aboutsummaryrefslogtreecommitdiffhomepage
path: root/Eigen/src/Core/functors/NullaryFunctors.h
blob: 6a30466fb9f63c5852388ff3682189a14372999d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
// 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_interPacket(plset<Packet>(0)),
    m_flip(numext::abs(high)<numext::abs(low))
  {}

  template<typename IndexType>
  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator() (IndexType i) const {
    if(m_flip)
      return (i==0)? m_low : (m_high - (m_size1-i)*m_step);
    else
      return (i==m_size1)? m_high : (m_low + 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 = padd(pset1<Packet>(Scalar(i-m_size1)),m_interPacket);
      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 = padd(pset1<Packet>(Scalar(i)),m_interPacket);
      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 Packet m_interPacket;
  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