text: /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
  /*
   *  Main authors:
   *     Christian Schulte <schulte@gecode.org>
   *
   *  Copyright:
   *     Christian Schulte, 2004
   *
   *  This file is part of Gecode, the generic constraint
   *  development environment:
   *     http://www.gecode.org
   *
   *  Permission is hereby granted, free of charge, to any person obtaining
   *  a copy of this software and associated documentation files (the
   *  "Software"), to deal in the Software without restriction, including
   *  without limitation the rights to use, copy, modify, merge, publish,
   *  distribute, sublicense, and/or sell copies of the Software, and to
   *  permit persons to whom the Software is furnished to do so, subject to
   *  the following conditions:
   *
   *  The above copyright notice and this permission notice shall be
   *  included in all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   */
  
  #include <cmath>
  #include <climits>
  
  #include <gecode/int/div.hh>
  #include <gecode/int/support-values.hh>
  
  namespace Gecode { namespace Int { namespace Arithmetic {
  
    /*
     * Arithmetic help functions
     *
     */
    /// Multiply \a x and \y
    forceinline long long int
    mll(long long int x, long long int y) {
      return x*y;
    }
    /// Cast \a x into a long long int
    forceinline long long int
    ll(int x) {
      return static_cast<long long int>(x);
    }
    /// Increment \a x by one
    forceinline long long int
    ill(int x) {
      return static_cast<long long int>(x) + 1;
    }
    /// Decrement \a x by one
    forceinline long long int
    dll(int x) {
      return static_cast<long long int>(x) - 1;
    }
  
    /// Test whether \a x is postive
    template<class View>
    forceinline bool
    pos(const View& x) {
      return x.min() > 0;
    }
    /// Test whether \a x is negative
    template<class View>
    forceinline bool
    neg(const View& x) {
      return x.max() < 0;
    }
    /// Test whether \a x is neither positive nor negative
    template<class View>
    forceinline bool
    any(const View& x) {
      return (x.min() <= 0) && (x.max() >= 0);
    }
  
  
    /*
     * Propagator for x * y = x
     *
     */
  
    template<class View, PropCond pc>
    forceinline
    MultZeroOne<View,pc>::MultZeroOne(Home home, View x0, View x1)
      : BinaryPropagator<View,pc>(home,x0,x1) {}
  
    template<class View, PropCond pc>
    forceinline RelTest
    MultZeroOne<View,pc>::equal(View x, int n) {
      if (pc == PC_INT_DOM) {
        return rtest_eq_dom(x,n);
      } else {
        return rtest_eq_bnd(x,n);
      }
    }
  
    template<class View, PropCond pc>
    forceinline ExecStatus
    MultZeroOne<View,pc>::post(Home home, View x0, View x1) {
      switch (equal(x0,0)) {
      case RT_FALSE:
        GECODE_ME_CHECK(x1.eq(home,1));
        break;
      case RT_TRUE:
        break;
      case RT_MAYBE:
        switch (equal(x1,1)) {
        case RT_FALSE:
          GECODE_ME_CHECK(x0.eq(home,0));
          break;
        case RT_TRUE:
          break;
        case RT_MAYBE:
          (void) new (home) MultZeroOne<View,pc>(home,x0,x1);
          break;
        default: GECODE_NEVER;
        }
        break;
      default: GECODE_NEVER;
      }
      return ES_OK;
    }
  
    template<class View, PropCond pc>
    forceinline
    MultZeroOne<View,pc>::MultZeroOne(Space& home, MultZeroOne<View,pc>& p)
      : BinaryPropagator<View,pc>(home,p) {}
  
    template<class View, PropCond pc>
    Actor*
    MultZeroOne<View,pc>::copy(Space& home) {
      return new (home) MultZeroOne<View,pc>(home,*this);
    }
  
    template<class View, PropCond pc>
    ExecStatus
    MultZeroOne<View,pc>::propagate(Space& home, const ModEventDelta&) {
      switch (equal(x0,0)) {
      case RT_FALSE:
        GECODE_ME_CHECK(x1.eq(home,1));
        break;
      case RT_TRUE:
        break;
      case RT_MAYBE:
        switch (equal(x1,1)) {
        case RT_FALSE:
          GECODE_ME_CHECK(x0.eq(home,0));
          break;
        case RT_TRUE:
          break;
        case RT_MAYBE:
          return ES_FIX;
        default: GECODE_NEVER;
        }
        break;
      default: GECODE_NEVER;
      }
      return home.ES_SUBSUMED(*this);
    }
  
