Sacado_Fad_GeneralFad.hpp

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// @HEADER
// ***********************************************************************
//
//                           Sacado Package
//                 Copyright (2006) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
// USA
// Questions? Contact David M. Gay (dmgay@sandia.gov) or Eric T. Phipps
// (etphipp@sandia.gov).
//
// ***********************************************************************
//
// The forward-mode AD classes in Sacado are a derivative work of the
// expression template classes in the Fad package by Nicolas Di Cesare.
// The following banner is included in the original Fad source code:
//
// ************ DO NOT REMOVE THIS BANNER ****************
//
//  Nicolas Di Cesare <Nicolas.Dicesare@ann.jussieu.fr>
//  http://www.ann.jussieu.fr/~dicesare
//
//            CEMRACS 98 : C++ courses,
//         templates : new C++ techniques
//            for scientific computing
//
//********************************************************
//
//  A short implementation ( not all operators and
//  functions are overloaded ) of 1st order Automatic
//  Differentiation in forward mode (FAD) using
//  EXPRESSION TEMPLATES.
//
//********************************************************
// @HEADER

#ifndef SACADO_FAD_GENERALFAD_HPP
#define SACADO_FAD_GENERALFAD_HPP

#include "Sacado_Fad_Expression.hpp"

namespace Sacado {

  namespace Fad {

#ifndef SACADO_FAD_DERIV_LOOP
#if defined(SACADO_VIEW_CUDA_HIERARCHICAL_DFAD) && !defined(SACADO_DISABLE_CUDA_IN_KOKKOS) && defined(__CUDA_ARCH__)
#define SACADO_FAD_DERIV_LOOP(I,SZ) for (int I=threadIdx.x; I<SZ; I+=blockDim.x)
#else
#define SACADO_FAD_DERIV_LOOP(I,SZ) for (int I=0; I<SZ; ++I)
#endif
#endif

#ifndef SACADO_FAD_THREAD_SINGLE
#if (defined(SACADO_VIEW_CUDA_HIERARCHICAL) || defined(SACADO_VIEW_CUDA_HIERARCHICAL_DFAD)) && !defined(SACADO_DISABLE_CUDA_IN_KOKKOS) && defined(__CUDA_ARCH__)
#define SACADO_FAD_THREAD_SINGLE if (threadIdx.x == 0)
#else
#define SACADO_FAD_THREAD_SINGLE /* */
#endif
#endif


    template <typename T, typename Storage>
    class GeneralFad : public Storage {

    public:

      typedef typename RemoveConst<T>::type value_type;

      typedef typename ScalarType<value_type>::type scalar_type;


      SACADO_INLINE_FUNCTION
      GeneralFad() : Storage(T(0.)) {}


      template <typename S>
      SACADO_INLINE_FUNCTION
      GeneralFad(const S& x, SACADO_ENABLE_VALUE_CTOR_DECL) :
        Storage(x) {}


      SACADO_INLINE_FUNCTION
      GeneralFad(const int sz, const T & x, const DerivInit zero_out = InitDerivArray) :
        Storage(sz, x, zero_out) {}


      SACADO_INLINE_FUNCTION
      GeneralFad(const int sz, const int i, const T & x) :
        Storage(sz, x, InitDerivArray) {
        this->fastAccessDx(i)=1.;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad(const Storage& s) : Storage(s) {}

