a new bitset class with static size

* spot/misc/bitset.hh: implement it
* spot/misc/Makefile.am: distribute it

spot/misc/Makefile.am

@@ -1,5 +1,5 @@
 ## -*- coding: utf-8 -*-
-## Copyright (C) 2011, 2012, 2013, 2014, 2016 Laboratoire de Recherche
+## Copyright (C) 2011, 2012, 2013, 2014, 2016, 2018 Laboratoire de Recherche
 ## et Développement de l'Epita (LRDE).
 ## Copyright (C) 2003, 2004, 2005, 2006 Laboratoire d'Informatique de
 ## Paris 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
@@ -32,6 +32,7 @@ DISTCLEANFILES = _config.h
 misc_HEADERS = \
   bareword.hh \
   bddlt.hh \
+  bitset.hh \
   bitvect.hh \
   casts.hh \
   common.hh \

spot/misc/bitset.hh

@@ -0,0 +1,349 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2018 Laboratoire de Recherche et Développement
+// de l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <array>
+#include <spot/misc/hashfunc.hh>
+#include <spot/misc/common.hh>
+
+namespace spot
+{
+  template<size_t N>
+  class bitset
+  {
+    using word_t = unsigned;
+    // the number of bits must hold on an unsigned
+    static_assert(8*N*sizeof(word_t) < -1U, "too many bits in bitset");
+
+    std::array<word_t, N> data;
+
+    /// a special constructor for -1 (cf. mone below)
+    struct minus_one_tag {};
+    explicit bitset(minus_one_tag)
+      : data{0}
+    {
+      for (auto& v : data)
+        v -= 1;
+    }
+
+    constexpr explicit bitset(word_t s)
+      : data{s}
+    {
+      SPOT_ASSERT(s == 0U || s == 1U);
+    }
+
+  public:
+    // constructor
+    bitset() = default;
+    ~bitset() = default;
+
+    /// the 0
+    static constexpr bitset zero() { return bitset{0U}; }
+    /// the 1
+    static constexpr bitset one() { return bitset{1U}; }
+    /// the -1 (all bits are set to 1)
+    static bitset mone() { return bitset(minus_one_tag{}); }
+
+    explicit operator bool() const
+    {
+      for (const auto& v : data)
+        if (v)
+          return true;
+      return false;
+    }
+
+    size_t hash() const
+    {
+      return fnv_hash(data.begin(), data.end());
+    }
+
+    bool operator==(const bitset& other) const
+    {
+      // TODO use std::algorithms instead?
+      for (unsigned i = 0; i != N; ++i)
+        if (data[i] != other.data[i])
+          return false;
+      return true;
+    }
+
+    bool operator!=(const bitset& other) const
+    {
+      return !this->operator==(other);
+    }
+
+    bool operator<(const bitset& other) const
+    {
+      for (unsigned i = 0; i != N; ++i)
+        if (data[i] < other.data[i])
+          return true;
+        else if (data[i] > other.data[i])
+          return false;
+      return false;
+    }
+
+    bool operator<=(const bitset& other) const
+    {
+      for (unsigned i = 0; i != N; ++i)
+        if (data[i] < other.data[i])
+          return true;
+        else if (data[i] > other.data[i])
+          return false;
+      return true;
+    }
+
+    bool operator>(const bitset& other) const
+    {
+      return other.operator<(*this);
+    }
+
+    bool operator>=(const bitset& other) const
+    {
+      return other.operator>(*this);
+    }
+
+    bitset operator<<(unsigned s) const
+    {
+      bitset r = *this;
+      r <<= s;
+      return r;
+    }
+    bitset operator>>(unsigned s) const
+    {
+      bitset r = *this;
+      r >>= s;
+      return r;
+    }
+
+    bitset& operator<<=(unsigned s)
+    {
+      if (SPOT_UNLIKELY(s >= 8*N*sizeof(word_t)))
+        throw std::runtime_error("bit shift overflow is undefined behavior");
+
+      if (s == 0)
+        return *this;
+      const unsigned wshift = s / (8*sizeof(word_t));
+      const unsigned offset = s % (8*sizeof(word_t));
+
+      if (offset == 0)
+      {
+        for (unsigned i = N-1; i >= wshift; --i)
+          data[i] = data[i - wshift];
+      }
+      else
+        {
+          const unsigned sub_offset = 8*sizeof(word_t) - offset;
+          for (unsigned i = N-1; i > wshift; --i)
+            data[i] = ((data[i - wshift] << offset) |
+                       (data[i - wshift - 1] >> sub_offset));
+          data[wshift] = data[0] << offset;
+        }
+      std::fill(data.begin(), data.begin() + wshift, word_t(0));
+      return *this;
+    }
+
+    bitset& operator>>=(unsigned s)
+    {
+      if (SPOT_UNLIKELY(s >= 8*N*sizeof(word_t)))
+        throw std::runtime_error("bit shift overflow is undefined behavior");
+
+      if (s == 0)
+        return *this;
+      const unsigned wshift = s / (8*sizeof(word_t));
+      const unsigned offset = s % (8*sizeof(word_t));
+      const unsigned limit = N - wshift - 1;
+
+      if (offset == 0)
+        for (unsigned i = 0; i <= limit; ++i)
+          data[i] = data[i + wshift];
+      else
+        {
+          const unsigned sub_offset = 8*sizeof(word_t) - offset;
+          for (unsigned i = 0; i < limit; ++i)
+            data[i] = ((data[i + wshift] >> offset) |
+                       (data[i + wshift + 1] << sub_offset));
+          data[limit] = data[N-1] >> offset;
+        }
+      std::fill(data.begin() + limit + 1, data.end(), word_t(0));
+      return *this;
+    }
+
+    bitset operator~() const
+    {
+      bitset r = *this;
+      for (auto& v : r.data)
+        v = ~v;
+      return r;
+    }
+
+    bitset operator&(const bitset& other) const
+    {
+      bitset r = *this;
+      r &= other;
+      return r;
+    }
+
+    bitset operator|(const bitset& other) const
+    {
+      bitset r = *this;
+      r |= other;
+      return r;
+    }
+
+    bitset operator^(const bitset& other) const
+    {
+      bitset r = *this;
+      r ^= other;
+      return r;
+    }
+
+    bitset& operator&=(const bitset& other)
+    {
+      for (unsigned i = 0; i != N; ++i)
+        data[i] &= other.data[i];
+      return *this;
+    }
+    bitset& operator|=(const bitset& other)
+    {
+      for (unsigned i = 0; i != N; ++i)
+        data[i] |= other.data[i];
+      return *this;
+    }
+    bitset& operator^=(const bitset& other)
+    {
+      for (unsigned i = 0; i != N; ++i)
+        data[i] ^= other.data[i];
+      return *this;
+    }
+
+    bitset operator-(word_t s) const
+    {
+      bitset r = *this;
+      r -= s;
+      return r;
+    }
+    bitset& operator-=(word_t s)
+    {
+      for (auto& v : data)
+        {
+          if (s == 0)
+            break;
+
+          if (v >= s)
+            {
+              v -= s;
+              s = 0;
+            }
+          else
+            {
+              v -= s;
+              s = 1;
+            }
+        }
+      return *this;
+    }
+
+    bitset operator-() const
+    {
+      bitset res = *this;
+      unsigned carry = 0;
+      for (auto& v : res.data)
+        {
+          v += carry;
+          if (v < carry)
+            carry = 2;
+          else
+            carry = 1;
+          v = -v;
+        }
+      return res;
+    }
+
+    unsigned count() const
+    {
+      unsigned c = 0U;
+      for (auto v : data)
+        {
+#ifdef __GNUC__
+          c += __builtin_popcount(v);
+#else
+          while (v)
+            {
+              ++c;
+              v &= v - 1;
+            }
+#endif
+        }
+      return c;
+    }
+
+    unsigned highest() const
+    {
+      unsigned res = 0;
+      for (auto v: data)
+        {
+          if (v == 0)
+            {
+              res += 8*sizeof(v);
+              continue;
+            }
+          while (v)
+            {
+              ++res;
+              v >>= 1;
+            }
+          return res-1;
+        }
+      return 0;
+    }
+
+    unsigned lowest() const
+    {
+      unsigned res = 0;
+      for (auto v: data)
+        {
+          if (v == 0)
+            {
+              res += 8*sizeof(v);
+              continue;
+            }
+          while ((v & 1) == 0)
+            {
+              ++res;
+              v >>= 1;
+            }
+          return res;
+        }
+      return 0;
+    }
+  };
+
+}
+
+namespace std
+{
+  template<size_t N>
+  struct hash<spot::bitset<N>>
+  {
+    size_t operator()(const spot::bitset<N>& b) const
+    {
+      return b.hash();
+    }
+  };
+}