  
    /*
     * Positive bounds consistent multiplication
     *
     */
    template<class VA, class VB, class VC>
    forceinline ExecStatus
    prop_mult_plus_bnd(Space& home, Propagator& p, VA x0, VB x1, VC x2) {
      assert(pos(x0) && pos(x1) && pos(x2));
      bool mod;
      do {
        mod = false;
        {
          ModEvent me = x2.lq(home,mll(x0.max(),x1.max()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
        {
          ModEvent me = x2.gq(home,mll(x0.min(),x1.min()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
        {
          ModEvent me = x0.lq(home,floor_div_pp(x2.max(),x1.min()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
        {
          ModEvent me = x0.gq(home,ceil_div_pp(x2.min(),x1.max()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
        {
          ModEvent me = x1.lq(home,floor_div_pp(x2.max(),x0.min()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
        {
          ModEvent me = x1.gq(home,ceil_div_pp(x2.min(),x0.max()));
          if (me_failed(me)) return ES_FAILED;
          mod |= me_modified(me);
        }
      } while (mod);
      return x0.assigned() && x1.assigned() ?
        home.ES_SUBSUMED(p) : ES_FIX;
    }
  
    template<class VA, class VB, class VC>
    forceinline
    MultPlusBnd<VA,VB,VC>::MultPlusBnd(Home home, VA x0, VB x1, VC x2)
      : MixTernaryPropagator<VA,PC_INT_BND,VB,PC_INT_BND,VC,PC_INT_BND>
    (home,x0,x1,x2) {}
  
    template<class VA, class VB, class VC>
    forceinline
    MultPlusBnd<VA,VB,VC>::MultPlusBnd(Space& home, MultPlusBnd<VA,VB,VC>& p)
      : MixTernaryPropagator<VA,PC_INT_BND,VB,PC_INT_BND,VC,PC_INT_BND>
    (home,p) {}
  
    template<class VA, class VB, class VC>
    Actor*
    MultPlusBnd<VA,VB,VC>::copy(Space& home) {
      return new (home) MultPlusBnd<VA,VB,VC>(home,*this);
    }
  
    template<class VA, class VB, class VC>
    ExecStatus
    MultPlusBnd<VA,VB,VC>::propagate(Space& home, const ModEventDelta&) {
      return prop_mult_plus_bnd<VA,VB,VC>(home,*this,x0,x1,x2);
    }
  
    template<class VA, class VB, class VC>
    forceinline ExecStatus
    MultPlusBnd<VA,VB,VC>::post(Home home, VA x0, VB x1, VC x2) {
      GECODE_ME_CHECK(x0.gr(home,0));
      GECODE_ME_CHECK(x1.gr(home,0));
      GECODE_ME_CHECK(x2.gq(home,mll(x0.min(),x1.min())));
      GECODE_ME_CHECK(x2.lq(home,mll(x0.max(),x1.max())));
      (void) new (home) MultPlusBnd<VA,VB,VC>(home,x0,x1,x2);
      return ES_OK;
    }
  
  
    /*
     * Bounds consistent multiplication
     *
     */
    forceinline
    MultBnd::MultBnd(Home home, IntView x0, IntView x1, IntView x2)
      : TernaryPropagator<IntView,PC_INT_BND>(home,x0,x1,x2) {}
  
    forceinline
    MultBnd::MultBnd(Space& home, MultBnd& p)
      : TernaryPropagator<IntView,PC_INT_BND>(home,p) {}
  
    /*
     * Positive domain consistent multiplication
     *
     */
    template<class View>
    forceinline ExecStatus
    prop_mult_dom(Space& home, Propagator& p, View x0, View x1, View x2) {
      Region r;
      SupportValues<View,Region> s0(r,x0), s1(r,x1), s2(r,x2);
      while (s0()) {
        while (s1()) {
          if (s2.support(mll(s0.val(),s1.val()))) {
            s0.support(); s1.support();
          }
          ++s1;
        }
        s1.reset(); ++s0;
      }
      GECODE_ME_CHECK(s0.tell(home));
      GECODE_ME_CHECK(s1.tell(home));
      GECODE_ME_CHECK(s2.tell(home));
      return x0.assigned() && x1.assigned() ? home.ES_SUBSUMED(p) : ES_FIX;
    }
  
    template<class VA, class VB, class VC>
    forceinline
    MultPlusDom<VA,VB,VC>::MultPlusDom(Home home, VA x0, VB x1, VC x2)
      : MixTernaryPropagator<VA,PC_INT_DOM,VB,PC_INT_DOM,VC,PC_INT_DOM>
    (home,x0,x1,x2) {}
  
    template<class VA, class VB, class VC>
    forceinline
    MultPlusDom<VA,VB,VC>::MultPlusDom(Space& home, MultPlusDom<VA,VB,VC>& p)
      : MixTernaryPropagator<VA,PC_INT_DOM,VB,PC_INT_DOM,VC,PC_INT_DOM>
        (home,p) {}
  
    template<class VA, class VB, class VC>
    Actor*
    MultPlusDom<VA,VB,VC>::copy(Space& home) {
      return new (home) MultPlusDom<VA,VB,VC>(home,*this);
    }
  
    template<class VA, class VB, class VC>
    PropCost
    MultPlusDom<VA,VB,VC>::cost(const Space&,
                                    const ModEventDelta& med) const {
      if (VA::me(med) == ME_INT_DOM)
        return PropCost::ternary(PropCost::HI);
      else
        return PropCost::ternary(PropCost::LO);
    }
  
    template<class VA, class VB, class VC>
    ExecStatus
    MultPlusDom<VA,VB,VC>::propagate(Space& home, const ModEventDelta& med) {
      if (VA::me(med) != ME_INT_DOM) {
        GECODE_ES_CHECK((prop_mult_plus_bnd<VA,VB,VC>(home,*this,x0,x1,x2)));
        return home.ES_FIX_PARTIAL(*this,VA::med(ME_INT_DOM));
      }
      IntView y0(x0.varimp()), y1(x1.varimp()), y2(x2.varimp());
      return prop_mult_dom<IntView>(home,*this,y0,y1,y2);
    }
  
    template<class VA, class VB, class VC>
    forceinline ExecStatus
    MultPlusDom<VA,VB,VC>::post(Home home, VA x0, VB x1, VC x2) {
      GECODE_ME_CHECK(x0.gr(home,0));
      GECODE_ME_CHECK(x1.gr(home,0));
      GECODE_ME_CHECK(x2.gq(home,mll(x0.min(),x1.min())));
      GECODE_ME_CHECK(x2.lq(home,mll(x0.max(),x1.max())));
      (void) new (home) MultPlusDom<VA,VB,VC>(home,x0,x1,x2);
      return ES_OK;
    }
  
  
    /*
     * Domain consistent multiplication
     *
     */
    forceinline
    MultDom::MultDom(Home home, IntView x0, IntView x1, IntView x2)
      : TernaryPropagator<IntView,PC_INT_DOM>(home,x0,x1,x2) {}
  
    forceinline
    MultDom::MultDom(Space& home, MultDom& p)
      : TernaryPropagator<IntView,PC_INT_DOM>(home,p) {}
  
  }}}
  
  // STATISTICS: int-prop
  
  