      SACADO_INLINE_FUNCTION
      GeneralFad(const GeneralFad& x) :
        Storage(x) {}

      template <typename S>
      SACADO_INLINE_FUNCTION
      GeneralFad(const Expr<S>& x, SACADO_ENABLE_EXPR_CTOR_DECL)  :
        Storage(x.size(), T(0.), NoInitDerivArray)
      {
        const int sz = x.size();

        if (sz) {
          if (x.hasFastAccess())
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) = x.fastAccessDx(i);
          else
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) = x.dx(i);
        }

        this->val() = x.val();
      }

      SACADO_INLINE_FUNCTION
      ~GeneralFad() {}


      SACADO_INLINE_FUNCTION
      void diff(const int ith, const int n) {
        if (this->size() != n)
          this->resize(n);

        this->zero();
        this->fastAccessDx(ith) = T(1.);
      }

      SACADO_INLINE_FUNCTION
      void setUpdateValue(bool update_val) {  }

      SACADO_INLINE_FUNCTION
      bool updateValue() const { return true; }

      SACADO_INLINE_FUNCTION
      void cache() const {}

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(bool) isEqualTo(const Expr<S>& x) const {
        typedef IsEqual<value_type> IE;
        if (x.size() != this->size()) return false;
        bool eq = IE::eval(x.val(), this->val());
        const int sz = this->size();
        SACADO_FAD_DERIV_LOOP(i,sz)
          eq = eq && IE::eval(x.dx(i), this->dx(i));
        return eq;
      }



      SACADO_INLINE_FUNCTION
      int availableSize() const { return this->length(); }

      SACADO_INLINE_FUNCTION
      bool hasFastAccess() const { return this->size()!=0; }

      SACADO_INLINE_FUNCTION
      bool isPassive() const { return this->size()==0; }

      SACADO_INLINE_FUNCTION
      void setIsConstant(bool is_const) {
        if (is_const && this->size()!=0)
          this->resize(0);
      }



      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_VALUE_FUNC(GeneralFad&) operator=(const S& v) {
        this->val() = v;
        if (this->size()) this->resize(0);
        return *this;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad&
      operator=(const GeneralFad& x) {
        // Copy value & dx_
        Storage::operator=(x);
        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(GeneralFad&) operator=(const Expr<S>& x) {
        const int xsz = x.size();

        if (xsz != this->size())
          this->resizeAndZero(xsz);

        const int sz = this->size();

        // For ViewStorage, the resize above may not in fact resize the
        // derivative array, so it is possible that sz != xsz at this point.
        // The only valid use case here is sz > xsz == 0, so we use sz in the
        // assignment below

        if (sz) {
          if (x.hasFastAccess()) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) = x.fastAccessDx(i);
          }
          else
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) = x.dx(i);
        }

        this->val() = x.val();

        return *this;
      }



      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_VALUE_FUNC(GeneralFad&) operator += (const S& v) {
        this->val() += v;
        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_VALUE_FUNC(GeneralFad&) operator -= (const S& v) {
        this->val() -= v;
        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_VALUE_FUNC(GeneralFad&) operator *= (const S& v) {
        const int sz = this->size();
        this->val() *= v;
        SACADO_FAD_DERIV_LOOP(i,sz)
          this->fastAccessDx(i) *= v;
        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_VALUE_FUNC(GeneralFad&) operator /= (const S& v) {
        const int sz = this->size();
        this->val() /= v;
        SACADO_FAD_DERIV_LOOP(i,sz)
          this->fastAccessDx(i) /= v;
        return *this;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad& operator += (const GeneralFad& x) {
        const int xsz = x.size(), sz = this->size();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) += x.fastAccessDx(i);
          }
          else {
            this->resizeAndZero(xsz);
            SACADO_FAD_DERIV_LOOP(i,xsz)
              this->fastAccessDx(i) = x.fastAccessDx(i);
          }
        }

        this->val() += x.val();

        return *this;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad& operator -= (const GeneralFad& x) {
        const int xsz = x.size(), sz = this->size();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) -= x.fastAccessDx(i);
          }
          else {
            this->resizeAndZero(xsz);
            SACADO_FAD_DERIV_LOOP(i,xsz)
              this->fastAccessDx(i) = -x.fastAccessDx(i);
          }
        }

        this->val() -= x.val();


        return *this;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad& operator *= (const GeneralFad& x) {
        const int xsz = x.size(), sz = this->size();
        T xval = x.val();
        T v = this->val();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) = v*x.fastAccessDx(i) + this->fastAccessDx(i)*xval;
          }
          else {
            this->resizeAndZero(xsz);
            SACADO_FAD_DERIV_LOOP(i,xsz)
              this->fastAccessDx(i) = v*x.fastAccessDx(i);
          }
        }
        else {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) *= xval;
          }
        }

        this->val() *= xval;

        return *this;
      }

      SACADO_INLINE_FUNCTION
      GeneralFad& operator /= (const GeneralFad& x) {
        const int xsz = x.size(), sz = this->size();
        T xval = x.val();
        T v = this->val();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) =
                ( this->fastAccessDx(i)*xval - v*x.fastAccessDx(i) )/ (xval*xval);
          }
          else {
            this->resizeAndZero(xsz);
            SACADO_FAD_DERIV_LOOP(i,xsz)
              this->fastAccessDx(i) = - v*x.fastAccessDx(i) / (xval*xval);
          }
        }
        else {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) /= xval;
          }
        }

        this->val() /= xval;

        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(GeneralFad&) operator += (const Expr<S>& x) {
        const int xsz = x.size(), sz = this->size();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) += x.fastAccessDx(i);
            else
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) += x.dx(i);
          }
          else {
            this->resizeAndZero(xsz);
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = x.fastAccessDx(i);
            else
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = x.dx(i);
          }
        }

        this->val() += x.val();

        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(GeneralFad&) operator -= (const Expr<S>& x) {
        const int xsz = x.size(), sz = this->size();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) -= x.fastAccessDx(i);
            else
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) -= x.dx(i);
          }
          else {
            this->resizeAndZero(xsz);
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = -x.fastAccessDx(i);
            else
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = -x.dx(i);
          }
        }

        this->val() -= x.val();


        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(GeneralFad&) operator *= (const Expr<S>& x) {
        const int xsz = x.size(), sz = this->size();
        T xval = x.val();
        T v = this->val();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) = v*x.fastAccessDx(i) + this->fastAccessDx(i)*xval;
            else
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) = v*x.dx(i) + this->fastAccessDx(i)*xval;
          }
          else {
            this->resizeAndZero(xsz);
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = v*x.fastAccessDx(i);
            else
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = v*x.dx(i);
          }
        }
        else {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) *= xval;
          }
        }

        this->val() *= xval;

        return *this;
      }

      template <typename S>
      SACADO_INLINE_FUNCTION
      SACADO_ENABLE_EXPR_FUNC(GeneralFad&) operator /= (const Expr<S>& x) {
        const int xsz = x.size(), sz = this->size();
        T xval = x.val();
        T v = this->val();

#if defined(SACADO_DEBUG) && !defined(__CUDA_ARCH__ )
        if ((xsz != sz) && (xsz != 0) && (sz != 0))
          throw "Fad Error:  Attempt to assign with incompatible sizes";
#endif

        if (xsz) {
          if (sz) {
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) = ( this->fastAccessDx(i)*xval - v*x.fastAccessDx(i) )/ (xval*xval);
            else
              SACADO_FAD_DERIV_LOOP(i,sz)
                this->fastAccessDx(i) = ( this->fastAccessDx(i)*xval - v*x.dx(i) )/ (xval*xval);
          }
          else {
            this->resizeAndZero(xsz);
            if (x.hasFastAccess())
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = - v*x.fastAccessDx(i) / (xval*xval);
            else
              SACADO_FAD_DERIV_LOOP(i,xsz)
                this->fastAccessDx(i) = -v*x.dx(i) / (xval*xval);
          }
        }
        else {
          if (sz) {
            SACADO_FAD_DERIV_LOOP(i,sz)
              this->fastAccessDx(i) /= xval;
          }
        }

        this->val() /= xval;

        return *this;
      }


    }; // class GeneralFad

  } // namespace Fad

} // namespace Sacado

#endif // SACADO_FAD_GENERALFAD_HPP