
+    template <typename ConstraintRange> void unbindBel(TagState *tags, const ConstraintRange constraints);
+
+    template <typename ConstraintRange>
+    bool isValidBelForCellType(const Context *ctx, uint32_t prototype, const TagState *tags,
+                               const ConstraintRange constraints, IdString object, IdString cell, BelId bel,
+                               bool explain_constraints) const;
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif