| Current File : //usr/include/eigen3/Eigen/src/Core/functors/NullaryFunctors.h |
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2016 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef EIGEN_NULLARY_FUNCTORS_H
#define EIGEN_NULLARY_FUNCTORS_H
namespace Eigen {
namespace internal {
template<typename Scalar>
struct scalar_constant_op {
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE scalar_constant_op(const scalar_constant_op& other) : m_other(other.m_other) { }
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE scalar_constant_op(const Scalar& other) : m_other(other) { }
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() () const { return m_other; }
template<typename PacketType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const PacketType packetOp() const { return internal::pset1<PacketType>(m_other); }
const Scalar m_other;
};
template<typename Scalar>
struct functor_traits<scalar_constant_op<Scalar> >
{ enum { Cost = 0 /* as the constant value should be loaded in register only once for the whole expression */,
PacketAccess = packet_traits<Scalar>::Vectorizable, IsRepeatable = true }; };
template<typename Scalar> struct scalar_identity_op {
EIGEN_EMPTY_STRUCT_CTOR(scalar_identity_op)
template<typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (IndexType row, IndexType col) const { return row==col ? Scalar(1) : Scalar(0); }
};
template<typename Scalar>
struct functor_traits<scalar_identity_op<Scalar> >
{ enum { Cost = NumTraits<Scalar>::AddCost, PacketAccess = false, IsRepeatable = true }; };
template <typename Scalar, typename Packet, bool IsInteger> struct linspaced_op_impl;
template <typename Scalar, typename Packet>
struct linspaced_op_impl<Scalar,Packet,/*IsInteger*/false>
{
linspaced_op_impl(const Scalar& low, const Scalar& high, Index num_steps) :
m_low(low), m_high(high), m_size1(num_steps==1 ? 1 : num_steps-1), m_step(num_steps==1 ? Scalar() : (high-low)/Scalar(num_steps-1)),
m_flip(numext::abs(high)<numext::abs(low))
{}
template<typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (IndexType i) const {
typedef typename NumTraits<Scalar>::Real RealScalar;
if(m_flip)
return (i==0)? m_low : (m_high - RealScalar(m_size1-i)*m_step);
else
return (i==m_size1)? m_high : (m_low + RealScalar(i)*m_step);
}
template<typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(IndexType i) const
{
// Principle:
// [low, ..., low] + ( [step, ..., step] * ( [i, ..., i] + [0, ..., size] ) )
if(m_flip)
{
Packet pi = plset<Packet>(Scalar(i-m_size1));
Packet res = padd(pset1<Packet>(m_high), pmul(pset1<Packet>(m_step), pi));
if(i==0)
res = pinsertfirst(res, m_low);
return res;
}
else
{
Packet pi = plset<Packet>(Scalar(i));
Packet res = padd(pset1<Packet>(m_low), pmul(pset1<Packet>(m_step), pi));
if(i==m_size1-unpacket_traits<Packet>::size+1)
res = pinsertlast(res, m_high);
return res;
}
}
const Scalar m_low;
const Scalar m_high;
const Index m_size1;
const Scalar m_step;
const bool m_flip;
};
template <typename Scalar, typename Packet>
struct linspaced_op_impl<Scalar,Packet,/*IsInteger*/true>
{
linspaced_op_impl(const Scalar& low, const Scalar& high, Index num_steps) :
m_low(low),
m_multiplier((high-low)/convert_index<Scalar>(num_steps<=1 ? 1 : num_steps-1)),
m_divisor(convert_index<Scalar>((high>=low?num_steps:-num_steps)+(high-low))/((numext::abs(high-low)+1)==0?1:(numext::abs(high-low)+1))),
m_use_divisor(num_steps>1 && (numext::abs(high-low)+1)<num_steps)
{}
template<typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
const Scalar operator() (IndexType i) const
{
if(m_use_divisor) return m_low + convert_index<Scalar>(i)/m_divisor;
else return m_low + convert_index<Scalar>(i)*m_multiplier;
}
const Scalar m_low;
const Scalar m_multiplier;
const Scalar m_divisor;
const bool m_use_divisor;
};
// ----- Linspace functor ----------------------------------------------------------------
// Forward declaration (we default to random access which does not really give
// us a speed gain when using packet access but it allows to use the functor in
// nested expressions).
template <typename Scalar, typename PacketType> struct linspaced_op;
template <typename Scalar, typename PacketType> struct functor_traits< linspaced_op<Scalar,PacketType> >
{
enum
{
Cost = 1,
PacketAccess = (!NumTraits<Scalar>::IsInteger) && packet_traits<Scalar>::HasSetLinear && packet_traits<Scalar>::HasBlend,
/*&& ((!NumTraits<Scalar>::IsInteger) || packet_traits<Scalar>::HasDiv),*/ // <- vectorization for integer is currently disabled
IsRepeatable = true
};
};
template <typename Scalar, typename PacketType> struct linspaced_op
{
linspaced_op(const Scalar& low, const Scalar& high, Index num_steps)
: impl((num_steps==1 ? high : low),high,num_steps)
{}
template<typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (IndexType i) const { return impl(i); }
template<typename Packet,typename IndexType>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(IndexType i) const { return impl.packetOp(i); }
// This proxy object handles the actual required temporaries and the different
// implementations (integer vs. floating point).
const linspaced_op_impl<Scalar,PacketType,NumTraits<Scalar>::IsInteger> impl;
};
// Linear access is automatically determined from the operator() prototypes available for the given functor.
// If it exposes an operator()(i,j), then we assume the i and j coefficients are required independently
// and linear access is not possible. In all other cases, linear access is enabled.
// Users should not have to deal with this structure.
template<typename Functor> struct functor_has_linear_access { enum { ret = !has_binary_operator<Functor>::value }; };
// For unreliable compilers, let's specialize the has_*ary_operator
// helpers so that at least built-in nullary functors work fine.
#if !( (EIGEN_COMP_MSVC>1600) || (EIGEN_GNUC_AT_LEAST(4,8)) || (EIGEN_COMP_ICC>=1600))
template<typename Scalar,typename IndexType>
struct has_nullary_operator<scalar_constant_op<Scalar>,IndexType> { enum { value = 1}; };
template<typename Scalar,typename IndexType>
struct has_unary_operator<scalar_constant_op<Scalar>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_binary_operator<scalar_constant_op<Scalar>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_nullary_operator<scalar_identity_op<Scalar>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_unary_operator<scalar_identity_op<Scalar>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_binary_operator<scalar_identity_op<Scalar>,IndexType> { enum { value = 1}; };
template<typename Scalar, typename PacketType,typename IndexType>
struct has_nullary_operator<linspaced_op<Scalar,PacketType>,IndexType> { enum { value = 0}; };
template<typename Scalar, typename PacketType,typename IndexType>
struct has_unary_operator<linspaced_op<Scalar,PacketType>,IndexType> { enum { value = 1}; };
template<typename Scalar, typename PacketType,typename IndexType>
struct has_binary_operator<linspaced_op<Scalar,PacketType>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_nullary_operator<scalar_random_op<Scalar>,IndexType> { enum { value = 1}; };
template<typename Scalar,typename IndexType>
struct has_unary_operator<scalar_random_op<Scalar>,IndexType> { enum { value = 0}; };
template<typename Scalar,typename IndexType>
struct has_binary_operator<scalar_random_op<Scalar>,IndexType> { enum { value = 0}; };
#endif
} // end namespace internal
} // end namespace Eigen
#endif // EIGEN_NULLARY_FUNCTORS_H